[MITEI Seed] Multisolvent osmotic flow batteries for low-cost grid-scale energy storage

Description

The proposed research will pioneer the development of a new multisolvent osmotic flow battery (MOFB) concept, where chemical potential gradients are used to store energy in fully miscible multisolvent mixtures. During charging reverse osmosis (RO) is used to store energy in concentrated solvent mixtures, with higher energy densities than redox flow batteries. Energy can then be released using pressure retarded osmosis (PRO) achieving power densities that are orders of magnitude higher than previously studied concentration gradient batteries. MOFBs have the potential to drastically reduce the cost of grid-scale energy storage by using widely available solvents and low-cost size-selective membranes in densely packed modules (like those used in desalination). By leveraging the large chemical potential gradients generated by mixing miscible solvents, MOFBs can provide high energy and power densities addressing the critical need for energy storage capacity, while overcoming key shortcomings of pumped storage hydropower (needs suitable geographical locations and is capital-intensive to build), lithium-ion batteries (relies on critical metals and undergoes degradation leading to capacity loss with use), and redox flow batteries (requires expensive redox active compounds, ion-exchange membranes, and electrodes).

The proposed research will build an open-source platform to quantify the performance envelope of MOFBs for the first time, optimizing process design and solvent selection. Chemical potential and multicomponent mass transfer models will be combined into a computational framework to quantify round-trip energy efficiency and power density of MOFBs across a wide range of solvent pairs and process configurations. System-scale optimization will then be performed using alongside a technoeconomic analysis to understand the impact of material and equipment cost on optimal process design and battery mixture selection. By developing energy-storage technologies that do not require large amounts of supply-constrained materials, such as lithium or redox-active metal-based compounds, MOFBs can improve grid resilience while minimizing geopolitical risks to supply chains. By developing and analyzing MOFBs for the first time, the proposed research represents a critical step in quantifying the potential of this new energy storage concept, increasing cheap grid-scale energy storage, and, ultimately, improving grid resilience and accelerating the clear energy transition.