High-Density Thermochemical Energy Storage Using CaCl2-Loaded Biocarbon Composites

Thermochemical energy storage (TES) offers 2-10 times higher energy density than conventional methods through efficient sorption-desorption reactions. This study addresses challenges faced by salt hydrates, such as deliquescence and mass transfer barriers, by impregnating affordable CaCl2 into bio-based porous biocarbon from wood biomass to be used for efficient TES. The salt-biocarbon composite was prepared via a vacuum impregnation method and characterized using scanning electron microscopy (SEM), BET surface area and simultaneous thermal analysis (STA). SEM and BET confirmed successful impregnation, reducing the biocarbon’s surface area from 450 m²/g to approximately 60 m²/g post-impregnation, without leakage or agglomeration of salt. STA demonstrated a storage capacity of up to 1.3 kJ/g. These findings highlight the potential of salt-impregnated biocarbon as a sustainable and effective TES composite.