Constructing a conductive and buffer network on microscale silicon-based anodes for high-performance lithium-ion batteries

Abstract

The structure and characteristics of the electrodes are essential for the performance of microscale silicon-based anodes for lithium-ion batteries. In this study, various carbon sources with different degrees of graphitization, morphologies, and dispersities were utilized as conductive agents for a microstructured silicon electrode. The findings indicate that micron-sized silicon electrodes can benefit from the addition of flake-conductive graphite, particularly SFG-6, which possesses a high degree of graphitization and dispersion, as well as a particle size similar to that of silicon. This combination results in a well-distributed, uniform conductive and buffering network, leading to improved electrochemical performance overall. After 450 cycles, the Si-SFG-6 composite anode exhibited exceptional long-term stability, delivering a specific capacity of 1102 mA·h g−1 at a current density of 200 mA g−1. Furthermore, even at a higher current density of 2000 mA g−1, the reversible capacity remained impressive at 964 mA·h g−1. The results of this study offer valuable insights for optimizing the structure and properties of microstructured silicon-based anodes, with the aim of achieving superior performance in Li-ion batteries.