Photothermally Powered Wearable Thermal Battery Through Segmental Polymer Motion-Driven, Solid-Solid Phase Change...

Area of Science:

• Materials Science
• Energy Storage
• Polymer Chemistry

Background:

• Thermal batteries require materials for efficient solar charging and high energy/power density.
• Existing materials often face trade-offs between energy density and power density.
• Need for stable, reusable materials for phase-change thermal storage.

Purpose of the Study:

• To develop a hybrid polymer composite for direct solar thermal charging.
• To achieve high energy and power density simultaneously in a thermal storage material.
• To create a wearable thermal storage solution for personalized comfort.

Main Methods:

• Single-pot cross-linking of polyethene glycol (PEG) with polystyrene co-allyl alcohol framework in the presence of graphene oxide (GO).
• Characterization using temperature-dependent diffraction and NMR spectroscopy.
• Fabrication of a wearable patch incorporating the GO-PTP composite.

Main Results:

• The resulting graphene oxide incorporated poly (ethylene glycol)-toluene diisocyanate-poly(styrene-co-allyl alcohol) (GO-PTP) composite shows a reversible phase transition (323-333 K) with 121 J/g enthalpy.
• GO incorporation enhanced thermal conductivity (2.5x) and enabled direct photo-thermal charging (97% efficiency).
• Achieved high energy density (50 Wh/kg) and power density (129 W/kg) with stable cycling (>300 cycles), exceeding DoE targets.

Conclusions:

• The GO-PTP composite overcomes the mutual exclusivity of high energy and power density for thermal storage.
• The material demonstrates potential for direct solar charging and stable, long-term performance.
• Wearable patches made from GO-PTP offer rapid solar charging for personalized thermal comfort.