Rationally designed high‐conductivity Hydrangea macrophylla‐like Si@NiO@Ni/C composites as a high‐performance anode material for lithium‐ion batteries

Abstract

Reasonable design of the core-shell structure with a high conductive stable substrate is an effective way to solve the huge volume expansion and low intrinsic conductivity of Si-based anode materials in Li-ion batteries (LIBs). In this work, the Hydrangea macrophylla-like composites (Si@NiO@Ni/C) have been successfully synthesized by staged calcination of the Si@Ni(OH) 2 @C precursor. This design achieved a stable loading of Si nanoparticles on the high conductive substrate by forming chemical bonds and provided enough space for the expansion of Si. Furthermore, the existence of a hybrid coating layer could stabilize the formation of the solid electrolyte layer and accelerate the migration of Li + and electrons, which greatly improved the kinetics performance on the electrode surface. As a consequence, the design showed excellent cycle stability (1265.5 mAh g -1 after 300 cycles at 0.5 A/g) and rate performance (982.2, 876.1, 766.6, 645.8, 572 mAh/g at 0.2, 0.5, 1, 2, 3 A/g, respectively), providing a simple and controllable method to synthesize Si-based anode materials for high-performance LIBs.