Preparation And Electrochemical Performance Of Tin-based Sulfide/Carbon Composites

Lithium-ion battery anode material is one of the core materials of lithium-ion battery,improve the anode material to improve the overall performance of lithium-ion batteries has a greater impact.Tin-based sulfide materials with high safety,non-toxic and high quality of volume and volume ratio capacity is considered to be promising graphite alternative anode materials,but the tin-based sulfides during charge and discharge alloying and de-alloying process,Resulting in a huge volume expansion caused by the destruction of the electrode structure,the electrode capacity dropped sharply.In order to address this problem,tin-based sulfides with special morphology and complexation with carbon materials are generally used to improve the conductivity and reduce the volume expansion during charging and discharging.In this paper,SnS2 and SnS special micro-morphology preparation and electrochemical performance of two aspects:(1)hydrothermal method by changing the reaction time to prepare different morphology of SnS2.The results demonstrate that with the extension of reaction time,SnS2 gradually changes from sheet-like structure to multi-level micro-nano structure.The sheet-like structure and multi-level micro-nano structure SnS2 have a specific discharge capacity of 368.5 mAh/g and 232.2 mAh/g after the 100 cycles at a current density of 100 mA/g.(2)Microparticle,rod-shaped and multi-level micro/nano structure SnS were prepared by hydrothermal method and heat treatment.Specific capacity of SnS discharge after the 100 cycles at 100 mA/g current density have 232 mAh/g,276 mAh/g and 121 mAh/g,respectively.In this paper,the porous spherical carbon with a specific surface area of 900.5 m2g-1 was developed for the first time using rape pollen as a bio-template,and was hydrothermally combined with tin disulfide.It was found that the specific discharge capacity of the 14%SnS2/porous spherical carbon composite after 412 cycles at a current density of 100 mA/g was 412.9 mAh/g.In order to realize the application of tin-based sulfides in the commercialization in the future,SnS2/GCP composites were obtained by hydrothermal method combined with commercial graphite conductive carbon powder(GCP).The SnS2/GCP composites were sintered at 100 mA/g current densities after 100 cycles of discharge capacity can still be maintained at 795.6 mAh/g,and have a good rate performance.In this paper,the more recent studies of multi-walled carbon nanotubes and tin-based sulfide complex.It was found that the SnS@MWCNTs composites,granular SnS well embedded in the surface of multi-walled carbon nanotubes at 100 mA/g current density after 100 cycles,reversible capacity remained at 468.5 mAh/g.