TY - JOUR AU - Qiangfeng Xiao AU - Meng Gu AU - Hui Yang AU - Bing Li AU - Cunman Zhang AU - Yang Liu AU - Fang Liu AU - Fang Dai AU - Li Yang AU - Zhongyi Liu AU - Xingcheng Xiao AU - Gao Liu AU - Peng Zhao AU - Sulin Zhang AU - Chongmin Wang AU - Yunfeng Lu AU - Mei Cai AB -

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.

BT - Nature Communications DA - 05/2015 DO - 10.1038/ncomms9844 LA - eng N2 -

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.

PY - 2015 EP - 8844 ST - Nat Comms T2 - Nature Communications TI - Inward lithium-ion breathing of hierarchically porous silicon anodes VL - 6 ER -