Application of Spatiotemporal Thermal Energy Storage Phase Change Materials in Batteries Thermal Management
Year: 2026
Type: article
Abstract: ABSTRACT Thermal management of lithium‐ion batteries is crucial for both performance and safety, yet existing solutions struggle to address heating and cooling demands simultaneously across a wide temperature range. Here, we design a eutectic phase change material based on sodium acetate trihydrate and urea (SAT‐Urea) that combines a suitable phase transition temperature (≈34.1°C), high phase change enthalpy (232.7 J g − 1 ), and a supercooling degree exceeding 64°C, enabling spatiotemporal thermal energy storage. Density functional theory and molecular dynamics simulations reveal that Na + ‐centered solvation cages formed by acetate, water, and urea, together with a highly dynamic, competitive hydrogen‐bond network, suppress nucleation and stabilize the deeply supercooled state down to −30°C. Further incorporation into a carboxymethyl cellulose matrix yields a shape‐stable composite (SAT‐Urea‐CMC) with good cycling stability. When applied to 18650 cells, SAT‐Urea‐CMC provides bidirectional thermal regulation: at 25°C, it reduces the cell surface temperature by up to 17.9°C during 3C discharge; at −12°C, pre‐triggered crystallization elevates the operating temperature, lowers internal resistance, and increases discharge capacity by more than 12.5%. This work demonstrates a lightweight, passive material platform for spatiotemporal battery thermal management in both hot and cold environments.
Source: Small
DOI: 10.1002/smll.73832
Language: English
Subfield: Automotive Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Award: G5819612423
OpenAlex ID: W7162019599