The effect of electrode designs and hydration conditions on the electrochemical performance of cement-based batteries

초록

This study proposes an innovative design of a cement-based battery (CBB) incorporating embedded metal plates to improve electrochemical performance, and also examines the effect of moisture content on battery behavior. Copper and zinc were used as the cathode and anode materials, respectively, in three electrode configurations: powder-type (POT), parallel-plate type (PPT), and meshed-plate type (MPT). The electrical conductivities of PPT (0.559 & times; 10(-6) S/m) and MPT (3.36 & times; 10(-6) S/m) were 2-3 times and 13 times higher than that of POT (0.258 & times; 10(-6) S/m), respectively, suggesting that plate-type electrodes are favorable for electron transport through the metal plate network. Under water-saturated conditions, the cement electrolyte exhibited an ionic conductivity of 2.98 & times; 10(-4) S/cm, demonstrating effective ion transport to stabilize redox reactions in the CBB. Electrochemical analyses showed that the MPT-CBB exhibited peak CV currents of +4.0/-2.0 mA, Coulombic efficiencies of 98-99%, voltage efficiencies of 44-47%, energy efficiencies of 43-46%, and an energy density of approximately 0.052 Wh/m(2) at 100 cycles, corresponding to 11-fold and 3-fold improvements over POT (similar to 0.006 Wh/m(2)) and PPT (similar to 0.030 Wh/m(2)), respectively. Long-term cycling tests demonstrated that the CE, VE, and EE remained stable for 500 cycles under water-saturated conditions. In contrast, parallel experiments conducted without water addition showed significantly reduced electrochemical performance, indicating that maintaining water saturation is essential for sustaining redox activity and ensuring long-term charge-discharge stability. These findings emphasize the importance of electrode configuration and moisture management in improving cement-based battery technology.

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