Eco-Efficient, Nonacidic Etched and Cost-Effective Micron-Sized Porous Si–C Anodes for High-Performance Li-Ion Batteries

Silicon (Si) is considered a promising candidate anode for next-generation high-performance lithium-ion batteries (LIBs) due to its ultrahigh theoretical capacity. However, silicon anodes suffer from huge volume expansion and inherently low electron conductivity for LIBs. Nanostructured silicon could address the limitations of bulk Si anodes, but the high cost would limit its commercial application. Herein, an eco-efficient, nonacidic etched, and cost-effective method is successfully proposed to prepare high-performance micron-sized porous silicon/carbon composites. The physicochemical/electrochemical characterizations demonstrated that the abundant pores and continuous conductive network structure in the pSi@C composites can effectively alleviate the volume expansion of silicon and largely enhance the electrical conductivity in long-term cycling. The designed pSi@C anode can largely enhance the long-term cycling performance and rate capability, with a high capacity of 629.6 mA h g–1 after 400 cycles at 0.5 A g–1 and a superior rate performance of 501.3 mA h g–1 even at 1 A g–1. Furthermore, the full cells with the pSi@C anodes and LiNi0.8Co0.1Mn0.1O2 (NCM811) cathodes deliver a high specific capacity of 143.5 mA h g–1 and 83.9% capacity retention after 300 cycles. This eco-efficient and cost-effective method provides a promising and practical way for commercializing high-performance silicon–carbon anode materials for LIBs.