Enhanced Initial Coulombic Efficiency of Lithium-Ion Battery Silicon-Carbon Anodes with Phosphorus Doping

Abstract

Enhancing the initial Coulombic efficiency (ICE) and suppressing the volume expansion of silicon-based anodes remain a challenge. In this work, we proposed a strategy of incorporating phosphorus (P) atoms into silicon-carbon composites, through the mechanical ball milling and high-temperature calcination, the P atoms were uniformly distributed within the carbon layer and silicon particles. This approach not only reduced the interfacial charge transfer resistance by ~70% but also increased the Li⁺ diffusion capability by ~11%. As a result, the ICE of 88.6% and an initial discharge capacity of 2730 mAh g-1 were recorded. Moreover, the reversible capacity kept 1108 mAh g-1 at 1 A g-1 after 150 cycles. And the reversible capacities at 0.1 A g-1, 0.5 A g-1, 1 A g-1 and 2 A g-1 were 3204 mAh g-1, 1966 mAh g-1, 1510 mAh g-1 and 798 mAh g-1, respectively. The results indicated the P-doping was a promising way to enhance the ICE of silicon-based anodes.