碳化制度对锌基电池ZnO@C负极电化学性能的影响

Effect of Carbonization Conditions on Electrochemical Performance of ZnO@C Anode Material for Zinc-based Battery

以间苯二酚-甲醛树脂为碳源,采用原位聚合加碳化处理的方法 ,成功制备了碳包覆氧化锌负极材料。结果表明,纳米氧化锌表面的碳层厚度均匀,结构完整。延长碳化时间提高了碳层的石墨化度,升高碳化温度增加了碳层的缺陷。电化学测试考察了碳化时间和碳化温度对碳包覆氧化锌负极材料电化学性能的影响,当碳化时间由6h延长至10h,材料的电荷转移阻抗减小,初始放电容量由400mA·h/g提高到530mA·h/g,循环性能在8h时最好;当碳化温度由600℃提高至800℃,材料在700℃时的电荷转移阻抗最小,循环性能最优,85次循环后容量保持率为97.8%,因此最佳的碳化条件为700℃碳化8h。

Carbon-coated ZnO anode materials were successfully synthesized by in-situ polymerization followed with a carbonization process using resorcinol-formaldehyde resin as carbon source.The experimental results show that the thickness of the carbon layer on the surface of nanosized ZnO particles is uniform and the structure is intact.The degree of graphitization of the carbon layer increases with the extending of carbonization time.And the lattice defects increase with the rise of carbonization temperature.The effects of carbonization time and temperature on electrochemical performances of carbon-coated ZnO were investigated,and the optimized carbonization condition obtained is that carbonizing precursor at 700℃for 8 h.When the carbonization time extends from 6 hto 10 h,the charge transfer resistance of the materials decreases and the initial discharge capacity increases from 400 mA·h/g to530 mA ·h/g,and the cycling performance of sample prepared with 8 his best. When the carbonization temperature increases from 600℃to 800℃,the sample prepared at 700 ℃ shows least charge transfer resistance and best cycle performance with a capacity retention rate of 97.8% after 85 charge-discharge cycle.