Carbon Nanotube Based Textiles for Energy Storage Applications

c19a37be-4ade-4454-8359-b29bfbcce7e5

Closed

EPSRC
EPSRC
EPSRC
EPSRC
EPSRC

£1,274,540

Sept. 30, 2013

March 31, 2017

Addressing energy storage system economics, technical performance, and design issues requires advanced materials research and development. Material selection will play an essential role in making storage technologies affordable, efficient, and reliable options for tackling the increasing demand for energy and its generation via renewables-based sources.

Current battery technology cannot compete with energy densities associated with existing sources such as petrol. In order to compete in the market with petrol-based vehicles, the energy density of batteries in electric vehicles (EVs) will have to greatly improve to enable long-range distance EVs widely affordable. Moreover, despite portable electronic devices becoming increasingly small and flexible, the energy management components tend to lag behind the other components when it comes to performance at small size and high flexibility. Another application area that requires innovative energy storage technologies is for military applications. Batteries integrated into textiles could turn military uniforms into "smart fabrics" providing uniforms with a single power source to ensure efficiency and effectiveness of military operations.

Thus, the research outlined in the proposal will be focused on advancing the science and technology for multifunctional carbon nanotube (CNT) textiles for energy storage applications. Particular focus will be placed on the optimization of the cathode structure of Lithium-air (Li-air) batteries and the development of all-textile flexible electrochemical double layer supercapacitor (SC). The novel two- and three-dimensional (2D and 3D) textiles developed during this project will be based on CNT fibers and yarns made by a wet-spinning process and a dry-spinning process respectively. Fibers will be plied, twisted and textured to form several geometries with a wide range of mechanical outcomes. Twisting fibers into yarns and then knitting or weaving the yarns into a fabric will facilitate the formation of well defined porous structures with versatile porosity and ultra-high specific surface area providing a highly conductive, low density scaffold for energy storage. The gained understanding and resulting improvements in device performance could facilitate diverse applications of CNTs: electronic textiles that store energy and fibres having unrivalled toughness. When coupled with an inexpensive process for CNT synthesis, a practical process for making continuous, high performance CNT fibres is likely to result in important new products for an aging fibre industry.

Before Li-air batteries can be realized as high-performance, commercially viable products there are still numerous scientific and technical challenges that must be overcome. Considerable difficulties are faced in preparing structures for the precipitation of lithium peroxide at the cathode in the discharge process. If the cathode air electrode is fully blocked, the O2 from the atmosphere cannot be reduced which will prevent battery operation. One milestone for this proposal is to develop and fabricate new nanostructured air cathodes consisting of hierarchical arrangement of CNT fibers in a textile form so as to optimize transport of all reactants to the active catalyst surfaces and provide appropriate space for solid lithium oxide products.

It is also anticipated that the project will substantially enhance the energy/power densities of SCs. Although SCs are already used in many fields, more lightweight, compact and mechanically flexible energy storage devices with greater energy densities are required for a significant number of applications from wearable energy that could be incorporated into garments to space applications.

Potential Impact:
As fuel prices continue to rise, electrification of transportation is increasingly important. This importance highlights the need for improved energy storage solutions with high performance in order to meet consumer and manufacturer demands. One answer is found in Li-air batteries and supercapacitors (SCs). It is expected that such new innovations will help overcome manufacturer and consumer concerns regarding reliability and seamless supply and further accelerate the adoption of storage based systems such as electric vehicles (EV). However, as IBM says (leader in the development of Lithium-air batteries): "You'll have to be patient if you want to get your hands on a long-range EV powered with lithium-air batteries. We won't see these being sold in a showroom this decade, but if the science and engineering hurdles are cleared, they could be on the streets between 2020 and 2030".

The main beneficiary of knowledge arising from energy storage research is anticipated to be society. Energy storage in the form of batteries is currently only used on a small scale for propulsion of EVs. For many, energy storage technology is associated with lead acid batteries and regarded as a mature science, and has been so since the start of the 20th Century with little major development since. Major societal benefits could result from the development of advanced energy storage devices which meet the power source criteria for larger populations of practical EVs. The shift from a petroleum fuel base for urban vehicles to electric power generated centrally from coal and/or nuclear fuel, and the higher efficiency of EVs in urban driving, offer potential for the displacement of petroleum resources and consequentially the decrease of urban air and noise pollution.

Dispersed energy storage in utility systems would defer or eliminate the need for the existing power supply infrastructure. In much the same way that mobile phones have obviated the need for developing countries to rely on a 1G infrastructure, energy storage as part of a distributed power network has the same potential. Modern industrial societies depend vitally on storage of very large amounts of energy, primarily in the form of fossil fuels. The multiplicity and complexity of energy dependent functions and services in this type of society open up broad opportunities and potential benefits from storage of energy in new forms.
The military will hugely benefit from the proposed research. Batteries integrated into textiles used in clothing (as part of the battery-less soldier concept) to materials integrated into vehicles would replace heavier conventional batteries improvine the efficiency and effectiveness of military operations.

The UK strives toward a knowledge-based economy. The success of this proposal will accomplish extremely important goals, extending the current state of knowledge in the area where the UK has the potential to be at the forefront. The topics proposed constitute one of the most exciting and promising challenges of the nanotechnology scene at the moment which is to provide dramatic increases in energy storage capacity. Success of this proposal would give the possibility for the creation of next-generation materials possessing defined features to tailor energy storage devices to suit the required industrial and societal applications. Therefore, if successful, this project would help position the UK as a leader in researchable battery manufacturing and SCs. Currently, the UK manufactures only a small percentage of all researchable batteries and SCs, with China and the US being at the forefront of the supply chain.

The research will strive towards producing 'proof-of-concept' demonstrators on new higher-risk concepts, as well as prototyping new technology concepts particularly as the project is closely aligned to the needs of my industrial collaborators.