During the reporting period, the consortium focused on baseline characterization, computational modeling, and physical prototyping to validate the ColteraTREC cooling system.
Component Characterization
The team began by measuring the physical properties of the baseline electrolytes, including water activity, viscosity, density, vapor pressure, and heat capacity. To evaluate electrochemical performance, an experimental test bench was assembled for half-cell measurements using cyclic voltammetry and electrochemical impedance spectroscopy. Outcome: Experimental data was fed into machine learning models (Gaussian Process Regression and LASSO) to accurately predict electrolyte behavior without requiring computationally heavy simulations.
Modeling and Simulations
Extensive digital modeling was conducted to understand and optimize the system before building physical parts:
Fluid and Heat Dynamics: Computational Fluid Dynamics (CFD) models were built in OpenFOAM to simulate the flow and calculate the latent heat transfer of water vapor crossing the heat exchanger membranes. Molecular Level: Molecular Dynamics (MD) simulations were used to observe ion solvation structures and thermal transport properties at a microscopic level.
System Efficiency: A power system model was developed in OpenModelica to calculate cooling loads and the Coefficient of Performance (COP). Outcome: The simulations revealed that increasing the total electrolyte concentration and maximizing heat exchanger efficiency are the two most critical factors for improving overall system performance.
System Build and Testing
Moving from digital to physical, the team designed and 3D-printed prototypes of the heat exchangers. After resolving initial leakage problems by sealing the components with epoxy resin, a fully functioning hydraulic test bench was constructed. Outcome: The test bench successfully runs hot (45°C) and cold (18°C) liquids through the isolated channels to measure pressure and temperature changes, providing real-world data to validate the CFD simulations.
Sustainability
To ensure the technology is environmentally viable, the team established the framework for a prospective Life Cycle Assessment (pLCA). Outcome: The system boundaries and functional units were defined for two primary application cases: electric vehicle (EV) cooling and data center cooling. A Life Cycle Inventory is currently being built using a Bill of Materials approach.
Key Technical Breakthroughs The team achieved two major technical advancements that pushed the project beyond its initial targets
Breaking the Solubility Limit: The original system was limited by a 0.8M solubility cap for the electroactive species. By introducing new counter-ions, the team increased solubility to over 2M. This outcome dramatically improves energy density and reduces the volume of fluid required to run the system.
Solid-State Pouches: Alongside the liquid-flow system, the consortium invented "Temporal ColteraTREC Pouches". By embedding the active chemicals into ultra-thin gel polymer matrices (under 5mm thick), they created solid-state, non-recirculating cooling patches. This outcome allows for instant management of thermal overloads without the need for pumps, unlocking applications in space hardware, drones, and dense battery cells.
