Thermoelectric performance of Li-based Heusler compounds: a multiscale computational review

Li-based Heusler compounds represent a promising class of thermoelectric materials due to their low atomic mass, chemical tunability, and potential for lattice thermal conductivity suppression through rattling effects. This review systematically examines four structural types-full-Heusler, half-Heusler, inverse-Heusler, and quaternary Heusler compounds-using a multiscale computational framework encompassing harmonic approximation, self-consistent phonon theory, and anharmonic corrections including bubble diagram contributions. We discuss the atomic structure, bonding characteristics, phonon dispersion, and electronic band structures of representative Li-based Heusler systems. Results show that strong acousto-optical separation, phonon band gaps, and high-frequency Li vibrations play crucial roles in reducing lattice thermal conductivity. Meanwhile, several compounds exhibit favorable electronic structures with multi-valley conduction bands and high Seebeck coefficients, yielding high power factors and competitive ZT values across a broad temperature range. The review concludes by outlining design principles and future research directions for optimizing thermoelectric performance in Li-based Heusler systems, emphasizing anharmonicity, electronic band convergence, defect engineering and entropy alloying design.