Lithium dendrite growth during repeated charge and discharge cycles of lithium-metal anodes often leads to short-circuiting by puncturing the porous separator. Here, a morphological design, the nano-shield, for separators to resist dendrites is presented. Through both mechanical analysis and experiment, it is revealed that the separator protected by the nano-shield can effectively inhibit the penetration of lithium dendrites owing to the reduced stress intensity generated and therefore mitigate the short circuit of Li metal batteries. More than 110 h of lithium plating life is achieved in cell tests, which is among the longest cycle life of lithium metal anode and five times longer than that of blank separators. This new aspect of morphological and mechanical design not only provides an alternative pathway for extending lifetime of lithium metal anodes, but also sheds light on the role of separator engineering for various electrochemical energy storage devices.
Bibliographical noteWe acknowledge the micro-fabrication center of National Laboratory of Solid-State Microstructures (NLSSM) for technique support. This work is jointly supported by the State Key Program for Basic Research of China (No. 2015CB659300), National Natural Science Foundation of China (Nos. 21805132, 11574143, 11874211, 11621091, 61735008), Natural Science Foundation of Jiangsu Province (Nos. BK20180341) and the Fundamental Research Funds for the Central Universities (Nos. 021314380150, 021314380140).
- lithium-metal batteries