Large-Scale Fabrication of Form-Stable Phase Change Nanotube Composite for Photothermal/Electrothermal Energy Conversion and Storage

Photothermal/electrothermal advanced functional form-stable phase change materials (FSPCMs) can efficiently make use of solar energy and electrical energy by using supporting materials to encapsulate phase change materials. Herein, a novel low-cost integrated supporting material, denoted PDVB-12/PPy NTs, is quickly constructed via wrapping the polypyrrole (PPy) on the mesoporous polydivinylbenzene nanotubes (PDVB-12 NTs) through a fast oxidative initiation method. PDVB-12/PPy NTs exhibits good loading capacity (72.9 wt %) for industrial paraffin wax (IPW) due to the large specific surface area, and the resulting FSPCM composite (IPW@PDVB-12/PPy) exhibits a large latent heat of fusion (145.7 J/g), high thermal stability, and excellent shape stability. In addition, PPy imparts the IPW@PDVB-12/PPy composite with high electrical conductivity (55.6 S m^-1) and high photoabsorption ability (whole visible light band). The energy stored in the IPW@PDVB-12/PPy composite could be triggered and released under relatively low voltages (2.5 V) with electrothermal energy conversion efficiency (89.6%) or solar radiation (100 mW cm^-2) with photothermal energy conversion efficiency (85.2%). This study provides a low-cost and fast method for large-scale fabrication of supporting materials, which can be a good candidate in energy storage applications.