Laser induction of hierarchically micro/nanostructured CoNi-LDH/C composite for high-performance lithium-sulfur batteries

Abstract

Li-S batteries suffer from limited electronic conductivity and shuttle effect of soluble LiPSs, which can hinder redox kinetics and reduce overall electrochemical performance. To solve these issues, we propose a strategy to synthesize a CoNi-layered double hydroxide/carbon composite (L-CoNi-LDH/C) through laser treatment and hydrothermal reaction. The resulting L-CoNi-LDH/C composite possesses a high specific surface area, enabling effectively anchor sulfur molecules and adsorb LiPSs. Moreover, the 2D layered structure of LDH and porous carbon framework can facilitate electron and ion transport. The Co and Ni species in the LDH structure act as catalysts, promoting the conversion of LiPSs into Li2S/Li2S2 and enhancing redox kinetics. A Li-S battery using CoNi-LDH/C as S host (S@CoNi-LDH/C) shows an initial capacity of 1574 mAh g−1 and maintains a reversible capacity of 1097 mAh g−1 after 100 cycles.