Bio-based membranes for energy storage

An environmentally friendly battery membrane made from cellulose could make redox flow cells more energy efficient

Spotted: While the transition to renewable energy is picking up pace all the time, there are still several technological challenges facing those looking to build a fully sustainable future. One of these is the need for a more efficient way to store energy. Many renewable sources, such as wind and solar power, are intermittent, and it is vital to find ways to store this energy when it is not needed. Redox flow batteries are among the most efficient energy storage technologies. Now, Swedish startup Cellfion is working to make redox flow batteries even more efficient with a unique, bio-based membrane.

Redox flow batteries are a type of electrochemical cell where dissolved chemicals are pumped through the system on separate sides of a membrane, leading to ion transfer and the flow of electric current through an external circuit. Cellfion has developed a novel ion-selective membrane derived from cellulose. The cellulose fibres are extracted from wood and fabricated into membrane sheets that are then used as components in energy storage and conversion devices.

The bio-based membranes have several advantages over traditional membranes, which are often made from chemical polymers such as perfluorosulfonic acid. Cellfion’s cellulose membranes are non-toxic and decomposable but retain the high ion selectivity and conductivity typical of traditional membranes. In addition, at the end of their life, they can be incinerated without releasing any toxins into the environment, unlike traditional membranes.

According to Liam Hardey, Cellfion CEO, “To the best of our knowledge and extensive research, we are the first company working towards the commercialisation of bio-based membranes with no toxic substances at all”. He adds this is vital because, “If the clean energy industry is to become sustainable, we need to ensure that the materials we are using are also truly sustainable.”

More efficient battery storage is a key part of the transition to renewable energy. This is why Springwise is seeing an increase in new, more sustainable battery technologies. Innovations in this space include a green battery made from abundant and locally-sourced components and batteries that dissolve in water.

Written By: Lisa Magloff