Electricity + Control

CMBlu Energy AG and MANN+HUMMEL GmbH have signed an agreement for the joint development and industrialisation of energy converters for organic redox flow batteries. The aim of the partnership is to develop the charging infrastructure and offer the energy sector a sustainable and cost-efficient storage technology that will support electric mobility and a successful energy transition.

CMBlu Organic Flow Battery Stack

The organic flow battery stack.

  • Organic energy storage from CMBlu is based on the plant-derived lignin – a mostly unused resource which is readily available in bulk as a (waste) by-product from the pulp and paper industry.

  • MANN+HUMMEL provides expertise in the area of filtration and skills from automotive series production.

From concept to production

The business idea for redox flow batteries with organic electrolytes derived from lignin (‘organic flow’) was conceived in 2011. Since 2014, CMBlu has carried out intensive research and development. The batteries essentially consist of two tanks of liquid electrolyte and an energy converter, which comprises a number of adjacent rows of cells and is therefore also referred to as a battery stack. The liquids are pumped through the battery stacks and the battery is charged or discharged as required.

The technology has now reached the prototype stage and the further development and industrialisation of the battery stack is being undertaken in terms of the cooperation agreement between CMBlu and MANN+HUMMEL. MANN+HUMMEL has created a spin-off named i2M GmbH (innovation-to-market), which is dedicated to the development and commercialisation of innovative technologies. In the next step the company will build a complete production line in a European plant. CMBlu will realise special pilot projects with reference customers over the next two years. The plan is to market the first commercial systems starting in 2021.

Benefits of organic flow batteries

Based on a principle similar to that of conventional redox flow batteries, CMBlu’s organic flow batteries store electrical energy in aqueous solutions of organic chemical compounds, which are pumped through the energy converter – the battery stack. The special feature of the flow batteries is that the capacity and electrical output can be scaled independently. The number of stacks defines the output of the batteries: a higher number multiplies the output. The capacity of the battery is limited only by the size of the tanks. This allows flexible customisation to suit different applications. For example, solar power can be stored for several hours then fed into the grid at night.

Applications in the grid

Organic flow batteries are suitable for numerous applications in the power grid, such as the intermediate storage of power from renewable energy generation, or in the balancing of demand peaks in industrial companies. An additional application area is in the charging infrastructure required for electric mobility. The batteries would enable a buffer storage to relieve power grids so they do not need to be upgraded for additional loads. They provide for fast charging of electric vehicles. Looking to the future, a decentralised charging network for electric vehicles will only be possible with a high performance and scalable energy storage system.

For more information contact Stefan von Westberg at CMBlu, email: stefan.von-westberg@cmblu.de, www.cmblu.com, or Patrick Löffel at MANN+HUMMEL, email: patrick.loeffel@mann-hummel.com,    www.mann-hummel.com