Manipulating Redox Kinetics using p‐n Heterojunction Biservice Matrix as both Cathode Sulfur Immobilizer and Anode Lithium Stabilizer for Practical Lithium–Sulfur Batteries

Abstract

AbstractAs an attractive high‐energy‐density technology, the practical application of lithium–sulfur (Li–S) batteries is severely limited by the notorious dissolution and shuttle effect of lithium polysulfides (LiPS), resulting in sluggish reaction kinetics and uncontrollable dendritic Li growth. Herein, a p‐n typed heterostructure consisting of n‐type MoS2 nanoflowers embedded with p‐type NiO nanoparticles is designed on carbon nanofibers (denoted as NiO‐MoS2@CNFs) as both cathode sulfur immobilizer and anode Li stabilizer for practical Li–S batteries. Such p‐n typed heterostructure is proposed to establish the built‐in electric field across the heterointerface for facilitated the positive charge to reach the surface of NiO‐MoS2, meanwhile inherits the excellent LiPS adsorption ability of p‐type NiO nanoparticles and catalytic ability of n‐type MoS2. As the anode matrix, the implementation of NiO–MoS2 heterostructure can prevent the growth of Li dendrites by enhancing the lithiophilicity and reducing local current density. The obtained Li–S full battery exhibits an ultra‐high areal capacity over 7.3 mAh cm−2, far exceeding that of current commercial Li‐ion batteries. Meanwhile, a stable cycling performance can be achieved under low electrolyte/sulfur ratio of 5.8 µL mg−1 and negative/positive capacity ratio of 1. The corresponding pouch cell maintains high energy density of 305 Wh kg−1 and stable cycling performance under various bending angles.