The Research And Influence Of Different Cobalt On Structure And Electrochemcial Performance Of SnCo/C Anode Material

Commercialized Li-ion battery used carbon as the anode materials. But with the demand of people improving, commercialized battery has not met the demand of people. Sn has the high capacity and the good safety performance, which make it become the focus of research.The introduction of Co in the Sn-based can improve cycling performance. The SnCo/C composites as anode materials for lithium-ion batteries were synthesized from different Cobalt,Sn powders and carbon black using solid-state sintering at different temperatures firstly and then ball milling.The characterization of the composite was carried out by XRD,SEM and electricalproperties measurement.In SnCo_x/C(Co_x=Co₃O₄,CoC₂O₄,CoCO₃) system using solid-state sintering at 600 temperatures,XRD analyses reveal that the main phase of SnCo₃O₄/C system is SnO₂, the main phase of SnCo₃O₄/C system are SnO₂ and Sn, the main phase of SnCoCO₃/C system is Sn. Electrochemical analysis shows that the first lithium deintercalation capacity of the composite when Co Compounds selected CoCO₃ was 257mAh/g and initial charge-discharge efficiency was 71.8%,The capacity retention achieved 65.76% after 25 cycles.Element Co is added into SnCoCO₃/C sample because of its higher capacity and best cycle performance,and study the influence of element Co on structures and electrochemcial performance of material.In Sn(CoCO₃)_yCo_1-y/C(y=1,0.75,0.5,0.25,0.125,0.0625,0) system using solid-state sintering at 850 temperatures,XRD analysis showed that the main phase of all the Sn(CoCO₃)_yCo_1-y/C is CoSn. And the grain size of Sn(CoCO₃)_yCo_1-y/C composites are less than 100nm,belong to nanocrystalline composite.Electrochemical analysis shows that with the molar mass of CoCO₃ is increased, the first charge-discharge efficiency of Sn(CoCO₃)_yCo_1-y/C samples is improved,SnCoCO₃/C sample reaches to the maximum,the first charge-discharge efficiency is 64%.With the increasing of molar mass of elemental Co,the cycle performance of Sn(CoCO₃)_yCo_1-y/C samples is improved,SnCo/C sample reaches to the maximum,reaching 79.3%.The initial discharge capacity of Sn(CoCO₃)_0.75Co_0.25/C is 297mAh/g, The capacity retention achieved 60% after 25 cycles,It had good capacity and best cycle performance.