2.5 μm‐Thick Ultrastrong Asymmetric Separator for Stable Lithium Metal Batteries
Donghao Xie, Zekun Wang, Xin Ma, Yuchen Feng, Xiaomin Tang, Qiao Gu, Yonghong Deng, Ping Gao
Abstract
Lithium metal batteries (LMBs) are considered the ideal choice for high volumetric energy density lithium‐ion batteries, but uncontrolled lithium deposition poses a significant challenge to the stability of such devices. In this paper, we introduce a 2.5 μm‐thick asymmetric and ultrastrong separator, which can induce tissue‐like lithium deposits. The asymmetric separator, denoted by utPE@Cu 2 O, was prepared by selective synthesis of Cu 2 O nanoparticles on one of the outer surfaces of a nanofibrous (diameter ~10 nm) ultrastrong ultrahigh molecular weight polyethylene (UHMWPE) membrane. Microscopic analysis shows that the lithium deposits have tissue‐like morphology, resulting in the symmetric lithium cells assembled using utPE@Cu 2 O with symmetric Cu 2 O coating exhibiting stable performance for over 2000 h of cycling. This work demonstrates the feasibility of a facile approach ultrathin separators for the deployment of lithium metal batteries, providing a pathway towards enhanced battery performance and safety.