Constructing silicon(Si)-based composite electrodes that possess high energy density,long cycle life,and fast charging capability simultaneously is critical for the development of high performance lithium-ion batterie...Constructing silicon(Si)-based composite electrodes that possess high energy density,long cycle life,and fast charging capability simultaneously is critical for the development of high performance lithium-ion batteries for mitigating range anxiety and slow charging issues in new energy vehicles.Herein,a thick silicon/carbon composite electrode with vertically aligned channels in the thickness direction(VC-SC)is constructed by employing a bubble formation method.Both experimental characterizations and theoretical simulations confirm that the obtained vertical channel structure can effectively address the problem of sluggish ion transport caused by high tortuosity in conventional thick electrodes,conspicuously enhance reaction kinetics,reduce polarization and side reactions,mitigate stress,increase the utilization of active materials,and promote cycling stability of the thick electrode.Consequently,when paired with LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622),the VC-SC||NCM622 pouch type full cell(~6.0 mAh cm^(-2))exhibits significantly improved rate performance and capacity retention compared with the SC||NCM622 full cell with the conventional silicon/carbon composite electrode without channels(SC)as the anode.The assembled VC-SC||NCM622 pouch full cell with a high energy density of 490.3 Wh kg^(-1)also reveals a remarkable fast charging capability at a high current density of 2.0 mA cm^(-2),with a capacity retention of 72.0%after 500 cycles.展开更多
Thick electrodes can reduce the ratio of inactive constituents in a holistic energy storage system while improving energy and power densities.Unfortunately,traditional slurry-casting electrodes induce high-tortuous io...Thick electrodes can reduce the ratio of inactive constituents in a holistic energy storage system while improving energy and power densities.Unfortunately,traditional slurry-casting electrodes induce high-tortuous ionic diffusion routes that directly depress the capacitance with a thickening design.To overcome this,a novel 3D low-tortuosity,self-supporting,wood-structured ultrathick electrode(NiMoN@WC,a thickness of~1400 mm)with hierarchical porosity and artificial array-distributed small holes was constructed via anchoring bimetallic nitrides into the monolithic wood carbons.Accompanying the embedded NiMoN nanoclusters with well-designed geometric and electronic structure,the vertically low-tortuous channels,enlarged specific surface area and pore volume,superhydrophilic interface,and excellent charge conductivities,a superior capacitance of NiMoN@WC thick electrodes(~5350 mF cm^(-2)and 184.5 F g^(-1))is achieved without the structural deformation.In especial,monolithic wood carbons with gradient porous network not only function as the high-flux matrices to ameliorate the NiMoN loading via cell wall engineering but also allow fully-exposed electroactive substance and efficient current collection,thereby deliver an acceptable rate capability over 75%retention even at a high sweep rate of 20 mA cm^(-2).Additionally,an asymmetric NiMoN@WC//WC supercapacitor with an available working voltage of 1.0-1.8 V is assembled to demonstrate a maximum energy density of~2.04 mWh cm^(-2)(17.4 Wh kg^(-1))at a power density of 1620 mW cm^(-2),along with a decent long-term lifespan over 10,000 charging-discharging cycles.As a guideline,the rational design of wood ultrathick electrode with nanostructured transition metal nitrides sketch a promising blueprint for alleviating global energy scarcity while expanding carbon-neutral technologies.展开更多
Thick electrode,with its feasibility and cost-effectiveness in lithium-ion batteries(LIBs),has attracted significant attention as a promising approach maximizing the energy density of battery.Through raising the mass ...Thick electrode,with its feasibility and cost-effectiveness in lithium-ion batteries(LIBs),has attracted significant attention as a promising approach maximizing the energy density of battery.Through raising the mass loading of active materials without altering the fundamental chemical attributes,thick electrodes can boost the energy density of the batteries effectively.Nevertheless,as the thickness of the electrode increases,the ionic conductivity of the electrode decreases,leading to abominable polarization in the thickness direction,which severely hampers the practical application of a thick electrode.This work proposes a novel porous gradient design of high-performance thick electrodes for LIBs.By constructing a porous structure that serves as a fast transport pathway for lithium(Li)ions,the ion transport kinetics within thick electrodes are significantly enhanced.Meanwhile,a particle size gradient design is incorporated to further mitigate polarization effects within the electrode,leading to substantial improvements in reaction homogeneity and material utilization.Employing this strategy,we have fabricated a porous gradient nanocellulose-carbon-nanotube based thick electrode,which exhibits an impressive capacity retention of 86.7%at a high mass loading of LiCoO_(2)(LCO)active material(20 mg cm^(-2))and a high current density of 5mA cm^(-2).展开更多
In the contemporary era,lithium-ion batteries have gained considerable attention in various industries such as 3C products,electric vehicles and energy storage systems due to their exceptional properties.With the rapi...In the contemporary era,lithium-ion batteries have gained considerable attention in various industries such as 3C products,electric vehicles and energy storage systems due to their exceptional properties.With the rapid progress in the energy storage sector,there is a growing demand for greater energy density in lithium-ion batteries.While the use of thick electrodes is a straightforward and effective approach to enhance the energy density of battery,it is hindered by the sluggish reaction dynamics and insufficient mechanical properties.Therefore,we comprehensively review recent advances in the field of thick electrodes for lithium-ion batteries to overcome the bottlenecks in the development of thick electrodes and achieve efficient fabrication for high-performance lithium-ion batteries.Initially,a systematic analysis is performed to identify the factors affecting the performance of the thick electrodes.the correlation between electrode materials,structural parameters,and performance is also investigated.Subsequently,the viable strategies for constructing thick electrodes with improved properties are summarize,including high throughput,high conductivity and low tortuosity,in both material development and structural design.In addition,recent advances in efficient fabrication methods for thick electrode fabrication are reviewed,with a comprehensive assessment of their merits,limitations,and applicable scenarios.Finally,a comprehensive overview of the multiscale design and manufacturing process for thick electrodes in lithium-ion batteries is provided,accompanied by valuable insights into design considerations that are crucial for future advances in this area.展开更多
A practical and effective approach to increase the energy storage capacity of lithium ion batteries(LIBs)is to boost their areal capacity.Developing thick electrodes is one of the most crucial ways to achieve high are...A practical and effective approach to increase the energy storage capacity of lithium ion batteries(LIBs)is to boost their areal capacity.Developing thick electrodes is one of the most crucial ways to achieve high areal capacity but limited by sluggish ion/electron transport,poor mechanical stability,and high-cost manufacturing strategies.Here we address these constraints by engineering a unique hierarchical-networked 10 mm thick all-carbon electrode,providing a scalable strategy to produce high areal capacity LIB electrodes.The hierarchical-networked structure utilizes micrometer-sized carbon fibers(MCFs)as building blocks,nano-sized carbon nanotubes(CNTs)as good continuous network with excellent electrical conductivity,and pyrolytic carbon as the binder and active material with excellent storage capacity.The combination of the above features endows our HNT-MCF/CNT/PC electrode with excellent performance including high reversible capacity of 15.44 mAh cm^(-2) at 2.0 mA cm^(-2) and exhibits excellent rate capability of 2.50 mAh cm^(-2) under 10.0 mA cm^(-2) current density.The Li-ion storage mechanism in HNT-MCF/CNT/PC involves dual-storage mechanism including intercalation and surface adsorption(pseudocapacitance)confirmed by the cyclic voltammetry and symmetric cell analysis.This work provides insights into the construction of high mechanical stability thick electrode for the next generation high areal capacity LIBs and beyond.展开更多
Rapid developments in lithium-ion battery(LIB)technology have been fueled by the expanding market for electric vehicles and increased demands for energy storage.Recently,thick electrode fabrication by solvent-free met...Rapid developments in lithium-ion battery(LIB)technology have been fueled by the expanding market for electric vehicles and increased demands for energy storage.Recently,thick electrode fabrication by solvent-free methods has emerged as a promising strategy for enhancing the energy density of LIBs.However,as electrode thickness increases,the tortuosity of lithium-ion transport also increases,resulting in severe polarization and poor electrochemical performance.Here,we investigate the effect of conductive agent morphology on the structural and electrochemical properties of 250μm thick lithium iron phosphate(LFP)/conductive agent/polytetrafluoroethylene(PTFE)-based electrodes.Three commercially available conductive additives,namely 0D Super P,1D multi-walled carbon nanotubes(MWCNTs),and 2D graphene nanoplatelets(GNPs),were incorporated into LFP-based electrodes.The MWCNT-incorporated electrode with a high loading mass(42 mg cm^(-2))exhibited a high porosity(ε=51%)and low tortuosity(τ=4.02)owing to its highly interconnected fibrous network of MWCNTs.Due to the fast lithium-ion transport kinetics in the MWCNT-incorporated electrode,the electrochemical performances exhibited a high specific capacity of 157 mAh g^(-1)at 0.1 C and an areal capacity of 7.16 mAh cm^(-2)at 0.1 C with a high-rate capability and excellent cycling stability over 300 cycles at 0.1 C.This study provides a guidance for utilizing conductive agents to apply in the low tortuous thick electrode fabricated by a solvent-free process.Additionally,this work paves the way to achieve scalable and sustainable dry processing techniques for developing next-generation energy storage technologies.展开更多
The growing demand for advanced electrochemical energy storage systems(EESSs)with high energy densities for electric vehicles and portable electronics is driving the electrode revolution,in which the development of hi...The growing demand for advanced electrochemical energy storage systems(EESSs)with high energy densities for electric vehicles and portable electronics is driving the electrode revolution,in which the development of high-mass-loading electrodes(HMLEs)is a promising route to improve the energy density of batteries packed in limited spaces through the optimal enlargement of active material loading ratios and reduction of inactive component ratios in overall cell devices.However,HMLEs face significant challenges including inferior charge kinetics,poor electrode structural stability,and complex and expensive production processes.Based on this,this review will provide a comprehensive summary of HMLEs,beginning with a basic presentation of factors influencing HMLE electrochemical properties,the understanding of which can guide optimal HMLE designs.Rational strategies to improve the electrochemical performance of HMLEs accompanied by corresponding advantages and bottlenecks are subsequently discussed in terms of various factors ranging from inactive component modification to active material design to structural engineering at the electrode scale.This review will also present the recent progress and approaches of HMLEs applied in various EESSs,including advanced secondary batteries(lithium-/sodium-/potassium-/aluminum-/calcium-ion batteries,lithium metal anodes,lithium-sulfur batteries,lithium-air batteries,zinc batteries,magnesium batteries)and supercapacitors.Finally,this review will examine the challenges and prospects of HMLE commercialization with a focus on thermal safety,performance evaluation,advanced characterization,and production cost assessment to guide future development.展开更多
The advancement of supercapacitors(SCs)is closely bound up with the breakthrough of rational design of energy materials.Freestanding and thick carbon(FTC)materials with well-organized porous structure is promising SC ...The advancement of supercapacitors(SCs)is closely bound up with the breakthrough of rational design of energy materials.Freestanding and thick carbon(FTC)materials with well-organized porous structure is promising SC electrode delivering high areal capacitive performance.However,controllable and sustainable fabrication of such FTC electrode is still of great challenges.Inspired by natural honeycombs with cross-linked multichannel structure,herein,an innovative molecular-cooperative-interaction strategy is elaborately provided to realize honeycomb-like FTC electrodes.The nitrogen-doped porous carbon monolith(N-PCM)is obtained with advantages of interconnect pore structure and abundant nitrogen doping.Such strategy is based on naturally abundant molecular precursors,and free of pore-templates,expensive polymerization catalyst,and dangerous reaction solvent,rendering it a sustainable and cost-effective process.Systematic control experiments reveal that strong interactions among molecular precursors promise the structural stability of N-PCM during carbonization,and rational selection of molecular precursors with chemical blowing features is key step for well-developed honeycomb-like pore structure.Interestingly,the optimized sample exhibits hierarchical pore structure with specific surface area of 626.4 m^(2)g^(-1)and rational N-doping of 7.01 wt%.The derived SC electrode with high mass loading of 40.1 mg cm^(-2)shows an excellent areal capacitance of 3621 mF cm^(-2)at 1 mA cm^(-2)and good rate performance with 2920 mF cm^(-2)at 25 mA cm^(-2).Moreover,the constructed aqueous symmetric SC and quasi-solid-state SC produce high energy densities of 0.32 and 0.27 mWh cm^(-2),respectively.We believe that such a composition/microstructure controllable method can promote the fabrication and development of other thick electrodes for energy storage devices.展开更多
Lithium-sulfur batteries(LSBs)have emerged as a promising high energy density system in miniaturized energy storage devices.However,serious issues rooted in large volume change(80%),poor intrinsic conductivity,“shutt...Lithium-sulfur batteries(LSBs)have emerged as a promising high energy density system in miniaturized energy storage devices.However,serious issues rooted in large volume change(80%),poor intrinsic conductivity,“shuttle effect”of S cathode,and limited mass loading of traditional electrode still make it a big challenge to achieve high energy density LSBs in a limited footprint.Herein,an innovative carbon dioxide(CO_(2))assisted three-dimensional(3D)printing strategy is proposed to fabricate threedimensional lattice structured CO_(2)activated single-walled carbon nanotubes/S composite thick electrode(3DP S@CNTs-CO_(2))for high areal capacity LSBs.The 3D lattice structure formed by interwoven CNTs and printed regular macropores can not only act as fast electron transfer networks,ensuring good electronic conductivity of thick electrode,but is beneficial to electrolyte infiltration,effectively boosting ion diffusion kinetics even under a high-mass loading.In addition,the subsequent hightemperature CO_(2)in-situ etching can induce abundant nanopores on the wall of CNTs,which significantly promotes the sulfur loading as well as its full utilization as a result of shortened ion diffusion paths.Owing to these merits,the 3DP S@CNTs-CO_(2)electrode delivers an impressive mass loading of 10 mg·cm^(−2).More importantly,a desired attribute of linearly scale up in areal capacitance with increased layers is observed,up to an outstanding value of 5.74 mAh·cm^(−2),outperforming most reported LSBs that adopt strategies that physically inhibit polysulfides.This work provides a thrilling drive that stimulates the application of LSBs in new generation miniaturized electronic devices.展开更多
基金National Key R&D Program of China,Grant/Award Number:2023YFB2503900National Natural Science Foundation of China,Grant/Award Number:12172143Shenzhen Science and Technology Program,Grant/Award Numbers:JCYJ20220818100418040,JCYJ20220530160816038。
文摘Constructing silicon(Si)-based composite electrodes that possess high energy density,long cycle life,and fast charging capability simultaneously is critical for the development of high performance lithium-ion batteries for mitigating range anxiety and slow charging issues in new energy vehicles.Herein,a thick silicon/carbon composite electrode with vertically aligned channels in the thickness direction(VC-SC)is constructed by employing a bubble formation method.Both experimental characterizations and theoretical simulations confirm that the obtained vertical channel structure can effectively address the problem of sluggish ion transport caused by high tortuosity in conventional thick electrodes,conspicuously enhance reaction kinetics,reduce polarization and side reactions,mitigate stress,increase the utilization of active materials,and promote cycling stability of the thick electrode.Consequently,when paired with LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622),the VC-SC||NCM622 pouch type full cell(~6.0 mAh cm^(-2))exhibits significantly improved rate performance and capacity retention compared with the SC||NCM622 full cell with the conventional silicon/carbon composite electrode without channels(SC)as the anode.The assembled VC-SC||NCM622 pouch full cell with a high energy density of 490.3 Wh kg^(-1)also reveals a remarkable fast charging capability at a high current density of 2.0 mA cm^(-2),with a capacity retention of 72.0%after 500 cycles.
基金support from the National Natural Science Foundation of China(32171728)Wuhan Knowledge Innovation Project(2022020801020312).
文摘Thick electrodes can reduce the ratio of inactive constituents in a holistic energy storage system while improving energy and power densities.Unfortunately,traditional slurry-casting electrodes induce high-tortuous ionic diffusion routes that directly depress the capacitance with a thickening design.To overcome this,a novel 3D low-tortuosity,self-supporting,wood-structured ultrathick electrode(NiMoN@WC,a thickness of~1400 mm)with hierarchical porosity and artificial array-distributed small holes was constructed via anchoring bimetallic nitrides into the monolithic wood carbons.Accompanying the embedded NiMoN nanoclusters with well-designed geometric and electronic structure,the vertically low-tortuous channels,enlarged specific surface area and pore volume,superhydrophilic interface,and excellent charge conductivities,a superior capacitance of NiMoN@WC thick electrodes(~5350 mF cm^(-2)and 184.5 F g^(-1))is achieved without the structural deformation.In especial,monolithic wood carbons with gradient porous network not only function as the high-flux matrices to ameliorate the NiMoN loading via cell wall engineering but also allow fully-exposed electroactive substance and efficient current collection,thereby deliver an acceptable rate capability over 75%retention even at a high sweep rate of 20 mA cm^(-2).Additionally,an asymmetric NiMoN@WC//WC supercapacitor with an available working voltage of 1.0-1.8 V is assembled to demonstrate a maximum energy density of~2.04 mWh cm^(-2)(17.4 Wh kg^(-1))at a power density of 1620 mW cm^(-2),along with a decent long-term lifespan over 10,000 charging-discharging cycles.As a guideline,the rational design of wood ultrathick electrode with nanostructured transition metal nitrides sketch a promising blueprint for alleviating global energy scarcity while expanding carbon-neutral technologies.
基金financially supported by the National Key R&D Program of China(2023YFB2503900)the National Natural Science Foundation of China(U22A20140,52072138)the Shenzhen Science and Technology Program(JCYJ20220818100418040,JCYJ20220530160816038)。
文摘Thick electrode,with its feasibility and cost-effectiveness in lithium-ion batteries(LIBs),has attracted significant attention as a promising approach maximizing the energy density of battery.Through raising the mass loading of active materials without altering the fundamental chemical attributes,thick electrodes can boost the energy density of the batteries effectively.Nevertheless,as the thickness of the electrode increases,the ionic conductivity of the electrode decreases,leading to abominable polarization in the thickness direction,which severely hampers the practical application of a thick electrode.This work proposes a novel porous gradient design of high-performance thick electrodes for LIBs.By constructing a porous structure that serves as a fast transport pathway for lithium(Li)ions,the ion transport kinetics within thick electrodes are significantly enhanced.Meanwhile,a particle size gradient design is incorporated to further mitigate polarization effects within the electrode,leading to substantial improvements in reaction homogeneity and material utilization.Employing this strategy,we have fabricated a porous gradient nanocellulose-carbon-nanotube based thick electrode,which exhibits an impressive capacity retention of 86.7%at a high mass loading of LiCoO_(2)(LCO)active material(20 mg cm^(-2))and a high current density of 5mA cm^(-2).
基金supported by the National Natural Science Foundation of China(U22A20193,U22A20438)the Key R&D Plan of Hubei Province(2023BAB036).
文摘In the contemporary era,lithium-ion batteries have gained considerable attention in various industries such as 3C products,electric vehicles and energy storage systems due to their exceptional properties.With the rapid progress in the energy storage sector,there is a growing demand for greater energy density in lithium-ion batteries.While the use of thick electrodes is a straightforward and effective approach to enhance the energy density of battery,it is hindered by the sluggish reaction dynamics and insufficient mechanical properties.Therefore,we comprehensively review recent advances in the field of thick electrodes for lithium-ion batteries to overcome the bottlenecks in the development of thick electrodes and achieve efficient fabrication for high-performance lithium-ion batteries.Initially,a systematic analysis is performed to identify the factors affecting the performance of the thick electrodes.the correlation between electrode materials,structural parameters,and performance is also investigated.Subsequently,the viable strategies for constructing thick electrodes with improved properties are summarize,including high throughput,high conductivity and low tortuosity,in both material development and structural design.In addition,recent advances in efficient fabrication methods for thick electrode fabrication are reviewed,with a comprehensive assessment of their merits,limitations,and applicable scenarios.Finally,a comprehensive overview of the multiscale design and manufacturing process for thick electrodes in lithium-ion batteries is provided,accompanied by valuable insights into design considerations that are crucial for future advances in this area.
基金The National Natural Science Foundation of China(21875292)the Fundamental Research Funds for the Central Universities+1 种基金Guangxi Key Laboratory of Information Materials&Guilin University of Electronic Technology,China(191014K)the Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy(2020CB1007).
文摘A practical and effective approach to increase the energy storage capacity of lithium ion batteries(LIBs)is to boost their areal capacity.Developing thick electrodes is one of the most crucial ways to achieve high areal capacity but limited by sluggish ion/electron transport,poor mechanical stability,and high-cost manufacturing strategies.Here we address these constraints by engineering a unique hierarchical-networked 10 mm thick all-carbon electrode,providing a scalable strategy to produce high areal capacity LIB electrodes.The hierarchical-networked structure utilizes micrometer-sized carbon fibers(MCFs)as building blocks,nano-sized carbon nanotubes(CNTs)as good continuous network with excellent electrical conductivity,and pyrolytic carbon as the binder and active material with excellent storage capacity.The combination of the above features endows our HNT-MCF/CNT/PC electrode with excellent performance including high reversible capacity of 15.44 mAh cm^(-2) at 2.0 mA cm^(-2) and exhibits excellent rate capability of 2.50 mAh cm^(-2) under 10.0 mA cm^(-2) current density.The Li-ion storage mechanism in HNT-MCF/CNT/PC involves dual-storage mechanism including intercalation and surface adsorption(pseudocapacitance)confirmed by the cyclic voltammetry and symmetric cell analysis.This work provides insights into the construction of high mechanical stability thick electrode for the next generation high areal capacity LIBs and beyond.
基金supported by the Materials/Parts Technology Development Programs(RS-2024-00466920,RS-2024-00432627,and RS-2024-00421058)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘Rapid developments in lithium-ion battery(LIB)technology have been fueled by the expanding market for electric vehicles and increased demands for energy storage.Recently,thick electrode fabrication by solvent-free methods has emerged as a promising strategy for enhancing the energy density of LIBs.However,as electrode thickness increases,the tortuosity of lithium-ion transport also increases,resulting in severe polarization and poor electrochemical performance.Here,we investigate the effect of conductive agent morphology on the structural and electrochemical properties of 250μm thick lithium iron phosphate(LFP)/conductive agent/polytetrafluoroethylene(PTFE)-based electrodes.Three commercially available conductive additives,namely 0D Super P,1D multi-walled carbon nanotubes(MWCNTs),and 2D graphene nanoplatelets(GNPs),were incorporated into LFP-based electrodes.The MWCNT-incorporated electrode with a high loading mass(42 mg cm^(-2))exhibited a high porosity(ε=51%)and low tortuosity(τ=4.02)owing to its highly interconnected fibrous network of MWCNTs.Due to the fast lithium-ion transport kinetics in the MWCNT-incorporated electrode,the electrochemical performances exhibited a high specific capacity of 157 mAh g^(-1)at 0.1 C and an areal capacity of 7.16 mAh cm^(-2)at 0.1 C with a high-rate capability and excellent cycling stability over 300 cycles at 0.1 C.This study provides a guidance for utilizing conductive agents to apply in the low tortuous thick electrode fabricated by a solvent-free process.Additionally,this work paves the way to achieve scalable and sustainable dry processing techniques for developing next-generation energy storage technologies.
基金the National Basic Research Program of China(Grant No.2015CB251100)the National Natural Science Foundation of China(Grant No.21975026)the Beijing Natural Science Foundation(Grant No.L182056).
文摘The growing demand for advanced electrochemical energy storage systems(EESSs)with high energy densities for electric vehicles and portable electronics is driving the electrode revolution,in which the development of high-mass-loading electrodes(HMLEs)is a promising route to improve the energy density of batteries packed in limited spaces through the optimal enlargement of active material loading ratios and reduction of inactive component ratios in overall cell devices.However,HMLEs face significant challenges including inferior charge kinetics,poor electrode structural stability,and complex and expensive production processes.Based on this,this review will provide a comprehensive summary of HMLEs,beginning with a basic presentation of factors influencing HMLE electrochemical properties,the understanding of which can guide optimal HMLE designs.Rational strategies to improve the electrochemical performance of HMLEs accompanied by corresponding advantages and bottlenecks are subsequently discussed in terms of various factors ranging from inactive component modification to active material design to structural engineering at the electrode scale.This review will also present the recent progress and approaches of HMLEs applied in various EESSs,including advanced secondary batteries(lithium-/sodium-/potassium-/aluminum-/calcium-ion batteries,lithium metal anodes,lithium-sulfur batteries,lithium-air batteries,zinc batteries,magnesium batteries)and supercapacitors.Finally,this review will examine the challenges and prospects of HMLE commercialization with a focus on thermal safety,performance evaluation,advanced characterization,and production cost assessment to guide future development.
基金Guangdong Science and Technology Department,Grant/Award Number:2020B0909030004National Natural Science Foundation of China,Grant/Award Number:21975026。
文摘The advancement of supercapacitors(SCs)is closely bound up with the breakthrough of rational design of energy materials.Freestanding and thick carbon(FTC)materials with well-organized porous structure is promising SC electrode delivering high areal capacitive performance.However,controllable and sustainable fabrication of such FTC electrode is still of great challenges.Inspired by natural honeycombs with cross-linked multichannel structure,herein,an innovative molecular-cooperative-interaction strategy is elaborately provided to realize honeycomb-like FTC electrodes.The nitrogen-doped porous carbon monolith(N-PCM)is obtained with advantages of interconnect pore structure and abundant nitrogen doping.Such strategy is based on naturally abundant molecular precursors,and free of pore-templates,expensive polymerization catalyst,and dangerous reaction solvent,rendering it a sustainable and cost-effective process.Systematic control experiments reveal that strong interactions among molecular precursors promise the structural stability of N-PCM during carbonization,and rational selection of molecular precursors with chemical blowing features is key step for well-developed honeycomb-like pore structure.Interestingly,the optimized sample exhibits hierarchical pore structure with specific surface area of 626.4 m^(2)g^(-1)and rational N-doping of 7.01 wt%.The derived SC electrode with high mass loading of 40.1 mg cm^(-2)shows an excellent areal capacitance of 3621 mF cm^(-2)at 1 mA cm^(-2)and good rate performance with 2920 mF cm^(-2)at 25 mA cm^(-2).Moreover,the constructed aqueous symmetric SC and quasi-solid-state SC produce high energy densities of 0.32 and 0.27 mWh cm^(-2),respectively.We believe that such a composition/microstructure controllable method can promote the fabrication and development of other thick electrodes for energy storage devices.
基金supported by the National Natural Science Foundation of China(U22A20140,52072138)Shenzhen Science and Technology Program(JCYJ20220818100418040 and JCYJ20220530160816038)。
基金supported by the National Natural Science Foundation of China(Nos.51933007 and 51673123)the National Key Research and development Program of China(No.2017YFE0111500)the Program for Featured Directions of Engineering Multidisciplines of Sichuan University(No.2020SCUNG203).
文摘Lithium-sulfur batteries(LSBs)have emerged as a promising high energy density system in miniaturized energy storage devices.However,serious issues rooted in large volume change(80%),poor intrinsic conductivity,“shuttle effect”of S cathode,and limited mass loading of traditional electrode still make it a big challenge to achieve high energy density LSBs in a limited footprint.Herein,an innovative carbon dioxide(CO_(2))assisted three-dimensional(3D)printing strategy is proposed to fabricate threedimensional lattice structured CO_(2)activated single-walled carbon nanotubes/S composite thick electrode(3DP S@CNTs-CO_(2))for high areal capacity LSBs.The 3D lattice structure formed by interwoven CNTs and printed regular macropores can not only act as fast electron transfer networks,ensuring good electronic conductivity of thick electrode,but is beneficial to electrolyte infiltration,effectively boosting ion diffusion kinetics even under a high-mass loading.In addition,the subsequent hightemperature CO_(2)in-situ etching can induce abundant nanopores on the wall of CNTs,which significantly promotes the sulfur loading as well as its full utilization as a result of shortened ion diffusion paths.Owing to these merits,the 3DP S@CNTs-CO_(2)electrode delivers an impressive mass loading of 10 mg·cm^(−2).More importantly,a desired attribute of linearly scale up in areal capacitance with increased layers is observed,up to an outstanding value of 5.74 mAh·cm^(−2),outperforming most reported LSBs that adopt strategies that physically inhibit polysulfides.This work provides a thrilling drive that stimulates the application of LSBs in new generation miniaturized electronic devices.
