Wen Kaihua, Liu Lili, Chen Shimou, Zhang Suojiang
Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences Beijing 100190 P. R. China
University of Chinese Academy of Sciences Beijing 100049 P. R. China.
RSC Adv. 2018 Apr 9;8(23):13034-13039. doi: 10.1039/c8ra02140f. eCollection 2018 Apr 3.
The issue of uncontrollable Li dendrite growth, caused by irregular lithium deposition, restricts the wide applications of Li metal based high energy batteries. In this paper, a polypropylene separator with a sputtered platinum nanolayer has been developed to improve the stability of the Li metal anodes. It was found that cells using the modified separators resulted in a smooth Li surface and a stable "electrode-electrolyte" interface. On the one hand, platinum nanolayers can enhance the mechanical properties and micro-structures of commercial polypropylene separators. On the other hand, platinum nanolayers provide stable Li deposition during repeated charging/discharging by a bidirectional growth mechanism. After long-time cycling, the dendrites from opposite directions and dead Li are integrated into a flat and dense new-formed Li anode, decreasing the risk of low Coulombic efficiency and cycling instability that may end in cell failure. This design may provide new ideas in next-generation energy storage systems for advanced stable metallic battery technologies.
由不规则锂沉积导致的锂枝晶不可控生长问题，限制了锂基金属高能电池的广泛应用。在本文中，已开发出一种带有溅射铂纳米层的聚丙烯隔膜，以提高锂金属负极的稳定性。研究发现，使用改性隔膜的电池会形成光滑的锂表面和稳定的“电极-电解质”界面。一方面，铂纳米层可以增强商用聚丙烯隔膜的机械性能和微观结构。另一方面，铂纳米层通过双向生长机制在反复充电/放电过程中提供稳定的锂沉积。经过长时间循环后，来自相反方向的枝晶和死锂会整合到一个平整致密的新形成的锂负极中，降低了可能导致电池失效的低库仑效率和循环不稳定性的风险。这种设计可能为先进稳定金属电池技术的下一代储能系统提供新思路。
