Ä¢¹½Ö±²¥

BitKein is a consortium project coordinated by VTT to find large-scale solutions for regulating the electricity system and storing energy. 

Flow batteries are well suited as a solid, large-scale energy storage technology that can be integrated into the electricity grid and renewable energy sources. Flow batteries can be used to even out fluctuations in renewable energy production and thereby reduce fluctuations in energy prices. 

A subproject of the Ä¢¹½Ö±²¥ is developing a method for manufacturing carbon electrodes for flow batteries. The aim is to optimize the efficiency of flow batteries and replace graphite on electrodes by utilizing biomass and/or different side streams as a source of conductive carbon. The project will first screen the suitability of different biomasses for producing conductive carbon material. The second step is to search for the availability of suitable carbon raw materials in Central Finland. The aim is to create added value for biomass from Central Finland and to enhance the utilization of side streams. 

For the manufacture of electrodes, powder-bed 3D printing will be used as the primary technique. With 3D printing, the porosity and flow-through properties of the electrode, as well as mechanical properties, can be optimized. 3D printing is primarily used to manufacture carbon/polymer hybrid electrodes. With printing, conductive carbon material can be easily varied while seeking the optimal carbon-polymer ratio in terms of efficiency and durability. 

In a flow battery, the charge balance is maintained by protons. Therefore, they must be able to pass from one half of the battery to the other while the other ions remain on their own halves. The two halves of the battery are separated by a proton-selective membrane. The membranes, commonly used today, are not optimal in terms of efficiency, mechanical resistance, and cost-efficiency. Especially when developing new types of electrodes, proton transfer properties are emphasized. In this project, we are searching for a more effective and more durable replacement for the sulfonated perfluoropolymer membranes. The starting point is to utilize porous metal-organic coordination polymer materials as an active component in proton transfer membrane.