In-situ coupling SnS with nitrogen-doped porous carbon for boosting Li-storage in lithium-ion battery and capacitor

Tin sulfide (SnS) becomes a competitive alternative anode material for lithium ion batteries (LIBs) due to its cost-effects and high theoretical capacity. Herein, a simple freeze-drying and annealing synthetic strategy was exploited to in-situ couple SnS with nitrogen-doped porous carbon nanosheets to fabricate SnS@NPC nanocomposites. In this nanostructure, SnS nanoparticles were well embedded into citric acid-derived nitrogen-doped carbon hierarchical frameworks with enlarged surface areas and abundant porosity. Besides, the reversible Li-ion storage property of this novel nanostructured anode in LIBs was also investigated and compared with the bare SnS counterpart. It was indicated that the SnS@NPC hybrid electrode exhibited a tremendously boosted electrochemical performance. After cycling 200 times at 100 mA g⁻¹ and 300 times at 1000 mA g⁻¹, a high specific capacity of 851.5 mA h g⁻¹ and 607.6 mA h g⁻¹ was remained respectively. Furthermore, with SnS@NPC as anode and the activated carbon (AC) as cathode, a new-type of lithium ion capacitor (LIC) was also fabricated, which exhibited a specific capacitance of 70.1 F g⁻¹ at 0.1 A g⁻¹ and a maximum energy density of 155.5 Wh kg⁻¹ at 213.6 W kg⁻¹. The well-engineered nanostructures as well as the aroused synergistic effect between SnS and nitrogen-doped carbon materials are considered to be responsible for the enhanced electrochemical property.