New approaches for the manufacture of energy storage devices

Lead Research Organisation: University of Oxford
Department Name: Materials

Abstract

New ideas for manufacturing the electrodes used Li ion batteries, electrochemical supercapacitors and permeable fuel cell membranes will be investigated in order to produce improvements in one or more of energy density, power density, cycle life, safety and reduced cost. The research involves developing and exploring new ideas and equipment for layer-by-layer fabrication or 3D printing of the various parts of electrochemical energy storage devices, in which each part of the layered structure is optimised in terms of its local compositional, porosity, conductivity, etc so that it provides the maximum contribution possible for that location to the overall energy storage behaviour. Current manufacturing technology for supercapacitors and batteries uses slurry casting of the electrode materials to form a consistent and unvarying microstructure from place to place in the electrode. The scale-up of this process has produced the dramatic year on year cost-reductions seen in Li ion batteries, even though the underlying electrochemical Li-ion technology has changed little for 30 years. Thus, recognising the importance of manufacturing technology, not just electrochemistry, in electrochemical energy storage devices if there are to translate from the laboratory towards technological impact, the research will develop and apply manufacturing technologies that deliberately produce heterogeneous electrode and device structures according to rational design methodology. The objective is to develop scalable manufacturing approaches for structured electrode that will allow both existing and future electrode materials to operate closer to their full potential.

Aims and objectives
To explore manufacturing approaches to improved energy storage devices, principally by arranging the various materials used in these devices, such as the anode, cathode, electrical conductivity enhancer, binder, porosity, separator membrane, electrolyte and current collectors.
To characterise the arising structures in 2D and 3D by using a mixture of electron microscopy, X-ray tomography and various spectroscopic devices.

To characterise the energy storage performance of devices and to rationalise trends in energy storage capacity, power and cycle life in terms of the structure, using this information to design and realise progressively improved electrochemical performance.
To interact with those undertaking complementary ion mobility modelling studies and other characterisation investigation in order to establish a robust methodology for the rational design of electrochemical electrode and device structures.

Novelty of research methodology
Layer by layer processing will be used to adjust the electrode microstructure progressively during fabrication to improve ion mobility from place to place in the electrode, to reduce charge and discharge times for high power applications. New processing methodologies will be established, with the potential for patent protection.

Alignment to EPSRC strategies and research areas
The primary alignment areas are Manufacturing the Future and Energy, notably energy storage.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509711/1 30/09/2016 29/09/2021
1802032 Studentship EP/N509711/1 30/09/2016 30/03/2020 Lukas Fieber
 
Description Multi-material, multi-technology fabrication systems provide opportunities for unprecedented design freedom, increased manufacturing efficiency and additional in-line functionality. We demonstrate a novel, modular hybrid additive manufacturing (hybrid-AM) framework, comprised of up to 9 complementing, interchangeable functional modules (e.g. fabrication and characterization). The inherent flexibility of the hybrid-AM process provided an opportunity to address conventional manufacturing limitations including time-consuming, multi-step assembly and restrictions on geometric form factors. Functioning, free-form energy storage devices (supercapacitors, EDLC's) were manufactured in a single, multi-material operation. Furthermore, an integrated dielectric surface mapping technique has been demonstrated for the non-destructive, real-time reconstruction of the 3D dielectric permittivity distribution within functional devices (RF optics) throughout build. The finite volume method provided a form of in-line quality control. A bespoke, modular printing host (GUI) was developed to, among other things, control the hybrid-AM machine, interface with 3rd party scientific equipment, as well as log and analyse production/characterisation data in real-time.
Exploitation Route The exploration of more novel geometric form factors, optimisation of materials compositions for improved electrochemical performance and integration with functional demonstrators may be considered when taking forward the work done on 3D printing of supercapacitors.
Sectors Electronics,Energy,Manufacturing, including Industrial Biotechology