ZIF-8@ZIF-67衍生的Co_(3)O_(4)-GN-CNT网络用作高性能锂离子电池负极

Co_(3)O_(4)-GN-CNT network derived from ZIF-8@ZIF-67 as high-performance lithium-ion battery anode material

Co_(3)O_(4)由于较高的理论容量近年来被视为锂离子电池新型负极材料的热门候选之一,然而其较差的电导率和循环性能制约了其进一步发展。以ZIF-8@ZIF-67为自模板,三聚氰胺和g-C_(3)N_(4)为碳源,通过碳化和氧化处理制备了碳纳米管和石墨烯作为导电桥梁和外壳的Co_(3)O_(4)/C三维导电网络。颗粒纳米化的策略和锌的高温挥发造孔使其在0.5、2 A/g的电流密度下循环200、800圈后仍具有1 139.7、1 002.1 mAh/g的比容量,从0.2 A/g逐渐增大充放电的电流密度至10 A/g又恢复到0.2 A/g后比容量仍有初始容量的94.9%。该网络结构和同类材料相比表现出较为优异的循环和倍率性能。

Due to the high theoretical capacity,Co_(3)O_(4) has been regarded as one of the popular candidates for new anode materials in lithium-ion batteries recent years.However,the poor conductivity and cycling performance hinder its further development.In this work,Co_(3)O_(4)/C three-dimensional conductive networks with carbon nanotubes and graphene as conductive bridges and shells were prepared through carbonization and oxidation treatment using melamine and g-C_(3)N_(4) as carbon sources and ZIF-8@ZIF-67 as self templates.The strategy of nanosizing particles and the evaporation and pore formation of zinc at high temperature result in the specific capacity of 1 139.7 mAh/g and 1 002.1 mAh/g after cycling for 200 and 800 cycles at current densities of 0.5 A/g and 2 A/g.Gradually increasing the current density of charging and discharging from 0.2 A/g to 10 A/g and then returning to 0.2 A/g,the material still reaches 94.9% of the initial capacity.This network structure exhibits superior cycling and rate performance compared to similar materials.