The world is facing an ever-growing global energy crisis with unprecedented depth and complexity.The sustainable development of high energy density lithium-ion batteries for electric vehicles and portable electric dev...The world is facing an ever-growing global energy crisis with unprecedented depth and complexity.The sustainable development of high energy density lithium-ion batteries for electric vehicles and portable electric devices has become a feasible way to deal with this problem.Silicon suboxides(SiO_(x))have been deemed as one of the most promising anode materials because of their ultrahigh theoretical lithium storage capacity,proper working potential,natural abundance,and environmental friendliness.However,the mass utilization of SiO_(x)-based anodes is severely obstructed by their low electrical conductivity and inevitable volume expansion.While lithium silicate and lithium oxide formed in the first lithiation process act as buffer layers to some extent,it is urgent to address the accompanying low initial Coulombic efficiency and unsatisfactory cycling stability.In this review,we summarized recent advances in the synthesis methods of SiO_(x)-based materials.Besides,the benefits and shortcomings of the various methods are briefly concluded.Then,we discussed the effective combination of SiO_(x) with carbon materials and designs of porous structure,which could considerably enhance the electrochemical performance in detail.Furthermore,progresses on the modified strategies,advanced characteristics and industrial applications for SiO_(x)-based anodes are also mentioned.Finally,the remaining challenges encountered and future perspectives on SiO_(x)-based anodes are highlighted.展开更多
Pressure composition isotherms, crystal structures and electrochemical capacities of MmB5 alloy-hydrogen systems have been investigated, where Mm represents La-rich mischmetals and B5 take a composition of Ni3.8Co0.5M...Pressure composition isotherms, crystal structures and electrochemical capacities of MmB5 alloy-hydrogen systems have been investigated, where Mm represents La-rich mischmetals and B5 take a composition of Ni3.8Co0.5Mn0.4Al0.3. All these multicomponent alloys belong to CaCu5-type hexagonal crystal structuxe. The volume of unit cell (or say,the interstitial hole size) becomes larger with increasing of La content and decreasing of Ce content in Mm. The larger interstitial hole leads to a decrease of dissociation pressure of their hydride, hence improves the stability of MmB5H6 and the electrochendcal capacity of the MmB5 alloy. The expansion ratio of the MmB5 for hydrogen absorption was obviously smaner than that of LaNi5 alloy. For MmB5 alloy, especially with high content of La in Mm, a lot of properties for the application in MH/Ni battery, such as against pulverization, long cycle lifetime etc can be promoted.展开更多
基金This work was supported partially by the National Key Research and Development Program(No.2022YFC3900905)the National Natural Science Foundation of China(Nos.52234001,62104703,and 52074119)+4 种基金the Science and Technology Planning Project of Hunan Province(No.2018TP1017)the Scientific Research Fund of Hunan Provincial Education Department(No.22A0045)the Science and Technology Innovation Program of Hunan Province(No.2021RC1003)the Changsha Science and Technology Foundation(No.kq2208162)Joint Funds of Hunan Provincial Innovation Foundation for Post-graduate(No.CX20220512).
文摘The world is facing an ever-growing global energy crisis with unprecedented depth and complexity.The sustainable development of high energy density lithium-ion batteries for electric vehicles and portable electric devices has become a feasible way to deal with this problem.Silicon suboxides(SiO_(x))have been deemed as one of the most promising anode materials because of their ultrahigh theoretical lithium storage capacity,proper working potential,natural abundance,and environmental friendliness.However,the mass utilization of SiO_(x)-based anodes is severely obstructed by their low electrical conductivity and inevitable volume expansion.While lithium silicate and lithium oxide formed in the first lithiation process act as buffer layers to some extent,it is urgent to address the accompanying low initial Coulombic efficiency and unsatisfactory cycling stability.In this review,we summarized recent advances in the synthesis methods of SiO_(x)-based materials.Besides,the benefits and shortcomings of the various methods are briefly concluded.Then,we discussed the effective combination of SiO_(x) with carbon materials and designs of porous structure,which could considerably enhance the electrochemical performance in detail.Furthermore,progresses on the modified strategies,advanced characteristics and industrial applications for SiO_(x)-based anodes are also mentioned.Finally,the remaining challenges encountered and future perspectives on SiO_(x)-based anodes are highlighted.
文摘Pressure composition isotherms, crystal structures and electrochemical capacities of MmB5 alloy-hydrogen systems have been investigated, where Mm represents La-rich mischmetals and B5 take a composition of Ni3.8Co0.5Mn0.4Al0.3. All these multicomponent alloys belong to CaCu5-type hexagonal crystal structuxe. The volume of unit cell (or say,the interstitial hole size) becomes larger with increasing of La content and decreasing of Ce content in Mm. The larger interstitial hole leads to a decrease of dissociation pressure of their hydride, hence improves the stability of MmB5H6 and the electrochendcal capacity of the MmB5 alloy. The expansion ratio of the MmB5 for hydrogen absorption was obviously smaner than that of LaNi5 alloy. For MmB5 alloy, especially with high content of La in Mm, a lot of properties for the application in MH/Ni battery, such as against pulverization, long cycle lifetime etc can be promoted.
