Rakib, Sakhawat Hossen · Rakib, Sakhawat Hossen · Imtiaz Bin Hamid, Nafiz · et al.
1.7 MB
This dataset contains 5,625 finite element simulation records generated using COMSOL Multiphysics 6.3 (RF Module, Electromagnetic Waves Frequency Domain interface) for a modified microstrip patch antenna (MPA) sensor designed for non-invasive electrolyte monitoring from sweat at 2.4 GHz. The sensor incorporates a circular analyte well and 45-degree chamfered stubs to enhance dielectric sensitivity. Simulations were conducted across three substrate materials (Rogers RO4003C, FR4, and Cellulose Paper/Whatman Grade 3) and five physiologically relevant NaCl concentrations (20, 40, 60, 80, and 100 mmol/L). Each record corresponds to a unique combination of five geometric and electrolyte input parameters: patch width (WP), patch length (LP), analyte well diameter (d_well), feed inset offset (xf), and NaCl concentration (c), sampled on a systematic grid of 5 x 5 x 5 x 3 levels per substrate and 5 concentration levels, yielding 1,875 records per substrate. The two output (target) variables per record are the minimum reflection coefficient (S11_min, in dB) and the resonant frequency at the S11 minimum (fr, in GHz), both extracted from the Asymptotic Waveform Evaluation (AWE) frequency sweep. The permittivity of the NaCl analyte complex at each concentration is modeled using the Cole-Cole dispersion parameters established by Peyman, Gabriel, and Grant (Bioelectromagnetics, 2007). The dataset was used to train and validate three machine learning regression models — Extreme Gradient Boosting (XGBoost), Support Vector Regression (SVR), and Gaussian Process Regression (GPR) — for surrogate-based optimization of sensor dimensions. XGBoost achieved the lowest prediction error: S11 RMSE of 0.81-1.14 dB and concentration RMSE of 1.31-1.82 mmol/L across the three substrates. The dataset is provided as a structured Excel workbook (XLSX) containing the full 5,625-record dataset, per-substrate subsets, summary statistics, a stratified 80/20 train-test split, XGBoost feature importance results, and model performance comparisons. The research targets clinical patient populations where continuous sweat electrolyte monitoring is medically significant, including palmar hyperhidrosis, chronic kidney disease (hemodialysis patients), motor paralysis, and congestive heart failure.
Lemor, Antoine · Pillod, Alizée · Taylor, Matthew · et al.
266,271 rows × 10 cols
7 numeric · 3 text
The Canadian Climate Framing (CCF) Database is a comprehensive, machine-learning-annotated corpus of climate-change media coverage in Canada. It comprises 266,271 articles from 20 major Canadian newspapers (1978-2024) processed into 9,198,958 two-sentence analytical units (82.9% English, 17.1% French). Each unit is annotated across 65 hierarchical categories by 128 BERT and CamemBERT classifiers, with a macro F1 of 0.866 on a 1,000-sentence gold standard double-coded by an independent annotator (Gwet's AC1 = 0.894, Krippendorff's α = 0.698, Cohen's κ = 0.596 on the 400 blind sentences). Each category receives an A/B/C reliability tier summarising annotation quality from classifier performance and inter-coder agreement. The deposit ships six relational tables (bibliographic metadata, sentence-level annotations, named-entity rollups, article-level aggregates, per-category reliability tiers, and 9,462,845 BAAI/bge-m3 sentence-and-title embeddings). Raw newspaper text is excluded for copyright reasons; bibliographic coordinates (media, date, title, author, page_number) are sufficient for any researcher with institutional access to Factiva, Eureka.cc or ProQuest Canadian Major Dailies to recover the original sentences. This deposit accompanies a methodology paper currently under revision at Scientific Data (Nature Portfolio). This deposit is the Apache Parquet mirror of the canonical PostgreSQL edition (cross-referenced in Related identifiers ). Each of the six relational tables is provided as a standalone .parquet file with ZSTD compression; the 1024-dimensional BAAI/bge-m3 embedding column is materialised as a list<float> , and JSONB entity arrays are serialised as UTF-8 JSON strings. The schemas are otherwise identical to the PostgreSQL edition. The Parquet bundle is readable natively by pandas , polars , R/ arrow , DuckDB , and Spark without any database backend: import pandas as pd agg = pd.read_parquet('CCF_article_aggregates.parquet') emb = pd.read_parquet('CCF_sentence_embeddings.parquet') The HNSW index that ships with the PostgreSQL edition is not transferable to Parquet; brute-force cosine similarity remains tractable on the embedding column (≈ 9.46 M × 1024 float16). The full annotation pipeline, training data, manual-annotation JSONL, intercoder-reliability benchmark, methodology manuscript (LaTeX sources + PDF), and reproducibility scripts are bundled with this deposit as ccf_code_and_paper.tar.gz . The same materials are also available on the project's OSF companion deposit ( 10.17605/OSF.IO/Q5W47 ) and on the development mirror at GitHub .
Lemor, Antoine · Pillod, Alizée · Taylor, Matthew · et al.
2.2 MB
The Canadian Climate Framing (CCF) Database is a comprehensive, machine-learning-annotated corpus of climate-change media coverage in Canada. It comprises 266,271 articles from 20 major Canadian newspapers (1978-2024) processed into 9,198,958 two-sentence analytical units (82.9% English, 17.1% French). Each unit is annotated across 65 hierarchical categories by 128 BERT and CamemBERT classifiers, with a macro F1 of 0.866 on a 1,000-sentence gold standard double-coded by an independent annotator (Gwet's AC1 = 0.894, Krippendorff's α = 0.698, Cohen's κ = 0.596 on the 400 blind sentences). Each category receives an A/B/C reliability tier summarising annotation quality from classifier performance and inter-coder agreement. The deposit ships six relational tables (bibliographic metadata, sentence-level annotations, named-entity rollups, article-level aggregates, per-category reliability tiers, and 9,462,845 BAAI/bge-m3 sentence-and-title embeddings). Raw newspaper text is excluded for copyright reasons; bibliographic coordinates (media, date, title, author, page_number) are sufficient for any researcher with institutional access to Factiva, Eureka.cc or ProQuest Canadian Major Dailies to recover the original sentences. This deposit accompanies a methodology paper currently under revision at Scientific Data (Nature Portfolio). This deposit is the canonical PostgreSQL edition. It contains a pg_dump -Fd directory archive (compressed into a single .tar file) of the six relational tables, including the pgvector extension and HNSW cosine indexes for sub-second semantic-similarity search. Restoration is a one-liner: tar -xf CCF_Database.tar && createdb CCF_Database && psql -d CCF_Database -c 'CREATE EXTENSION IF NOT EXISTS vector;' && pg_restore -d CCF_Database --no-owner --no-privileges -j 8 CCF_Database_dump A column-oriented Apache Parquet mirror of the same six tables is available as the sister deposit on Zenodo (cross-referenced in Related identifiers ). The Parquet mirror is recommended for users without PostgreSQL access (it is directly readable by pandas, polars, R/arrow, DuckDB, and Spark). The full annotation pipeline, training data, manual-annotation JSONL, intercoder-reliability benchmark, methodology manuscript (LaTeX sources + PDF), and reproducibility scripts are bundled with this deposit as ccf_code_and_paper.tar.gz . The same materials are also available on the project's OSF companion deposit ( 10.17605/OSF.IO/Q5W47 ) and on the development mirror at GitHub . Requirements: PostgreSQL 16 or 17 with pgvector ≥ 0.8.2 (for halfvec(1024) storage of the sentence embeddings).
[Material Complementario] Integración Económica Internacional: Una Revisión Sistemática de la Literatura Los autores ponen a disposición de los lectores la bitácora general elaborada durante el desarrollo de la revisión sistemática de la literatura sobre "Integración Económica Internacional". Este documento contiene la bitácora general elaborada durante el desarrollo de la revisión sistemática de la literatura. En ella se registra de manera detallada el proceso de búsqueda, identificación, selección y clasificación de los documentos analizados, incluyendo la información correspondiente a cada registro bibliográfico, tales como la fuente de datos, título, año de publicación, URL de acceso, estado de revisión, categoría temática y clasificación final. La publicación de este material tiene como finalidad contribuir a la transparencia metodológica, facilitar la comprensión del proceso de investigación y promover la reproducibilidad de los resultados presentados en el artículo. El material es de libre acceso y puede ser utilizado con fines académicos, docentes y de investigación, citando adecuadamente la fuente correspondiente. Autores María Laura Cabrera & Arturo González
This dataset quantifies the uncertainty in mapping late-successional and old-growth (LSOG) forest across the approximately 4.2 million hectares of Maine's unorganized townships, and tests whether LSOG is rapidly disappearing. Three to four independent, credible mapping methods are compared on a common 100 m grid: (M1) a reproduction of the Hagan et al. (2026) airborne-LiDAR canopy random forest, rebuilt from their public Zenodo deposit; (M2) a logistic model of the FIA field-structure LSOG class on Potapov (GEDI-calibrated) canopy height; (M3) a direct canopy-height threshold; and (M4) the FIA structural class imputed to every pixel via USFS TreeMap (2016, 2020, 2022). Version 1.2.0 additions. This version adds the materials behind the formal Ecosphere Comment on Hagan et al. (2026): (a) a cross-validated accuracy assessment (AUC) of each mapping approach on the original authors' own training plots, showing that high training accuracy does not transfer to agreement among independent maps; (b) an FIA design-based estimate of older forest with sampling-error confidence intervals, the unbiased ground reference the original analysis lacked, putting older forest at about 3.9 percent (3.3 to 4.6) and rising, including on private commercial timberland; (c) a threshold-sensitivity sweep and a 20-seed reproduction ensemble; (d) an ownership-resolved breakdown (private commercial versus public); (e) a hex-scale (8 km) summary of cross-method disagreement; and (f) the Comment manuscript and Supporting Information. Headline findings. Credible methods disagree by roughly 2.8 times on how much LSOG exists and on the location of most LSOG hectares, while agreeing closely on the rare, well-defined old-growth core. Protecting the top 5 to 20 percent of hectares by one map versus another overlaps on only 16 to 30 percent of the ground, so single-map patch-level prioritization for large expenditures is fragile. The design-based FIA estimate and TreeMap imputation both show older forest stable to increasing rather than rapidly declining; the apparent loss reported elsewhere is a gross harvest flux, not a net stock decline. Contents. Derived 100 m GeoTIFFs (reproduced Hagan class, v5.1-GEDI probability, TreeMap class, a per-cell method-consensus layer), summary tables (area by method, pairwise agreement, concordance, prioritization fragility, AUC by approach, design-based older-forest trend with CIs, ownership breakdown, and FIA validation), the analysis R scripts, quick-look figures, the Ecosphere Comment manuscript and Supporting Information, and a full methods-and-findings report (PDF). Privacy. No FIA plot coordinates are included; all products are derived rasters or aggregate summary tables. Caveats: the robust temporal signal is direction rather than precise rate; FIA stand age is modeled, so a structural large-tree domain is reported alongside the age domain; cross-validated intervals are best read as lower bounds because plots are spatially dispersed but not independent. See the README and report for full methods, provenance, and limitations. Version 1.12.0 additions. The cross-map comparison is refined to independent remote-sensing operationalizations only. (a) A three-map remote-sensing ensemble over Maine on a common 100 m grid: reproduced Hagan airborne-LiDAR (any-LSOG 21.9 percent), an FIA-structure class on Potapov GEDI-calibrated spaceborne canopy height (14.0 percent), and the ORNL/Bruening national old-growth stratum (36.1 percent); the three span a 2.6-fold range and agree on only 2.7 percent of flagged hectares, with the ORNL stratum spatially uncorrelated with the structure maps. The USFS TreeMap imputation is reclassified as a second FIA-anchored accounting, reported with the design-based estimate rather than as an independent map. (b) A design-based estimate of LSOG itself: integrated any-LSOG 14.1 percent (12.9 to 15.3) and strict four-axis true LSOG 3.1 percent (2.5 to 3.7) of Maine forestland, the airborne map exceeding even the inclusive ground estimate. (c) A balanced-model LSOG probability surface at 100 m, with a binary class calibrated to the design-based area to bound over-prediction. (d) A multi-objective support vector regression pilot tracing the Pareto front of total versus systematic (attenuation) error. Derived rasters, the three-map agreement layer, the ORNL stratum reprojected to the study grid, tables, R scripts, the updated Comment, and the companion manuscript are included. No FIA plot coordinates are included. Version 1.13.0. Final consolidated release. Adds: a rare-class remedy menu for the reproduced random forest (default vs class weighting vs balanced sub-sampling vs voting-threshold; old-growth detection 0.24 to 0.82, mapped old-growth area 1.0 to 2.3 percent); the definitive five-model LSOG probability map for Maine with across-model uncertainty and reference reserves (MNAP/TNC network, Baxter, Big Reed) over real state and county boundaries; design-based 95 percent confidence intervals for forest-type and ecoregion representation and for disturbance shares; a full robustness/stress-test matrix; and the copy-edited, sole-authored Comment, companion manuscript, and Maine Forest Products Council technical report. Authorship updated to Aaron R. Weiskittel.
Xiang Echo Chen · Wenhan Zhu · Guoshuai Albert Shi · et al.
29 KB
This replication package accompanies the paper "An Empirical Study of GenAI Adoption in Open-Source Game Development: Tools, Tasks, and Developer Challenges." The package contains the data and supplementary materials used in the study, including the classified GitHub issue corpus, manual coding assignments, label definitions, task and challenge cluster mappings, task-tool mappings, and DeepSeek prompt materials. The issue corpus covers GenAI, traditional AI (TradAI), and non-AI (NonAI) issues collected from selected open-source game repositories, with the observation snapshot ending on May 31, 2025 (Toronto time). The materials support the quantitative corpus overview, issue life-cycle analyses, and qualitative comparisons of issue types, development tasks, reported challenges, and tool involvement across the three issue categories.
This repository contains the datasets and supplementary materials used in the study "Pre-Adoption Barriers and Ecosystem Maturity in Live-Streaming Commerce". The materials include survey datasets from China and Portugal, construct measurements (A-E), quantitative analysis outputs, interview documents, and supporting materials used in the study The files are provided to enhance transparency and reproducibility of the research.
This replication package contains the data, code, output files, figures, appendix materials, and documentation required to reproduce the empirical results reported in the manuscript "Digital Core Infrastructure Centrality and National Connectivity Disruption Exposure: A 36-Country Comparative Analysis." The package includes the country-level dataset for 36 countries, DGCI component data, strict connectivity disruption coding notes, diagnostic tables, model outputs, figures, appendix tables, and documentation. The materials are provided to support transparency and reproducibility. During double-anonymous peer review, identifying author information has been removed from the package where possible.
Ahmmed, Imtiaz · Masud, Md Hasan · Sarker, Monosij Kanti · et al.
4.6 MB
This repository contains the reproducibility package associated with the study: "Bridging the Gap Between Awareness and Action: An Empirical Study of Technical Debt Management in Agile Software Development." The package includes: • Survey questionnaire • Survey dataset • Supporting documentation The dataset contains responses from software engineering professionals regarding technical debt awareness, causes, impacts, and management practices in agile software development environments. The materials are provided to facilitate verification, replication, and future research based on the study findings.
de Paula Oliveira, Hugo · Jacob Machado, Denis · Prieto Oliveira, Paula · et al.
1.4 MB
Appendix A - Supplementary Digital Materials These materials contain the supplementary digital materials for the manuscript " Evidence for recombination in dengue virus genomes ," written by Hugo de Paula Oliveira (ORCiD: 0000-0001-5842-7187), Denis Jacob Machado (ORCiD: 0000-0001-9858-4515), Paula Prieto-Oliveira (ORCiD: 0000-0001-6999-3221), and Kary Ocaña (ORCiD: 0000-0002-2151-7418) . All files use open, machine-readable formats (CSV, Markdown, plain text, FASTA, NEXUS, Python, Bash). Directory and file names contain no spaces or special characters. SupplementaryData1_Tables - Supplementary Tables See SupplementaryData1.tar.gz . Nine comma-separated value (CSV) files, one per supplementary table. SupplementaryTables.md describes the contents of each file. File Contents SupplementaryTables.md Brief description of each table and its columns. Table_S1.csv List of 6,906 DENV genomes retrieved from BV-BRC, including accession numbers and associated metadata (87 columns). Table_S2.csv Summary of software tools, versions, and parameter settings used in the analyses. Table_S3.csv Proportion of recombinants across clades and branch lengths from the phylogenetic tree. Table_S4.csv Taxa assigned to recombination events. Table_S5.csv Evolutionary models and parameter settings used to simulate alignments for RECOSIM performance evaluation. Table_S6.csv Distribution of recombinant DENV genomes per continent and country. Table_S7.csv Recombination events in DENV genomes detected both in this study and in previous published research. Table_S8.csv Evaluation of RECOSIM clustering strategies and parameter combinations. Table_S9.csv Comparison of RECOSIM and RDP5 detection performance. SupplementaryData2_Figures - Supplementary Figures See SupplementaryData2.tar.gz . A Markdown document with a contextual preamble and figure captions, together with eight PNG image files. Images are embedded in the Markdown and also available as standalone files. File Contents SupplementaryFigures.md Preamble describing the phylogenetic workflow and seven recombination case studies, followed by all figures with their captions. Figure_S1.png Conceptual workflow of the phylogenetic inference pipeline. Figure_S2.png SNP and similarity analysis for recombinant JQ922559 (DENV-4-I intra-genotypic event). Figure_S3.png SNP and similarity analysis for recombinant KX452048 (DENV-4-I intra-genotypic event). Figure_S4.png SNP and similarity analysis for recombinant MG560143 (DENV-2 inter-genotypic event). Figure_S5.png SNP and similarity analysis for recombinant KC964095 (DENV-2 inter-genotypic event). Figure_S6.png SNP and similarity analysis for recombinant KU517845 (DENV-2 inter-genotypic event). Figure_S7.png SNP and similarity analysis for recombinant JF295012 (DENV-3 inter-serotypic event). Figure_S8.png SNP and similarity analysis for recombinant ON123656 (DENV-1 inter-genotypic event). SupplementaryData3_Sequences - Sequence Data See SupplementaryData3.tar.gz . The multiple sequence alignment, genome partition scheme, and accession list for the DENV phylogenomic dataset. File Contents README.md Detailed description of each file in this directory. accessions.txt Plain-text list of 6,638 unique DENV genome accession IDs, one per line. alignment.fasta Multiple sequence alignment of DENV genomes in FASTA format, aligned against the FLAVi flavivirus reference framework. partitions.nexus Genome partition scheme in NEXUS format defining the boundaries of DENV genomic regions in FLAVi coordinates. tree.nwk Newick tree file of 6,642 unique flavivirus sequences generated with the phylogenetic inference pipeline. denv_zikv_wnv_alignment.fasta Multiple sequence alignment of DENV, ZIKV, and WNV genomes in FASTA format, aligned against the FLAVi flavivirus reference framework. SupplementaryData4_Scripts - Phylogenomic Analysis Scripts See SupplementaryData4.tar.gz . Python and Bash scripts supporting the phylogenomic analyses, with a Markdown methods description and a README. File Contents README.md Description of each script, including usage instructions and dependencies. PhylogenomicAnalyses.md Methods for the branch-length, phylogenetic placement, and tree topology analyses; includes accession IDs of the 192 sequences in the pruned DENV tree. ReproducePhylogenomicAnalyses.md Steps required to reproduce the phylogenomic analyses. Script_S1.py Phylogenetic inference pipeline integrating RAxML, TNT, and IQ-TREE2. Script_S2.py Extraction of recombinant proportions and branch lengths from phylogenetic trees. Script_S3.py Branch-length analysis: Mann-Whitney U test and Spearman rank correlation. Script_S4.py Clade-distance computation: smallest clade containing each recombinant and its parents. Script_S5.sh Visualisation of clade-size comparisons as a three-panel box-and-strip plot. Script_S6.sh Bash script generating TNT batch run files for the leave-one-out topology analysis. SupplementaryData5_Performance - RECOSIM Performance Evaluation See SupplementaryData5.tar.gz . File Contents performance.md Description of RECOSIM, the simulation design, evaluation protocol, and performance metrics (Hits ratio, Fails ratio, sensitivity, and precision).
This record provides a governance-compatible reproducibility and transparency package accompanying the manuscript "Risk-adapted surveillance for lung and bone metastasis in hepatocellular carcinoma: international evaluation and prospective two-wave pathway implementation". The package includes fixed LM/BM threshold definitions, predictor and endpoint dictionaries, denominator maps, missing-data rules, pathway-assignment code, reviewer-oriented analysis-code skeletons, synthetic example data, table-generation workflows, software-environment files, validation scripts, model-card documentation, source-document materials, and a public-calculator manifest. No identifiable patient-level data are included. Controlled-access analytic extracts are governed by institutional approvals, data-use agreements, and confidentiality agreements.
Source data used to produce the journal article " Predominant proton insertion during electrochemical cycling of ε-VOPO 4 in a non-aqueous Ca ion electrolyte"
Chaumeil, Pierre-Alain · Hugenholtz, Philip · Parks, Donovan
1.3 MB
This repository provides the supplementary data and materials associated with the gTranslate manuscript. Files included: Supplementary Tables and Figures: All supplementary data referenced in the main text. Codebook: A detailed reference guide explaining the numerical categories used throughout the supplementary tables.
This review presents numerous studies in which mass spectrometry has been used to assist forensic investigation. Due to its unique capabilities, mainly high-resolution mass data and structural information, high sensitivity, and cooperation with separation techniques, this method provides access to many tools streamlining and accelerating sample analysis. Low analyte consumption, advanced derivatization procedures and availability of isotopically labeled standards offer opportunities to study materials previously not considered viable evidence, opening new avenues in forensic investigations.
An ion removal device based on electrochemical and photoelectrochemical methods, and the application of energy conversion and storage are provided. In the ion removal process based on the electrochemical and photoelectrochemical fluidization battery device, the positive active material in the flow battery is the positive pole of device, the negative active material in the fluid battery is the negative pole of the device, and the salt solution is the electrolyte in the middle stream. The positive and negative active materials include organic materials such as 4-hydroxy-piperidinol oxide, riboflavin sodium phosphate or methyl viologen, which have the advantages of low raw material cost, environmental friendliness, high sustainability, excellent electrochemical performance, high specific capacity and good cycle stability etc. The electrolyte can be separated from the positive and negative active liquid flow materials according to the fixed sequence of self-assembly of fluid battery mold.
The present invention discloses methods and materials for adding a polymer material to a liquified gas electrolyte solution for use in an electrochemical energy storage device such as a lithium-ion battery or a related technology to further improve the battery cell's safety properties. An example device includes an ionically conducting electrolyte comprised of a liquefied gas solvent, a salt, and a polymer. The liquefied gas solvent has a vapor pressure above 100 kPa at a temperature of 293.15 K, and the polymer is at a low enough concentration that it is fully dissolved into the liquefied gas solvent. The device may include an anode, a cathode, and a separator layer in contact with the ionically conducting electrolyte. A housing may enclose the ionically conducting electrolyte, the anode, the cathode and the separator layer.
A process for low temperature hydrothermal relithiation of spent lithium-ion battery cathode materials adds a reducing agent to an aqueous Li solution at 80-100° C. followed by a short anneal to achieve complete recovery of composition, crystal structure, and electrochemical performance for heavily degraded cathode materials.
SHENZHEN WARRANT NEW ENERGY CO LTD · granted 2024-12-24
The present invention relates to the field of lithium battery material preparation technologies, particularly to a method for preparing lithium iron phosphate using the by-product ferrous sulfate from titanium dioxide. The method comprises the following steps: dissolving by-product ferrous sulfate from titanium dioxide in acidic aqueous solution, stirring with iron powder for reaction; adding iron phosphate or lithium iron phosphate waste powder to the solution, heating and stirring the mixture, allowing the mixture to settle and cool, and filtering the cooled mixture to obtain a purified ferrous sulfate solution; and adding phosphoric acid and a lithium hydroxide solution in an autoclave, and finally adding the purified ferrous sulfate solution, heating the mixture under stirring, then filtering, washing, and drying the mixture to obtain lithium iron phosphate powder; Using it as an iron source to prepare positive electrode materials for lithium-ion batteries has excellent electrochemical performance.
The present invention discloses methods and materials for adding a polymer material to a liquified gas electrolyte solution for use in an electrochemical energy storage device such as a lithium-ion battery or a related technology to further improve the battery cell's safety properties. An example device includes an ionically conducting electrolyte comprised of a liquefied gas solvent, a salt, and a polymer. The liquefied gas solvent has a vapor pressure above 100 kPa at a temperature of 293.15 K, and the polymer is at a low enough concentration that it is fully dissolved in the liquefied gas solvent. The device may include an anode, a cathode, and a separator layer in contact with the ionically conducting electrolyte. A housing may enclose the ionically conducting electrolyte, the anode, the cathode and the separator layer.
Set forth herein are garnet material compositions, e.g., lithium-stuffed garnets and lithium-stuffed garnets doped with alumina, which are suitable for use as electrolytes and catholytes in solid state battery applications. Also set forth herein are lithium-stuffed garnet thin films having fine grains therein. Disclosed herein are novel and inventive methods of making and using lithium-stuffed garnets as catholytes, electrolytes and/or anolytes for all solid state lithium rechargeable batteries. Also disclosed herein are novel electrochemical devices which incorporate these garnet catholytes, electrolytes and/or anolytes. Also set forth herein are methods for preparing novel structures, including dense thin (<50 um) free standing membranes of an ionically conducting material for use as a catholyte, electrolyte, and, or, anolyte, in an electrochemical device, a battery component (positive or negative electrode materials), or a complete solid state electrochemical energy storage device. Also, the methods set forth herein disclose novel sintering techniques, e.g., for heating and/or field assisted (FAST) sintering, for solid state energy storage devices and the components thereof.
The present disclosure is directed to methods of forming polyamic acid and polyimide gels in water. The resulting polyamic acid and polyimide gels may be converted to aerogels, which may further be converted to carbon aerogels. Such carbon aerogels have the same physical properties as carbon aerogels prepared from polyimide aerogels obtained according to conventional methods, i.e., organic solvent-based. The disclosed methods are advantageous in reducing or avoiding costs associated with use and disposal of potentially toxic solvents and byproducts. Gel materials prepared according to the disclosed methods are suitable for use in environments involving electrochemical reactions, for example as an electrode material within a lithium-ion battery.
SUZHOU GAOBO ENERGY STORAGE SCITECH CO LTD · granted 2024-09-03
The present invention discloses an iron-based cathode material for a sodium-ion battery, which comprises a Na3Fe2(SO4)3F material and a carbon-based material embedded into the bulk structure of Na3Fe2(SO4)3F material. The weight percentage of the carbon-based material is ranked between 1% and 10%. The present invention also provides a method for preparing the above-mentioned iron-based cathode material for a sodium-ion battery, and a corresponding sodium-ion full battery using the Na3Fe2(SO4)3F-based cathode material. The Na3Fe2(SO4)3F cathode material ensures desired electrochemical sodium storage performance, involving high specific sodium storage capacity, improved cycle stability and superior rate performance in comparison with that of various pristine NaxFey(SO4)z materials. The actual operating potential of the reported sodium-ion full battery in the present invention is significantly higher than the output potential of existing commercial sodium-ion full batteries, and the increase in battery energy density is also achieved.
Devices and methods disclosed herein relate to forming superior mechanical and electrical connections between stacks of foils such as those used in electrochemical cells. The connections described herein use multiple weld types and choice of materials to promote electrical and mechanical connectivity using separate weld types.
Provided are materials that may be used in or as a separator in an electrochemical cell such as a lithium sulfur battery. The separator includes a material capable of absorbing and desorbing a polysulfide. The inclusion of the materials in a separator provide for reduced sulfur loss from a cathode during cycling thereby improving cycle life.
Inorganic-based lithium mixed electrode materials have a low charge transfer rate and thus have poor fast charging or discharging characteristics. Positive electrode active materials include LCO (lithium cobalt oxide, LiCoO2), NCM (nickel cobalt manganese, Li(NiCoMn)O2), NCA(nickel cobalt aluminum, Li(NiCoAl)O2), LMO(lithium manganese oxide, LiMn2O4), LFP(Lithium iron phosphate, LiFePO4), etc. High nickel technology is attracting attention because if nickel is used a lot, the capacity of lithium ions can be increased. However, as the content of nickel increases, the reactivity increases, resulting in a risk of explosion of the battery and deterioration in cycle life characteristics. As the negative active material, carbon, transition metal oxide, nickel metal, silicon-nickel alloy, and the like may be used. As the carbon, natural graphite, artificial graphite, soft carbon, hard carbon, etc. can be used. As the transition metal oxide, Co3O4, CoO, FeO, NiO, and the like can be used.The present invention adds a polymer additive containing free radicals in the molecular structure to the electrode to solve the problems of the existing secondary battery. The polymer additive contains free radicals and undergoes an oxidation-reduction reaction through ionic interactions. When this polymer additive is included in the electrode, the fast charging and fast discharging characteristics are improved, and the stability of the electrode is improved. When the stability of the electrode is improved, the cycle life characteristics of the electrode are improved. Because the polymer additive participates in the electrochemical reaction, it increases the practical capacity of nickel. When dissolved in a solvent, the polymer additive can increase the viscosity and act as a binder.
Disclosed herein is a method of recovering lithium or sodium from an active material of a lithium or sodium ion battery. In a preferred embodiment, the method comprises a redox-targeting reaction of a used active material LiFeP04 with a redox mediator [Fe(CN) 6 ] 3− in a tank to produce lithium ions, circulating the reacted redox solution into a cell to regenerate said redox mediator and enabling said lithium ions to migrate through a membrane towards a cathode wherein said lithium ions are captured as LiOH through an electrochemical reaction.
A multi-layer cathode coating for positive electrode of a rechargeable electrochemical cell (or secondary cell) (such as a lithium-ion secondary battery) and a secondary battery including a cathode having a multi-layer cathode coating. Multi-layer cathode coatings containing blends of one or more cathode active materials in certain weight ratios thereof.
A lithium-ion battery includes an electrode with a plurality of channels formed at least partially through its thickness. Each channel has a diameter in a range from 5 μm to 100 μm and/or is spaced apart from another channel by a distance in a range from 10 μm to 200 μm as measured between centerlines of the channels. The electrode may be an anode and includes carbonaceous material such as graphite and/or additional electrochemically active lithium host materials. The battery can be charged at a C-rate greater than 2 C.
PACIFIC IND DEVELOPMENT CORPORATION · granted 2024-06-25
A negative electrode for use in an electrochemical cell, such as a lithium-ion secondary battery that includes a positive electrode with an active material that acts as a cathode and a current collector; a negative electrode with an active material that acts as an anode and a current collector; a non-aqueous electrolyte; and a separator placed between the positive and negative electrodes. The negative electrode, includes an inorganic additive dispersed therein or applied as a coating thereon, the inorganic additive being in the form of one or more zeolites having a Si:Al ratio ranging from 1-50 that absorbs one or more of moisture, free transition metal ions, or hydrogen fluoride that become present in the cell. One or more of the cells may be combined in a housing to form a lithium-ion secondary battery.
A system for initiating a recycling program of consumer electronic devices, wherein the system includes a collection device configured to collect a plurality of consumer electronic devices from users, a processing unit located within a permitted facility, communicatively connected to the collection device, wherein the processing unit is configured to disassemble each consumer electronic device of the plurality of consumer electronic devices into a plurality of base components through an electronic device disassembling process, wherein the plurality of base components includes a plurality of plastic components and at least a battery component, process the plurality of base components, wherein processing the plurality of base components includes disintegrating the plurality of plastic components into a plurality of granules and decomposing the at least one battery component into a plurality of electrochemical materials, and generate a recycled output using the processed plurality of base components.
A battery plate having a substrate with opposing surfaces and one or more nonplanar structures and one or more active materials disposed on at least one of the opposing surfaces; wherein the battery plate includes one or more of: i) one or more projections disposed within but do not extend beyond the active material; ii) one or more projections which project beyond the active material and substantially free of the active material or dust formed from the active material; and/or iii) a frame about the periphery of the substrate which projects beyond the active material and is substantially free of the active material or dust formed from the active material; and wherein the battery plate is adapted to form part of one or more electrochemical cells in a battery assembly.
Provided are examples of electrochemically active electrode materials, electrodes using such materials, and methods of manufacturing such electrodes. Electrochemically active electrode materials may include a high surface area template containing a metal silicide and a layer of high capacity active material deposited over the template. The template may serve as a mechanical support for the active material and/or an electrical conductor between the active material and, for example, a substrate. Due to the high surface area of the template, even a thin layer of the active material can provide sufficient active material loading and corresponding battery capacity. As such, a thickness of the layer may be maintained below the fracture threshold of the active material used and preserve its structural integrity during battery cycling.
The Li-ion paradigm of battery technology is fundamentally constrained by the monovalency of the Li-ion. A straightforward solution is to transition to multivalent ion chemistries, with Mg 2+ the most obvious candidate due to considerations of size and mass. Despite early interest, the realization of Mg batteries has faced myriad obstacles, including a sparse selection of cathode materials demonstrating the ability to reversibly insert divalent ions. Disclosed herein is evidence of reversible topochemical and electrochemical insertion of Mg 2+ into a metastable one-dimensional polymorph of V 2 O 5 . Not only does ζ-V 2 O 5 represent a rare addition to the pantheon of functional Mg battery cathode materials, but is also distinctive in exhibiting a combination of high stability, high specific capacity due to ion insertion, and moderately high operating voltage.
The present disclosure relates to blended cathode materials for use as a positive electrode material of a rechargeable electrochemical cell (or secondary cell) (such as a lithium-ion secondary battery) and also relates to a secondary battery including a cathode having the blended cathode materials. In particular, disclosed are blends of lithium vanadium fluorophosphate (LVPF) or a derivative thereof with one or more conventional cathode active materials in certain weight ratios thereof.
The present disclosure is directed to methods of forming polyimide gels. The methods generally include forming a polyamic acid and dehydrating the polyamic acid with a dehydrating agent in the presence of water. The resulting polyimide gels may be converted to polyimide or carbon xerogels or aerogels. The methods are advantageous in providing rapid or even instantaneous gelation, which may be particularly useful in formation of beads comprising the polyimide gels. Polyimide or carbon gel materials prepared according to the disclosed method are suitable for use in environments containing electrochemical reactions, for example as an electrode material within a lithium-ion battery.
An electrochemical device includes an anode containing a phosphorus-carbon composite including a conductive carbon matrix and nano-sized phosphorus particles, wherein the nano-sized phosphorus particles are uniformly dispersed on the surface and/or pores of the carbon matrix.
CONTEMPORARY AMPEREX TECHNOLOGY CO LTD · granted 2024-03-05
This application relates to the battery field, and specifically, to a positive electrode plate, an electrochemical apparatus, and an apparatus. The positive electrode plate in this application includes a current collector and an electrode active material layer disposed on at least one surface of the current collector, where the current collector includes a support layer and a conductive layer disposed on at least one surface of the support layer. A single-sided thickness D 2 of the conductive layer satisfies 30 nm≤D 2 ≤3 μm. A thickness D 1 of the support layer satisfies 1 μm≤D 1 ≤30 μm. The support layer is made of a polymer material or a polymer composite material. The electrode active material layer includes electrode active materials, a binder, and a conductive agent.
A cathode slurry comprises a cathode active material, especially a nickel-containing cathode active material, a binder, a solvent and a base having a formula of R 1 R 2 R 3 N, with improved stability in water. Pre-treatment of nickel-containing cathode active materials may improve stability of the cathode by preventing undesirable decomposition of the material. In addition, battery cells comprising the cathode prepared by the cathode slurry exhibit impressive electrochemical performances.
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Presently, sustainable energy as well as efficient and economical energy conversion and storage technologies has become important work in light of the rising environmental issues and dependence on portable and uninterrupted power sources. Increasingly more researchers are focusing on harvesting and converting solar energy, mechanical vibration, waste heat, and wind to electricity. Electrical energy storage technologies play a significant role in the demand for green and sustainable energy. Rechargeable batteries or secondary batteries, such as Li-ion batteries, Na-ion batteries, and Mg-ion batteries, reversibly convert between electrical and chemical energy via redox reactions, thus storing the energy as chemical potential in their electrodes. The energy density of a rechargeable battery is determined collectively by the specific capacity of electrodes and the working voltage of the cell, which is the differential potential between the cathode and the anode. Over the past decades, a significant number of studies have focused on enhancing this specific capacity; however, studies to understand and manipulate the electrochemical potential of the electrode materials are limited. In this review, the material characteristics that determine and influence the electrochemical potentials of electrodes are discussed. In particular, the cathode materials that convert electricity and chemical potential through electrochemical intercalation reactions are investigated. In addition, we summarize the selection criteria for elements or compounds and the effect of the local atomic environment on the discharge potential, including the effects of site energy, defects, crystallinity, and microstructure, using LiMn 2 O 4 , V 2 O 5 , Mo 6 S 8 , LiFePO 4 , and LiCoO 2 as model samples for discussion.
Akshaya K. Padhi, K.S. Nanjundaswamy, John Bannister Goodenough · Journal of The Electrochemical Society · 1997
Reversible extraction of lithium from (triphylite) and insertion of lithium into at 3.5 V vs. lithium at 0.05 mA/cm 2 shows this material to be an excellent candidate for the cathode of a low‐power, rechargeable lithium battery that is inexpensive, nontoxic, and environmentally benign. Electrochemical extraction was limited to ∼0.6 Li/formula unit; but even with this restriction the specific capacity is 100 to 110 mAh/g. Complete extraction of lithium was performed chemically; it gave a new phase, , isostructural with heterosite, . The framework of the ordered olivine is retained with minor displacive adjustments. Nevertheless the insertion/extraction reaction proceeds via a two‐phase process, and a reversible loss in capacity with increasing current density appears to be associated with a diffusion‐limited transfer of lithium across the two‐phase interface. Electrochemical extraction of lithium from isostructural (M = Mn, Co, or Ni) with an electrolyte was not possible; but successful extraction of lithium from was accomplished with maximum oxidation of the occurring at x = 0.5. The couple was oxidized first at 3.5 V followed by oxidation of the couple at 4.1 V vs. lithium. The interactions appear to destabilize the level and stabilize the level so as to make the energy accessible.
John Bannister Goodenough, Youngsik Kim · Chemistry of Materials · 2009
The challenges for further development of Li rechargeable batteries for electric vehicles are reviewed. Most important is safety, which requires development of a nonflammable electrolyte with either a larger window between its lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) or a constituent (or additive) that can develop rapidly a solid/electrolyte-interface (SEI) layer to prevent plating of Li on a carbon anode during a fast charge of the battery. A high Li + -ion conductivity (σ Li > 10 −4 S/cm) in the electrolyte and across the electrode/electrolyte interface is needed for a power battery. Important also is an increase in the density of the stored energy, which is the product of the voltage and capacity of reversible Li insertion/extraction into/from the electrodes. It will be difficult to design a better anode than carbon, but carbon requires formation of an SEI layer, which involves an irreversible capacity loss. The design of a cathode composed of environmentally benign, low-cost materials that has its electrochemical potential μ C well-matched to the HOMO of the electrolyte and allows access to two Li atoms per transition-metal cation would increase the energy density, but it is a daunting challenge. Two redox couples can be accessed where the cation redox couples are “pinned” at the top of the O 2p bands, but to take advantage of this possibility, it must be realized in a framework structure that can accept more than one Li atom per transition-metal cation. Moreover, such a situation represents an intrinsic voltage limit of the cathode, and matching this limit to the HOMO of the electrolyte requires the ability to tune the intrinsic voltage limit. Finally, the chemical compatibility in the battery must allow a long service life.
Kudakwashe Chayambuka, Grietus Mulder, Dmitri L. Danilov et al. · Advanced Energy Materials · 2018
Abstract The demand for electrochemical energy storage technologies is rapidly increasing due to the proliferation of renewable energy sources and the emerging markets of grid‐scale battery applications. The properties of batteries are ideal for most electrical energy storage (EES) needs, yet, faced with resource constraints, the ability of current lithium‐ion batteries (LIBs) to match this overwhelming demand is uncertain. Sodium‐ion batteries (SIBs) are a novel class of batteries with similar performance characteristics to LIBs. Since they are composed of earth‐abundant elements, cheaper and utility scale battery modules can be assembled. As a result of the learning curve in the LIB technology, a phenomenal progression in material development has been realized in the SIB technology. In this review, innovative strategies used in SIB material development, and the electrochemical properties of anode, cathode, and electrolyte combinations are elucidated. Attractive performance characteristics are herein evidenced, based on comparative gravimetric and volumetric energy densities to state‐of‐the‐art LIBs. In addition, opportunities and challenges toward commercialization are herein discussed based on patent data trend analysis. With extensive industrial adaptations expected, the commercial prospects of SIBs look promising and this once discarded technology is set to play a major role in EES applications.
Veronica Augustyn, Patrice Simon, Bruce Dunn · Energy & Environmental Science · 2014
Electrochemical energy storage technology is based on devices capable of exhibiting high energy density (batteries) or high power density (electrochemical capacitors). There is a growing need, for current and near-future applications, where both high energy and high power densities are required in the same material. Pseudocapacitance, a faradaic process involving surface or near surface redox reactions, offers a means of achieving high energy density at high charge–discharge rates. Here, we focus on the pseudocapacitive properties of transition metal oxides. First, we introduce pseudocapacitance and describe its electrochemical features. Then, we review the most relevant pseudocapacitive materials in aqueous and non-aqueous electrolytes. The major challenges for pseudocapacitive materials along with a future outlook are detailed at the end.
John Bannister Goodenough, Kyu‐Sung Park · Journal of the American Chemical Society · 2013
Each cell of a battery stores electrical energy as chemical energy in two electrodes, a reductant (anode) and an oxidant (cathode), separated by an electrolyte that transfers the ionic component of the chemical reaction inside the cell and forces the electronic component outside the battery. The output on discharge is an external electronic current I at a voltage V for a time Δt. The chemical reaction of a rechargeable battery must be reversible on the application of a charging I and V. Critical parameters of a rechargeable battery are safety, density of energy that can be stored at a specific power input and retrieved at a specific power output, cycle and shelf life, storage efficiency, and cost of fabrication. Conventional ambient-temperature rechargeable batteries have solid electrodes and a liquid electrolyte. The positive electrode (cathode) consists of a host framework into which the mobile (working) cation is inserted reversibly over a finite solid-solution range. The solid-solution range, which is reduced at higher current by the rate of transfer of the working ion across electrode/electrolyte interfaces and within a host, limits the amount of charge per electrode formula unit that can be transferred over the time Δt = Δt(I). Moreover, the difference between energies of the LUMO and the HOMO of the electrolyte, i.e., electrolyte window, determines the maximum voltage for a long shelf and cycle life. The maximum stable voltage with an aqueous electrolyte is 1.5 V; the Li-ion rechargeable battery uses an organic electrolyte with a larger window, which increase the density of stored energy for a given Δt. Anode or cathode electrochemical potentials outside the electrolyte window can increase V, but they require formation of a passivating surface layer that must be permeable to Li(+) and capable of adapting rapidly to the changing electrode surface area as the electrode changes volume during cycling. A passivating surface layer adds to the impedance of the Li(+) transfer across the electrode/electrolyte interface and lowers the cycle life of a battery cell. Moreover, formation of a passivation layer on the anode robs Li from the cathode irreversibly on an initial charge, further lowering the reversible Δt. These problems plus the cost of quality control of manufacturing plague development of Li-ion rechargeable batteries that can compete with the internal combustion engine for powering electric cars and that can provide the needed low-cost storage of electrical energy generated by renewable wind and/or solar energy. Chemists are contributing to incremental improvements of the conventional strategy by investigating and controlling electrode passivation layers, improving the rate of Li(+) transfer across electrode/electrolyte interfaces, identifying electrolytes with larger windows while retaining a Li(+) conductivity σ(Li) > 10(-3) S cm(-1), synthesizing electrode morphologies that reduce the size of the active particles while pinning them on current collectors of large surface area accessible by the electrolyte, lowering the cost of cell fabrication, designing displacement-reaction anodes of higher capacity that allow a safe, fast charge, and designing alternative cathode hosts. However, new strategies are needed for batteries that go beyond powering hand-held devices, such as using electrode hosts with two-electron redox centers; replacing the cathode hosts by materials that undergo displacement reactions (e.g. sulfur) by liquid cathodes that may contain flow-through redox molecules, or by catalysts for air cathodes; and developing a Li(+) solid electrolyte separator membrane that allows an organic and aqueous liquid electrolyte on the anode and cathode sides, respectively. Opportunities exist for the chemist to bring together oxide and polymer or graphene chemistry in imaginative morphologies.
Yonggang Wang, Yanfang Song, Yongyao Xia · Chemical Society Reviews · 2016
Electrochemical capacitors (i.e. supercapacitors) include electrochemical double-layer capacitors that depend on the charge storage of ion adsorption and pseudo-capacitors that are based on charge storage involving fast surface redox reactions. The energy storage capacities of supercapacitors are several orders of magnitude higher than those of conventional dielectric capacitors, but are much lower than those of secondary batteries. They typically have high power density, long cyclic stability and high safety, and thus can be considered as an alternative or complement to rechargeable batteries in applications that require high power delivery or fast energy harvesting. This article reviews the latest progress in supercapacitors in charge storage mechanisms, electrode materials, electrolyte materials, systems, characterization methods, and applications. In particular, the newly developed charge storage mechanism for intercalative pseudocapacitive behaviour, which bridges the gap between battery behaviour and conventional pseudocapacitive behaviour, is also clarified for comparison. Finally, the prospects and challenges associated with supercapacitors in practical applications are also discussed.
Naoki Nitta, Feixiang Wu, Jung Tae Lee et al. · Materials Today · 2014
This review covers key technological developments and scientific challenges for a broad range of Li-ion battery electrodes. Periodic table and potential/capacity plots are used to compare many families of suitable materials. Performance characteristics, current limitations, and recent breakthroughs in the development of commercial intercalation materials such as lithium cobalt oxide (LCO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium iron phosphate (LFP), lithium titanium oxide (LTO) and others are contrasted with that of conversion materials, such as alloying anodes (Si, Ge, Sn, etc.), chalcogenides (S, Se, Te), and metal halides (F, Cl, Br, I). New polyanion cathode materials are also discussed. The cost, abundance, safety, Li and electron transport, volumetric expansion, material dissolution, and surface reactions for each type of electrode materials are described. Both general and specific strategies to overcome the current challenges are covered and categorized.
Martin Winter, Jürgen Otto Besenhard, Michael E. Spahr et al. · Advanced Materials · 1998
Insertion electrode materials are included in the majority of ambient-temperature rechargeable batteries. The reason for their widespread application is the fact that electrochemical insertion ("electroinsertion") reactions are intrinsically simple and reversible. The term electroinsertion refers to a host/guest solid-state redox reaction involving electrochemical charge transfer coupled with insertion of mobile guest ions from an electrolyte into the structure of a solid host, which is a mixed electronic and ionic conductor. [...]
Jingfa Li, Shenglin L. Xiong, Yurong Liu et al. · ACS Applied Materials & Interfaces · 2013
Binary metal oxides have been regarded as ideal and potential anode materials, which can ameliorate and offset the electrochemical performance of the single metal oxides, such as reversible capacity, structural stability and electronic conductivity. In this work, monodisperse NiCo(2)O(4) mesoporous microspheres are fabricated by a facile solvothermal method followed by pyrolysis of the Ni(0.33)Co(0.67)CO(3) precursor. The Brunauer-Emmett-Teller (BET) surface area of NiCo(2)O(4) mesoporous microspheres is determined to be about 40.58 m(2) g(-1) with dominant pore diameter of 14.5 nm and narrow size distribution of 10-20 nm. Our as-prepared NiCo(2)O(4) products were evaluated as the anode material for the lithium-ion-battery (LIB) application. It is demonstrated that the special structural features of the NiCo(2)O(4) microspheres including uniformity of the surface texture, the integrity and porosity exert significant effect on the electrochemical performances. The discharge capacity of NiCo(2)O(4) microspheres could reach 1198 mA h g(-1) after 30 discharge-charge cycles at a current density of 200 mA g(-1). More importantly, when the current density increased to 800 mA·g(-1), it can render reversible capacity of 705 mA h g(-1) even after 500 cycles, indicating its potential applications for next-generation high power lithium ion batteries (LIBs). The superior battery performance is mainly attributed to the unique micro/nanostructure composed of interconnected NiCo(2)O(4) nanocrystals, which provides good electrolyte diffusion and large electrode-electrolyte contact area, and meanwhile reduces volume change during charge/discharge process. The strategy is simple but very effective, and because of its versatility, it could be extended to other high-capacity metal oxide anode materials for LIBs.
Wu Xu, Jiulin Wang, Fei Ding et al. · Energy & Environmental Science · 2013
Lithium (Li) metal is an ideal anode material for rechargeable batteries due to its extremely high theoretical specific capacity (3860 mA h g−1), low density (0.59 g cm−3) and the lowest negative electrochemical potential (−3.040 V vs. the standard hydrogen electrode). Unfortunately, uncontrollable dendritic Li growth and limited Coulombic efficiency during Li deposition/stripping inherent in these batteries have prevented their practical applications over the past 40 years. With the emergence of post-Li-ion batteries, safe and efficient operation of Li metal anodes has become an enabling technology which may determine the fate of several promising candidates for the next generation energy storage systems, including rechargeable Li–air batteries, Li–S batteries, and Li metal batteries which utilize intercalation compounds as cathodes. In this paper, various factors that affect the morphology and Coulombic efficiency of Li metal anodes have been analyzed. Technologies utilized to characterize the morphology of Li deposition and the results obtained by modelling of Li dendrite growth have also been reviewed. Finally, recent development and urgent need in this field are discussed.
Xing Gao, Jianli Bao, G. L. Pan et al. · The Journal of Physical Chemistry B · 2004
A simple and efficient approach is developed for the synthesis of copper oxide nanorods with different morphology and crystallographic structure. Polycrystalline fine rods 10−20 nm thick and several hundred nanometers long and single crystalline thick rods 60−100 nm thick and up to 1 μm long were obtained from the reactions of copper hydrate with caustic soda solution at room temperature and 100 °C, respectively. The fine CuO nanorods as anode materials for Li ion battery exhibit a high electrochemical capacity of 766 mA h/g and relatively poor capacity retention as compared to thick nanorods with the single crystalline structure. The correlation between the structural features of the nanorods and their electrode performance is discussed in detail.
Alexandru Vlad, Neelam Singh, Julien Rolland et al. · Scientific Reports · 2014
High energy and high power electrochemical energy storage devices rely on different fundamental working principles--bulk vs. surface ion diffusion and electron conduction. Meeting both characteristics within a single or a pair of materials has been under intense investigations yet, severely hindered by intrinsic materials limitations. Here, we provide a solution to this issue and present an approach to design high energy and high power battery electrodes by hybridizing a nitroxide-polymer redox supercapacitor (PTMA) with a Li-ion battery material (LiFePO4). The PTMA constituent dominates the hybrid battery charge process and postpones the LiFePO4 voltage rise by virtue of its ultra-fast electrochemical response and higher working potential. We detail on a unique sequential charging mechanism in the hybrid electrode: PTMA undergoes oxidation to form high-potential redox species, which subsequently relax and charge the LiFePO4 by an internal charge transfer process. A rate capability equivalent to full battery recharge in less than 5 minutes is demonstrated. As a result of hybrid's components synergy, enhanced power and energy density as well as superior cycling stability are obtained, otherwise difficult to achieve from separate constituents.