Optimising cement-based electrolytes: Ionic strength analysis and electrical performance in cement-based battery applications

Abstract

A fully developed and commercialised cement-based battery system has the potential to revolutionise building technology. This paper evaluates the performance of cement-based batteries and explores the effect of adding Supplementary Cementitious Materials (SCMs) like fly ash, silica fume and blast slag, and ion-conductive particles, with copper and aluminium as electrode combinations. Cement-based matrix as the electrolyte of the developed battery system, is characterised for its ionic strength and is correlated to the electrical performance of the system. The solid phase of the different electrolyte mixes is also characterised using FE-SEM and XRD. Electrical performance parameters like open circuit voltage, discharge performance under constant current rate, and capacity measurements of devised battery systems are reported in this paper. The combination of cement with silica fume at 5%, along with epsomite (SF5) resulted in a 250% (approx.) higher discharge life and capacity in comparison to the control system (CM45). The ionic strength of the pore solution also showed a strong positive correlation (R2 = 0.92) with the discharge life across all mixes, highlighting its critical role in the battery system’s performance. The SF5 mix also showed sufficient mechanical stability with a compressive strength of 19.3 and 29.4 MPa at 7-d and 28-day, respectively. © 2025 Informa UK Limited, trading as Taylor & Francis Group.