%0 Journal Article
%A Qiangfeng Xiao
%A Meng Gu
%A Hui Yang
%A Bing Li
%A Cunman Zhang
%A Yang Liu
%A Fang Liu
%A Fang Dai
%A Li Yang
%A Zhongyi Liu
%A Xingcheng Xiao
%A Gao Liu
%A Peng Zhao
%A Sulin Zhang
%A Chongmin Wang
%A Yunfeng Lu
%A Mei Cai
%B Nature Communications
%D 2015
%G eng
%P 8844
%R 10.1038/ncomms9844
%T Inward lithium-ion breathing of hierarchically porous silicon anodes
%V 6
%8 05/2015
%! Nat Comms
%X <p>Silicon has been identified as a highly promising anode for next-generation lithium-ion batteries (LIBs). The key challenge for Si anodes is large volume change during the lithiation/delithiation cycle that results in chemomechanical degradation and subsequent rapid capacity fading. Here we report a novel fabrication method for hierarchically porous Si nanospheres (hp-SiNSs), which consist of a porous shell and a hollow core. On charge/discharge cycling, the hp-SiNSs accommodate the volume change through reversible inward Li breathing with negligible particle-level outward expansion. Our mechanics analysis revealed that such inward expansion is enabled by the much stiffer lithiated layer than the unlithiated porous layer. LIBs assembled with the hp-SiNSs exhibit high capacity, high power and long cycle life, which is superior to the current commercial Si-based anode materials. The low-cost synthesis approach provides a new avenue for the rational design of hierarchically porous structures with unique materials properties.</p>