  Solid-state lithium-ion batteries (SSLIBs) are considered to be the new
generation of devices for energy storage due to better performance and safety.
Poly (ethylene oxide) (PEO) based material becomes one of the best candidate of
solid electrolytes, while its thermal conductivity is crucial to heat
dissipation inside batteries. In this work, we study the thermal conductivity
of PEO by molecular dynamics simulation. By enhancing the structure order,
thermal conductivity of aligned crystalline PEO is obtained as high as 60 W/m-K
at room temperature, which is two orders higher than the value (0.37 W/m-K) of
amorphous structure. Interestingly, thermal conductivity of ordered structure
shows a significant stepwise negative temperature dependence, which is
attributed to the temperature-induced morphology change. Our study offers
useful insights into the fundamental mechanisms that govern the thermal
conductivity of PEO but not hinder the ionic transport, which can be used for
the thermal management and further optimization of high-performance SSLIBs.
