Interface-homogenized engineering of red phosphorus/activated carbon for high-performance lithium-ion battery anodes

Abstract

The contrasting volumetric changes and unstable formation of solid electrolyte interface films make it difficult to apply red phosphorus in lithium-ion batteries in spite of its high capacity, moderate lithiation potential and low cost. Conventional interface engineering could effectively improve the performance of red phosphorus, but generally performance improvement relies on complex processes to deal with the intrinsic interfacial incompatibility. An unconventional surface phosphorylation process is designed to achieve surface homogenization and interface integration to configure a high reversible phosphorus/carbon composite, where the phosphorylated surface of red phosphorus creates a highly reactive reaction micro-region to induce the surface phosphorylation and interface binding reaction around active carbon microparticles. The results demonstrate that this approach could create a homogenized solid electrolyte interface film and robust interface binding, resulting in enhanced cycling stability and high pseudocapacitive attribution with improved kinetics. The optimized composite electrode achieves a high reversible capacity of 778 mAh g⁻¹ after 350 cycles, significantly outperforming the surface unhomogenized material. The strategy of interface-homogenized engineering provides a potential facile avenue to improve the interface integration of a high-capacity electrode composite for advanced LIBs.