Large Scale Energy Storage based on Lignin
In recent years, concerns resulting from environmental consequences of
exploiting fossil fuels asthe main energy sources have led to an
increasing demand of renewable energy systems e.g. solar and wind power
generation. The intermittent nature of renewable energy sources however
makes it difficult to fully integrate these energy sources into
electrical grids. A solution to this problem arelarge-scale energy
storage systems, which are vital for distributed power generation
development and grid stabilization. One of the most promising
technologies in this field are redox-flow batteries (RFBs), first
developed by NASA during the 1970’s. RFBs are electrochemical systems
that can repeatedly store and convert electrical energy to chemical
energy and vice versa when needed. Redox reactions are employed to store
energy in the form of a chemical potential in liquid electrolyte
solutions, which are pumped through electrochemical cells. To meet the
worldwide need for energy storage systems which exceeds the multi TWh
capacity, a resource in the multi-million-ton scale is needed. Lignin is
one of the few renewableraw materials that is already produced in such
quantities and at the same time the major share is burnt. It is composed
of aromatic ring moieties that form the core structure of most organic
electrolytes. The abundance of the material without any competing
application makes Lignin the ideal raw material source for organic
electrolytes in large scale redox-flow batteries.