Hydrated Salt/Graphite/Polyelectrolyte Organic-Inorganic Hybrids for Efficient Thermochemical Storage

Area of Science:

• Materials Science
• Energy Storage
• Chemical Engineering

Background:

• Hydrated salt thermochemical energy storage (TES) offers high-density energy storage potential, particularly for seasonal applications.
• Current TES materials face limitations in thermal and mechanical stability during hydration/dehydration cycles, hindering large-scale use.

Purpose of the Study:

• To develop and characterize novel composite materials for improved hydrated salt thermochemical energy storage.
• To investigate the stabilizing and functional role of an organic polyelectrolyte in strontium bromide hexahydrate-based composites.

Main Methods:

• Composite materials were prepared using a wet impregnation method with strontium bromide hexahydrate (SBH) and expanded natural graphite (G).
• An organic polyelectrolyte, polydiallyldimethylammonium chloride (PDAC), was incorporated into the composite structure.
• Material morphology, water sorption/desorption properties, and mechanical resistance were analyzed using electron microscopy, X-ray diffraction, thermogravimetry, differential calorimetry, and climatic chamber testing.

Main Results:

• The addition of PDAC significantly improved the water sorption capabilities of the SBH/G composite.
• PDAC enhanced the mechanical resistance of the composite material during hydration/dehydration cycling.
• Electron microscopy and X-ray diffraction confirmed PDAC's influence on material morphology and stability.

Conclusions:

• The incorporation of polydiallyldimethylammonium chloride (PDAC) is an effective strategy to enhance the performance and durability of strontium bromide hexahydrate-based thermochemical energy storage materials.
• This approach offers a promising pathway for fabricating efficient and robust TES devices for various applications.