Enhancing the Performance of Nanocrystalline Nickel Cathodes via Electrodeposition for Use in Ni-Zn Batteries: Morphological and Crystallographic Structure Optimization

Rechargeable Ni-Zn batteries are gaining interest owing to their adequate performance for achieving net-zero carbon goals, low cost, and safety. However, the nickel electrodes still face significant challenges due to its limited stability and low capacity. This study investigates the development and comparison of different nickel morphologies produced by electrodeposition techniques. Ni nanocrystalline coatings with different surface morphologies were successfully electrodeposited using direct (DC), pulsed (PC), and pulsed reverse (PRC) current techniques and their physical and electrochemical properties of were investigated. Notably, the electrodeposition method significantly impacted the morphology and electrochemical performance of the prepared Ni coatings. Among the obtained structures, the PRC-deposited coating displayed a unique nano-rod like morphology, exceptional uniformity, highest surface oxygen content (61.51%), and lowest surface roughness (5.12 nm). Furthermore, electrochemical measurements revealed that this structure possesses the lowest coating resistance (459.6 Ω.cm −1 ), minimal corrosion potential (5 mV vs SCE), enhanced oxidation/reduction peaks, the longest charge/discharge time, and highest discharge (26.2 mF.cm −2 ) areal capacity. These findings suggest that the Ni nanorod structure exhibits superior surface and electrochemical properties. This work offers valuable insights into how morphology and structure affect the electrochemical performance and capacity of nickel electrodes, advancing battery technologies.