Development and manufacture of printable next-generation gel polymer ionic liquid electrolyte for Zn/MnO2 batteries

While much energy storage research focuses on the performance of individual components, such as the electrolyte or a single electrode, few investigate the electrochemical system as a whole. This research reports on the design, composition, and performance of a Zn/MnO2 battery as affected by the manufacturing method and next-generation gel polymer electrolyte composed of the ionic liquid [BMIM][Otf], ZnOtf salt, and PVDF-HFP polymer binder. Materials and manufacturing tests are discussed with a focus on water concentration, surface features as produced by printing processes, and the effect of including a gel polymer phase. Cells produced for this research generated open circuit voltages from 1.0 to 1.3 V. A dry [BMIM][Otf] electrolyte was found to have 87.3 ppm of H2O, while an electrolyte produced in ambient conditions contained 12400 ppm of H2O. Cells produced in a dry, Ar environment had an average discharge capacity of 0.0137 mAh/cm, while one produced in an ambient environment exhibited a discharge capacity at 0.05 mAh/cm. Surface features varied significantly by printing method, where a doctor blade produced the most consistent features. The preliminary results herein suggest that water, surface roughness, and the gel polymer play important roles in affecting the performance of printed energy storage.