Ultrafast microwave heated form-stable thermal package providing operating temperature for PEO all-solid-state batteries

All-solid-state batteries (ASSBs) have been regarded as satisfying future energy storage devices owing to the advantages of notably high energy density and outstanding safety. However, their attainable energy density, especially in poly(ethylene oxide) (PEO)-based ASSBs, is limited by low operating ambient temperature due to sluggish lithium-ion transport of solid electrolyte. Herein, a functional anti-leakage skeleton (alumina ceramic and boron nitride) with efficient graphene-modified phase change material (GPCM) and microwave thermal energy storage system is proposed for providing the operating temperature of ASSBs. The composite, prepared by alumina ceramic fiber, boron nitride, and GPCM, presenting excellent thermal properties such as great enhancement of thermal conductivity (64.6%) and low enthalpy loss (11.27%). The superior thermal effect is confirmed by experiments and simulations of microwave absorption. Through microwave irradiating the ASSBs wrapped with the composite, ASSBs can realize cold-starting in 1 min from room temperature in a fast, safe and low-power heating pathway. Significantly, the combination of multi-scale characteristics in graphene increases the thermal energy generated by the composite during microwave processing. Furthermore, the composite material (GPBC), used as portable auxiliary heating equipment, enables the ASSB to exhibit 92% capacity of those ASSBs placed in 55 °C ovens at 1C. This work provides a distinctive route to achieve efficient and extensive applications of ASSBs through external preheating.