Abstract
Zn-ion batteries are targeted for non-portable applications, such as grid-scale energy storage, and provide several advantages over the Li-ion batteries currently used for these applications, including safety due to the aqueous electrolytes employed, while relying on Zn that is inexpensive, non-toxic and mined/produced within Canada. Zn-ion batteries consist of: (i) negative Zn electrode where direct plating and stripping of Zn occurs (Zn ↔ Zn2+ + 2e−); (ii) near-neutral ZnSO4 (aq) electrolyte, complete with a separator; and (iii) positive electrolytic MnO2 electrode capable of reversibly intercalating Zn2+ cations (Zn2+ + 2e− ↔ Zn). The research objective is to determine the cause of the parasitic corrosion (self-corrosion) that occurs at negative Zn metal electrode in rechargeable Zn-ion batteries, which limits cycle life and adversely produces H2 gas. Determining the corrosion mechanism is essential to develop methods to suppress corrosion to improve overall battery performance. Zinc corrosion in being investigated in terms of contributing factors, which include electrolyte type and concentration, pH, dissolved oxygen content and the possibility of cathodic activation. Mass loss measurements, including volumetric hydrogen gas evolution measurements, coupled with electrochemical polarization measurements under bulk immersion conditions are being used for this purpose. The poster presents and discusses the experimental results acquired to date.