Achieving highly stable Sn-based anode by a stiff encapsulation heterostructure  

牢固的封装异质结构实现锡基负极的长循环稳定性

作　　者：Ruizhe Li Jijian Xu Zhuoran Lv Wujie Dong Fuqiang Huang 李睿哲;徐吉健;吕卓然;董武杰;黄富强(State Key Laboratory of High Performance Ceramics and Superfine Mincrostructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese of Academy of Sciences,Beijing 100049,China;State Key Laboratory of Rare Earth Materials Chemistry and Applications,College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,China)

机构地区：[1]State Key Laboratory of High Performance Ceramics and Superfine Mincrostructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China [2]Center of Materials Science and Optoelectronics Engineering,University of Chinese of Academy of Sciences,Beijing 100049,China [3]State Key Laboratory of Rare Earth Materials Chemistry and Applications,College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,China

出　　处：《Science China Materials》2022年第3期695-703,共9页中国科学（材料科学（英文版）

基　　金：supported by China Postdoctoral Science Foundation(2020M671242 and 2021T140688);the Special Research Assistant program of CAS;the Super Postdoctoral Fellow Program of Shanghai。

摘　　要：Rationally designed heterostructures provide attractive prospects for energy storage electrodes by combining different active materials with distinct electrochemical properties.Herein,through a phase separation strategy,a heterostructure of SnO_(2) encapsulated by amorphous Nb_(2)O_(5) is spontaneously synthesized.Insertion-type anode Nb_(2)O_(5) outer shell,playing as reaction containers and fast ionic pathways,physically inhibits the Sn atoms’migration and enhances the reaction kinetics.Moreover,strong chemical interactions are found at the SnO_(2)/Nb_(2)O_(5) interfaces,which ensure the solid encapsulation of the SnO_(2) cores even after 500 cycles.When used for lithium-ion batteries,this heterostructured anode exhibits high cycling stability with a capacity of 626 mAhg^(-1) after 1000 cycles at 2Ag^(-1)(85% capacity retention)and good rate performance with the capacity of 340 mAhg^(-1) at 8Ag^(-1).通过异质结构可以将不同电化学性质的电极材料人为地进行设计组合实现优势互补,这一方法为储能材料的未来发展提供了广阔前景.本文中,我们通过一步自发相分离策略,实现了SnO_(2)包封于无定形Nb_(2)O_(5)中的特殊异质结构.嵌入型反应负极Nb_(2)O_(5)充当合金型负极SnO_(2)的反应容器和快速离子传输层,空间上限制了Sn原子的迁移并增强了反应动力学.此外,我们在SnO_(2)/Nb_(2)O_(5)界面处发现了强化学相互作用,使得Nb_(2)O_(5)封装层即使在500次充放电循环后仍能牢固包封在SnO_(2)核的表面.这种异质结构材料作为锂离子电池负极表现出高循环稳定性,在2 Ag^(-1)的大电流下循环1000次后容量为626 mAhg^(-1)(容量保持率为85%),同时在8 Ag^(-1)的电流下容量仍可保持在339.9 mAhg^(-1),展现出良好的倍率性能.

关 键 词：HETEROSTRUCTURE ENCAPSULATION SnO2/Nb2O5 interface chemical interaction atom migration 

分 类 号：TQ134.32[化学工程—无机化工] TM912[电气工程—电力电子与电力传动]