Electrocatalytic Activity of Carbon in N-Doped Graphene to Achieve High-Energy Density Li-S Batteries

Abstract

High-energy and cost-effective lithium-sulfur battery (LSB) technology has been regarded as a promising alternative to current rechargeable lithium-ion batteries. However, the utilization of LSB suffered from the gap between the theoretical expectation and practical observation. Here, we propose the mechanistic origin of the electrocatalytic role of carbon in the N-doped graphene (NDG) layer placed on the entire cathode. We understand that the carbon in NDG acts as an electrocatalyst by interactions with polysulfide, leading to efficient electrochemical charge and discharge behaviors. A sufficient sulfur loading amount (ca. 5.75 mg cm-2) is successfully achieved, and the developed cell in this work enables remarkable energy density (200 W h kgtotal cell -1) and high areal capacity (4 mA h cm-2). © 2018 American Chemical Society.