Researchers at the University of Cincinnati have developed an innovative redox-flow battery that could lead to more environmentally friendly energy. The battery, which does not have the usual expensive and comparatively inefficient membrane, could be a significant advance for green energy since they can store renewable energy not just when it is produced but also for when it is needed, a key breakthrough for optimizing the large-scale energy storage required by wind and solar farms.


There is much research into inexpensive and more efficient batteries. Although standard car batteries contain a mixture of sulfuric acid and water, and are quite cheap to make from easily available materials, they offer very low energy density, something not useful for storing large amounts of power. In addition, they have a low threshold for electrochemical stability, which can lead to them combusting. For instance, if the voltage of an aqueous battery is more than the stability window of 1.5 volts, the water can decompose or be split into hydrogen and oxygen, causing an explosion.


Large-scale electrical energy storage (EES) systems are crucial to efficiently use renewable energy sources such as solar and wind energy to reduce the mismatch between the generation and consumption of electrical energy. As energy generation and energy consumption are always mismatched, it is crucial to identify a device able to store that energy temporarily and release it when required.


As reported in Nature Communications [Gautam et al. Nat. Commun. (2023) DOI: 10.1038/s41467-023-40374-y], this study introduces a water-less battery able to generate almost 4 volts of power without the need for a membrane-separator. As co-author Jack McGrath said, “We’ve managed to eliminate the membrane in a battery, which is a huge component of upfront costs”. In addition, membranes cannot fully separate the positive and negative sides, which means there is always crossover.


Rechargeable batteries are important for building advanced EES systems because of their high efficiency and flexible installation, with redox-flow batteries seen as promising candidates. Here, a high-voltage lithium-based nonaqueous redox flow battery (LRFB) based on an all-organic biphasic system was demonstrated. LRFBs are seen as a viable alternative to standard aqueous redox flow batteries due to their higher operating voltage and theoretical energy density. Although there remains much technological improvement necessary before implementation, the hope is that in the future all houses will be powered by renewable energy that is stored in advanced batteries.

“We’ve managed to eliminate the membrane in a battery, which is a huge component of upfront costs”Jack McGrath