关键词: 脉冲电沉积, 固体电解质界面膜, 锂枝晶, 占空比

Abstract:

A pulse charge method was used to suppress the formation of lithium dendrite on the copper electrode in 0.5 mol·L^-1 LiBr/propylene carbonate (PC) electrolyte. The surface variation of lithium deposition was investigated by scanning electron microscope and impedance measurement. The SEM test showed that the lithium dendrites were formed on the copper electrode during the traditional process of electrodeposition. However, the formed dendrite was suppressed by pulse charge method. The results of the impedance measurement confirmed that the pulse electrodeposition could suppress the dendrite under the optimized duty ratio (0.5). The long single pulse deposition time decreased the resistance of SEI film and led to the lithium dendrite growth. The current density had an effect on dendrite and the dendrite could be effectively suppressed with no less than 2 mA·cm^-2 of current density.

Key words: pulse electrodeposition, SEI film, lithium dendrites, duty ratio