Electrolyte matrix materials for structural battery composites

Structural battery composites are a class of electrochemical energy storage materials that have the additional functionality of being able to carry a mechanical load. This allows them to be used as structural components in electrified transport applications, where their multifunctionality provides the potential for significant mass savings when they are used instead of conventional lithium-ion batteries. Structural battery composites are comprised of carbon fibre-based electrodes in a matrix material, which acts as the electrolyte. This matrix must have high stiffness, to transfer mechanical loads between the carbon fibres, and it must also have high lithium ion conductivity, to facilitate lithium ion transport between the electrodes. One of the major factors preventing the commercialisation of structural battery composites is the lack of a solvent-free matrix material that has these desired properties.
The aim of this project is to develop matrix materials with desirable properties for structural battery composite applications. Desirable properties include: high stiffness, high lithium ion conductivity and a solvent-free system. Part of the focus of this project will be on improving the stiffness and lithium ion conductivity properties of current state-of-the-art matrix materials, which are not solvent-free. This will be achieved by investigating the effect of material selection and battery cycling on the interface between the matrix and the carbon fibre anode. The other part of this project will focus on developing a solvent-free matrix material. This will involve the development of new assembly strategies and battery architectures that facilitate the use of solvent-free matrix materials with good stiffness and lithium ion conductivity.
Increasing the energy density of electrochemical energy storage devices is critical to accelerating the uptake of electrified transport and transitioning away from fossil-based fuels. Structural battery composites offer an enticing pathway to achieving this, however, a full structural battery cell has not yet been developed. The lack of both a suitable matrix material and a process for incorporating it into a full cell is one of the main reasons for this, and therefore the work carried out here will provide valuable steps towards the milestone of constructing a full cell. This research is also relevant to the Engineering and Physical Sciences Research Council since it fits in with the energy storage research area.

Impact Summary

This proposal has been developed from the ground up to guarantee the highest level of impact. The two principal routes towards impact are via the graduates that we train and by the embedding of the research that is undertaken into commercial activity. The impact will have a significant commercial value through addressing skills requirements and providing technical solutions for the automotive industry - a key sector for the UK economy.

The graduates that emerge from our CDT (at least 84 people) will be transformative in two distinct ways. The first is a technical route and the second is cultural.

In a technical role, their deep subject matter expertise across all of the key topics needed as the industry transitions to a more sustainable future. This expertise is made much more accessible and applicable by their broad understanding of the engineering and commercial context in which they work. They will have all of the right competencies to ensure that they can achieve a very significant contribution to technologies and processes within the sector from the start of their careers, an impact that will grow over time. Importantly, this CDT is producing graduates in a highly skilled sector of the economy, leading to jobs that are £50,000 more productive per employee than average (i.e. more GVA). These graduates are in demand, as there are a lack of highly skilled engineers to undertake specialist automotive propulsion research and fill the estimated 5,000 job vacancies in the UK due to these skills shortages. Ultimately, the CDT will create a highly specialised and productive talent pipeline for the UK economy.

The route to impact through cultural change is perhaps of even more significance in the long term. Our cohort will be highly diverse, an outcome driven by our wide catchment in terms of academic background, giving them a 'diversity edge'. The cultural change that is enabled by this powerful cohort will have a profound impact, facilitating a move away from 'business as usual'.

The research outputs of the CDT will have impact in two important fields - the products produced and processes used within the indsutry. The academic team leading and operating this CDT have a long track record of generating impact through the application of their research outputs to industrially relevant problems. This understanding is embodied in the design of our CDT and has already begun in the definition of the training programmes and research themes that will meet the future needs of our industry and international partners. Exchange of people is the surest way to achieve lasting and deep exchange of expertise and ideas. The students will undertake placements at the collaborating companies and will lead to employment of the graduates in partner companies.

The CDT is an integral part of the IAAPS initiative. The IAAPS Business Case highlights the need to develop and train suitably skilled and qualified engineers in order to achieve, over the first five years of IAAPS' operations, an additional £70 million research and innovation expenditure, creating an additional turnover of £800 million for the automotive sector, £221 million in GVA and 1,900 new highly productive jobs.

The CDT is designed to deliver transformational impact for our industrial partners and the automotive sector in general. The impact is wider than this, since the products and services that our partners produce have a fundamental part to play in the way we organise our lives in a modern society. The impact on the developing world is even more profound. The rush to mobility across the developing world, the increasing spending power of a growing global middle class, the move to more urban living and the increasingly urgent threat of climate change combine to make the impact of the work we do directly relevant to more people than ever before. This CDT can help change the world by effecting the change that needs to happen in our industry.