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

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 [9]. 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 [12]. 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. [11]. A stable lithium anode is essential for maintaining the good cycle stability of Li-S batteries in practical applications [13]. 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 [9]. 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. In this study, prelithiated graphite and graphene-based anode materials are obtained by the 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. A pouch cell was assembled with prelithiated graphene anode showing an energy density of about 360 Wh kg^-1 in the first cycle and protected its specific capacity of 60% after 100 cycles in a liquid-based Li-S battery.<br/><b>Keywords: </b>Lithium Sulfur Battery, Prelithiation, Graphene Anode<br/><br/><b>Acknowledgments</b><br/>This work is supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under contract number 120N492. The authors thank the TUBITAK workers for their financial support.<br/>This work also receives funding from the European Union's Horizon 2020 research and innovation program (under grant agreement no. 100825) under the scope of Joint Programming Platform Smart Energy Systems (MICall19).