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ENERGIX-Stort program energi

Surface treatment of Artificial Graphite for Anodes in Lithium-Ion Batteries

Alternative title: Overflatebehandling av syntetisk grafitt for anoder i litium-ion batterier

Awarded: NOK 8.0 mill.

Project Number:

309351

Project Period:

2020 - 2022

Funding received from:

Organisation:

Location:

Graphite is today the dominating anode material for lithium-ion batteries (LIB) and represents around 15% of the batteries weight. During charging, the Li-ion will insert in between the layers in the graphite. The more you charge the battery, the more Li-ions will be inserted into the graphite. This will in turn make it harder for new Li-ion insertion and therefore strongly limit how fast the battery can be charged without causing damage. In this project, SAGA, we want to utilise new surface treatment methods of graphite powder to improve the fast charge (and discharge) properties. If we succeed with the development, this will cause tomorrow?s batteries that use these modified materials to have much better fast charging capabilities, especially at low temperatures. For Vianode, it will be of huge benefit for further growth in this market if we are able to supply new graphite products with superior properties for battery cell producers. In addition to better fast charge performance, surface modification can be employed to also utilize alternative and more sustainable raw material sources than petroleum coke, such as bio-based or recycled feedstocks. The project will therefore be important to make future batteries even more sustainable. IFE and SINTEF industry are the central R&D partners in the project with leading knowledge and experience in material/surface characterization and battery cell testing. By utilizing a broad spectrum of advanced characterization equipment, we will be able to make a much better understanding of the relationship between surface properties and behavior and performance in real battery cells. The project was started in February 2020 and will continue until the end of 2022. The main goal is to develop a new surface treatment method and material that results in a doubling of charging rate in real LIB compared to the best LIB you can get on the market today. In the initial phase of the SAGA project, a different process has been employed to modify the graphite surface in the lab scale reactors. With the support of SINTEF, a fast and easy physical characterization method to monitor the surface modification and to check the uniformity of the samples were developed in the first two quarters, Q1 and Q2, of 2021. The quality of the surface modification from different processes are compared and the method was useful to select the process type and process flow. The advanced electrochemical characterization method was established with the support of IFE to find the Li diffusion rate and the resistance from each electrical element in the electrodes. The values obtained from the electrochemical characterization methods were correlated with the process conditions and the quality of the modification. In the last quarter of 2021, the optimized condition from the lab scale was checked in the pilot plant and got initial results. The reproducibility from lab scale to pilot scale is promising and optimizing the process conditions for continuous operation in pilot scale are in progress. Vianode also started the product qualification for products with surface modifications developed in the SAGA project and initiated the larger battery testing in the external testing facility.

Elkem is planning industrial scale production of artificial graphite for anodes in lithium-ion batteries in the coming years, to be able to supply the growing demand in Europe for lithium-ion batteries. Particularly the battery demand for electric vehicles will be high, which requires high performance material capable of fast charge without compromising lifetime, energy density and safety. EU has a strong focus on sustainability throughout the value chain, and securing raw materials in Europe with low carbon footprint is highly valued. The idea of this project is therefor to improve the fast charging capability and reduce the carbon footprint of artificial graphite. This will be accomplished by increasing the first generation product life of graphite and developing second generation products of recycled and bio based graphite materials. Charging of lithium-ion batteries, and in particular fast and low temperature charging of graphite is the most important ageing mechanism in lithium- ion batteries so will be the focus for extending the first generation product life. The technical approach will focus on advanced surface treatments and mixed potential composite surface designs to encourage fast ion transport through the solid electrolyte interface. Reuse of graphite from end of life lithium-ion cells with new surface treatment methods and replacement of virgin fossil based coating materials with bio materials will be the technical approach for second generation materials.

Funding scheme:

ENERGIX-Stort program energi