The Study On The Electrochemical Behavior Of Magnesium Alloy In Composite Electrolyte

Magnesium battery has become a research hotspot recently, owing to itsenvironment friendly, discharge excellent, wide work temperature range and low cost.In China magnesium is abundant, which has unique advantages in the development ofmagnesium battery. Due to the corrosion resistance of magnesium alloys is poor, affectthe service life of the batteries, and the voltage delay has become the key problems torestrict the development of magnesium battery. Currently, the research of magnesiumbattery is mainly focuses on magnesium alloy and electrochemical behavior ofmagnesium electrode in single component electrolyte and electrolyte additive. But thereis little research on electrochemical behavior of magnesium battery electrode incomposite electrolyte. Therefore, it is important to research the composite electrolyte,and this study is very useful for the development of magnesium battery.In this paper, we proposed the composite electrolyte series which include twocomponents and three components composite electrolyte in magnesium battery, basedon the study on electrochemical behavior of magnesium electrode in singleelectrolyte. Electrochemical behavior of magnesium electrode in composite electrolyteand the influence of immersion time on magnesium alloy film and magnesium batteryelectrode were investigated by means of linear sweep voltammetry, open circuitpotential(OCP), electrochemical impedance spectroscopy(EIS), chronopotentiometry(CP), scanning electron microscopy(SEM), Fourier-transform infrared spectroscopy.Results indicate that the corrosion of magnesium alloy is serious and the surface film isthickness in MgSO4solution, the delay time become long with the immersion timeincreasing. The voltage delay time is within two seconds with the immersion timeincreasing in Mg(ClO4)2solution. In two components composite electrolyte ofMg(ClO4)2+La(NO3)3solution, the corrosion resistance is improved and the delay timeis shortened, but the anodic discharge curves become unstable. In three componentscomposite electrolyte series of Xmol/LMg(ClO4)2+Ymol/LMgSO4+0.05mol/LLa(NO3)3(X=0.5,0.67; Y=1,0.67), there is little relationship between the delay time and theaddition of MgSO4and Mg(ClO4)2. The voltage delay time is about two seconds, theanodic discharge curves become stable, and the corrosion resistance is improved byadding La(NO3)3. In three components composite electrolyte solution series of1mol/LMg(ClO4)2+Zmol/LMgSO4(Z=0.5,1.0)+0.05mmol/LLa(NO3)3, with the MgSO4 concentrations increasing, corrosion will be accelerated, the voltage delay time will beshortened. By comprehensive consideration, three components composite electrolyte of0.67mol/LMg(ClO4)2+0.67mol/LMgSO4+0.05mol/LLa(NO3)3is excellent, and it hassome advantages, such as discharge stable, delay time short and corrosion resistanceperformance good.