Dual-Carbon-Confined SnS Nanostructure with High Capacity and Long Cycle Life for Lithium-ion Batteries

[摘要] SnS with high theoretical capacity is a promising anode material for lithium-ion batteries. However, dramatic volume changes of SnS during repeated discharge/charge cycles result in fractures or even pulverization of electrode, leading to rapid capacity degradation. To solve this problem, we construct a dual-carbon-confined SnS nanostructure (denoted as SnS@C/rGO) by depositing semi-graphitized carbon layers on reduced graphene oxide (rGO) supported SnS nanoplates during high-temperature reduction. The dual carbon of rGO and in situ formed carbon coating confines growth of SnS during the high-temperature calcination. Moreover, during the reversible Li + storage the dual-carbon modification enables good electronic conductivity, relieves the volume effect, and provides double insurance for the electrical contact of SnS even after repeated cycles. Benefiting from the dual-carbon confinement, SnS@C/rGO exhibits significantly enhanced rate capability and cycling stability compared with the bare and single carbon modified SnS. SnS@C/rGO presents reversible capacity of 1029.8 mAh g −1 at 0.2 A g −1 . Even at a high current density of 1 A g −1 , it initially delivers reversible capacity of 934.0 mAh g −1 and retains 98.2% of the capacity (918.0 mAh g −1 ) after 330 cycles. This work demonstrates potential application of dual-carbon modification in the development of electrode materials for high-performance lithium-ion batteries.

[关键词] conformal carbon coating;dual-carbon confinement;lithium-ion battery;reduced graphene oxide;SnS