Establishing links between process parameters and product performance in the manufacture of battery electrode materials for automotive applications.

This project fits EPSRC research areas of Energy Storage and Complex Fluids and Rheology.

Rechargeable Li-ion cells are used in a wide variety of applications. With the introduction of more electric vehicles onto the road, next generation batteries with greater demands in; power, energy and lifetime are required. In order to achieve these targets, a better understanding of the performance and materials relationships is required. This collaborative project between the School of Chemical Engineering at the University of Birmingham and WMG at the University of Warwick will investigate how the formulation and mixing of battery electrode inks, which are used in the manufacture of automotive batteries, affects their physical and chemical properties. This understanding is critical, since the nano- to microstructure of the inks affects their coating properties and performance of the battery, in terms of capacity and longevity.

The electrode inks are high solids fraction suspensions (>40% wt) containing multiple components. The mixing and blending of the components to form the final coatable slurry will be the focus of this project. Model electrode inks will be designed and formulated using combinations of low shear and high shear mixing devices and their physical microstructures evaluated. These measurements will be related to the hydrodynamics of the mixing processes enabling structure-process relationships to be developed.

The project will involve rheological measurements of the inks as well as microstructural characterisation using a range of analytical methods included microscopy and tomography. WMG, has a UK-leading research facility for the development, scale-up and characterisation of cells, housed within the Energy Innovation Centre (EIC). This includes a facility for the manufacture of A5 pouch cells, coatings and cells at pilot scale. The mixing process will be performed and analysed at WMG, using the state of the art electrode mixing capability for pouch cell manufacture. At the University of Birmingham a combination of optical flow measurements on model transparent fluids (Particle Image Velocimetry) as well as measurements on the actual inks during mixing using Birmingham's unique Positron Emission Particle Tracking (PEPT) technique, in collaboration with the School of Physics at the University of Birmingham, will investigate these processes in more detail.