Concerns about climate change and urban pollution have prompted a shift from our current over-reliance on energy derived from oil, coal and gas. Technological advances have made it easier to extract energy from "renewable " sources - solar, wind, tidal - however a defining feature of such sources is their intermittent nature, so they can only be reliably exploited if there are ways to store that energy. Electricity cannot be stored, but electricity can be used to drive electrochemical reactions which store the electrical energy as chemical energy. This is the basis of a battery - achieving efficient energy storage, using electrochemical means, is therefore one of the most prominent technological challenges facing the UK and, indeed, all advanced economies.

Small scale devices based on lithium ion battery (LIB) technology have revolutionised power requirements for mobile devices over the last decade. In the current decade, a shift in energy storage methods for electric vehicles is underway with increasing interest (and sales) of LIB powered cars . The next challenge is to "scale up" the energy storage process to the scale of the electrical grid - can we develop large scale batteries which would enable us to store large amounts of electricity to power houses, schools and factories? The UK is blessed with ample (potential) wind, tidal and wave resources: although there are technical challenges involved in harnessing these resources, there is also a need to develop cheaper batteries which would not necessarily be based on LIB technology - because the batteries themselves would be stationary, so their mass and size becomes less important than their cost and lifetime.
This proposal seeks to develop the basis of an alternative battery technology called the redox flow battery which is designed for large-scale storage. The proposal does not seek to develop a battery which would be ready to deploy at the end of the project, further optimisation and engineering studies would be required to achieve such a goal. Rather we seek to develop the fundamental scientific principles which could lead to better performing (in terms of energy, cost and lifetime) redox flow batteries - based on two advances we propose: one which develops a "membrane-free" flow battery, the other develops novel types of materials to be used as the battery membranes.

Potential Impact:
Three main routes for the dissemination, and hence maximisation of the impact, of the work are envisaged. The first is the conventional scientific publication route: both the PI and co-I have excellent publication records for their respective career stages (see Track Record). The second involves dissemination via presentation of the research at suitable conferences, both national and international. Support for post-doc and academic attendance at national and international meetings, both more "general" and specialised RFB meetings, has been requested (see Justification of Resources). Attendance at such meetings is important both for the presentation of the findings of the project to a suitable audience, but also to permit informal networks to be maintained and developed. Finally, industrial engagement/uptake of the research outputs is extremely important. Again, both the participating academics possess a large network of industrial collaborators and currently have various industrially supported projects underway in their laboratories. Specific routes to industrial dissemination will be achieved by the active participation of two collaborators who will provide materials, technical support and strategic advice to the project (see Letters of Support).
Further details are provided in the Pathways to Impact section.