Page 38 - Energize June 2022

VIEWS AND OPINION

Benefits of vanadium redox flow batteries for

energy storage

An interview with Mikhail Nikomarov, the CEO of Bushveld Energy, a division of Bushveld Minerals.

ll over the world, energy storage is a growing, successful business sector. It is
needed to smooth out the variances typical of renewable energy electricity
Ageneration and ensure a continuous supply of power. Storage can also be used to
reduce demand on the utility at peak times when tariffs are highest. Although a number of
different energy storage systems exist, chemical batteries are still the most popular. There
are various battery technologies available, such as Li-ion, flooded lead-acid, flow batteries,
and others.
Energize spoke recently to Mikhail Nikomarov, the CEO of Bushveld Energy, about the
technology and how this South African company helps to make these batteries available for
the world market.

Energize: Why does Bushveld Energy promote vanadium redox flow batteries?

Mikhail Nikomarov (MN): The vanadium redox flow battery (VRFB) is the simplest and most
widely deployed flow battery. It offers attractive benefits over alternative energy storage
configurations and battery chemistries for daily, long duration energy storage applications. Mikhail Nikomarov
We are promoting an electro-chemical battery technology with a flow process which uses a
liquid electrolyte, consisting of water, vanadium and sulphuric acid.
The second benefit of VRFBs is that
Energize: How do vanadium batteries differ from other flow batteries? the power (in kW) and the energy (in kWh)
are decoupled. In other words, there is
MN: The difference is the vanadium. Other flow batteries have different chemicals in the two no relation between the power rating of
tanks: that is, they will have one chemical in a cathodic tank and a different chemical in the the battery and the duration for which the
anodic tank. Iron, zinc, bromine are the typical chemicals used in those flow batteries. battery can delivery that power. With a
Vanadium flow batteries use vanadium in both tanks. The difference between them is lead-acid, Li-ion, or most other batteries,
that they are at different stages of oxidation. A useful characteristic of vanadium is that it is to gain power for a longer period, one
water-soluble and can exist in various stages of oxidation. has to increase both power capacity and
With VRFBs there is no cross-contamination, since there is only one battery element, energy capacity together. In a VRFB that is
which is unique among flow batteries. unnecessary.
It is important to know that vanadium flow batteries are the only ones which work The main advantage of a VRFB is its
consistently, both in the lab and in the field. Other types are far less successful in real-life long lifespan cycles, i.e., the ability to
applications. For this reason, VRFBs have been operating in the field for over 30 years in repeatedly charge and discharge more
hundreds of applications around the world. than 35 000 times for a lifespan of over
20 years. Other unique features of VRFBs
Energize: How do VRFBs compare with other battery technologies in large utility-scale is their ability to offer 100% depth of
applications? What are the key benefits of a VRFB? discharge without material performance
degradation and offer low cost/kWh, when
MN: Firstly, the liquid electrolyte process is reversible. This is a unique feature. In the case fully used at least once daily.
of a Li-ion battery, for example, every time an electron moves across, a path is made. As They are also very safe to use since
those paths grow, the battery loses some of its capacity – a little at first, but more and more there is no risk of fire or smoke arising
over time. In a flow battery with a liquid electrolyte, that doesn’t happen. It’s a completely from thermal runaway. VRFBs also offer
reversible chemical reaction. The only degradation you get is where some of the component a 30% lower carbon footprint than Li-ion
parts wear out. That means that you have a virtually unlimited lifetime for the battery and an batteries, since vanadium is re-usable
unlimited cycle life – at least for the chemical part of the battery. And it’s the chemical part on decommissioning of a system. They
that’s the important part because it’s the chemistry that determines the useful lifetime and are ideal for energy storage in grid
charge-discharge cycle life of any battery. applications.

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