Finless intestine-mimic devices for high power density and high energy density latent heat storage

Latent heat storage (LHS) technology provides an approach solution to addressing the mismatch between intermittent thermal energy supply and continuous demand but suffers from slow thermal charging/discharging processes, resulting in low power density. Various fin designs have been proposed to overcome this challenge, though at the cost of reduced energy density and increased system complexity. Here, inspired by the internal structure and function of the intestine, we propose a novel finless double-gradient LHS device integrated with MgO nanoparticles (NPs) to achieve high energy and power densities simultaneously. By synergistically reducing interfacial thermal resistance and increasing atomic density around the NPs, the addition of 4 wt% MgO NPs to the LiNO₃-KCl eutectic salt enhances its thermal conductivity and energy storage density by 35 % and 10.2 %, respectively. Moreover, the power density of the finless intestine-mimicking device is improved by remarkably 114.2 % compared to conventional LHS devices, driven by the improved thermal conductivity of the eutectic salt and enhanced vortex effects from structural optimization. This work offers a straightforward yet effective strategy for designing advanced LHS devices to achieve both high power and energy densities.