Analysis of pressure variations in a low-pressure nickel–hydrogen battery. Part 2: Cells with metal hydride storage

Abstract

A sub-atmospheric pressure nickel hydrogen (Ni-H2) battery with metal hydride for hydrogen storage is developed for implantable neuroprosthetic devices. Pressure variations during charge and discharge of the cell are analyzed at different states of charge and are found to follow the desorption curve of the pressure composition isotherm (PCI) of the metal hydride. The measured pressure agreed well with the calculated theoretical pressure based on the PCI and is used to predict the state of charge of the battery. Hydrogen equilibration with the metal hydride during charge/discharge cycling is fast when the pressure is in the range from 8 to 13 psia and slower in the range from 6 to 8 psia. The time constant for the slower hydrogen equilibration, 1.37h, is similar to the time constant for oxygen recombination and therefore pressure changes due to different mechanisms are difficult to estimate. The self-discharge rate of the cell with metal hydride is two times lower in comparison to the cell with gaseous hydrogen storage alone and is a result of the lower pressure in the cell when the metal hydride is used.

The Current Status of Hydrogen Storage Alloy Development for Electrochemical Applications

“…New types of V-flow/NiMH [16,17] and lead-acid/NiMH hybrid batteries [18] have been developed at the University of Hong Kong. Pd-treated LaNi 4.7 Al 0.3 has been used in a Ni-hydrogen battery [19]. Another application of LaNi 5 is the use as a cathode in a photo-electrochemical cell for water decomposition [20].…”

Electrochemical hydrogen storage: Achievements, emerging trends, and perspectives

“…Various efforts to increase cycle stability of the Mg-based alloys thus have been made by researchers. 123,124 It is an efficient approach to increase the corrosion performance on the alloy electrodes to introduce one or more items into multi-component composites. 128…”

Novel DAZO Film with a Negative Temperature Coefficient Effect and Its Application Prospects for the Thermal Runaway Warning System in Batteries

“…New energy batteries such as lithium-ion batteries, , nickel–hydrogen batteries, , and fuel cells , are widely used in energy storage systems , and electric vehicles , because of their advantages such as high energy density, low self-discharge rate, and reduction in carbon emissions. However, the characteristics of the battery system, such as the high current required for rapid charging and discharging, high energy density, the use of a flammable electrolyte, collisions, and needles, make the batteries prone to thermal runaway, − resulting in dangerous accidents such as fire incidents.…”