Zhang Tao, Li Xiaoxuan, Miao Xianguang, Sun Rui, Li Jiafeng, Zhang Zhiwei, Wang Rutao, Wang Chengxiang, Li Zhaoqiang, Yin Longwei
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Ji'nan 250061, P. R. China.
ACS Appl Mater Interfaces. 2022 Mar 30;14(12):14264-14273. doi: 10.1021/acsami.2c00768. Epub 2022 Mar 18.
To develop a high-energy-density lithium battery, there still are several severe challenges for Li metal anode: low Coulombic efficiency caused by its high chemical reactivity, Li dendrite formation, and "dead" Li accumulation during repeated plating/stripping processes. Especially, lithium dendrite growth imposes inferior cycling stability and serious safety issues. Herein, we propose a facile but effective strategy to suppress lithium dendrite growth through an artificial inorganic-polymer protective layer derived from sulfurized polyacrylonitrile on a polyethylene separator. Benefiting from the lithiated sulfurized polyacrylonitrile and poly(acrylic acid), the flexible and ion-conductive protective layer could regulate Li flux and facilitate dendrite-free lithium deposition. Consequently, lithium metal with the meritorious protective layer can achieve a long-term cycling with negligible overpotential rise in Li-Li symmetric cells, even at a high areal capacity of 5 mAh cm. Remarkably, such a protective layer enables stable cycling performance of Li-S cell with a high areal capacity (∼9 mAh cm). This work provides a valuable exploration strategy for potential industrial applications of high-performance lithium metal batteries.
为了开发高能量密度锂电池，锂金属负极仍面临几个严峻挑战：其高化学反应性导致的低库仑效率、锂枝晶形成以及在反复的镀锂/脱锂过程中“死”锂的积累。特别是，锂枝晶生长会导致较差的循环稳定性和严重的安全问题。在此，我们提出一种简便而有效的策略，通过在聚乙烯隔膜上由硫化聚丙烯腈衍生的人工无机聚合物保护层来抑制锂枝晶生长。受益于锂化的硫化聚丙烯腈和聚丙烯酸，这种柔性且离子导电的保护层可以调节锂通量并促进无枝晶锂沉积。因此，具有优异保护层的锂金属在锂-锂对称电池中即使在5 mAh cm的高面积容量下也能实现长期循环，过电位上升可忽略不计。值得注意的是，这种保护层能够使具有高面积容量（约9 mAh cm）的锂硫电池具有稳定的循环性能。这项工作为高性能锂金属电池的潜在工业应用提供了有价值的探索策略。
