ARFBs with mild pH-decoupling show promise for long-lasting and cost-effective energy storage Harvard researchers develop pH-decoupling technology to improve efficiency of energy storage solutions

New technologies for storing energy generated by solar panels and wind turbines could be crucial for reducing the carbon footprint of the energy sector. Both solar and wind power rely on specific weather conditions, and large-scale energy storage solutions can help store the energy produced during optimal conditions for later use.

One of the most promising energy storage solutions is the aqueous redox flow battery (ARFB), which uses chemical solutions to store energy. These batteries have several advantages, such as being safe, long-lasting, and cost-effective.

However, creating reliable ARFBs with long lifetimes can be challenging. This is because the battery's performance is heavily influenced by the balance between its two sides, which contain positively and negatively charged electrolytes. The competing water-splitting reactions inside the battery can decrease its efficiency and lifespan.

In an effort to address this issue, researchers at Harvard University have introduced a new strategy utilizing mild pH-decoupling aqueous flow batteries. This approach, published in Nature Energy, involves using mildly acidic and alkaline electrolytes to reduce crossover between chemical solutions and prevent efficiency losses.

The ARFB developed by the team consists of a negatively charged electrolyte with a pH of approximately 13 and a positively charged electrolyte with a pH of around 3. This design significantly decreases crossover between electrolytes, resulting in an open-circuit energy efficiency of over 1.7V and a long operation lifetime.

To maintain the battery's performance, the researchers implemented an acid-base regeneration system to periodically restore the electrolytes' initial pH values. This combined system demonstrated a capacity fade rate of less than 0.07% per day, round-trip energy efficiency of over 85%, and a Coulombic efficiency of approximately 99% during stable operation for more than a week.

By employing a mild pH-decoupling approach, the researchers hope to enhance the performance, lifetime, rate capability, and energy efficiency of ARFBs. This advancement has the potential to significantly impact the storage of renewable energy sources and improve grid-scale, remote power, and electric vehicle charging systems.

David Lamy
David Lamy Author
David Lamy owns the Bachelor in Atmospheric Science Degree. He is associated with Industry News USA from last 2 years. With proficiency in his work, David obtained a strong position at Industry News USA and heads the Science section. “Weather forecasting” is the field of his interest. He bags total 5 years of experience in this field. Apart from his routine work, David loves to explore his cooking skills. He has participated in various cookery shows.