MOF衍生碳包覆硅纳米颗粒限制于石墨烯复合负极材料的制备及性能研究

采用原位生长法设计并合成了MOF衍生碳包覆硅纳米颗粒限制于石墨烯的复合材料(Si/C@G),并应用于锂离子电池负极材料,该材料结构有效缓解硅基负极材料充放电过程的体积变化,促进了稳定的固态电解质中间相层的形成,提高了电极材料的电导率。Si/C@G负极材料在电流密度500 mA/g时经100次循环可逆比容量仍有1081.2 mAh/g;在电流密度5.0 A/g时其可逆容量达到949.6 mAh/g。Si/C@G负极在1.0 A/g的恒电流密度下循环500次后可逆比容量可保持在677.2 mAh/g左右,库仑效率可达99.84%,表现出良好的循环稳定性。

Preparation and Properties of Composite Anode Material by Using MOF-Derived Carbon Coated Silicon Nanoparticles Confined in Graphene Composite

A kind of composite (Si/C@G) was designed and synthesized by in-situ growth with MOF-derived carbon coated silicon nanoparticles that was confined in graphene composite, which was used as anode material of Li-ion batteries. Its special structure can effectively reduce the variation in the volume of silicon-based anode material during the charge-discharge process, thus promoting the formation of stable solid electrolyte interphase films, and improving conductivity of electrode materials. As a result, the anode material of Si/C@G composite can have reversible specific capacity still remaining at 1081.2 mAh/g after 100 cycles at a current density of 500 mA/g, and have reversible capacity reaching 949.6 mAh/g at a current density of 5.0 A/g. Besides, the anode material of Si/C@G can have the specific capacity remaining around 677.2 mAh/g after 500 cycles at a constant current density of 1.0 A/g, with the Coulomb efficiency up to 99.84%, indicating that it delivers a good cycling stability.