Dual Enhancement of Sodium Storage Induced through Both S-Compositing and Co-Doping Strategies

As a promising alternative to lithium-ion batteries (LIBs), rechargeable sodium-ion batteries (SIBs) are attracting enormous attention due to the abundance of sodium. However, the lack of high-performance sodium anode materials limits the commercialization of SIBs. In this work, the dual enhancement of SnS2/graphene anodes in sodium storage is achieved through S-compositing and Co doping via an innovative one-step hydrothermal reaction at a relatively low temperature of 120 degrees C. The asprepared 7% Co-SnS2/Spr-G composite consisting of 15.4 wt % S and 1.49 atom % Co shows both superior cycling stability (over 1000 cycles) and rate capability, giving high reversible specific capacities of 878, 608, and 470 mAh g(-1) at 0.2, 5, and 10 A g(-1), respectively. More encouragingly, the full-cell also exhibits an outstanding long-term cycling performance under 0.5 A g(-1), which delivers a reversible capacity of 500 mAh g(-1) over 200 cycles and still retains a high reversible capacity of 432 mAh C-1 over 400 cycles. The enhancement mechanism is attributed to the favorable three-dimensional structure of the composite, Co doping, and S-composition, which can induce a synergistic effect.

Automated summary

In this study, a dual enhancement of SnS2/graphene composite anodes for sodium-ion batteries was achieved through S-compositing and Co doping via a one-step hydrothermal reaction. The composite showed superior cycling stability and rate capability, with high reversible specific capacities at different current densities. The enhancement mechanism was attributed to the composite's favorable three-dimensional structure, Co doping, and S-composition inducing a synergistic effect.