Organic batteries
Mechanism
These types of batteries, like conventional ones, base their operation on chemical oxidation-reduction reactions, the difference is that, unlike conventional metal-based systems, organic molecules derived from lignin are used for storage. Lignin can be found in all plants, such as trees or herbs; it is a renewable natural source and it’s extracted as a residual product in the production of pulp and paper in quantities of millions of tons, which guarantees that lignin is a raw material constantly available for large-scale energy storage systems.
The choice of an electrode material for a rechargeable battery, either for the cathode or the anode, is mainly based on the reversibility of the electrochemical (redox) reaction of the active material. For organic molecules, redox chemistry is based on changing the state of charge of the molecule.
Besides lignin-based batteries, different projects are being developed that allow the use of water, quinones and air as materials to produce batteries that are strong and contribute to a safe, efficient and sustainable electricity supply.
Capacities and lifecycle
Organic flow batteries have a lifespan of around 10 years, which is equivalent to 3000 charge and discharge cycles. They lose 1% of their duration every 1000 cycles, which differentiates them on a large scale with lithium-ion batteries, as these degrade on a large scale after about 1,000 cycles and cost 10 times more to manufacture. These are low-cost batteries, approximately $ 100 per kWh.
Applications
They can be used in intermediate storage of renewable energies, renovation of peak loads in industrial plants, charging infrastructure for electromobility and as an auxiliary method in medium voltage electrical networks.
Advantages
Among the advantages that can be mentioned for this type of batteries is that non-toxic or corrosive and have an exceptionally long service life. They also have the potential to significantly reduce production costs.These are usually stored in tanks which can be of any size compared to cells, so the total amount of energy that the system can store depends on how large the tanks are.
Disadvantages
After several cycles of loading and unloading, storage capacity is degraded, which requires periodic maintenance.