Artificial mitochondrion for fast latent heat storage: Experimental study and lattice Boltzmann simulation

The packed-bed latent heat storage technique has been widely applied in thermal energy management and harvesting, but its extensive deployment remains limited due to its slow charging rate. Here, inspired by mitochondrion, a bionic design of a PCM capsule is proposed for fast latent heat storage, whose performances are evaluated by both experiment and lattice Boltzmann simulation. The melting time is found to mainly depend on the harmonic mean distance between the centroid and every wall rather than the surface/volume ratio. The mitochondrion-shaped capsule has the fastest thermal storage rate with melting time prominently reduced by 48% compared with the spherical capsule due to its shortest harmonic mean distance. Meanwhile, this capsule has the lowest drag force among six different PCM capsules. In addition, artificial mitochondrion, obtained by mimicking both external shapes and internal membrane conformation of the mitochondrion, can further decrease the melting time by 53% compared with the spherical counterpart. The present study provides a new way to design high-performance PCM capsules and promotes the application of bionics in latent heat storage fields.