ISCF Wave 1: Improved lifetime performance and safety of electrochemical energy stores through functionalization of passive materials and components

Lead Research Organisation: University of Southampton
Department Name: Faculty of Engineering & the Environment

Abstract

High-performance batteries had disruptive impact in the electronics sector, are pivotal in electrifying transport, and will play a crucial role in grid-scale storage solutions. In particular, Li-Ion and Na-Ion batteries are set to facilitate greater and more efficient use of renewable energy. Application demand for highest possible energy density and power, however, necessitates volatile chemistries and careful consideration of safety aspects as a number of high-profile battery accidents have made strikingly clear in recent years. The most catastrophic failure of Li-ion battery systems is a cascading thermal runaway. Thermal runaway can occur due to thermal, electrical, or mechanical abuse. It can result in the venting of toxic and highly flammable gases and the release of significant heat, potentially leading to explosions and severe damage to the battery, surrounding equipment and/or people.

This project will provide materials technologies to physically safeguard Li-Ion and Na-Ion batteries against thermal runaway and thermally accelerated degradation, superseding existing external safety measures. Rather than changing the active material on the positive side, we will replace conductivity additives, an otherwise passive component of the electrodes, with smart materials. Electrical resistivity of the smart additives will increase by orders of magnitude at or above temperatures where it would otherwise be unsafe to operate the battery. As a consequence, uncontrolled electrochemical reactions, the initial heat source in a thermal runaway event, will cease, making electrochemically initiated thermal runaway impossible.

The approach has several advantages:
(1) it provides a drop-in solution, applicable to all active material chemistries in Li-Ion and Na-Ion batteries;
(2) it is transferable to other battery technologies (e.g, Al-Ion);
(3) it safeguards against a full range of abuse scenarios triggering thermal runaway; and
(4) the protection mechanisms will be reversible with lifetime benefits of batteries under real-world situations.

Smart additives will be developed utilising rational materials design driven by close integration between simulations at the atomistic and micro-scale with a comprehensive synthesis and characterisation program including a full array of in operando advanced electrochemical/spectroscopic techniques and x-ray tomography, complemented by state-of-the-art ex situ materials characterisation. Relevant abuse protocols will be developed and utilised to test batteries comprising electrodes with the smart additives at the cell and pack level. Further, we will exploit secondary characteristics of the smart additives to realise and demonstrate high-fidelity, non-invasive diagnostics and battery management to add an active safety layer for superior longevity.

Alignment with ISCF objectives:
Bringing together a complete value chain including SMIs (REAPsystems, Denchi), tier 1+2 suppliers (Johnson Matthey, Faradion, Yuasa), and larger OEMs (QinetiQ, Lloyd's, Dstl) with leading academics from engineering and chemistry (objectives 3+4), this project will innovate to deliver safer battery technologies and associated IP for automotive and other applications, increasing the UKs attractiveness for inward investment (objective 5) from global automotive OEMs and suppliers. Leveraged with over £150k support from industry, the program will increase the UKs R&D capacity/capability in battery research and deliver a world-leading, multi-disciplinary research program (objective 1) that is perfectly aligned with the 'Faraday Challenge' objectives, a UK flagship investment to develop and manufacture batteries for the electrification of vehicles (objective 2).

Planned Impact

1) Impact will be achieved through physical and knowledge-based outputs:

Physical outputs of the programme:
- Smart battery electrode additives (ceramics and polymer composites) to arrest hot spots and thermal runaway
- Electrodes comprising these new smart additives with optimised morphology
- Safe and durable batteries and battery packs with high-fidelity battery management

Knowledge-based outputs of the programme:
- Examine operating batteries using x-ray tomography and associated multi-physics electrode models
- First Principles based phase diagrams and design maps of ceramic PTCR materials
- Optimised, high-fidelity battery management models
- Appropriate and validated thermal, electrical, and mechanical battery abuse testing protocols at cell and pack level

2) These outputs will have impact on:

Improvement in battery operational life and durability:
The new materials, modelling frameworks, and control strategies described above and produced within the project will lead to an improvement in battery operational life through divergence of current away from local hot-spots and non-invasive sensing of temperature rises and associated pre-emptive, high-fidelity BMS action. The associated reduction in whole-life costs will accelerate the uptake of these systems.

Improvement in battery safety:
The smart electrode additives developed in the programme provide a drop-in solution to make ANY active material chemistry resilient against thermal runaway, enabling exploitation of volatile chemistries with highest energy density and rate capability without compromising safety. Electrode conductivity additives could potentially be replaced weight/volume neutral or with a moderate increase of specific weight/volume at electrode level. The resulting redundancy of some external, standard safety measures, however, will reduce system size, complexity, and cost and, hence, increase energy density on the system level in terms of Wh/g and Wh/l. Likewise, the potential to classify Li-Ion and Na-Ion batteries as non-hazardous goods would reduce life-cycle costs (e.g., for certification, transport, and insurance) providing some leeway to exploit higher value materials.

3) Impact will be ensured by:

Academic dissemination routes:
- Research publications as described under "Academic beneficiaries"
- Regular contributions to the "UKES201x" conferences
- Publication of datasets and other digital output (including minting DOIs) and developed codes

Knowledge transfer between industry and academia:
The proposal enjoys strong industry support with in-kind support in excess of £150k. Our industrial collaborators, ranging from UK SMEs to multinationals, form a complete value chain. Knowledge transfer will be facilitated by
- Annual industrial steering group meetings
- Combination of one of the steering group meetings with a dedicated workshop
- Opportunities for targeted placements of staff with industry
- Development of a strong IP position with support from the Universities Research and Innovation Service

Engagement with regulatory bodies:
- Steering group representation of regulatory bodies
- Publication of abuse testing protocols and associated data

Engagement with the interested public (outreach):
- Contributions to the 'Bring Research to Life' Roadshow
- Curation of battery reliability and safety knowledge on Wikipedia
 
Description A key objective of the award is the development of functional materials that show high electronic conductivity at "normal" operating temperatures of batteries, but become insulating if safe operating temperatures are exceeded. We have developed a novel modification of a known PTCR material that has a room temperature conductivity on par with many carbons (the state-of-the-art conductivity additive in Li-Ion batteries) and shows an electronic phase transition close to 80 degC with electronic conductivity droping two orders of magnitude.
Exploitation Route The novel PTCR material shows unusually high room temperture conductivity whilst retaining a substantial PTCR effect. This could lead to novel "smart" sensors in applications other than batteries. As the novel material is derived from industrially used PTCR materials, we expect that adoption in other industries could be relatively swift.
Sectors Electronics

Energy

 
Description Ada Lovelace Fellowship
Amount £50,000 (GBP)
Organisation Science and Technologies Facilities Council (STFC) 
Sector Public
Country United Kingdom
Start 03/2021 
End 02/2022
 
Title Dataset supporting the publication of "Solvothermal synthesis of nanoscale BaTiO3 in benzyl alcohol-water mixtures and effects of manganese oxide coating to enhance the PTCR effect". 
Description Dataset supporting the article "Solvothermal synthesis of nanoscale BaTiO3 in benzyl alcohol-water mixtures and effects of manganese oxide coating to enhance the PTCR effect" by Min Zhang, Thomas Caldwell, Andrew L. Hector, Nuria Garcia-Araez and Joseph Falvey, published in in Dalton Transactions Original data was used to produce the figures that are provided in Microsoft Excel format, with column titles explaining their content. 
Type Of Material Database/Collection of data 
Year Produced 2022 
Provided To Others? Yes  
URL https://eprints.soton.ac.uk/id/eprint/472509
 
Description Collaboration with Faraday Institution to Develop 'Living Review' (2019 - Still Active) 
Organisation The Faraday Institution
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Part of the Research Team has engaged with the Faraday Institution Multi-Scale Modelling Project and joined them on a workshop to produce an online review (constantly revising) on all aspects of battery modelling. Our team has contributed aspects of image-based modelling to the effort.
Collaborator Contribution Participating team members had opportunity to network with the FI researchers and received input for scientific dissemination.
Impact An online review of battery modelling
Start Year 2019
 
Description Working with the ISIS Materials Chemistry Lab on XRF and variable temperature conductivity and impedance measurements 
Organisation Science and Technologies Facilities Council (STFC)
Department ISIS Neutron and Muon Source
Country United Kingdom 
Sector Academic/University 
PI Contribution We provide materials and technical expertise to characterise PTCR materials using ISIS facilties and capabilities.
Collaborator Contribution ISIS provides access to facilities to combine XRF with variable temperature conductivity and impedance measurements. The collaboration also benefits from their expertise to characterise complex materials.
Impact not yet published
Start Year 2018
 
Title Large-scale Tortuosity Calculator 
Description This software computes properties of composite electrodes using large-scale x-ray tomography data. It uses high-performance parallel solvers to scale to millions of voxels in a dataset. The HPC-based parallel design allows to operate on extremely large datasets (40GB and larger) in a timely fashion. This code allows to process tomographies with an order of magnitude improvement in computation speed (minutes rather than days) over alternative existing codes. 
Type Of Technology Software 
Year Produced 2019 
Impact The principle researcher developing this software (James Le Houx) has been invited onto the Scientific Steering Commitee of the IBFEM (Image-Based FE Modelling) series of conferences. Conference URL: https://ibfem.co.uk 
URL https://gitlab.com/JLeHoux/image-based-battery-modelling
 
Description Battery Recycling - Festival of Doctoral Research 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Held at the Doctoral Research Showcase, this activity gave PGRs and members of University Staff the chance to try their hand at shredding an AA alkaline battery. They also got to join in on the rest of the battery recycling process to recover valuable materials for reuse.
Year(s) Of Engagement Activity 2018
URL https://www.southampton.ac.uk/doctoral-college/research-community/main-festival-page.page
 
Description Power Playground 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact This is an event from Manchester Science Festival 2018 where PhD researchers supported by this grant participated
Year(s) Of Engagement Activity 2018
URL https://www.manchestersciencefestival.com/event/power-playground
 
Description Southampton Engineering Outreach 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Through the programs briefing days for teachers and careers advisers, demonstrations and talks in schools and colleges and public events, we are bringing our enthusiasm for engineering sciences to the wider community.
Year(s) Of Engagement Activity 2019
URL https://www.southampton.ac.uk/engineering/outreach/index.page