Graphene-enhanced binder-free cathode formulation for next generation lithium ion batteries (GraFREE)

Purpose and goal:

The aim has been to develop a binder-free electrode for more sustainable lithium-ion battery applications by combining Aros® graphene, lithium iron phosphate (LFP) and binders. Expected results and effects:

A free-standing film containing functionalized graphene (Aros® graphene),LFP, cross-linker and plasticizer has been developed. Thus, both the fluoropolymer (PVDF) and the toxic organic solvent (NMP) were eliminated from the traditional slurry-based electrode manufacturing process. However, further optimization of the mechanical and electrochemical properties of the film is needed.

Approach and implementation:

In this project several possible ways forward were literature researched and assessed; Of these 4 different “best” candidates were chosen to be tested in the project as binder-free, waterborne, graphene-enhanced cathode formulation. We used a common cathode active material, LFP as the model system. After some tweaking and formulation screening, it was found that it is possible to use graphene as a binder for LFP cathodes.

Also, in some cases, we were able to achieve the “binding effect” using lower than 3% of graphene loads and casting films from waterborne dispersions.