Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fi...Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fibrils(CEFs)as a class of deagglomerated binder for high-mass-loading electrodes.Derived from natural wood,CEF represents the most fundamental unit of cellulose with nanoscale diameter.The preparation of the CEFs involves the modulation of intermolecular hydrogen bonding by the treatment with a proton acceptor and a hydrotropic agent.This elementary deagglomeration of the cellulose fibers increases surface area and anionic charge density,thus promoting uniform dispersion with carbon conductive additives and suppressing interfacial side reactions at electrodes.Consequently,a homogeneous redox reaction is achieved throughout the electrodes.The resulting CEF-based cathode(overlithiated layered oxide(OLO)is chosen as a benchmark electrode active material)exhibits a high areal-mass-loading(50 mg cm^(-2),equivalent to an areal capacity of 12.5 mAh cm^(-2))and a high specific energy density(445.4 Wh kg–1)of a cell,which far exceeds those of previously reported OLO cathodes.This study highlights the viability of the deagglomerated binder in enabling sustainable high-mass-loading electrodes that are difficult to achieve with conventional synthetic polymer binders.展开更多
Strategies for achieving high-energy-density lithium-ion batteries include using high-capacity materials such as high-nickel NCM,increasing the active material content in the electrode by utilizing high-conductivity c...Strategies for achieving high-energy-density lithium-ion batteries include using high-capacity materials such as high-nickel NCM,increasing the active material content in the electrode by utilizing high-conductivity carbon nanotubes(CNT)conductive materials,and electrode thickening.However,these methods are still limited due to the limitation in the capacity of high-nickel NCM,aggregation of CNT conductive materials,and nonuniform material distribution of thick-film electrodes,which ultimately damage the mechanical and electrical integrity of the electrode,leading to a decrease in electrochemical performance.Here,we present an integrated binder-CNT composite dispersion solution to realize a high-solids-content(>77 wt%)slurry for high-mass-loading electrodes and to mitigate the migration of binder and conductive additives.Indeed,the approach reduces solvent usage by approximately 30%and ensures uniform conductive additive-binder domain distribution during electrode manufacturing,resulting in improved coating quality and adhesive strength for high-mass-loading electrodes(>12 mAh cm^(−2)).In terms of various electrode properties,the presented electrode showed low resistance and excellent electrochemical properties despite the low CNT contents of 0.6 wt%compared to the pristine-applied electrode with 0.85 wt%CNT contents.Moreover,our strategy enables faster drying,which increases the coating speed,thereby offering potential energy savings and supporting carbon neutrality in wet-based electrode manufacturing processes.展开更多
Nickel/cobalt-based materials are promising cathodes owing to the high redox potential,high specific capacity,and long cycling performance.However,with the mass-loading of the electrode increasing,it greatly hinders t...Nickel/cobalt-based materials are promising cathodes owing to the high redox potential,high specific capacity,and long cycling performance.However,with the mass-loading of the electrode increasing,it greatly hinders the ion diffusion and charge transport,resulting in serious decrease of the electrode capacity.Herein,a hierarchical nickel-cobalt-based porous nanoflower structure(NiCo-Nanoflower)composed of numerous ultrathin nanosheets is synthesized,which significantly enhances the surface area and provides additional active sites.Besides,the abundant oxygen defects in NiCo-Nanoflower significantly enhance its electrical conductivity.Therefore,the NiCo-Nanoflower electrode exhibits a high reversible capacity of up to 210.4 mAh g^(−1)at 0.5 A g^(−1)and excellent rate retention of 180.4 mAh g^(−1)at 8 A g^(−1)(104 mA cm^(−2))even under high areal mass loading of 13 mg cm^(−2).Upon assembly in a NiCo//Zn battery system,the configuration demonstrates exceptional electrochemical stability,maintaining 74.3%capacity retention after 5000 cycles.This work demonstrates that NiCo-Nanoflower,equipped with three-dimensional microstructure and oxygen-enriched defects,holds significant potential for application in high-mass-loading cathodes for alkaline aqueous zinc batteries.展开更多
基金supported by the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration and Ministry of Trade,Industry and Energy of Korean government under grant No 23-CM-AI-08.
文摘Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fibrils(CEFs)as a class of deagglomerated binder for high-mass-loading electrodes.Derived from natural wood,CEF represents the most fundamental unit of cellulose with nanoscale diameter.The preparation of the CEFs involves the modulation of intermolecular hydrogen bonding by the treatment with a proton acceptor and a hydrotropic agent.This elementary deagglomeration of the cellulose fibers increases surface area and anionic charge density,thus promoting uniform dispersion with carbon conductive additives and suppressing interfacial side reactions at electrodes.Consequently,a homogeneous redox reaction is achieved throughout the electrodes.The resulting CEF-based cathode(overlithiated layered oxide(OLO)is chosen as a benchmark electrode active material)exhibits a high areal-mass-loading(50 mg cm^(-2),equivalent to an areal capacity of 12.5 mAh cm^(-2))and a high specific energy density(445.4 Wh kg–1)of a cell,which far exceeds those of previously reported OLO cathodes.This study highlights the viability of the deagglomerated binder in enabling sustainable high-mass-loading electrodes that are difficult to achieve with conventional synthetic polymer binders.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2022M3H4A6A0103720142)the National Research Council of Science&Technology(NST)grant by the Korea government(MSIT)(No.GTL24011-000)+1 种基金the Technology Innovation Program(RS-2024-00404165)through the Korea Planning&Evaluation Institute of Industrial Technology(KEIT)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)supported by the Samsung SDI Co.Ltd.and the Korea Institute of Science and Technology(KIST)institutional program(2E33942,2E3394B)。
文摘Strategies for achieving high-energy-density lithium-ion batteries include using high-capacity materials such as high-nickel NCM,increasing the active material content in the electrode by utilizing high-conductivity carbon nanotubes(CNT)conductive materials,and electrode thickening.However,these methods are still limited due to the limitation in the capacity of high-nickel NCM,aggregation of CNT conductive materials,and nonuniform material distribution of thick-film electrodes,which ultimately damage the mechanical and electrical integrity of the electrode,leading to a decrease in electrochemical performance.Here,we present an integrated binder-CNT composite dispersion solution to realize a high-solids-content(>77 wt%)slurry for high-mass-loading electrodes and to mitigate the migration of binder and conductive additives.Indeed,the approach reduces solvent usage by approximately 30%and ensures uniform conductive additive-binder domain distribution during electrode manufacturing,resulting in improved coating quality and adhesive strength for high-mass-loading electrodes(>12 mAh cm^(−2)).In terms of various electrode properties,the presented electrode showed low resistance and excellent electrochemical properties despite the low CNT contents of 0.6 wt%compared to the pristine-applied electrode with 0.85 wt%CNT contents.Moreover,our strategy enables faster drying,which increases the coating speed,thereby offering potential energy savings and supporting carbon neutrality in wet-based electrode manufacturing processes.
基金supported by the Joint Funds of the National Natural Science Foundation of China(No.U22A20140)University of Jinan Disciplinary Cross-Convergence Construction Project 2023(No.XKJC-202309)+4 种基金Jinan City-School Integration Development Strategy Project(No.JNSX2023015)National Natural Science Foundation of China(No.22409071)Natural Foundation of Shandong Province(No.ZR2024QB120)Youth Innovation Group Plan of Shandong Province(No.2024KJG046)Higher-Level Talent Initial Scientific Research and Discipline Construction Fund(511/1009530).
文摘Nickel/cobalt-based materials are promising cathodes owing to the high redox potential,high specific capacity,and long cycling performance.However,with the mass-loading of the electrode increasing,it greatly hinders the ion diffusion and charge transport,resulting in serious decrease of the electrode capacity.Herein,a hierarchical nickel-cobalt-based porous nanoflower structure(NiCo-Nanoflower)composed of numerous ultrathin nanosheets is synthesized,which significantly enhances the surface area and provides additional active sites.Besides,the abundant oxygen defects in NiCo-Nanoflower significantly enhance its electrical conductivity.Therefore,the NiCo-Nanoflower electrode exhibits a high reversible capacity of up to 210.4 mAh g^(−1)at 0.5 A g^(−1)and excellent rate retention of 180.4 mAh g^(−1)at 8 A g^(−1)(104 mA cm^(−2))even under high areal mass loading of 13 mg cm^(−2).Upon assembly in a NiCo//Zn battery system,the configuration demonstrates exceptional electrochemical stability,maintaining 74.3%capacity retention after 5000 cycles.This work demonstrates that NiCo-Nanoflower,equipped with three-dimensional microstructure and oxygen-enriched defects,holds significant potential for application in high-mass-loading cathodes for alkaline aqueous zinc batteries.
