A salty solution
AquaBattery’s Dr Jiajun Cen wants to revolutionise the energy storage market.
Interview: Clare Thorp
The need for long-duration energy storage is often overlooked in the rush to move towards more renewable energy sources. Energy supply from sources such as solar and wind can be intermittent, and if the energy is not stored at the time of capture, it is lost. So what’s the answer?
Traditionally, batteries are the primary method of renewable energy storage, but battery technology has lagged behind advances in things such as wind and solar production. Batteries can store energy, but most conventional ones are toxic, expensive and unsafe. Which is where AquaBattery comes in. Our process sees a saltwater solution flow through a specialised membrane stack during charging, which produces acid and base under an electric field. The acid and base are then stored in separate tanks to keep energy. During discharging, these two solutions are recombined to form saltwater, and this process generates electricity.
The idea came to me and my colleagues after we attended Fujifilm’s innovation competition for desalination. There we did some brainstorming and figured out that you can use energy to purify water and get salt out of salty water – but you can also do the reverse and get energy out of salty water.
Fast forward to 2022 and we are commercialising the technology. There are several advantages to our battery. Firstly, it’s safe. It is also very affordable and it allows you to store energy using local resources. Once the power unit is onsite, water and salt can be bought locally. There’s no need to ship heavy toxic chemicals, meaning a much lower carbon footprint. By storing excess energy in the batteries and then supplying it back when demand is greater than supply, we can help make the whole system more efficient.
Imperial have been integral to the AquaBattery journey. First, my studies – which focused on the dynamics and physics of fluids going through a porous medium – gave me the expertise to understand very complicated fluid element problems. I also benefited from being part of the Grantham Institute, where I met many inspirational and entrepreneurialminded peers. The whole ecosystem has taught me how to present ideas and apply for funding, which is vital in transforming an idea into a reality.
Earlier this year we were awarded €2.5 million in grant funding from the highly competitive European Innovation Council’s Accelerator, and if we do well, they can co-finance investment rounds up to €15 million. The money will help us grow from the small-scale pilot stage to being a commercial product. Our aim is to have an official launch in 2025.
My long-term goal is to revolutionise the energy storage market. I don’t expect AquaBattery to do it alone – and I hope we don’t. It’s great if we end up having competition, because I want others to be invested in making the transition to renewable energy happen, too.
Dr Jiajun Cen (PhD Chemical Engineering 2020) is CEO of AquaBattery.