Anchoring LiZn Nanocrystals With Oligomer Binders for Enhanced Interfacial Stability in Lithium Metal Batteries

ABSTRACT Lithium (Li) metal batteries have emerged as one of the most promising candidates for next‐generation energy storage systems due to the potentially high energy density. Nevertheless, repeated interfacial breakdown causes a short lifespan and poor safety. Inspired by the role of plant root systems in anchoring soil, an oligomer‐anchored LiZn nanocrystal composite interphase is constructed on the Li metal anode via a simple spray‐coating strategy, simultaneously enhancing the electrochemical stability and thermal safety of Li metal batteries. The LiZn alloy in the composite interphase restructures the interface energy distribution and reduces the local current density, thereby facilitating uniform lateral Li deposition. The oligomer serves as a binder to glue LiZn particles together and preserve the structural integrity of the interphase. A Li||LiNi 0.5 Co 0.2 Mn 0.3 O 2 coin cell with the composite interphase exhibits a lifespan of 700 cycles at 1 C with a high cathode loading of 3.06 mAh cm −2 . The 1.38 Ah Li||LiNi 0.8 Co 0.1 Mn 0.1 O 2 pouch cell achieves a capacity retention of 86% after 200 cycles. When the cycled pouch cells undergo forced thermal runaway, the composite interphase elevates the trigger temperature from 124°C to 191°C. This interphase design provides novel insights to enhance the service lifespan and thermal safety of high energy density batteries.