Bidirectionally polarizing surface chemistry of heteroatom-doped carbon matrix towards fast and longevous lithium-sulfur batteries

Abstract

Herein, a bidirectional polarization strategy is proposed for hosting efficient and durable lithium-sulfur battery (Li-S) electrochemistry. By co-doping electronegative N and electropositive B in graphene matrix (BNrGO), the bidirectional electron redistribution enables a higher polysulfide affinity over its mono-doped counterparts, contributing to strong sulfur immobilization and fast conversion kinetics. As a result, BNrGO as the cathode host matrix realizes excellent cycling stability over 1000 cycles with a minimum capacity fading of 0.027% per cycle, and superb rate capability up to 10 C. Meanwhile, decent areal capacity (6.46 mAh/cm2) and cyclability (300 cycles) are also achievable under high sulfur loading and limited electrolyte. This work provides instructive insights into the interaction between doping engineering and sulfur electrochemistry for pursuing superior Li-S batteries.