EAGER: Carbon-Free and Binder-Free Cathode Configurations for High-Energy Lithium-Sulfur Batteries

电池技术的进步一直是新电动汽车和电网可再生能源储存系统发展的驱动力。需要在性能和成本上都优于现有电池系统的新化学物质。在各种替代方案中，锂硫(Li/S)化学是最有前途的下一代储能技术，因为它们具有理论能量密度高、工作温度范围宽、成本低等优点。然而，需要对锂/S电池进行基础研究，以解决循环寿命短、库仑效率低和自放电等问题。这个迫切的项目的主要目标是在锂/S电池中引入电催化多孔集流材料，这将从根本上改变电化学性能，克服许多电流缺陷。所获得的关键见解可应用于广泛的材料和能源相关研究领域，如太阳能电池、氧化还原液流电池和燃料电池。与该项目相关的教育和外展活动包括来自代表性不足群体的本科生积极参与研究计划，并通过韦恩州立大学的移动能源实验室计划向高中生提供实践经验。这一基础性研究项目的目标是解决锂/S电池充电效率低、循环寿命短的问题。使用的方法是将溶解的中间多硫化物限制在电池的阴极内。本研究基于Li/S电池中多硫化物穿梭过程可以通过电催化驱动动力学和表面吸附化学来控制的假设。目的是利用集成了电催化剂的工程多孔催化集电体，将溶解的中间体多硫化物限制在电池的阴极内，同时提高中间体的利用率和反应速度。PI将研究电催化剂的以下拟议作用：(I)将溶解的中间多硫化物吸附在催化剂表面，以防止多硫化物穿梭过程；(Ii)加速中间多硫化物转化为低阶多硫化物的反应动力学；以及(Iii)在充电过程中将放电过程的最终产物转化为固体硫，以提高循环寿命。这个急切的项目引入了一种新的电催化缓解概念，可以定义一条新的途径，以设计具有出色电化学性能的无碳电极配置。

Advances in battery technology have been the driving force for the development of new electric vehicles and renewable energy storage systems for the electric grid. New chemistries are needed that are superior to current battery systems for both performance and cost. Among the various alternatives, lithium-sulfur (Li/S) chemistries are the most promising next-generation energy storage technologies, as they lead to advantages such as high theoretical energy density, wide range of operational temperature, and low cost. However, fundamental research is needed on Li/S batteries to address issues including short cycle life, poor coulombic efficiency and self-discharge. The primary goal of this EAGER project is to introduce electrocatalytic porous current collectors in the Li/S battery, which will fundamentally alter electrochemical properties and overcome many current shortcomings. The critical insight gained can be applied to a broad range of materials and energy related research fields such as solar cells, redox flow batteries and fuel cells. The educational and outreach activities associated with the project include active participation of undergraduates from underrepresented groups in the research program and hands-on experiences to high school students through Wayne State's Mobile Energy Lab program. The goal of this fundamental research project is to address low charging efficiency and short cycle life issues of Li/S batteries. The approach used is to confine the dissolved intermediate polysulfides within the cathode of the cell. The research is based on the hypothesis that the polysulfide-shuttle process in the Li/S cell can be controlled by using electrocatalysis driven kinetics and surface adsorption chemistries. The objective is to confine the dissolved intermediate polysulfides within the cathode of the cell while enhancing the intermediate's utilization and reaction rate using engineered porous catalytic current collectors with the electrocatalysts integrated in it. The PI will investigate the following proposed roles of the electrocatalyst: (i) adsorb dissolved intermediate polysulfides on the catalyst surface to prevent polysulfide shuttle process; (ii) accelerate the reaction kinetics for transforming intermediate polysulfides to lower order polysulfides; and (iii) convert end product of discharge process back to solid sulfur during the charge process to improve cycle life. This EAGER project introduces a new concept of electrocatalytic mitigation that could define a novel pathway towards designing carbon-free electrode configurations with outstanding electrochemical properties.