Solar-driven energy storage enhancement of nickel hydroxide nanomaterials

Abstract

Nickel hydroxide (Ni(OH)2) is one of the most promising cathode materials that are widely used in rechargeable batteries, for instance, the nickel-metal hydride battery (NiMH). The challenge relating to Ni(OH)2 is the charge transfer process during the electrochemical reaction. In this work, Ni(OH)2 was explored as both photo-harvesting and energy storage materials under UV-visible light (AM1.5) illumination to enhance the charge transfer process for the electrochemical reaction of Ni(OH)2 via the photovoltaic effect. The generation of polaron, an electron-hole pair of Ni(OH)2, under light and potential bias increases the charge carrier density for the electrochemical reaction. The result suggests that the capacity was enhanced by 14.4% compared with that under the dark condition. This new finding may further improve the charge storage capacity and development of NiMH and others using metal oxide and hydroxide materials as electrode materials for sustainability.