Availability of Suitable Raw Materials Determining the Prospect for Energy Storage Systems Based on Redox Flow Batteries

Abstract

Successful large-scale deployment and manufacturing of newly designed products depends on the availability of raw materials and therefore even fundamental research on electrochemical energy sources cannot ignore the need to secure enough construction and active mass materials. Increasing use of renewable energy sources (for example, wind and solar) require some means of energy storage to balance fundamentally periodic or irregular energy supply. This storage can be electrochemical. One of the most interesting types of electrochemical cells suitable for energy storage are the so-called redox flow batteries (RFB) that store energy in reservoirs. Unlike in conventional cells and batteries, where the amount of stored energy directly depends on the size or volume of the battery electrodes, in the flow cells the advantage is that their energy capacity can be adjusted by refilling the connected containers. The paper describes the basic principles, design and types of flow systems, as well as interesting modern developmental trends related, among other things, to the availability, supplies, mining and market prices of raw materials used in these storage devices. The present concept of RFB is based on utilisation of various oxidation forms of vanadium. However, since the world supplies of vanadium are limited and unsuitable to meet the whole theoretical demand for energy storage, other concepts, based on more common metals (zinc, lead) or organic redox systems, are being discussed.Successful large-scale deployment and manufacturing of newly designed products depends on the availability of raw materials and therefore even fundamental research on electrochemical energy sources cannot ignore the need to secure enough construction and active mass materials. Increasing use of renewable energy sources (for example, wind and solar) require some means of energy storage to balance fundamentally periodic or irregular energy supply. This storage can be electrochemical. One of the most interesting types of electrochemical cells suitable for energy storage are the so-called redox flow batteries (RFB) that store energy in reservoirs. Unlike in conventional cells and batteries, where the amount of stored energy directly depends on the size or volume of the battery electrodes, in the flow cells the advantage is that their energy capacity can be adjusted by refilling the connected containers. The paper describes the basic principles, design and types of flow systems, as well as interesting modern developmental trends related, among other things, to the availability, supplies, mining and market prices of raw materials used in these storage devices. The present concept of RFB is based on utilisation of various oxidation forms of vanadium. However, since the world supplies of vanadium are limited and unsuitable to meet the whole theoretical demand for energy storage, other concepts, based on more common metals (zinc, lead) or organic redox systems, are being discussed.