Mg-1Ge-1In镁空气电池阳极的放电性能研究

Research on the discharge performance of Mg-1Ge-1In magnesium-air battery anode

提出了一种利用锗和铟在镁中的固溶度差异调控Mg-1Ge-1In合金显微组织的策略。经过均匀化退火处理,合金中的Mg_(2)Ge相呈现出连续的网络状结构。Mg-1Ge-1In合金展现出优异的阳极放电性能,包括低至2.48 mm/y的腐蚀速率、在1 mA/cm^(2)放电电流下达-1.70 V的放电电压,以及在10 mA/cm^(2)放电1 h后高达59.49%的阳极利用率。此外,在5 mA/cm^(2)的放电条件下,Mg-1Ge-1In合金能维持稳定电压,表面呈现层状剥落现象;但当放电电流增至10 mA/cm^(2)时,其放电电压减小且放电稳定性降低。Mg-1Ge-1In合金的放电活化机理基于Mg_(2)Ge相的电偶效应与In原子的氧化-还原循环,放电活性位点正是源于Mg_(2)Ge相与镁基体间的连续网状界面,而In元素的加入则进一步增强了镁基体表面的活化,两者协同作用,确保了放电反应的稳定持续进行。

This study proposes a strategy to regulate the microstructure of Mg-1Ge-1In alloy by using the difference in solid solubility of germanium and indium in magnesium.After homogenization annealing,the Mg_(2)Ge phase in the alloy exhibits a continuous network-like structure.The Mg-1Ge-1In alloy demonstrates exceptional anode discharge performance,encompassing a low corrosion rate of 2.48 mm/y,a discharge voltage of-1.70 V at a discharge current of 1 mA/cm^(2),and a remarkable anode utilization efficiency of up to 59.49%after discharging at 10 mA/cm^(2) for 1 h.In addition,under a discharge condition of 5 mA/cm^(2),the Mg-1Ge-1In alloy maintains a stable voltage,accompanied by a layered peeling phenomenon on its surface.However,as the discharge current increases to 10 mA/cm^(2),the discharge voltage undergoes some decay,accompanied by a decrease in discharge stability.The discharge activation mechanism of the Mg-1Ge-1In alloy is based on the galvanic effect of the Mg_(2)Ge phase and the oxidation-reduction cycle of In atoms.The discharge active sites originate from the continuous network interface between the Mg_(2)Ge phase and the magnesium matrix.The addition of In further enhances the activation of the magnesium matrix surface.The synergistic effect of these two factors ensures the stable and continuous progress of the discharge reaction.