Effect of Novel Substrates on Zinc Anode - Secondary Alkaline Battery Performance

Abstract

Zinc electrodeposition in alkaline battery has important effect on the performance of the battery and the substrate metal has a strong effect on the performance of zinc anodes, especially at the earliest stages. Rotating disk electrodes were fabricated using 99.9%+ pure metal rods to investigate the performance of zinc deposition on silver, bismuth, copper, iron, nickel and tin substrates. The amount of charge passed in all the experiments was 5 C/cm2. Iron and nickel do not have desirable performance, due to hydrogen evolution. The hydrogen evolution on iron is rapid and soon covers the entire surface of the electrode. Bismuth and tin have desirable performance. The coulombic efficiency on each of these substrates is well in excess of 90% when deposited at -20 mA/cm2. Due to their relatively low cost, tin and bismuth are seen as promising choices of substrate metals in zinc anodes.The morphology of zinc deposition and crystal orientation on copper, nickel and tin substrates was investigated. Zinc deposition is more compact on Sn than on Ni and Cu for the same amount of charge passed. Additionally, Ni and Cu have a propensity to evolve mossy zinc much more easily.The extent of preferred orientation decreases with zinc deposition, and mossy zinc is depositied with almost no texture. Compact zinc has preferred orientation, strongest on Sn.Zinc-based rechargeable batteries are attractive electrical energy storage systems due to their low cost, high energy density and low toxicity. However, zinc redistribution on periodic cycling and dendrite formation is known to severely limit battery life. Short cycle life due to internal short circuits have prevented wide spread secondary storage applications.Zinc electrodeposition in alkaline battery has important effect on the performance of the battery and the substrate metal has a strong effect on the performance of zinc anodes, especially at the earliest stages. Rotating disk electrodes were fabricated using 99.9%+ pure metal rods to investigate the performance of zinc deposition on silver, bismuth, copper, iron, nickel and tin substrates. The amount of charge passed in all the experiments was 5 C/cm2. Iron and nickel do not have desirable performance, due to hydrogen evolution. The hydrogen evolution on iron is rapid and soon covers the entire surface of the electrode. Bismuth and tin have desirable performance. The coulombic efficiency on each of these substrates is well in excess of 90% when deposited at -20 mA/cm2. Due to their relatively low cost, tin and bismuth are seen as promising choices of substrate metals in zinc anodes.The morphology of zinc deposition and crystal orientation on copper, nickel and tin substrates was investigated. Zinc deposition is more compact on Sn than on Ni and Cu for the same amount of charge passed. Additionally, Ni and Cu have a propensity to evolve mossy zinc much more easily.The extent of preferred orientation decreases with zinc deposition, and mossy zinc is depositied with almost no texture. Compact zinc has preferred orientation, strongest on Sn.