"THE METAL OF THE FUTURE"

“All the great ways we have to generate electricity – solar, wind, geothermal – they’re nothing without an efficient way to store it…This is the biggest, most significant thing we’re facing this century.”
-Ian Clifford, CEO of Zenn Motor Co.

VANADIUM REDOX BATTERIES

The Vanadium-Redox Flow Battery (VRB), invented at the University of New South Wales in Australia, is structurally and chemically different from any other battery in ways that could help overcome current shortcomings in battery technologies. VRBs are nontoxic, have an indefinite lifespan, and do not self-discharge while idle or generate high amounts of heat while charging.

Vanadium is stored in two separate containers in liquid form - one is charged with energy and one has a depleted energy charge. When new energy is gathered, non-charged Vanadium gets re-energized and stored until needed.

The main advantage is It can absorb and release huge amounts of electricity instantly and do so over and over again, making it the only battery technology today capable of connecting directly to power grids and stream lining the intermittent flow of energy from wind turbines and solar cells while being fully scalable to meet almost any capacity.

Vanadium has also proven to be an effective additive to existing batteries in small scale applications. For instance, in the case of electric cars, vanadium, when combined with lithium, acts as a ‘supercharger’ that increases the battery’s energy density — and in the case of vehicles, this equates to the distance a car can travel.

The future will be battery powered. The best battery will win. Vanadium makes the best batteries.

INTERVIEW WITH MariA Skyllas-Kazacos ON VRBs

The vanadium redox (and redox flow) battery is a type of rechargeable flow battery that employs vanadium redox couples in both half-cells, thereby eliminating the problem of cross contamination by diffusion of ions across the membrane. The present form (with sulfuric acid electrolytes) was patented by the University of New South Wales in Australia in 1986.  The first successful demonstration and commercial development was by Maria Skyllas-Kazacos and co-workers at the University of New South Wales in the 1980s. The vanadium redox battery exploits the ability of vanadium to exist in solution in four different oxidation states, and uses this property to make a battery that has just one electroactive element instead of two.

The main advantages of the Vanadium redox battery are that it can offer almost unlimited capacity simply by using larger and larger storage tanks, it can be left completely discharged for long periods with no ill effects, it can be recharged simply by replacing the electrolyte if no power source is available to charge it, and if the electrolytes are accidentally mixed the battery suffers no permanent damage.

A vanadium redox battery consists of an assembly of power cells in which the two electrolytes are separated by a proton exchange membrane. Both electrolytes are vanadium based, the electrolyte in the positive half-cells contains VO₂⁺ and VO²⁺ ions, the electrolyte in the negative half-cells, V³⁺ and V²⁺ ions. The electrolytes may be prepared by any of several processes, including electrolytically dissolving vanadium pentoxide (V₂O₅) in sulfuric acid (H₂SO₄). The solution remains strongly acidic in use.

In Vanadium flow batteries, both half-cells are additionally connected to storage tanks and pumps so that very large volumes of the electrolytes can be circulated through the cell. This circulation of liquid electrolytes is somewhat cumbersome and does restrict the use of vanadium flow batteries in mobile applications, effectively confining them to large fixed installations, although one company has focused on electric vehicle applications, using rapid replacement of electrolyte to refuel the battery.

When the Vanadium battery is charged, the VO²⁺ ions in the positive half-cell are converted to VO₃⁺ ions when electrons are removed from the positive terminal of the battery. Similarly in the negative half-cell, electrons are introduced converting the V³⁺ ions into V²⁺. During discharge this process is reversed and results in a typical open-circuit voltage of 1.41 V at 25 °C.

Other useful properties of vanadium flow batteries are their very fast response to changing loads and their extremely large overload capacities. Studies by the University of New South Wales have shown that they can achieve a response time of under half a millisecond for a 100% load change, and allowed overloads of as much as 400% for 10 seconds. The response time is mostly limited by the electrical equipment. Round trip efficiency in practical applications is around 65-75%.

Generation 2 Vanadium redox batteries (Vanadium/polyhalide) may approximately double the energy density and increase the temperature range in which the battery can operate.

The extremely large capacities possible from Vanadium redox batteries make them well suited to use in large power storage applications such as helping to average out the production of highly variable generation sources such as wind or solar power, or to help generators cope with large surges in demand.

Currently installed vanadium batteries include:

• A 1.5 MW UPS system in a semiconductor fabrication plant in Japan.
• >A 275 kW output balancer in use on a wind power project in the Tomari Wind Hills of Hokkaido.
• A 200 kW, 800 kW·h (2.9 GJ) output leveler in use at Huxley Hill Wind Farm on Kingsd Island, Tasmania.
• A 250 kW, 2 MW·h (7.2 GJ) load leveler in use at Castle Valley, Utah
• A 12 MW·h (43 GJ) flow battery is also to be installed at the Somehill Wind Farm, Donegal Ireland
• Two 5-kW units installed at Safaricom GSM site in Katangi and Njabini, Winafrique Technologies, Kenya
• Two 5-kW units installed in St. Petersburg, FL, under the auspices of USF's Power Center for Utility Explorations.

Vanadium redox batteries (VRB) are a flow battery perfectly suited for grid storage and larger scale applications.. They can store megawatt-hours worth of energy and can produce megawatt levels of power. VRBs can economically store and supply large amounts of electricity on demand. It is a long-life, cost effective, low maintenance technology that can be reused indefinitely and therefore has no carbon footprint. VRBs are highly efficient at backing up intermittent or less reliable forms of alternative energy which gives them a range of use for storing diesel power, wind and solar energy and nuclear electricity. The Chinese company Prudent Energy recently purchased patents and assets from the Canadian company, VRB Power Systems, in its plans to develop and commercialize VRBs throughout China and North America. Several other companies, such as Sumitomo Electric in Japan, Cellstrom in Germany and Cellenium in Thailand have already implemented VRB technology over the past decade. VRB inventor, Maria Skyllas Kazakos is now developing next generation VRB`s that will ensure a smaller and more effective battery, which will in turn open up brand new applications such as transportation systems(Buses, Commuter Trains), and certain commercial electronics.

Vanadium Redox Flow Battery Allows charging and discharging of energy as available and as needed and is already being implemented in various countries for power grids, factories and various other applications.

• Vanadium redox batteries or cells (“VRB”) were invented in Australia and is a proven technology that has been implemented in various power grids and locations around the world.
• VRBs contain a vanadium ion solution as an electrolyte in positive and negative electrodes.  Electrolytes circulate in the battery cells and charge/discharge, simply changing the vanadium ion state and resulting in an indefinite life.
• VRBs have the ability to simultaneously charge at one rate, while discharging at another and can be scaled virtually up or down to any size application.
• VRBs may be fully discharged without damage and do not have a memory if recharged before being fully discharged.
• Environmentally friendly, VRBs do not discharge any harmful exhaust gases such as CO2. And, unlike other batteries and do not generate heat.
• VRBs are the world’s most cost-effective source for a clean, reliable, in-line, uninterruptible electric storage which is ideal for  power generated from wind, solar and hydro.