Thermal management of electronics from −40 °C to 150 °C enabled by hydrate salt composite with efficient thermal energy storage

Integration and miniaturization of electronic devices means efficient thermal management is urgently required. In this paper, thermally conductive but electrically insulated boron nitride (BN) is strung by polyacrylonitrile (PAN) fibers to form a flexible and porous BN@PAN film. Subsequently, solution impregnation combining cold pressing is used to fabricate sandwich-like structure SAT/BN@PAN (SBP) that alternately layered by hydrate salt sodium acetate trihydrate (SAT) and BN@PAN film. The flexible and electrically insulated SBP film possesses high leakage-proof temperature and latent heat. Meanwhile, the sandwich-like structure increases in-plane thermal conductivity by 20 times thus largely promotes anisotropic heat transfer. Consequently, the SBP film heats electronics by 10 °C at −40 °C via heat release from solidification maintaining its steady working cycles. More importantly, the SBP film can suppress overheating by 50 °C at 150 °C via melting and thermal chemical reaction indicating potential in thermal runaway prevention. The wide-range (-40 ∼ 150 °C) thermal management capability and simple fabrication technique of the sandwich-like SBP film provide application potential in advanced electronics devices.