摘要:
分别以石墨烯、科琴黑、乙炔黑为导电剂,研究了采用不同导电剂对Li3V2(PO4)3锂离子电池电化学性能的影响,获得了性能较佳的科琴黑导电剂;然后改变配比,研究了不同科琴黑配比对电池电化学性能的影响。结果表明:在三种导电剂下,充放电电压范围为3.0~4.3 V,放电倍率为0.2C时,石墨烯、科琴黑、乙炔黑首次放电比容量分别为108、114、104 mAh/g;通过循环性能曲线表明,经过50次循环,放电比容量只发生了微小的变化。改变导电剂的配比,分别是LVP∶PVDF∶导电剂=85∶10∶5、LVP∶PVDF∶导电剂=80∶10∶10以及LVP∶PVDF∶导电剂=75∶10∶15,结果表明:在充放电电压范围为3.0~4.3 V,放电倍率为0.2 C时,三种配比下,首次放电比容量分别为105、114、96 mAh/g,这说明,导电剂的含量也能在一定程度上影响电池的化学性能,导电剂含量不宜过高,也不能过低,含量在10%时,其电化学性能最佳。
Abstract:
The effect of conductive agent on the electrochemical performances of the cathode material of Li3V2（PO4）3 lithium ion batteries（LIBs） was studied respectively using graphene, Ketjen black and acetylene black as the conductive agent, and then the ratio of Ketjen black was adjusted to investigate its effect on the electrochemical performances of LIBs. The results show that the first specific discharge capacity of the battery is 108, 114 and 104 mAh/g respectively with graphene, Ketjen black and acetylene black, at charge and discharge voltage range of 3.0～4.3 V and discharge rate of 0.2 C. The cycling performances show that the specific discharge capacity changes slightly after 50 times of cycling. By changing the conductive agent ratio, the first specific discharge capacity of the battery is 105, 114 and 96 mAh/g respectively for LVP∶PVDF∶conductive agent=85∶10∶5, 80∶10∶10 and 75∶10∶15, at charge and discharge voltage range of 3.0～4.3 V and discharge rate of 0.2 C. It indicates that the content of conductive agent influences the electrochemical performances of LIBs as well. When the content of conductive agent is 10%, the battery has the best electrochemical properties.
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