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