Rigid Additives Enabling Inorganic‐Rich Interphase via Steric Effects and Van der Waals Force for Stable Lithium Metal Batteries

Abstract

Electrolyte additives (EAs) are cost‐effective for stabilization of lithium metal batteries (LMBs). Nevertheless, most EAs are gradually consumed during the lithium deposition process, rendering them inadequate for long‐term cyclability. Herein, a novel hybrid metal–organic framework (MOF)‐based non‐expendable additive is prepared through polymerization of pentaerythritol tetraacrylate (PETEA) on a zeolitic imidazolate framework (ZIF‐67). Owing to the partial coating by PETEA‐based polymer, the exposed unsaturated metal sites of ZIF‐67 still attenuate the interaction between lithium ions (Li+) and anions, enabling rapid electrochemical kinetics and uniform Li deposition. Concurrently, the polymerized PETEA partially enters the Li+ solvation sheath and expels some organic solvents through Van der Waals interactions, which promotes the derivation of an inorganic‐rich SEI and inhibits dendrite formation. Accordingly, this additive‐contained Li||Li symmetric cell exhibits a stability over 1200 h with a small overpotential of 75 mV. Additionally, the assembled Li||LiFePO4 full cells with negative/positive ratio of 1.76 delivers a stable cyclability over 400 cycles at 0.5 C. Moreover, the Li||LiNi0.8Mn0.1Co0.1O2 high‐voltage full cell displays an impressive capacity retention of 80% over 311 cycles at 0.5 C. This study provides a valuable guidance to design non‐expendable multifunctional EAs for advancing high‐performance LMBs.