Mechanically Interlocked Interphase with Energy Dissipation and Fast Li‐Ion Transport for High‐Capacity Lithium Metal Batteries
Zhangqin Shi, Yongming Wang, Xinyang Yue, Jun Zhao, Mingming Fang, Jijiang Liu, Yuanmao Chen, Yongteng Dong, Xuzhou Yan, Zheng Liang
Abstract
Abstract Constructing an artificial solid electrolyte interphase (ASEI) on Li metal anodes (LMAs) is a potential strategy for addressing the dendrite issues. However, the mechanical fatigue of the ASEI caused by stress accumulation under the repeated deformation from the Li plating/stripping is not taken seriously. Herein, this work introduces a mechanically interlocked [ a n]daisy chain network ( DC MIN) into the ASEI to stabilize the Li metal/ASEI interface by combining the functions of energy dissipation and fast Li‐ion transport. The DC MIN featured by large‐range molecular motions is cross‐linked via efficient thiol‐ene click chemistry; thus, the DC MIN has flexibility and excellent mechanical properties. As an ASEI, the crown ether units in DC MIN not only interact with the dialkylammonium of a flexible chain, forming the energy dissipation behavior but also coordinate with Li ion to support the fast Li‐ion transport in DC MIN. Therefore, a stable 2800 h‐symmetrical cycling (1 mA cm −2 ) and an excellent 5 C‐rate (full cell with LiFePO 4 ) performance are achieved by DC MIN‐based ASEI. Furthermore, the 1‐Ah pouch cell (LiNi 0.88 Co 0.09 Mn 0.03 O 2 cathode) with DC MIN‐coated LMA exhibits improved capacity retention (88%) relative to the Control. The molecular design of DC MIN provides new insights into the optimization of an ASEI for high‐energy LMAs.