Free-standing SnS/carbonized cellulose film as durable anode for lithium-ion batteries

Metal sulfides have recently attracted broad attention for lithium-ion batteries (LIB) owing to their high theoretical capacity and long lifetime. However, the inferior structural integrity and low electron conductivity of metal sulfides limit their practical applications. A feasible strategy is to distribute these materials in conductive carbonaceous substrates with shapeable morphology. Here we report the design of free-standing films of tin sulfide (SnS) nanosheets distributed uniformly on carbonized bacterial cellulose (CBC) nanofibers. The SnS/CBC composites possess three dimensional interconnected nanostructures, which is crucial for the high conductivity and high lithium storage capacity. LIB using SnS/CBC as anode exhibits a reversible capacity of 872 mA h g^-1 at 100 mA g^-1 after 100 cycles, and the capacity remains as high as 527 mA h g^-1 at 2000 mA g^-1 after 1000 cycles. The free-standing sulfide-based nanocomposites with unique nanostructure composition and flexibility could be utilized as promising electrode materials for future LIB systems.