Energy Storage Electrode Manufacturing (ELEMENT)

This EPSRC First Grant project will concentrate on the use of so-called 'Electrophoretic Deposition (EPD)' to manufacture energy storage electrodes with spatially distributed properties; in order to further advance the performance of electrochemical power devices. The research is aimed at realising a full capacity utilisation while meeting all relevant power extractions. This will be achieved by developing new electrode designs, manufacture them at a meaningful scale, microstructural characterisation and energy storage measurement. Electrodes built in this way will have their energy storage functions met more rationally than conventional monolithic design. Whilst in-depth investigation of materials chemistry is beyond the scope of this manufacturing centred project, the research will perform exemplary experiments involving Nb2O5 and C, in Li-ion battery context. The improved electrodes will be designed, manufactured and validated in the UK's first full battery prototyping lines in a non-commercial environment at the WMG Energy Innovation Centre.

Specifically, this project directly challenges the existing manufacturing paradigm in which electrode designs are driven by outdated manufacturing considerations, such as the casting and calendaring of powder-based viscous slurry. The existing technologies, which are clearly scalable and robust, dominate today's electrode manufacturing for batteries and supercapacitors devices. But, the manufacturing approach greatly limit the 'usable' energy density (Wh/kg) and 'usable' capacity (Ah) at device cell level and creates an undesirable viscous circle. This is because calendaring powder-based electrodes for high fraction of active materials results in pore networks with high tortuosity, filled with undesirable quantity of inactive materials such as polymeric binders and electrical conductivity enhancer carbon black particles. In this context, the electrodes must then be thin for high rate. But, thin electrodes result in high fraction of inactive materials; which consequently lowers the maximum achievable 'usable' energy density and 'usable' capacity. A real-world need therefore persists to expand our knowledge about realising high density active material electrodes, whilst having low pore tortuosity and of adequate electrical conductivity, but is less affected by the demanding manufacturing requirements and engineering constraints.

The proposed EPD approach is sufficiently generic that it can be applied for any energy storage materials and their chemistries, and the developed tools, processes and methodologies are common across scale can be of direct relevance for systematic optimisation of any existing Li-ion batteries, beyond Li-ion chemistries (e.g., Na-ion, Mg-ion) and higher energy density electrochemical capacitors (based on metal oxides).

In short, this project will explore a new direction: the scientific challenges and technological opportunities enabled by the design of 'high density active material electrodes of spatially distributed properties' through modern approaches in electrochemical manufacturing. The project outcomes are expected to impact scientific understandings of how charged materials and electric field interact, and will create improved electrode designs for future energy storage.

This project has been designed with impact at the core. It is about future-proofing a more modern step-change approach in the design and manufacture of energy storage electrodes, specifically targeting improved energy storage. The project outcomes are expected to bring a series of impacts to the academic community and industry in general, especially targeting UK manufacturing sectors.

Research Team
This project will aid the PI's academic development as an independent researcher working in the field of energy storage. Specifically, this project will enable him to explore and innovate the technology of EPD for the production of energy storage electrodes. Through developing processes and manufacturing methodologies that are compatible with industry, the PI and one postdoctoral researcher will benefit from working on a leading project with opportunities aiding their career progression. This will accelerate their developments in shaping manufacturing research capability in the UK, and allow them to develop leadership capacity by interacting with relevant colleagues, especially those involved in energy storage manufacturing research.

Industry
Because this project focuses on manufacturing research at a meaningful scale, especially generating knowledge in the manufacturing science of EPD, it will lead the research team to establishing a knowledge platform for UK industry to exploit the developed tools, processes and methodologies. This means industry will have the relevant evidence to take the next steps forward into making viable high value added energy storage electrodes. Hence, this project is highly timely to high value manufacturing in the UK, especially driving forward the science and innovation in EPD technology for the competitive yet high economic prize energy storage market. Because this project aligns directly with 'Productive Nation' pillar of the EPSRC's Delivery Plan 2016/17-2019/20, it will contribute to enabling a strategic direction supporting the UK's long term aspiration for manufacturing industry that is built upon a 'make it local, make it bespoke' approach.

Economic
With market forecasts around $46 billion worldwide for Li-ion batteries from 2016-22 (Allied Market Research 2016) and $7 billion for supercapacitor from 2015-23 (Transparency Market Research 2016), this project can contribute to these economic opportunities by interacting with UK manufacturing companies (largely high technologies businesses) from the outset of this project. Since 2015/2016, the PI have developed active interactions with two key SMEs relevant to this project (DZP Technologies Ltd. and LVH Coatings Ltd.) through several Innovate UK technology development programmes. The Support Letters from these companies showed that this project would be relevant for them, and offer a clear platform for realising any potential economic benefits. The Support Letters from WMG, The UK Institute of Materials Finishing and WMG centre HVM Catapult have also indicated that this project overlaps strategically with some of their core research themes; especially relevant to their members in addressing key manufacturing challenges faced by the energy storage industry.