Thermal conductivity of intercalation, conversion, and alloying lithium-ion battery electrode materials as function of their state of charge

Upon insertion and extraction of lithium, materials important for electrochemical energy storage can undergo changes in thermal conductivity (${\Lambda}$) elastic modulus ($\it M$). These are attributed to evolution the intrinsic carrier lifetime interatomic bonding strength associated with structural transitions electrode varying degrees reversibility. Using situ time-domain thermoreflectance (TDTR) picosecond acoustics, we systemically study $\Lambda$ $\it M$ conversion, intercalation alloying during cycling. The V$_{2}$O$_{5}$ TiO$_{2}$ exhibit non-monotonic reversible ${\Lambda}$ switching up a factor 1.8 1.5 M$) as function lithium content. conversion Fe$_{2}$O$_{3}$ NiO irreversible decays upon first lithiation. Sb shows largest partially order magnitude between delithiated (18 W m$^{-1}$ K$^{-1}$) lithiated states (<1 K$^{-1}$). is degradation pulverization resulting from substantial volume findings provide new understandings mechanical property cycling importance battery design, also point pathways forming thermally switchable properties.