Electrothermal cellulose-silver nanowire-eicosane aerogels with integrated latent heat storage for thermal buffering in cold environments

Efficient thermal management in extremely cold environments requires materials that can combine excellent insulation, rapid controllable heating, and long-duration heat retention. However, conventional composite phase change materials generally suffer from low thermal conductivity, poor shape stability, and sluggish heating response. In this study, a lightweight multifunctional cellulose nanofibril-silver nanowire-n-eicosane composite aerogel was designed to integrate heat storage, enhanced heat conduction, and electrothermal heating within a single system. The three-dimensional cellulose scaffold reinforced with high-aspect-ratio silver nanowires forms continuous conductive pathways, effectively improving both thermal and electrical transport. This unique structure enables fast and uniform charging of the embedded phase change medium during Joule heating, achieving an encapsulation efficiency of 93.4 %, a latent heat of 217.6 J g −1 , and a 74.7 % increase in thermal conductivity compared to pure n-eicosane. The material rapidly heats to 40.0 °C within 80 s under a 9 V input and exhibits over 1200s of stable heat release, mitigating heat loss even under −5 °C ambient conditions. Numerical simulations confirm that the synergistic effect of conductive networks and latent heat buffering allows efficient thermal regulation. This work provides a practical materials strategy for low-energy building envelopes, personal heating devices, and cold-region thermal protection applications.