Multifunctional Ni/NiO heterostructure nanoparticles doped carbon nanorods modified separator for enhancing Li–S battery performance

Abstract

The shuttle effect caused by soluble polysulfide diffusion and slow redox kinetics seriously hinder the further practical application of Li–S batteries. In order to overcome above problems, herein, we designed a novel carbon nanorods composite doped with Ni/NiO heterostructure nanoparticles (Ni/NiO-C) using a simple and high-yield in-situ technique. On the one hand, abundant heterointerface on the surface of nanoparticles provides a more effective polysulfide anchoring behavior. On the other hand, the electrical conductivity of Ni/NiO promotes rapid reaction kinetics of lithium polysulfides. Therefore, as multifunctional separator modification materials, Ni/NiO-C nanorods effectively regulates the polysulfide reactions from both physical and chemical aspects, and improves the electrochemical performance of the sulfur cathode. As a result, a high reversible capacity of 1462 mAh g−1 (0.2 C) and a low capacity decay rate of ∼0.078% per cycle are obtained. Even at a high sulfur loading of 3.8 mg cm−2, a considerable areal capacity of 4.24 mAh cm−2 can be reached. This work provides a new method for rationally design of separator modification by heterostructure composite for Li–S batteries.