Article ID: 24-00118
Rechargeable Zinc battery (RZB) is one of most promising candidates for large-scale energy storage facilities because of their advantages such as high energy, availability of safe aqueous electrolytes, and abundant zinc resources. Additives in aqueous electrolyte solutions are known to improve the charge-discharge cycle performance of RZBs, but further investigation of additives applicable to concentrated alkaline solutions is needed. In this study, starch, which is an environmentally friendly, safe and inexpensive polymer, was used as an additive. Raman spectra showed that starch was highly stable in alkaline solutions. The viscosity of the (4 mol dm−3 (= M) KOH + 0.3 M ZnO) electrolyte solution increased by 9.1-fold as 0.1 g mL−1 starch was added. Cyclic voltammograms showed that the addition of starch significantly improved the reversibility of the Zn deposition/dissolution wave. A Zn/Zn symmetric cell with the (4 M KOH + 0.3 M ZnO) solution including 0.1 g mL−1 starch exhibited sustained charge and discharge capabilities without short circuit for over 90 h due to the inhibition of dendrite growth. In-situ Raman spectra exhibited that the starch additive was adsorbed on the Ag electrode to inhibit the adsorption of zincate, and reduced the activity of free water during the Zn deposition.
