Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercia...Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercialization. Herein, we use industrial ferrosilicon as low-cost Si source and introduce a facile and scalable method to fabricate a micrometer-sized ferrosilicon/C composite anode, in which ferrosilicon microparticles are wrapped with multi-layered carbon nanosheets. The multi-layered carbon nanosheets could effectively buffer the volume variation of Si as well as create an abundant and reliable conductivity framework, ensuring fast transport of electrons. As a result, the micrometer-sized ferrosilicon/C anode achieves a stable cycling with 805.9 m Ah g-1 over 200 cycles at 500 mA g-1 and a good rate capability of455.6 mAh g-1 at 10 A g-1. Therefore, our approach based on ferrosilicon provides a new opportunity in fabricating cost-effective, pollution-free, and large-scale Si electrode materials for high energy lithium-ion batteries.展开更多
The solid-state lithium battery is considered as an ideal next-generation energy storage device owing to its high safety,high energy density and low cost.However,the poor ionic conductivity of solid electrolyte and lo...The solid-state lithium battery is considered as an ideal next-generation energy storage device owing to its high safety,high energy density and low cost.However,the poor ionic conductivity of solid electrolyte and low interfacial stability has hindered the application of solid-state lithium battery.Here,a flexible polymer/garnet solid electrolyte is prepared with poly(ethylene oxide),poly(vinylidene fluoride),Li6.75La3 Zr1.75Ta0.25O12,lithium bis(trifluoromethanesulfonyl)imide and oxalate,which exhibits an ionic conductivity of 2.0 ×10^(-4) S cm^(-1) at 55℃,improved mechanical property,wide electrochemical window(4.8 V vs.Li/Li+),enhanced thermal stabilities.Tiny acidic OX was introduced to inhibit the alkalinity reactions between Li6.75La3 Zr1.75Ta0.25O12 and poly(vinylidene fluoride).In order to improve the interfacial stability between cathode and electrolyte,an Al2 O3@LiNi0.5Co0.2Mn0.3O2 based composite cathode framework is also fabricated with poly(ethylene oxide) polymer and lithium salt as additives.The solid-state lithium battery assembled with polymer/garnet solid electrolyte and composite cathode framework demonstrates a high initial discharge capacity of 150.6 mAh g^(-1) and good capacity retention of 86.7% after 80 cycles at 0.2 C and 55℃,which provides a promising choice for achieving the stable electrode/electrolyte interfacial contact in solid-state lithium batteries.展开更多
LiNiPO_(4)(working at~5.1 V)shows potential advantages in the competition of cathode materials for lithium-ion batteries(LIBs)because of high energy density.However,the high-voltage electrolyte developed can only rema...LiNiPO_(4)(working at~5.1 V)shows potential advantages in the competition of cathode materials for lithium-ion batteries(LIBs)because of high energy density.However,the high-voltage electrolyte developed can only remain relatively stable in the range of less than 4.8V,so the operating voltage of LiNiPO_(4)needs to be adjusted to smaller to better exploit its high-voltage advantages.To regulate the operating voltage of LiNiPO_(4)while ensuring the relative stability of its electrochemical properties,in this work,all the 3d,4d,and 5d transition metals(TMs)are,respectively,doped into the Ni site of LiNiPO_(4)to screen out the doped models with excellent electrochemical performance.In particular,the changes in lattice structure,electronic properties,formation energy,mechanical properties,anisotropy,and working voltage were used as screening criteria.By considering the above screening criteria,the Cr-and Fe-doped LiNiPO_(4)with open circuit voltage~4.7 and~4.8 V are considered to have leading performance and can be used for applicable high-voltage LIBs.The screening results of this work can provide an overall understanding of the doping of LiNiPO_(4)by TMs and have advanced a theoretical idea for the design of new high-voltage LIBs cathode materials.展开更多
基金the National Natural Science Foundation of China(No:21703285)。
文摘Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercialization. Herein, we use industrial ferrosilicon as low-cost Si source and introduce a facile and scalable method to fabricate a micrometer-sized ferrosilicon/C composite anode, in which ferrosilicon microparticles are wrapped with multi-layered carbon nanosheets. The multi-layered carbon nanosheets could effectively buffer the volume variation of Si as well as create an abundant and reliable conductivity framework, ensuring fast transport of electrons. As a result, the micrometer-sized ferrosilicon/C anode achieves a stable cycling with 805.9 m Ah g-1 over 200 cycles at 500 mA g-1 and a good rate capability of455.6 mAh g-1 at 10 A g-1. Therefore, our approach based on ferrosilicon provides a new opportunity in fabricating cost-effective, pollution-free, and large-scale Si electrode materials for high energy lithium-ion batteries.
基金Financial supports from the National Natural Science Foundation of China (51575030, 51532002 and 51872027)Beijing Natural Science Foundation (L172023)National Basic Research Program of China (2017YFE0113500)。
文摘The solid-state lithium battery is considered as an ideal next-generation energy storage device owing to its high safety,high energy density and low cost.However,the poor ionic conductivity of solid electrolyte and low interfacial stability has hindered the application of solid-state lithium battery.Here,a flexible polymer/garnet solid electrolyte is prepared with poly(ethylene oxide),poly(vinylidene fluoride),Li6.75La3 Zr1.75Ta0.25O12,lithium bis(trifluoromethanesulfonyl)imide and oxalate,which exhibits an ionic conductivity of 2.0 ×10^(-4) S cm^(-1) at 55℃,improved mechanical property,wide electrochemical window(4.8 V vs.Li/Li+),enhanced thermal stabilities.Tiny acidic OX was introduced to inhibit the alkalinity reactions between Li6.75La3 Zr1.75Ta0.25O12 and poly(vinylidene fluoride).In order to improve the interfacial stability between cathode and electrolyte,an Al2 O3@LiNi0.5Co0.2Mn0.3O2 based composite cathode framework is also fabricated with poly(ethylene oxide) polymer and lithium salt as additives.The solid-state lithium battery assembled with polymer/garnet solid electrolyte and composite cathode framework demonstrates a high initial discharge capacity of 150.6 mAh g^(-1) and good capacity retention of 86.7% after 80 cycles at 0.2 C and 55℃,which provides a promising choice for achieving the stable electrode/electrolyte interfacial contact in solid-state lithium batteries.
基金Ministry of Science and Technology of China,Grant/Award Numbers:2019YFA0705703,2019YFE0100200China Postdoctoral Science Foundation,Grant/Award Numbers:2021M701873,2022M711791,2022M720080National Natural Science Foundation of China,Grant/Award Numbers:22175106,22279071,52007099,52073161,U21A20170。
文摘LiNiPO_(4)(working at~5.1 V)shows potential advantages in the competition of cathode materials for lithium-ion batteries(LIBs)because of high energy density.However,the high-voltage electrolyte developed can only remain relatively stable in the range of less than 4.8V,so the operating voltage of LiNiPO_(4)needs to be adjusted to smaller to better exploit its high-voltage advantages.To regulate the operating voltage of LiNiPO_(4)while ensuring the relative stability of its electrochemical properties,in this work,all the 3d,4d,and 5d transition metals(TMs)are,respectively,doped into the Ni site of LiNiPO_(4)to screen out the doped models with excellent electrochemical performance.In particular,the changes in lattice structure,electronic properties,formation energy,mechanical properties,anisotropy,and working voltage were used as screening criteria.By considering the above screening criteria,the Cr-and Fe-doped LiNiPO_(4)with open circuit voltage~4.7 and~4.8 V are considered to have leading performance and can be used for applicable high-voltage LIBs.The screening results of this work can provide an overall understanding of the doping of LiNiPO_(4)by TMs and have advanced a theoretical idea for the design of new high-voltage LIBs cathode materials.
