Conventional lithium-ion batteries(LIBs)with graphite anodes are approaching their theoretical limitations in energy density.Replacing the conventional graphite anodes with high-capacity Si-based anodes represents one...Conventional lithium-ion batteries(LIBs)with graphite anodes are approaching their theoretical limitations in energy density.Replacing the conventional graphite anodes with high-capacity Si-based anodes represents one of the most promising strategies to greatly boost the energy density of LIBs.However,the inherent huge volume expansion of Si-based materials after lithiation and the resulting series of intractable problems,such as unstable solid electrolyte interphase layer,cracking of electrode,and especially the rapid capacity degradation of cells,severely restrict the practical application of Sibased anodes.Over the past decade,numerous reports have demonstrated that polymer binders play a critical role in alleviating the volume expansion and maintaining the integrity and stable cycling of Si-based anodes.In this review,the state-of-the-art designing of polymer binders for Si-based anodes have been systematically summarized based on their structures,including the linear,branched,crosslinked,and conjugated conductive polymer binders.Especially,the comprehensive designing of multifunctional polymer binders,by a combination of multiple structures,interactions,crosslinking chemistries,ionic or electronic conductivities,soft and hard segments,and so forth,would be promising to promote the practical application of Si-based anodes.Finally,a perspective on the rational design of practical polymer binders for the large-scale application of Si-based anodes is presented.展开更多
Silicon anodes have drawn ever-increasing attention in lithium-ion batteries(LIBs) owing to their extremely high theoretical capacity and abundance in the earth. Despite promising advantages, the wide use of silicon a...Silicon anodes have drawn ever-increasing attention in lithium-ion batteries(LIBs) owing to their extremely high theoretical capacity and abundance in the earth. Despite promising advantages, the wide use of silicon anodes in LIBs is highly hindered by their fast capacity fading and low Coulombic efficiency arising from their substantial volumetric variation(>300%). Herein, we report a novel aqueous hybrid gel binder for silicon anodes via crosslinking sodium carboxymethyl cellulose(NaCMC) by an inorganic crosslinker-sodium borate. Not only this gel polymer binder can chemically bond to silicon nanoparticle, but also the deformable framework of this crosslinked binder is capable of maintaining electrode integrity, thus buffering dramatic volume change of silicon. Consequently, the silicon anode with this gel binder exhibits good cycle life(1211.5 mAh/g after 600 cycles) and high initial Coulombic efficiency(88.95%).展开更多
Developing high-performance lithium-ion batteries (LIBs) with high energy density, rate capability and long cycle life are essential for the ever-growing practical application. Among all battery components, the binder...Developing high-performance lithium-ion batteries (LIBs) with high energy density, rate capability and long cycle life are essential for the ever-growing practical application. Among all battery components, the binder plays a key role in determining the preparation of electrodes and the improvement of battery performance, in spite of a low usage amount. The main function of binder is to bond the active material, conductive additive and current collector together and provide electron and ion channels to improve the kinetics of electrochemical reaction. With the ever-increasing requirement of high energy density by LIBs, technical challenges such as volume expansion and active material dissolution are attracting worldwide attentions, where binder is thought to provide a new solution.There are two main categories (organic solvent soluble binder and water-soluble binder) and abundant polar functional groups providing adhesion ability. It is of great significance to timely summarize the latest progress in battery binders and present the principles for designing novel binders with both robust binding interaction and outstanding electrode stabilization function. This review begins with an introduction of the binding mechanism and the related binding forces, including mechanical interlocking forces and interfacial forces. Then, we discussed four different strategies (the enhancement of binding force,the formation of three-dimensional (3D) network, the enhancement of conductivity and binders with special functions) for constructing ideal binder system in order to satisfy the specific demands of different batteries, such as LIBs and lithium–sulfur (Li–S) batteries. Finally, some prospective and promising directions of binder design are proposed based on the existing and emerging binders and guide the development of the next-generation LIBs.展开更多
基金Beijing National Laboratory for Molecular Sciences,Grant/Award Number:2019BMS20022National Natural Science Foundation of China,Grant/Award Number:22005314+3 种基金Strategic Priority Research Program of the Chinese Academy of Sciences,Grant/Award Number:XDA21070300The China Postdoctoral Science Foundation,Grant/Award Number:2019M660805The National Key R&D Program of China,Grant/Award Number:2019YFA0705600The Special Financial Grant from the China Postdoctoral Science Foundation,Grant/Award Number:2020T130658。
文摘Conventional lithium-ion batteries(LIBs)with graphite anodes are approaching their theoretical limitations in energy density.Replacing the conventional graphite anodes with high-capacity Si-based anodes represents one of the most promising strategies to greatly boost the energy density of LIBs.However,the inherent huge volume expansion of Si-based materials after lithiation and the resulting series of intractable problems,such as unstable solid electrolyte interphase layer,cracking of electrode,and especially the rapid capacity degradation of cells,severely restrict the practical application of Sibased anodes.Over the past decade,numerous reports have demonstrated that polymer binders play a critical role in alleviating the volume expansion and maintaining the integrity and stable cycling of Si-based anodes.In this review,the state-of-the-art designing of polymer binders for Si-based anodes have been systematically summarized based on their structures,including the linear,branched,crosslinked,and conjugated conductive polymer binders.Especially,the comprehensive designing of multifunctional polymer binders,by a combination of multiple structures,interactions,crosslinking chemistries,ionic or electronic conductivities,soft and hard segments,and so forth,would be promising to promote the practical application of Si-based anodes.Finally,a perspective on the rational design of practical polymer binders for the large-scale application of Si-based anodes is presented.
基金supported by the National Natural Science Foundation of China(No.51602250)Thousand Youth Talents Plan Project of China
文摘Silicon anodes have drawn ever-increasing attention in lithium-ion batteries(LIBs) owing to their extremely high theoretical capacity and abundance in the earth. Despite promising advantages, the wide use of silicon anodes in LIBs is highly hindered by their fast capacity fading and low Coulombic efficiency arising from their substantial volumetric variation(>300%). Herein, we report a novel aqueous hybrid gel binder for silicon anodes via crosslinking sodium carboxymethyl cellulose(NaCMC) by an inorganic crosslinker-sodium borate. Not only this gel polymer binder can chemically bond to silicon nanoparticle, but also the deformable framework of this crosslinked binder is capable of maintaining electrode integrity, thus buffering dramatic volume change of silicon. Consequently, the silicon anode with this gel binder exhibits good cycle life(1211.5 mAh/g after 600 cycles) and high initial Coulombic efficiency(88.95%).
基金supported by the National Natural Science Foundation of China (52090034)the Ministry of Science and Technology of China (2020YFA0711500)the Higher Education Discipline Innovation Project (111 Project B12015)。
基金financially supported by the National Key R&D Program of China (No. 2019YFA0705104)Guangdong Province Science and Technology Department under Project (No. 2020A0505100014)。
文摘Developing high-performance lithium-ion batteries (LIBs) with high energy density, rate capability and long cycle life are essential for the ever-growing practical application. Among all battery components, the binder plays a key role in determining the preparation of electrodes and the improvement of battery performance, in spite of a low usage amount. The main function of binder is to bond the active material, conductive additive and current collector together and provide electron and ion channels to improve the kinetics of electrochemical reaction. With the ever-increasing requirement of high energy density by LIBs, technical challenges such as volume expansion and active material dissolution are attracting worldwide attentions, where binder is thought to provide a new solution.There are two main categories (organic solvent soluble binder and water-soluble binder) and abundant polar functional groups providing adhesion ability. It is of great significance to timely summarize the latest progress in battery binders and present the principles for designing novel binders with both robust binding interaction and outstanding electrode stabilization function. This review begins with an introduction of the binding mechanism and the related binding forces, including mechanical interlocking forces and interfacial forces. Then, we discussed four different strategies (the enhancement of binding force,the formation of three-dimensional (3D) network, the enhancement of conductivity and binders with special functions) for constructing ideal binder system in order to satisfy the specific demands of different batteries, such as LIBs and lithium–sulfur (Li–S) batteries. Finally, some prospective and promising directions of binder design are proposed based on the existing and emerging binders and guide the development of the next-generation LIBs.
