Preparation of LDHs-derived Co-Ni3N heterostructure modified porous carbon nanofibers as advanced interlayers for lithium-sulfur batteries

Abstract

There are shuttle effects and slow kinetic transformation processes of polysulfides that must be overcome to attain excellent lithium-sulfur batteries (LSBs). Recently, developing catalysts to facilitate lithium polysulfides (LiPSs) conversion has attracted a large amount of attention. In this paper, a novel layered double hydroxides-derived (LDHs-derived) Co-Ni3N heterostructure anchored on nitrogen-doped carbon nanofibers (CNFs) is developed. The Co-Ni3N heterostructure with high catalytic activity and strong adsorption is capable of adsorbing long-chain polysulfides and significantly promotes LiPSs redox kinetics. Moreover, the Co-Ni3N-CNFs (450 °C/2 h) interlayer with hemp rope-like network structure accelerates the Li2S nucleation and provides high-conductivity channels. LSBs with the Co-Ni3N-CNFs (450 °C/2 h) interlayer exhibit remarkable initial discharge specific capacity (1359.9 mAh g−1 at 0.1C), exceptional rate performance (775.2 mAh g−1 at 2C), impressive cycling stability (with a capacity decay rate of 0.042 % over 1000 cycles at 2C), and high Coulombic efficiency (CE exceeding 99.5 %).