Stationary power in developing countries currently relies on polluting diesel generators, or solar-powered micro-grids supported by Li-ion or Pb-acid batteries. Li-ion batteries require temperature control which adds significant parasitic load, while Pb-acid batteries have shorter lifetime and are liable to theft. Batteries deployed in developing countries must be low cost and rugged, allowing installation, repairs, reconditioning and remanufacture to be carried out in-country by non-experts with limited resources. Designing for remanufacture is an enabler for the circular economy and will improve cost and durability of systems.

We have been developing a low-cost, long duration lithium polysulfide flow battery suited to warm climates which has unique potential for recycling and to meet these challenges. Lithium-sulfur batteries have the potential to be a very low cost and high energy density storage solution. Using soluble polysulfides in a liquid catholyte helps mitigate problems of charge retention and cyclability with the advantages of a flow battery configuration suited to large scale stationary applications. In our current collaborative research project we are investigating the compositional changes that occur in used catholyte and anode structures, and developing processes to recondition these components in order to enable servicing and remanufacture to be carried out in-country by local engineers.

In this talk we will present an overview of flow battery research in the Electrochemical Engineering group at Strathclyde University. We will go in-depth in understanding the redox cycling and degradation mechanisms of this unique flow battery chemistry, applying both operando methods and a range of physical and chemical characterisation of used components to establish a state of health profile for polysulfide catholytes and improved lithium anode performance.