Significant enhancement of thermal boundary conductance in graphite/Al interface by ion intercalation

Abstract The electrochemical intercalation of metal ions into layered materials is an innovative approach to actively and reversely regulate the thermal transport properties of layered materials. In this work, the molecular dynamics (MD) simulation and lattice dynamics calculation are performed to investigate the thermal boundary conductance (TBC) between metal aluminum (Al) and intercalated graphite with various lithium-ion (Li-ion) concentrations. Both the thermal relaxation simulation and the non-equilibrium MD simulation show that the TBC in the intercalated graphene/Al interface is significantly high as compared to that in pristine graphite/Al interface, by a factor of 5.5. Besides, the TBC presents a slightly increasing trend with increasing Li-ion concentration. This is because increasing the Li-ion concentration increases the out-of-plane phonon group velocity of the intercalated graphite, leading to a sharp increase of phonon irradiation heat flux. By calculating the phonon interfacial transmission coefficient that includes the inelastic scattering effects, it is found that the transmission from the intercalated graphite to Al significantly decreases with increasing Li-ion concentration. The competition between the increased phonon irradiation heat flux and the decreased phonon interfacial transmission coefficient results in the slight increase of the TBC at high Li-ion concentration. This study provides important guidance to develop novel electrode materials and structures for thermal management in Li-ion batteries.