Preparation and Characterization of Geopolymer-Based Batteries with Electrochemical Impedance Spectroscopy (EIS) and Discharge Performance

Abstract

This paper presents a geopolymer-based battery that has good potential as a solid-state battery owing to fast ionic conduction at room temperature, reduced battery leakage, and a non-flammable nature. The geopolymer was synthesized by alkali activation (10 M KOH) of ground granulated blast furnace slag (GGBFS), and has a similar mechanical behavior to cement, in addition to rapid hardening and a high ionic conductivity. Some researchers have used cement as an electrolyte to produce a sufficient, sustainable electrical output, but the operation voltage and discharge life are low. The experimental results showed that the geopolymer-based battery had a better electrochemical performance than cement-based batteries. Relationships between the age and polymerization of the geopolymer and the power density and operating voltage it produced were noted. The minimum bulk resistance and electrical resisivty of the geopolymer were 1.9Ω and 65Ω⋅cm on day 1, respectively. The discharge voltage, current density, and power density of the battery was investigated using a geopolymer electrolyte, a copper plate cathode, and an aluminum plate anode. Under a constant current density of 0.13 mAcm−2, the operating voltage was maintained at 0.97 V and remained stable for 600 s. The maximum current density was 1173 μAcm−2 at 0.4 V, and the maximum power density was 507μWcm−2.