Scottish researchers have helped energy storage company StorTera improve the efficiency of a graphite polysulfide single liquid flow battery for use in hot climates.
The team at University of Strathclyde said the project produced results which could reduce production costs by 50–70%. The technology has the potential to support critical infrastructure such as telecommunications towers, it said.
The work is part of early-stage testing and scale-up of innovative technologies and business models that will accelerate access to affordable, clean energy-based services to poor households and enterprises, especially in Africa. It is financially supported by the Faraday Institution.
The team said flow battery technologies operate well in widely varying temperatures, making them suitable for harsh climates. However, manufacturing is complex and the materials currently used are expensive, they said.
The Electrochemical Engineering group at Strathclyde, led by Dr Edward Brightman, worked closely with StorTera to synthesise and characterise novel electrolyte formulations, using cheaper and more sustainable solvents. They also investigated the influence of the graphite current collector and separator types on the cell performance.
They demonstrated a reduced catholyte cost of 50% and reduced production costs of 50–70%. This led to an overall reduction of over 20% in upfront costs of the system, to £70/kWh ($88/kWh), and a 20% increase in durability.
StorTera built a prototype system incorporating Strathclyde’s system improvements. The system tests demonstrated more than 99% round trip efficiency on charging and discharging in a 15W/20Wh configuration. Testing was during a heatwave in July 2022, which enabled tests at temperatures comparable to sub-Saharan Africa.
The aim is to build a 200kW/1.6MWh demonstrator by 2024, the university said.
Pasidu Pallawela, StorTera’s chief technology officer, said: “Using this kind of battery in developing countries, especially sub-Saharan Africa, is very feasible, and could be a cost-effective solution to integrate more renewable energy into the grid. These kinds of technologies will be required all around the world as we move towards net zero.”