Studies On Zinc Electrode Of High-Energy Mercury-Free Green Alkaline Manganese Batteries——Research On Functional Film Of High Hydrogen Over-Potential

Zinc acts as negative material of batteries, with the advantages of low equilibrium potential, good reversibility, high specific energy, rich resources, low cost, little poison and easy treatment. Alkaline zinc manganese dioxide batteries have been paid much attention to because of high specific energy, specific power and low cost. As the material of batteries, zinc electrode has many problems, such as dendrite growth, shape-changing, passivation, corrosion and so on. At present, the main way to solve the problems is to add mercury and its oxide to zinc electrode. But, mercury is poisonous and makes the environment polluted. Mercury must be substituted by something others. All countries of the world have made out treasurements to control the amount of mercury and are researching the mercury-free green batteries. In our country the batteries with mercury whose amount is more than 0.0001 percent of the batteries will be not allowed. CCTV reported the batteries would be forbidden to input and output in Nov. last year. The current collector lies in the three-phase interface, having direct effect on batteries characteristic. In this paper, we focus on the current collector to look for substitution for mercury. The metal or alloy with high over-potential of hydrogen was electroless deposited on the surface of the current collector or organic additives were used, too. The main experiments and their results or conclusion are as follows:1. Zn, In, Sn and their alloys are electroless deposited on the surface of current collector of copper and zinc alloy successfully. This method has not been reported on reference.2. As for cathode of mercury-free alkaline zinc manganese-dioxide battery, mono-layer plating of In, Zn, Sn and double-layer plating of Zn-In, Sn-In, Zn-Sn was electroless deposited on the surface of current collector respectively. Experiment of hydrogen evolution showed that the evolution hydrogen amount of current collector coated by mono-layer plating or double-layer plating was less than without them in 7.0M KOH solution with zinc power, and that of the double-layer plating of Zn-In, Sn-In was the least. Cyclic voltammetry -indicated that there is an obvious reduction peak ofhydrogen at the potential of about -0.8v VS. SCE on the curve of that without plating. And there is not the same peak on the curves of those with plating. It proved that the plating can control the electrochemical reaction. Polarization curve experiment came to the same conclusion. Discharging experiment proved that mercury-free alkaline zinc manganese-dioxide battery can be assembled by the current collector treated by mono-layer plating or double-layer plating of In, Zn, Sn, surpassing the properties of LR6 alkaline zinc manganese dioxide battery according to the standard of industry requirement of QB1185-91.3. The various organic surfactants were adsorbed on the surface of the current collector. The dynamic hydrogen evolution experiment proved that the evolution hydrogen amount of current collector adsorbing organic surfactants was less than without them in 7.0M KOH solution with zinc power. Polarization curve experiment showed that the cathode polarizing of the current collector with surfactant increased in alkaline solution. F1110 was adsorbed on the surface of current collector with zinc. The Fl 110 and zinc served for hydrogen evolution together and did better for it.