Environment-friendly efficient thermal energy storage paradigm based on sugarcane-derived eco-ceramics phase change composites: From material to device

Latent heat thermal energy storage (LHTES) technology can well alleviate the imbalance between intermittent energy supply and demand. However, the low thermal conductivity and poor shape stability of phase change materials (PCMs) seriously limit their practical applications. Here, sugarcane-derived biomimetic SiC ceramics are proposed for fast and efficient thermal energy storage. After loading paraffin, the composite phase change materials (CPCMs) demonstrate a high thermal conductivity of 10.34 W/mK and a high energy density of 151.20 kJ/kg at a porosity of 85%, outperforming state-of-the-art ceramics-based CPCMs. This benefits from continuous SiC skeletons composed of tightly stacked grains, so that both boundary and contact thermal resistances are reduced even at a high porosity. No prominent decay of thermal conductivity and energy storage density after 500 charging-discharging cycles, as well as good leakage resistance, confirm the good cyclic stability of proposed CPCMs. High-performance CPCMs are further packed into a fixed-bed LHTES device and investigated both experimentally and numerically. The melting time of LHTES device is prominently reduced by 44.3% benefiting from synergy of high thermal conductivity and non-coaxial arrangement of packed CPCMs cells. This work opens a new route for rapid thermal energy storage based on sugarcane-derived biomimetic materials.