Relentless research in materials sciences in recent years have focused on making solar energy storage more efficient, with photo-thermal batteries proving to be markedly promising technologies. Polymer-based systems for synthesizing these photo-thermal batteries have been found to be viable options for achieving high-energy density, better than the current electrochemical batteries. These storage units can store the solar or any other light-sourced energy in chemical bonds and release them as heat energy for various applications. However, achieving the required molecular packing in polymer structures is riddled with some challenges, putting these units at precise locations for high-energy density being the key one.
Processing Solvents and Thin Film Structure Boost Energy Density for Photo-Thermal Batteries
A recent work focusing on morphologically optimal structures for photo-thermal batteries has supposedly overcome this constraint.
A team of scientists at the University of Massachusetts Amherst, in collaboration with researchers at the Schrödinger, LLC, an U.S.-based scientific software and solutions company, have developed the required molecular packing with azobenzene units using unique processing solvents and a thin film-like polymer structure. This system could serve as the basis for developing potentially effective photo-thermal batteries, which will be used to heat residential spaces, food, or clothing with the help of solar energy.
The new system is able to achieve the high energy density—to the range of 510 Joules per gram—which can potential applications in no-grid areas.
The details of their work is discussed in a paper published online on December 19, 2017 in the journal Scientific Reports.
Controlled Polymerization Techniques to Achieve Required Molecular Packing
Materials chemists contended that the use of azobenzene-based materials for photo-thermal batteries (PTBs) calls for a controlled architecture of polymer materials used. Organic photo-thermal batteries function by light energy and are characterized by the release of energy by configurational isomerization. These do not release byproducts as well. However, in previous PTBs, carbon nanotubes (CNTs) acting as rigid scaffolds constrained the energy density due to the inefficient grafting of azobenzene units. So the chemists used azobenzene on polymer backbones, poly(methacrylate) (PMA), and tuned polymer-solvent interactions to achieve an energy density of 510 ± 115 J/g.