Simultaneously enhanced light absorption and heat transfer capability of melamine foam stabilized phase change composites by carbon black and metal fins for photothermal conversion and storage

Phase change material (PCM) based photothermal conversion and storage systems have received intensive attention in solar thermal applications because of their superior energy storage density and cyclic stability. However, the weak light absorption ability and low thermal conductivity of the organic PCMs lead to low solar energy conversion efficiency. Herein, we propose a facile strategy to simultaneously enhance the light absorption and heat transfer capability of PCMs by integrating carbon black and metal fins. The results indicate that the maximum photothermal conversion efficiency of the carbon black-doped composite is enhanced by 32.9 %, and the maximum temperature difference of the fin-intensified composite is reduced by 64.5 % compared to the pristine composite. Furthermore, the maximum photothermal conversion efficiency of the composites with carbon block and fins is increased by 15.9 %, and the corresponding temperature difference is 43.4 % lower compared to the carbon black-doped composite, which can be ascribed to the widening of the solar absorption band by pi-pi structure and the formation of multiple thermal conduction channels by fins. The results offer new insights into developing low-cost and high-efficiency phase change composites for scalable solar thermal utilization.