A Promising Approach towards the Commercialization of Lithium Sulfur Batteries: Prelithiated Graphene

Abstract

Lithium-sulfur (Li-S) batteries are a promising candidate technology for high-energy rechargeable batteries due to their advantages of abundant materials and inherently high energy. However, the practical applications of Li-S batteries are challenged by several obstacles, including the low sulfur utilization and poor lifespan, which are partly attributed to the shuttle of lithium polysulfides and lithium dendrite growth during cycling.[1] The shuttling of polysulfide ions between the electrodes in a Li-S battery is a major technical issue triggering the self-discharge and limiting the cycle life.[2] A stable lithium anode is essential for maintaining the good cycle stability of Li-S batteries in practical applications.[3] To address these lithium related issues, various carbon materials, including graphite and graphene, have been investigated as suitable lithium hosts to use as anode materials for Li-S batteries.[4] In this study, prelithiated graphite and graphene-based anode materials are obtained by galvanostatic charging method to improve the performance of Li-S batteries and compare the electrochemical properties especially in terms of capacity retention and rate capability. According to the results, graphene showed better performance due to its high lithium storage capacity and fast lithium-ion diffusion rate. Inductively Coupled Plasma Emission Spectrometer (ICP-OES) results showed that the Li+ content of the graphite, graphite/graphene, and graphene electrodes measured as 26.5, 33.2, and 45.6 wt%, respectively after the lithiation process. 1 Ah pouch cell was assembled with prelithiated graphene anode showing an energy density of about 400 Wh kg-1 in the first cycle and protected its specific capacity of 60 % after 100 cycles in a liquid-based Li-S battery system. Prelithiation is a crucial strategy to compensate for the lithium needs of the system when using lithium-free active materials, but most of the prelithiation reagents developed so far are highly reactive and sensitive to oxygen and moisture, making them difficult for practical battery application. This study reports the easy and effective method for lithiation of graphene anode for lithium sulfur battery.image