Study On Modification And Electrical Properties Of Silver Oxide Electrode

Aluminum oxide silver battery has the characteristics of high energy ratio,high power,good storage,especially large-rate discharge.It has been favored by most countries and thus been greatly developed.The high cost of the aluminum oxide silver battery limits its widely use,which mainly used in the military field.With the increasingly fierce competition of the market,there is a higher demand for performance of aluminum oxide silver batteries.The anode of aluminum oxide silver battery is an important part of the battery.The improvement of anode performance is of great significance to the improvement of battery performance.This paper mainly studies the modification and matching of active substances and current collectors of silver electrode.The specific research contents are as follows:(1)The electrical properties of silver acetate powder and nano-silver powder as active substances were investigated.Silver acetate powder was prepared by thermal decomposition method and the silver electrodes with thickness of 1.1mm and 1.4mm were prepared respectively.At a current density of 0.6A/cm~2 and an electro-hydraulic temperature of 80°C,the average voltage of a 1.4 mm thick silver electrode is 0.03V lower than that of a 1.1 mm silver electrode,but the utilization rate increases nearly 5%.Nano-silver oxide was synthesized by a new synthesis method,and the silver electrodes with thickness of 1.1mm and 1.4mm were prepared.The electrochemical properties of the1.4mm thick electrodes were general.Compared with the 1.1mm thick electrodes,the utilization rate of 1.4mm thick electrodes was lower by 7.86%,and the average voltage of1.4mm thick electrodes was lower by 0.014V.The electrochemical performances of the two kinds of thick electrodes vary greatly.When the porosity of the electrode is kept constant,concentration polarization increases as the thickness of the electrode increases.The comparison of two kinds of active silver powders shows that the voltage and utilization ratio of nano-silver powders are better than that of silver acetate powders.The increase of specific surface area of nano-silver oxide electrode is conducive to the improvement of the utilization ratio and average voltage of the electrode during the discharge process,and the increase of active substances can promote the discharge of the electrode,But the initial potential of the nano-silver oxide electrode did not increase at the initial stage of activation.Due to the high charging formation efficiency and large volume expansion,the traditional two-dimensional silver mesh could not be bound,so the silver mesh would be broken and the electrode damage rate would be high.(2)The properties of the silver-coated nickel foam electrode were investigated.Firstly,by comparing the properties of the silver electrode of the silver-coated nickel foam current collection and the silver net current collection,the discharge was performed at a current density of 600 mA/cm~2,the cut-off voltage was 1.4 V,the initial potential was0.335V,and the average voltage was 30 mV,the utilization rate reduced by 13.68%.Secondly,the alkali concentration increased from 4.5mol/Lto7.0mol/L.As the alkali concentration increased,the electrode also showed an upward trend.When the reaction temperature is greater than 65°C,the alkali concentration has a reduced influence on the voltage.When the reaction temperature is lower than 65°C,the alkali concentration has a significant effect on the voltage.When the concentration of the alkali solution is 4.5mol/L,the voltage platform is high,because the increase of the concentration of the alkali solution will further increase the thickness of the passivation film of the aluminum electrode to lower the voltage.In short,the performance of silver-plated foam is better than that of silver mesh collector,which has the initial activation potential increased obviously.But the specific surface area of acetic acid silver powder is low,the volume expansion is small,and the charging efficiency is low,the utilization rate did not increase obviously.(3)In order to improve early activation performance and late utilization rate,the silver electrode prepared by nano-silver oxide and nickel foamed silver plating was investigated.Silver electrode prepared by nanometer silver oxide and nickel foamed silver plating can simultaneously improve the electrode activation potential,discharge voltage and utilization rate.the rate performance of the silver-coated nickel foam was investigated,and the large current density was 0.62 to 0.84 A/cm~2,when the current density is 0.70 to 0.77A/cm~2,the average voltage and the electrochemical utilization rate are relatively stable.Therefore,the optimum current density of a silver electrode with silver-coated nickel foam as a current collector ranges from 0.70 to 0.77A/cm~2.The effect of electrolyte concentration and temperature on the properties of silver electrode was also investigate.