Solar-driven energy storage enhancement of nickel hydroxide nanomaterials

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 ex-plored 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 in-creases 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 im-prove the charge storage capacity and development of NiMH and others using metal oxide and hydroxide materials as electrode materials for sustainability. (C) 2021 Elsevier Ltd. All rights reserved.