多孔铜箔对硬碳负极电化学性能的影响

Effect of porous copper foils on the electrochemical performance of hard carbon anodes

负极集流体是锂离子电池的重要组成部分,直接决定电池的内阻,影响电池的倍率和循环稳定性。以常规铜箔和多孔铜箔作为集流体制备锂离子电池,通过SEM、极片电阻、接触角和恒流充放电等测试,研究铜箔带孔对电池容量、倍率性能及循环性能的影响。与常规铜箔相比,以多孔铜箔作为集流体制备的极片具有更低的电阻率和更佳的电解液浸润效果,制备的扣式半电池以0.1 C在0.001~2.500 V循环3次进行化成后,首次充放电比容量分别提高了149.50 mAh/g和207.03 mAh/g;在10.0 C倍率下的平均放电比容量达127.21 mAh/g,较常规铜箔制备的电池提升了46.28%;以1.0 C在0.001~2.500 V循环200次后,电池的容量保持率达52.85%,材料的倍率性能和循环稳定性得到提升。

The anode collector is an important part of Li-ion battery,which directly determines the internal resistance of the battery and affects the rate and cycle stability of the battery.Li-ion batteries with conventional copper foil and porous copper foil as the collector are prepared,and the effects of copper foil with holes on the battery capacity,rate capability and cycle performance are investigated by SEM,electrode resistivity,contact angle and galvanostatic charge-discharge tests.Compared with the conventional copper foil,the electrode prepared with porous copper foil as the collector has lower resistivity and better electrolyte wetting effect.After being formatted by cycling 3 times at 0.1 C in 0.001-2.500 V,the initial charge-discharge specific capacity of the prepared half battery is increased by 149.50 mAh/g and 207.03 mAh/g,respectively.The average specific discharge capacity reaches 127.21 mAh/g at a rate of 10.0 C,improving 46.28%compared to the battery prepared with conventional copper foil.After 200 cycles in 0.001-2.500 V at 1.0 C,the capacity retention rate of the battery is 52.85%,the rate and cycle stability of the material are improved.