One-Step In-Situ Conversion Method for Co9s8 Embedded in N-Doped Carbon Derived from Resin Waste Induced Ultra-Stable Li-S Batteries

Abstract

The effective suppression of the shuttle effect in lithium-sulfur batteries require thedevelopment of efficient electrocatalysts. Transition metal sulfides show greatpotential as S cathode electrocatalysts. However, the conventional secondarysulfidation or heat-treatment process used in their synthesis limits their catalyticperformance. In this study, we propose a simple and scalable “exchange-constriction-in-situ conversion” strategy to prepare Co9S8@NC electrocatalysts using CoSO4 andwaste resins as sources, through a one-step heating method. No additional sulfursource is required in this process. The resulting Co9S8@NC catalyst demonstratesoutstanding long-cycle performance, with a slight decay of only 0.028% per cycleafter 500 cycles at a current density of 2 C. Moreover, it exhibits excellentelectrochemical performance even at high surface loading and low electrolyte dosage(E/S). The combination of theoretical calculations and electrochemical analysesdemonstrates that Co9S8 possesses strong adsorption and superior catalytic capacitytowards lithium polysulfide and consequently leads to an enhancement in reactionkinetics. This study presents a novel approach for synthesizing high-performancesulfide electrocatalysts.

Keywords: Li-S batteries, Co9S8, N-doped Carbon, Resin Waste, S cathode