Enhanced Thermochemical Heat Capacity of Liquids: Molecular to Macroscale Modeling

Abstract

ABSTRACT Thermal fluids have many applications in the storage and transfer of thermal energy, playing a key role in heating, cooling, refrigeration, and power generation. However, the specific heat capacity of conventional thermal fluids, which is directly linked to energy density, has remained relatively low. To tackle this challenge, we explore a thermochemical energy storage mechanism that can greatly enhance the heat capacity of base fluids (by up to threefold based on simulation) by creating a solution with reactive species that can absorb and release additional thermal energy. Based on the classical theory of equilibrium thermodynamics, we developed a macroscale theoretical model that connects fundamental properties of the underlying reaction to the thermophysical properties of the liquids. This framework allows us to employ state-of-the-art molecular scale computational tools such as density functional theory calculations to identify and refine the most suitable molecular systems for subsequent experimental studies. Our approach opens up a new avenue for developing next-generation heat transfer fluids that may break traditional barriers to achieve high specific heat and energy storage capacity.