A monolithically integrated thermo-adsorptive battery

Abstract

A rechargeable thermal battery based on advanced zeolite or metal-organic framework water adsorbents promises extremely high capacity for both cooling (>800 kJ/L) and heating (>1150 kJ/L) applications. In the thermal battery, interdigitated adsorption and evaporation sites create hot and cold battery terminals analogous to the positive and negative terminals in an electrical battery. This work presents the new thermal battery concept, with a particular focus on the design required to overcome mass transfer limitations inherent in low-pressure (<1 kPa) water-based refrigeration. The theoretical and experimental performance of a 'button cell' thermo-adsorptive battery prototype is presented, along with the development of supporting technologies that enable its high capacity (>240 kJ/L heating) operation. These include an ambidextrous wetting surface for combined evaporation/condensation heat transfer, pre-percolated carbon-lined microchannels for simultaneous vapor and heat transport enhancement within the adsorbent bed, and adsorbate modifications that allow for a wider range of operating temperatures. The purview of the new thermal battery technology potentially includes many mobile or off-grid climate control applications.