DON’T YOU KNOW THIS BATTERIES YET? WHAT ARE REDOX FLOW BATTERIES (RFB)?

A flow battery  is a type of rechargeable battery in which electrolytes – electrically conductive fluids containing ions of one or more dissolved electroactive substances, e.g. vanadium – flow through an electrochemical cell that converts chemical energy directly into electrical energy (in a reduction-oxidation process, hence the term redox) through the separate sides of a protonic-exchange membrane (stack).

Liquid electrolytes are generally stored in tanks, and are pumped through the reactor cell(s) to the stack. Ion exchange within the cell, (as well as the flow of electrical current to an external circuit) occurs through the membrane, while both fluids circulate in their own, respective space.

The flow battery can be defined as a special type of rechargeable battery  in which the dissolution of electroactive fluids in the electrolyte and the reagents external storage allow the setting of electrical parameters. In addition, as the reagents are stored externally, it avoids self-discharge phenomena, which are present in first- or second-degree battery systems. 

There are various types of flow batteries including ‘redox’ (oxidation-reduction) batteries, in which all electroactive components are dissolved in the electrolyte. If one or more electroactive components are deposited in a solid layer, the system is instead called an hybrid flow battery (HFB). The main difference between those two types of batteries is that the energy of the RFB can be determined and it does not depend on the power of the battery, because the energy produced is proportional to the capacity of the tanks and the size of the reactor. 

The discharge time of the redox flow battery can vary, depending on the demand, from several minutes to many days, while a hybrid flow battery typically can last from a few minutes to a few hours.

FLOW BATTERIES: PROs AND CONs

The main advantage of RFB is that an almost unlimited capacity (even hundreds of MW) can be obtained by simply using tanks as large as desired and by putting them in parallel; moreover, RFBs can be left completely discharged for long spans without adverse effects and they can be recharged simply by replacing the electrolyte. Else, if there’s no other energy source available, they do not burn, and if the two electrolytes (fluids) get accidentally mixed they leave no permanent damage. 

The main “disadvantages” of the technology are a relatively low energy/volume ratio, and a more complex plant system compared to canonical accumulators.

SEE YOU AT

REDOX FLOW BATTERIES 2024, from October the 9th to the 11th, at the Rome Exhibition Centre, in conjunction with ZEROEMISSION MEDITERRANEAN and EOLICA MEDITERRANEAN, will be hosting  the leading specialists in the sector and all those operators interested in entering this promising industry. Our appointment is the first event in Italy and Southern Europe entirely dedicated to the RFB and all phases of its technological production chain: residential, commercial, industrial, utility scale, for self-consumption, long-duration storage for flexibility/balancing of the electrical system, etc. 

REDOX FLOW BATTERIES 2024 will be a great opportunity to meet and compare in an international environment, the reference event for Southern Europe and the whole Mediterranean basin: a unique opportunity for all companies and professionals in the sector to learn about this new electricity storage technology, to be informed and updated on the latest market trends, to implement business and networking. Thanks to their synergy, ZEROEMISSION MEDITERRANEAN, EOLICA MEDITERRANEAN and REDOX FLOW BATTERIES 2024 therefore represent a must-attend business event for all those that belong to the zero-emission electricity and energy storage industry.