Review: on rare-earth perovskite-type negative electrodes in nickel-hydride (Ni/H) secondary batteries

Rare-earth perovskites-type oxides are compounds with the general formula ABO(3). There are many industrial and research applications related to their properties such as photocatalytic activity, magnetism, or pyroferro and piezo-electricity, and interest in these compounds in the field of energy storage and conversion is growing. Rare-earth perovskite-type oxides may be used in nickel-metal hydride (Ni/MH) battery technology because these materials may store hydrogen in strong alkaline environments, and also because of their abundance and low cost. In this review, the use of rare-earth perovskite-type oxides in Ni/MH batteries is described, starting from their crystalline structure and production methods. In each category, a description concerning the latest advances and future research direction is presented. Electrochemical performance of the perovskite-type electrodes is reviewed extensively. In addition, various strategies for enhancing their hydrogen storage capacity as a negative electrode in hydrogen batteries are discussed. Drawbacks and challenges of this technology are also presented.