ZnO/ZnS heterostructure with enhanced interfacial lithium absorption for robust and large-capacity energy storage

Abstract

Heterostructure construction, especially for anodes, is an effective strategy to promote electron transfer and improve surface reaction dynamics, thus achieving high performance in lithium-ion batteries. Herein, in situ partial conversion of metal sulfide to oxide with high lattice match is utilized to engineer a ZnO/ZnS heterostructure. The mosaic ZnO/ZnS heterostructure with abundant interfaces is activated into homogeneous zinc oxysulfide with size optimization during cycling, which delivers 920 mA h g⁻¹ after 1300 cycles even at 2 A g⁻¹. A pouch-type full cell (LiCoO₂‖ZnO/ZnS) is assembled and maintains over 85% of its initial capacity after 300 cycles at 2C, confirming its potential practicability. Theoretical calculations predict that, combined with LiZn nanodots, the Li₂O/Li₂S matrix is endowed with more Li anchoring sites and higher Li adsorption energy. Therefore, the interfacial charge redistribution is modified to contribute high interfacial Li storage. The reasonable interfacial engineering by designing a mosaic heterostructure breaks new grounds for the design of large-capacity and high-reversibility conversion-alloying-type anodes.