(632j) Towards Solid Calcium Ion Batteries: Solid and Gel Polymer Electrolytes for Effective Calcium Ion Conduction and Battery Separator Operation

Solid and gel polymer electrolytes are key components in next generation battery architectures that promise to make electrochemical energy storage safe, more powerful, and possess greater capacities. Concurrently, research trends show a shift to a post-lithium battery era, in which more abundant, safe, and ethically-conscious metals are employed, with examples being sodium-ion batteries and magnesium-ion batteries. Particularly, Calcium ion batteries are attractive owing to calcium’s high abundance, low cost, large annual production, and high-power potential. However, the study and development of effective solid and gel electrolytes for calcium-ion batteries remains at nascent levels, inhibiting the creation of solid calcium ion batteries. In this work, we synthesize and study both solid and gel polymer electrolytes for calcium-ion conduction. The electrolytes are created from crosslinked polyether-based systems, formed through visible light photocuring. The electrolytes are characterized using AC impedance spectroscopy, thermogravimetric analysis, dynamical mechanical analysis, and spectroscopy to reveal their favorable conduction, mechanical, and thermal properties. We attain excellent conductivities on order of 10^-4 and 10^-3 S/cm for solid and gel electrolytes, respectively. The electrolytes are stable at battery operation temperatures and mechanically stiff to ensure stable battery charge/discharge cycling. The performance of prototyped 2032 coin cell batteries will be presented and discussed. This work holds promise for creating clean and sustainable energy storage devices that meet global economic and energy demands.