Metallic 1T-MoS2-Modified CuO@TiO2 Anodes Delivering Fast Kinetics and Stable Cycling in Li/Na-Ion Batteries

Abstract

Designing high-rate and long-life anode materials for lithium/sodium-ion batteries (LIBs/SIBs) remains challenging owing to sluggish reaction kinetics, limited electrical conductivity, and severe volume variation in conversion-type materials. A metallic 1T-MoS₂-enabled improved capacity and kinetic strategy is presented for a mesoporous core–shell CuO@TiO₂ anode, where the content of 1T-MoS₂ is systematically optimized to regulate interfacial charge transport and ion-diffusion behavior. The optimized CuO@TiO₂/1T-MoS₂ (10 wt%) composite integrates a nanosized CuO core, a TiO₂ shell that buffers volume expansion, and metallic 1T-MoS₂ nanosheets that form a highly conductive and defect-rich network. As a result, the optimized electrode delivers a high reversible capacity of ∼1017 mAh g⁻¹ with 84.8% capacity retention after 200 cycles at 200 mA g⁻¹ in LIBs. In sodium-ion batteries, it maintains a stable capacity of ∼223 mAh g⁻¹ after 200 cycles. Kinetic analyses confirm reduced charge–transfer resistance and a balanced contribution of surface-controlled capacitive and diffusion-controlled storage. Postmortem FESEM, TEM with EDX analyses further reveal preserved morphology and stable interfacial chemistry after prolonged cycling. Based on XPS and electron microscopy analysis, the mechanism for better performance of optimum concentration is also proposed.