Simple Physical Mixing of Graphitic Wood-Derived Carbon For High-Performance Ni(OH) ₂ Electrodes: A Sustainable Strategy Beyond Metal Additives

The replacement of expensive metal powders in Ni-(OH)₂-based cathodes is essential for reducing cost and environmental impact in aqueous Ni-Zn batteries. This work investigates graphitic wood-derived carbon (GWC) as a sustainable conductive additive to boost the performance of Ni-(OH)₂ pasted electrodes prepared by a simple physical mixing process. A number of graphitic wood-derived carbon qualities are explored as functional additives replacing expensive cobalt and nickel powder additives while maintaining the electrochemical performance of Ni-(OH)₂ electrodes in aqueous rechargeable Ni-Zn batteries. The GWC offers high electrical conductivity and a unique microsized particulate morphology. Optimizing the GWC content to 25 wt % yields a specific capacity of 284.2 mAh g^-1 at 0.2C, which is better than that of electrodes containing only Ni-(OH)₂, with Ni/Co powders, or commercial carbon black. Furthermore, the open-circuit voltage hysteresis and state of charge are studied to understand the charge/discharge process, suggesting that GWC is an effective alternative to expensive metal powders, providing a low-cost and sustainable strategy for improving Ni-(OH)₂-based electrodes through a straightforward manufacturing process.