Towards improving the performance of the negative Zn electrode in Zn-Ion batteries

可再充电锌离子电池针对非便携式应用，例如电网规模的能量存储，并且提供优于目前用于这些应用的锂离子电池的几个优点，包括由于所采用的水性电解质而具有的安全性，同时依赖于廉价、无毒且在加拿大开采/生产的锌。Salient Energy的锌离子电池包括：（i）锌的负电极，其中发生锌的直接电镀和剥离;（ii）接近中性的硫酸锌水溶液电解质，配有隔膜;以及（iii）能够可逆地嵌入二价锌阳离子的电解质二氧化锰正电极。在成功解决了负极电镀/剥离过程中存在的优先（树枝状）Zn生长问题（这会导致电池短路）后，Salient Energy现在面临着锌负极的新挑战：寄生腐蚀反应（自腐蚀），这会限制循环寿命并产生氢气。首要的研究目标是确定在电池循环期间在负Zn电极处发生的寄生自腐蚀的原因。这将通过三个研究子目标来实现：（i）表征从放大电池中取出的负电极上的腐蚀损伤累积，（ii）确定锌金属在近中性硫酸锌水溶液电解质中的腐蚀机制，以及（iii）确定层压负电极组件固有的锌-黄铜对的电偶腐蚀敏感性。该项目将创造新的知识，这是需要新的科学为基础的腐蚀控制策略被确定和评估。该项目将为两年的任务赠款项目培训一名PDF。

Rechargeable 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. Salient Energy's Zn-ion batteries consist of: (i) negative Zn electrode where direct plating and stripping of Zn occurs; (ii) near-neutral aqueous Zn sulphate electrolyte, complete with a separator; and (iii) positive electrolytic MnO2 electrode capable of reversibly intercalating divalent Zn cations. Having successfully addressed problematic preferential (dendritic) Zn growth during plating/stripping at the negative electrode, which serves to short-circuit the battery, Salient Energy now faces a new challenge with the negative Zn electrode: parasitic corrosion reactions (self-corrosion) that limit cycle life and produce hydrogen gas. The overarching research objective is to determine the cause of the parasitic self-corrosion that occurs during cycling of the battery at the negative Zn electrode. This will be achieved through the three research sub-objectives: (i) characterize the corrosion damage accumulation on negative electrodes removed from scaled-up batteries, (ii) determine the corrosion mechanism of Zn metal in near-neutral aqueous Zn sulphate electrolytes, and (iii) determine the galvanic corrosion susceptibility of the Zn-brass couple that is intrinsic to the laminated negative electrode assembly. The project will create new knowledge that is required for novel science-based corrosion control strategies to be identified and evaluated. The project will train one PDF for the two year Missions Grant project.