Carbide slag modified into a thermochemical energy storage material via a dual-effect modification method

Abstract

In this study, a dual-effect modification method for carbide slag modification into a thermochemical energy storage material was proposed. Results showed that the optimally formulated energy storage material CSMn10 contained CaO, Mn₂O₃ and CaMnO₃ as the main components, which not only inhibited the sintering of calcium oxide grains in the cycling process but also enhanced the alkalinity of the material. These components also promoted the generation of oxygen vacancies, which were favorable for the carbonation reaction. After 20 cycles, the energy storage density of CSMn10 was 1508.23 kJ kg⁻¹, and its average solar absorptivity was as high as 72.99%, which was 7.19 times higher than that of the unmodified calcium carbide slag (CS), significantly enhancing the cycling stability and light-absorbing ability of the material.