Shi Lili, Anderson Cassidy S, Mishra Lubhani, Qiao Hong, Canfield Nathan, Xu Yaobin, Wang Chengqi, Jang TaeJin, Yu Zhaoxin, Feng Shuo, Le Phung M, Subramanian Venkat R, Wang Chongmin, Liu Jun, Xiao Jie, Lu Dongping
Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA.
Walker Department of Mechanical Engineering, Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA.
Adv Sci (Weinh). 2022 Jul;9(21):e2201640. doi: 10.1002/advs.202201640. Epub 2022 May 7.
Lithium-sulfur (Li-S) batteries are one of the most promising next-generation energy storage technologies due to their high theoretical energy and low cost. However, Li-S cells with practically high energy still suffer from a very limited cycle life with reasons which remain unclear. Here, through cell study under practical conditions, it is proved that an internal short circuit (ISC) is a root cause of early cell failure and is ascribed to the crosstalk between the S cathode and Li anode. The cathode topography affects S reactions through influencing the local resistance and electrolyte distribution, particularly under lean electrolyte conditions. The inhomogeneous reactions of S cathodes are easily mirrored by the Li anodes, resulting in exaggerated localized Li plating/stripping, Li filament formation, and eventually cell ISC. Manipulating cathode topography is proven effective to extend the cell cycle life under practical conditions. The findings of this work shed new light on the electrode design for extending cycle life of high-energy Li-S cells, which are also applicable for other rechargeable Li or metal batteries.
锂硫（Li-S）电池因其高理论能量和低成本而成为最具前景的下一代储能技术之一。然而，实际能量较高的锂硫电池的循环寿命仍然非常有限，其原因尚不清楚。在此，通过实际条件下的电池研究，证明内部短路（ISC）是电池早期失效的根本原因，这归因于硫阴极和锂阳极之间的串扰。阴极形貌通过影响局部电阻和电解质分布来影响硫反应，特别是在贫电解质条件下。硫阴极的不均匀反应很容易反映在锂阳极上，导致局部锂电镀/剥离加剧、锂丝形成，并最终导致电池内部短路。事实证明，在实际条件下，控制阴极形貌可有效延长电池的循环寿命。这项工作的发现为延长高能锂硫电池循环寿命的电极设计提供了新的思路，这些思路也适用于其他可充电锂或金属电池。
