Electrochemical elucidation of phosphorus-doped and 3D graphene aerogel surface-modified SiOx porous nanocomposite electrode material for high-performance lithium-ion batteries

Abstract

Silicon oxide (SiOx) is promising as an earth abundant eco-friendly cost-effective anode material for lithium-ion batteries (LIBs), boasts a higher capacity compared to commercial graphite, garnering significant interest. Nevertheless, its practical application is hindered by issues related to poor cycling performance and low electronic conductivity. In this investigation, graphene aerogel-wrapped (GA) red phosphorus (P) doped SiOx (P-SiOx@GA) composite material is successfully constructed through ball-milling followed by freeze-drying and thermal treatment processes. The prepared materials are characterized the physico-chemical properties. The electrochemical performance is evaluated through Li-ion half and full (LiFePO4//P-SiOx@GA) cells configuration. The synthesized P-SiOx@GA electrode exhibits outstanding cyclic performance, demonstrating a specific capacity of 1094 mAh g−1 at 0.5C with a capacity retention of 80.3 % over 200 cycles in half-cell test. Furthermore, it demonstrates superior rate capability and delivers a reversible rate capacity of 754 mAh g−1 at 2C. Besides, the Li-ion punch cell configuration of LiFePO4//P-SiOx@GA shows good reversible capacity of 1.4 mAh at 0.5C over 300 cycles. The doping of P and porous 3D structure of GA forms an SiOx matrix network is facilitate the establishment of a 3D conductive pathway for electron transport and Li+ diffusion but also acts as a flexible matrix to accommodate the volume changes of SiOx. Therefore, the results and way of preparation promotes a practical feasibility of high-performance Si-based Li-ion batteries applications.