摘要
研究了Li的固态扩散对LiAl合金负极极化行为的影响,制备了具有不同比表面积的LiAl电极与不受Li固态扩散影响的Cu@Li电极。采用恒流充放电、循环伏安法、电化学阻抗与恒流间歇滴定测试对沉积容量为0.51mAh/cm^(2)的电沉积LiAl合金在半电池和全电池中的极化行为进行探究。结果表明:Li在LiAl中的固态扩散是导致LiAl电极在半电池和全电池中极化的主要原因;扩散捕获效应将增加电池内阻,使极化现象增强,最终导致LiAl‖S全电池约1.84和1.55V的低放电电位;通过破坏导致扩散捕获效应的表面α-Al层,可提高电解液中的Li+浓度,促进Li_(2)S析出,从而减轻极化,提高LiAl‖S全电池的放电电压,使其接近热力学放电电位。
The effect of solid state diffusion of Li on the polarization behavior of Li-Al alloy anode was studied,and Li-Al electrodes with different specific surface areas and Cu@Li electrodes without the effect of solid state diffusion of Li were prepared.The polarization behavior of electrodeposited Li-Al alloy with a deposited capacity of 0.51 mAh/cm^(2) in a half cell and a full cell were investigated by using galvanostatic charge-discharge measurement,cyclic voltammetry,electrochemical impedance spectroscopy(EIS),and galvanostatic intermittent titration technique.The results show that the solid-state diffusion of Li in Li-Al is the main reason for the polarization of Li-Al electrode in a half cell and a full cell,and the diffusional lithium trapping will increase the internal resistance of the cell,bringing in enhanced polarization phenomenon and finally resulting in the low discharge potential of about 1.84 and 1.55 V for Li-Al‖S battery.Surfaceα-Al layer causes diffusional lithium trapping,and disrupting it can not only increase the Li+concentration in the electrolyte and promote the precipitation of Li_(2) S,leading to reduced polarization,but also increase discharge voltage of LiAl‖S battery to approach the thermodynamic discharge potential.
作者
黄方铎
孙婷婷
刘俊良
丰雪帆
喻文瑞
张福勤
HUANG Fangduo;SUN Tingting;LIU Junliang;FENG Xuefan;YU Wenrui;ZHANG Fuqin(Powder Metallurgy Research Institute,Central South University,Changsha 410083,Hunan,China)
出处
《矿冶工程》
北大核心
2025年第1期171-178,共8页
Mining and Metallurgical Engineering
关键词
锂硫电池
锂铝合金负极
扩散捕获效应
结构退化
负极材料
极化行为
lithium-sulfur battery
Li-Al alloy anode
diffusional lithium trapping
structural degradation
cathode material
polarization behavior
