Double-Network Aerogel-Based Composite Phase Change Material Inspired by Beaver Damming for All-Weather Thermal Management of Lithium Batteries.

Phase change materials (PCMs) have shown significant potential in enhancing the thermal regulation of lithium-ion (Li-ion) batteries. However, existing organic solid-liquid PCMs encounter several issues, including leakage, limited energy density, and an inability to fulfill the demands of comprehensive thermal management across various environmental conditions. This study takes inspiration from beavers, which construct dams to regulate the temperature of their habitats in different climates, and introduces a dual-network aerogel-based composite PCM (CPCM) designed for the all-weather thermal control of Li-ion batteries. The developed CPCM incorporates tetradecanol (TD) as the core phase change material, a poly(vinyl alcohol)/carboxylated cellulose nanocrystal (PVA/CNC-C) aerogel as the potting material, borax for cross-linking, and graphene nanoplatelets (GNPs) to facilitate photothermal conversion. This CPCM demonstrates a high energy density of 199.1 J/g and remarkable cyclic durability. Furthermore, it features excellent shape retention, superior mechanical strength, and an impressive photothermal conversion efficiency of 94.5%. In addition, the CPCM effectively regulates the thermal behavior of Li-ion batteries: at elevated temperatures, it ensures that the battery's maximum operating temperature remains below 55 °C, while at lower temperatures, it maintains the battery above 10 °C for 30-40 min. Moreover, it possesses the capability to preheat batteries, enhancing their functionality in cold environments. This research presents an innovative approach to designing materials that address the comprehensive thermal management needs of Li-ion batteries under varying climatic conditions.