GrEnNaC: Investigation of Graphene-Enhanced Na-ion Cathodes

Purpose and goal:

This project has been part of the competence center program´s SME focus within the framework for Batteries Sweden (BASE). BASE is a competence center with a focus on forming a strong platform for battery development in Sweden. The aim of the project was to further develop the cathode material Prussian white, which only consists of sodium, iron, carbon and nitrogen, by incorporating graphene into Prussian white in order to increase the electrical conductivity and thereby reduce the need to include additives in the electrode and increase the battery life and effect.

Expected results and effects:

The results generated in the project have shown that graphene has great potential to improve the performance of a Prussian white-based sodium ion battery. The graphene material could be successfully incorporated into Prussian white, which could be confirmed by scanning electron microscopy. Electrochemical tests on half-cells based on cathode materials with graphene-containing Prussian white showed very positive results in the form of reduced internal resistance and increased ability to be discharged quickly, up to 8C.

Approach and implementation:

The project has been a collaboration between Altris and Graphmatech, two SMEs originating from Uppsala University. Both companies therefore possess deep knowledge in material development and analysis. Graphmatech has developed graphene grades that are optimized for integration into Altris´ manufacturing process of Prussian white.

The material´s properties were analyzed mainly with regard to structure, particle size distribution and conductivity, as well as how the material performed as a cathode in sodium ion batteries.