Regulation of Cobalt-Nickel-Based Compounds via Glucose-Induced Phase Transitions for Enhanced Performance in Zinc-Based Alkaline Batteries

Abstract

Zinc-based alkaline batteries (ZABs) have experienced tremendous breakthroughs in the past few years, particularly in the context of new energy storage solutions. Among various cathode materials, cobalt–nickel-based compounds have emerged as highly promising candidates. In this study, we introduce the novel synthesis of NiCo₂O₄ (NCO) and phase-transition CoNiO₂ (PT-CNO) via glucose and hydrothermal methods for the first time in aqueous zinc-based alkaline batteries. The phase transition process effectively regulates the morphology of the material. Specifically, glucose reduction transforms the material’s structure from nanoflowers composed of stacked nanowires (NCO) to self-assembled sheet-like formations (PT-CNO). This morphological transformation enhances the electrochemical activity specific surface area of the electrode, increases the number of active sites, and facilitates the electrochemical energy storage process. Furthermore, the phase transition and resulting morphological changes enhance charge transfer and electrolyte penetration, significantly reducing side reactions between the material and the electrolyte and thereby improving electrode stability. The Zn//PT-CNO configuration demonstrated a remarkable capacity retention rate of 70% after 10,000 cycles at a current density of 6 A/g. The phase transition strategy employed and the cobalt–nickel-based materials developed in this study offer valuable insights for designing advanced cathode materials in the realm of renewable and sustainable energy.