Supercapacitors are considered one of the newest innovations in the field of electrical energy storage. In hybrid electric vehicles, supercapacitors can be coupled with fuel cells or batteries to deliver high power needed during acceleration as well as to recover the available energy during regenerative braking.
The ElectroGraph project follows and will use an integrated technology driven approach in development of both electrode materials as well as the electrolyte solutions as required for optimizing the overall performance of supercapacitors. The combination of graphene and graphene-based material as electrode materials, and use of room temperature ionic liquids (RTILs) as electrolyte is the target of development. At the end of the project the performance of those materials is to be demonstrated in the functional model of supercapacitor.
Strategic Project Goals
- Position Europe as the scientific leader in synthesis, processing and application of graphene for industrial technology.
- Demonstrate to industry the enhanced performance and cost benefits of graphene.
- Contribute to creating an innovative European nanotechnology industry.
- Promote uptake of nanotechnology in existing sectors.
- Positioning Europe on supercapacitor/energy storage market.
Scientific and Technical Goals
- Production of graphene in volumes required and with properties adjusted for novel electronic components (electrodes/supercapacitors).
- To establish a feedback between material properties and design parameters.
- Optimizing overall performance of supercapacitors.
- To present a functional model of supercapacitor.
- Assessment of hazard and exposure associated with graphene materials as well as their life cycle impact.
- To identify the potential for value recovery from graphene electrodes.
- Bringing graphene from laboratory into the real application in a supercapacitor device.
- Incorporation of graphene into commercially available devices.
- Supercapacitor device that tops all market offerings.
- Supercapacitor device that opens up markets and applications currently outside reach.
- Integration in automotive components.
- Integration of materials and technologies into existing manufacturing automotive processes.
- Innovative components and systems for vehicle with autonomous power supply.
- Integration, miniaturization and cost reduction.
In order to realise a platform technology for the European market a functional model of the supercapacitor containing graphene-based electrodes will be developed. Work will be carried out in defined work packages as structured in tasks for research, development, exploitation, dissemination and management. The ElectroGraph project is divided into 12 work packages for ease of the management and to simplify measurement of the project outputs and deliverables. The scientific and technical work of the ElectroGraph project is divided into three main phases; the first is to synthesise a range of graphene materials and to engineer graphene via a multitude of post-treatment processing methods with an objective to develop material with specific and controllable properties. The second phase is to investigate graphene and graphene containing materials and systems with concern of the health and environmental aspects. The third and final phase focuses on the development of materials, components and devices for demonstration to industry and exploitation and is targeting the demonstration of the supercapacitor prototype device utilising graphene based electrodes. These three technical phases of the project are allocated between 10 work packages.
Work package 1is dealing with the design of the prototype device, with the specifications of the performance characteristics in comparison with and progressing beyond state-of-the-art. The modelling of the prototype device system for optimised performance will define all of the device components, with the special focus on electrodes and electrolyte.
Work packages 2 and 3are focused on synthesis and processing of graphene. In order to obtain graphene material of an appropriate quantity and quality for application in supercapacitors three different synthesis methods will be investigated and optimised. Following, in work package 3, graphene will be modified or functionalised within varying approaches in order to engineer and control the properties of final material.
Work package 4will be carried in parallel to work packages 2 and 3, and will target at detailed characterisation of materials produced within the project. The materials will be characterised from the point of view of graphene quality as well as its applicability in supercapacitors. The main objective of this work package is to determine whether graphene can be applied as electrode material, especially in comparison with other carbon materials.
One of the first graphene synthesis methods addressed in the ElectroGraph project is the direct growth of vertically oriented graphene sheets. Microwave plasma enhanced chemical vapour deposition is a well-known technique for the synthesis of carbon nanotubes and carbon nanowalls and is under development for producing vertically oriented graphene sheets. Furthermore, the synthesis of thin graphitic films on high surface Ni foam substrates has been demonstrated. This growth substrate offers a higher surface area compared with traditional planar foil substrates.
As the second class of production routes the exfoliation of graphite in liquid phase to give graphene-like materials is the subject of ElectroGraph project. For the synthesis of graphene oxide (GO) wet oxidation of graphite powder to GO flakes using several chemical routes are being investigated. Modified Hummer’s method (sulfuric acid and potassium manganate) was primarily investigated. Obtained materials are hydrophilic (easily dispersed in water) with high electrical resistivity, semitransparent and the size of flakes corresponds to size of graphite particles.
Electrochemical exfoliation is yet another graphene production methods belonging to the group of exfoliation processes. In this approach, electrochemical treatment in the presence of various electrolytes is employed in order to exfoliate graphene nanoplatelets from the graphitic electrodes. The as-prepared graphene nanoplatelets are available in the form of stable suspensions, ready to be isolated as multilayer graphene sheets. Furthermore, the process gives an advantage of simultaneous functionalization and surface modification of graphene sheets. The electrochemical exfoliation is carried out in parallel as two-electrode process, with the use of polyelectrolytes and bases and weak acids, as well as three-electrode process utilizing ionic liquids.
Additionally, several grades of commercial materials were included into investigations and will be used for the benchmarking purposes.
Regarding electrolytes, their main aspects involve performances characteristics and safety aspects. All preliminary characterizations performed within the framework of the ElectroGraph project have been addressed to the evaluation of chemical-physical properties of electrolytes, with main focus on electrochemical behaviour, thermal stability and safety aspects. In particular, the electrolyte should be characterized by a high ionic conductivity, high dielectri
Recycling is undertaken to reduce the environmental impact of products at the end of their useful life. For automobiles, there is an EC Directive (2000/53/EC) for end-of-life vehicles that specifically requires that there is 85% material recovery and a further 10% energy recovery by weight from all vehicles scrapped from 1st January 2015. The requirement applies to the vehicle as a whole and not to any particular sub-assembly or component.
Innovating for the future: technology and behaviour
- Promoting more sustainable development