A Chitosan-Based Gel Polymer Electrolyte for Improving Performance and Stability of Nickel-Zinc Batteries

A typical nickel zinc (Ni-Zn) battery uses a potassium hydroxide (KOH) alkaline electrolyte to operate. Primary disadvantages of a liquid electrolyte include high volatility and flammability, particularly in high energy density batteries. Gel polymer electrolytes offer a considerably safer alternative.

Chitosan-based gel polymer electrolyte have been gaining focus recently because the base material which is chitosan is obtained from a natural material, chitin. Chitin is obtained from crustaceans such as shrimp, crabs, and lobsters. Previous research has shown that chitosan is biocompatible and environmentally benign. Chitosan, when used as a gel polymer electrolyte enhances ionic conductivity and provides mechanical stability which is much needed for the efficiency of the battery. Additionally, studies have shown that use of chitosan as a gel polymer electrolyte has the potential to enhance ionic conductivity and battery performance, while providing mechanical stability and preventing extensive anode dendrite formation.

A gel polymer electrolyte will be prepared using a polymer binder. The viscosity of the gel and the surface tension will be examined to produce an optimal binder for enhancing the mobility of ions in the Ni-Zn battery. The gel polymer electrolyte (GPE) will be characterized using XRD and FTIR techniques. A Ni-Zn pouch battery will be fabricated using the chitosan-based GPE and its electrochemical performance tested using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The performance of the GPE will be compared with more traditional electrodes, such as KOH, and will also consider the changes experienced by the GPE and zinc anode during the testing period. Scanning electron microscopy will also be carried out to study the dendritic formation on the anode, which can affect its long-term stability.