Orderly hybrid aerogel-based hydrate salt for wide-temperature range thermal regulation and flame retardant of Li-ion battery

Abstract

Performance and safety of the Li-ion battery under extremely conditions need to be improved urgently due to the rapid expansion of electrical vehicle. Herein, ordered, porous and hybrid boron nitride/melamine formaldehyde/polyvinyl alcohol (BN/MF/PVA) aerogel was designed as skeleton for sodium acetate trihydrate (SAT) to fabricate hydrate salt composite. Benefiting from the structure design, the composite has large latent heat and superior shape-stability, thermal conductivity and mechanical performance. The outstanding comprehensive thermal properties integrating with phase change from -30 to 60℃ enable the composite to conduct thermal regulation efficiently in wide temperate range. Surprisingly, heat release from the composite warmed battery pack at -30℃ environment by 9.6℃ and improved discharge capacity by 25.6%. Furthermore, cooling from SAT thermochemical reaction combines with air isolation via MF thermal decomposition reduced heat release (14.7 kJg-1) and enhanced the tolerated temperature (511℃), thus to endure flame up to 30 seconds and extinguish it in 5 seconds with a few amount of coke. Owing to the competitive flame-retardant capacity and highly efficient wide-range thermal regulation, the aerogel based hydrate salt composite shows potential in the performance and safety enhancement of battery.