German biaxially oriented PP (BOPP) film manufacturer Treofan (Raunheim; www.treofan.com) is developing a more thermally stable separator for lithium-ion battery cells. The work is being undertaken as part of the "HiT-Cell" (high-temperature cell) research project, which is being funded with nearly EUR 2m from the German Federal Ministry of Education and Research (BMBF) in the area of "Battery 2020 – battery materials for future electro-mobile and stationary applications". The project will run until the end of 2020.

Treofan said the newly developed separator will have significantly higher temperature stability compared to existing polyolefinic separators, making it particularly suited for use in lithium-ion battery cells used in electric mobility. The company explained that current conventional ceramic separator coatings are not always able to prevent the separators from collapsing under thermal stress. These coatings also lead to additional resistance in the cell. This resistance heats the cell, especially during rapid charging and discharging, leading to a reduction in service life.

The project is being led by Forschungszentrum Jülich (Jülich / Germany; www.fz-juelich.de). Working with Treofan are EAS Germany (project management and cell production), RWTH Aachen University (further development of electrode production) and Münster Electrochemical Energy Technology (MEET), which is developing active electrode materials.