Breaking the structural anisotropy of ZnO enables dendrite-free lithium-metal anode with ultra-long cycling lifespan

Abstract

Crystalline materials have shown great potential for lithium-metal batteries. However, crystalline materials are prone to uncontrollable growth of lithium dendrites due to their anisotropic characteristics. Herein, we break the structural anisotropy of zinc oxide as an amorphous host to efficiently induce a uniform lithium deposition. Theoretical calculations first confirm that amorphous ZnO presents a much larger lithium adsorption energy. X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge structure (XANES) studies reveal that amorphous zinc oxide possesses both numerous “floppy” bonds and multiple vacancies, resulting in not only an increase in lithiophilic sites but also a more uniform distribution of the electric field. As a result, amorphous zinc oxide delivers an improved Coulomb efficiency of 98.2% even after 500 cycles at 1 mA cm−2 and an ultra-long cycling lifespan over 2,500 h in symmetric cells, outperforming most representative and state-of-the-art lithium-metal anodes. This work opens a new pathway to exploring amorphous materials for lithium-metal batteries.