Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effe...Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effectively addresses the aforementioned problems;however,the impact of its quality on lithium-ion transfer and structure durability is yet to be explored.Herein,the influence of an interface conductive network on ionic transport and mechanical stability under fast charging is explored for the first time.2D modeling simulation and Cryo-transmission electron microscopy precisely reveal the mitigation of interface polarization owing to a higher fraction of conductive inorganic species formation in bilayer solid electrolyte interphase is mainly responsible for a linear decrease in ionic diffusion energy barrier.Furthermore,atomic force microscopy and Raman shift exhibit substantial stress dissipation generated by a complete conductive network,which is critical to the linear reduction of electrode residual stress.This study provides insights into the rational design of optimized interface SiO-based anodes with reinforced fast-charging performance.展开更多
Silicon monoxide(SiO)is widely recognized as a promising anode material for next-generation lithium-ion batteries.Owing to its metastable amorphous structure,SiO exhibits a highly complex degree of crystallization at ...Silicon monoxide(SiO)is widely recognized as a promising anode material for next-generation lithium-ion batteries.Owing to its metastable amorphous structure,SiO exhibits a highly complex degree of crystallization at the microscopic level,which significantly influences its electrochemical behavior.As a consequence,accurately regulating the crystallization of SiO,and further establishing the relationship between crystallinity and electrochemical performance are very critical for SiO anodes.In this article,carbon-coated SiO materials with different crystallinity degrees were synthesized using lithium hydroxide monohydrate(LiOH·H_(2)O)as a structural modifier to reveal this rule.Additionally,moderate amount of LiOH·H_(2)O addition results in the forming of an oxygen-rich shell,which effectively inhibits the inward migration of oxygen atoms on the SiO surface and suppresses volume expansion.However,the crystallinity of SiO will gradually enhance and the crystalline phase appears with increasing the amount of LiOH·H_(2)O,which will generate a deteriorative Li+diffusion kinetic.After balancing the above two contradictions,a mass fraction of 1%LiOH·H_(2)O for the additive yielded SiO@C-1,characterized by optimal crystallinity.SiO@C-1 demonstrates exceptional long-cycle stability with 74.8%capacity retention after 500 cycles at 1 A·g^(-1).Furthermore,it achieves a capacity retention of 52.2%even at a high density of 5 A·g^(-1).This study first reveals the relationship between SiO crystallinity and electrochemical performance,which efficiently guides the design of high-performance SiO anodes.展开更多
Silicon-based anode is a promising candidate for all-solid-state batteries(ASSBs).However,it must be further improved because of its tremendous volume change.In this study,various interface treatment strategies for Si...Silicon-based anode is a promising candidate for all-solid-state batteries(ASSBs).However,it must be further improved because of its tremendous volume change.In this study,various interface treatment strategies for SiO/carbon composite anodes in ASSBs were investigated using a multiphysics modeling framework.By evaluating the effects of active(carbon)and inactive coating materials,as well as the geometric and mechanical parameters,this research provides critical insights into optimizing their electrochemical performance and mechanical stability.Computational results indicate that carbon coatings can greatly enhance lithiation kinetics by regulating the interfacial electrochemical potential gradients,reducing the residual lithium concentration,and homogenizing the lithium-ion distribution compared with uncoated or inactive-coated configurations.In addition,thinner carbon coatings further improve capacity retention and stress management by balancing shorter lithium diffusion pathways with mitigated interfacial stress accumulation.Despite their ability to mechanically stabilize the anode,inactive coatings exhibit tradeoffs between lithium transport kinetics and stress modulation,with optimal performance achieved at lower Young’s moduli.Mechanical analyses highlight distinct failure mechanisms at the anode–electrolyte(shear driven)and particle-coating(tension driven)interfaces,emphasizing the need for tailored adhesion strategies.These findings provide actionable guidelines for designing robust SiO-based anodes,emphasizing the interplay among electrochemical efficiency,stress regulation,and interfacial durability in ASSBs.展开更多
The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH g...The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH groups in PAA leads to the formation of intramolecular and intermolecular hydrogen bonds,greatly weakening the bonding force of the binder to SiO surface.However,strengthening the binder-material interaction from the perspective of binder molecular regulation poses a significant challenge.Herein,a modified PAA-Li_(x)(0.25≤x≤1)binder with prominent mechanical properties and adhesion strength is specifically synthesized for SiO anodes by quantitatively substituting the carboxylic hydrogen with lithium.The appropriate lithium substitution(x=0.25)not only effectively increases the number of hydrogen bonds between the PAA binder and SiO surface owing to charge repulsion effect between ions,but also guarantees moderate entanglement between PAA-Li_x molecular chains through the ion-dipole interaction.As such,the PAA-Li_(0.25)/SiO electrode exhibits exceptional mechanical properties and the lowest volume change,as well as the optimum cycling(1237.3 mA h g^(-1)after 100cycles at 0.1 C)and rate performance(1000.6 mA h g^(-1)at 1 C),significantly outperforming the electrode using pristine PAA binder.This work paves the way for quantitative regulation of binders at the molecular level.展开更多
基金the National Natural Science Foundation of China(Nos.22209095 and 22238004).
文摘Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effectively addresses the aforementioned problems;however,the impact of its quality on lithium-ion transfer and structure durability is yet to be explored.Herein,the influence of an interface conductive network on ionic transport and mechanical stability under fast charging is explored for the first time.2D modeling simulation and Cryo-transmission electron microscopy precisely reveal the mitigation of interface polarization owing to a higher fraction of conductive inorganic species formation in bilayer solid electrolyte interphase is mainly responsible for a linear decrease in ionic diffusion energy barrier.Furthermore,atomic force microscopy and Raman shift exhibit substantial stress dissipation generated by a complete conductive network,which is critical to the linear reduction of electrode residual stress.This study provides insights into the rational design of optimized interface SiO-based anodes with reinforced fast-charging performance.
基金supported by the National Natural Science Foundation of China(No.22138013)the Taishan Scholar Project(No.ts201712020).
文摘Silicon monoxide(SiO)is widely recognized as a promising anode material for next-generation lithium-ion batteries.Owing to its metastable amorphous structure,SiO exhibits a highly complex degree of crystallization at the microscopic level,which significantly influences its electrochemical behavior.As a consequence,accurately regulating the crystallization of SiO,and further establishing the relationship between crystallinity and electrochemical performance are very critical for SiO anodes.In this article,carbon-coated SiO materials with different crystallinity degrees were synthesized using lithium hydroxide monohydrate(LiOH·H_(2)O)as a structural modifier to reveal this rule.Additionally,moderate amount of LiOH·H_(2)O addition results in the forming of an oxygen-rich shell,which effectively inhibits the inward migration of oxygen atoms on the SiO surface and suppresses volume expansion.However,the crystallinity of SiO will gradually enhance and the crystalline phase appears with increasing the amount of LiOH·H_(2)O,which will generate a deteriorative Li+diffusion kinetic.After balancing the above two contradictions,a mass fraction of 1%LiOH·H_(2)O for the additive yielded SiO@C-1,characterized by optimal crystallinity.SiO@C-1 demonstrates exceptional long-cycle stability with 74.8%capacity retention after 500 cycles at 1 A·g^(-1).Furthermore,it achieves a capacity retention of 52.2%even at a high density of 5 A·g^(-1).This study first reveals the relationship between SiO crystallinity and electrochemical performance,which efficiently guides the design of high-performance SiO anodes.
基金supported by the startup funding from Shanghai Jiao Tong University(Grant No.WH220402052).
文摘Silicon-based anode is a promising candidate for all-solid-state batteries(ASSBs).However,it must be further improved because of its tremendous volume change.In this study,various interface treatment strategies for SiO/carbon composite anodes in ASSBs were investigated using a multiphysics modeling framework.By evaluating the effects of active(carbon)and inactive coating materials,as well as the geometric and mechanical parameters,this research provides critical insights into optimizing their electrochemical performance and mechanical stability.Computational results indicate that carbon coatings can greatly enhance lithiation kinetics by regulating the interfacial electrochemical potential gradients,reducing the residual lithium concentration,and homogenizing the lithium-ion distribution compared with uncoated or inactive-coated configurations.In addition,thinner carbon coatings further improve capacity retention and stress management by balancing shorter lithium diffusion pathways with mitigated interfacial stress accumulation.Despite their ability to mechanically stabilize the anode,inactive coatings exhibit tradeoffs between lithium transport kinetics and stress modulation,with optimal performance achieved at lower Young’s moduli.Mechanical analyses highlight distinct failure mechanisms at the anode–electrolyte(shear driven)and particle-coating(tension driven)interfaces,emphasizing the need for tailored adhesion strategies.These findings provide actionable guidelines for designing robust SiO-based anodes,emphasizing the interplay among electrochemical efficiency,stress regulation,and interfacial durability in ASSBs.
基金supported by the National Natural Science Foundation of China (Grant Nos.92372101,52162036 and 21875155)the Fundamental Research Funds for the Central Universities (Grant Nos.20720220010)the National Key Research and Development Program of China (Grant Nos.2021YFA1201502)。
文摘The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH groups in PAA leads to the formation of intramolecular and intermolecular hydrogen bonds,greatly weakening the bonding force of the binder to SiO surface.However,strengthening the binder-material interaction from the perspective of binder molecular regulation poses a significant challenge.Herein,a modified PAA-Li_(x)(0.25≤x≤1)binder with prominent mechanical properties and adhesion strength is specifically synthesized for SiO anodes by quantitatively substituting the carboxylic hydrogen with lithium.The appropriate lithium substitution(x=0.25)not only effectively increases the number of hydrogen bonds between the PAA binder and SiO surface owing to charge repulsion effect between ions,but also guarantees moderate entanglement between PAA-Li_x molecular chains through the ion-dipole interaction.As such,the PAA-Li_(0.25)/SiO electrode exhibits exceptional mechanical properties and the lowest volume change,as well as the optimum cycling(1237.3 mA h g^(-1)after 100cycles at 0.1 C)and rate performance(1000.6 mA h g^(-1)at 1 C),significantly outperforming the electrode using pristine PAA binder.This work paves the way for quantitative regulation of binders at the molecular level.
