Co-nucleated Co doped SnO2/SnS2 heterostructures to facilitate diffusion towards high-performance Li and Na ion storage

Abstract

Sn-based compounds are emerging as a promising category of alkali metal ion storage materials due to their relatively high theoretical specific capacity and natural abundance. However, inadequate ion diffusion, poor electron transfer, and significant volume fluctuations during prolonged charge and discharge cycles lead to severe structural deterioration and capacity loss, hindering their further practical application. Heterostructure engineering can not only alleviate the internal stresses and dramatic volume alterations induced by ion deintercalation, but also enhance the dynamics of ion transport. Adopting a dual-optimization strategy that incorporates heterogeneous structure construction and doping, we successfully synthesized ultra-thin Co doped SnS₂/SnO₂ heterostructure nanosheets on carbon cloth substrates via a co-nucleation growth process. After rigorous investigation into its lithium-ion storage performance and mechanisms, it exhibited excellent lithium storage capabilities (1518 mA h g⁻¹ at 330 mA g⁻¹, with 81% of the initial capacity retained after 100 cycles). Pleasingly, when incorporated into next-generation sodium-ion batteries, Co-doped SnS₂/SnO₂ anodes exhibit highly competitive sodium storage capabilities (1250 mA h g⁻¹ at 220 mA g⁻¹, with 97.8% of the initial capacity retained after 200 cycles). The incorporation of Co ions and the formation of heterostructures have been confirmed to enhance ion diffusion and reaction kinetics. This study presents a novel approach for the facile preparation of multifunctional Li and Na ion storage materials featuring element-doped heterogeneous compositions.