High-Performance Porous Silicon/Nanosilver Anodes from Industrial Low-Grade Silicon for Lithium-Ion Batteries
Fengshuo Xi, Zhao Zhang, Xiaohan Wan, Shaoyuan Li, Wenhui Ma, Xiuhua Chen, Ran Chen, Bin Luo, Lianzhou Wang
Abstract
Silicon (Si) has been considered as one of the most promising candidates for the next-generation lithium-ion battery (LIB) anode materials owing to its huge theoretical specific capacity of 4200 mA h g–1. However, the practical application of Si anodes in commercial LIBs is facing challenges because of the lack of scalable and cost-effective methods to prepare Si-based anode materials with proper microstructure and competitive electrochemical performances. Herein, we report a facile and scalable method to produce multidimensional porous silicon embedded with a nanosilver particle (pSi/Ag) composite from commercially available low-cost metallurgical-grade silicon (MG-Si) powder. The unique hybrid structure contributes to fast electronic transport and relieves volume change of silicon during the charge–discharge process. The pSi/Ag composite exhibits a large initial discharge capacity (3095 mA h g–1 at a high current of 1 A g–1), an excellent cycling performance (1930 mA h g–1 at 1 A g–1 after 50 cycles), and outstanding rate capacities (up to 1778 mA h g–1 at a higher current of 2 A g–1). After the samples are modified by reduced graphene oxide, the capacities of the pSi/Ag@RGO composite electrode can still be maintained over 1000 mA h g–1 after 200 cycles. This study provides a simple and effective strategy for production of high-performance anode materials.