Nickel-cadmium batteries with pocket electrodes as hydrogen energy storage units of high-capacity

Abstract

In this paper, the hydrogen accumulation was studied in the pocket electrodes of the Ni-Cd batteries during their operation. The gravimetric capacity of the active substance of the oxide-nickel electrode was found to be equal to 22 wt% and its volumetric capacity to 444.2 kg m−3. The results obtained are 4 times higher than previously obtained results in the world for any reversible metal hydrides and nanostructure carbon materials, as well as the requirements of the US Department of Energy for mobile hydrogen storage systems. The total energy density of the hydrogen stored in the active substance of the oxide-nickel electrode was equal to 79.40 kJ g−1 and 160.24 kJ cm−3. Note that the relevant parameters for the gasoline are 46 kJ g−1 and 32.7 kJ cm−3. The relevant specific capacities of the active substance of the cadmium electrode were found to be equal to 16.9 wt%, 404.4 kg m−3, while the total energy density of the hydrogen stored in the active substance of the cadmium electrode was equal to 60.99 kJ g−1 and 145.80 kJ cm−3. In this paper also, the reasons for such a large hydrogen storage capacity were established experimentally. The effect of a number of factors on the hydrogen accumulation was analyzed in the case of active substance with graphite use for the electrodes.