Historically known for its tensile strength and ability to resist corrosion, pure vanadium remains an important element incorporated into tubes and pipes used in the chemical industry, as well as an additive to steel in the form of ferrovanadium.
.jpg)
Furthermore, vanadium pentoxide (V2O5) is one of the most noted vanadium compounds, as it is used as a mordant to fix dyes to fabric materials, as well as catalyze specific chemical reactions within the ceramics industry1. While vanadium is found in about 65 different minerals around the world, it is never found unbound, therefore, it is often obtained as a byproduct of other metal ores2.
While the University of South Wales in Australia pioneered the first VRB technology in the early 1980s, it was not until the early 2000s that companies such as Prudent Energy of Canada and Cellstrom of Australia piloted some of the earliest VRB devices. In an effort to investigate possible alternatives to current energy storage systems, the United States Department of Energy Office of Electricity Delivery and Energy Reliability looked to vanadium options in January 20103. As the demand for electricity continues to rise in almost every country around the world, there is a corresponding demand to generate an efficient means of storing all types of energy to maintain the quality and consistency of its supplies. As Researchers continue to look towards ways in which fossil fuels can be replaced as a primary source of energy, the development of efficient energy systems makes the often-undependable nature of renewable energy sources a more realistic option for the future as well.
Redox flow batteries (RFBs) are a type of energy storage systems that utilize the chemical reduction and oxidation reactions to allow for the flow of liquid electrolyte solutions to move through one tank within the device to another during both electrochemical states of charge and discharge4. From the anode, or negative side, of the battery, an electron is released as a result of the completion of an oxidation reaction during discharge. A reduction reaction then follows to accept the free electron onto the cathode, or positive side, of the battery, which is separated from the anode by a permeable membrane. The direction of this flow of free electrons is reversed during the charging process. The determining factors of the total voltage that is generated by the RFB is attributed by the specific chemical nature of the elements involved in both the reduction and oxidation reactions, as well as the number of cells that are connected in the series4. To store energy in RFBs, two tanks that are separated.
The tank design within RFBs involves its separation from the cell stack that is responsible for converting the chemical energy to electrical energy. The size of the RFB tanks is also directly related to its storage capabilities, which serves as an advantageous purpose, as it can be independently modified for a specific industrial application. While there are numerous types of RFBs, some of which include iron/chromium and zinc/bromide devices, vanadium redox flow batteries (VRBs) are unique in that they require only one element to be used in both tanks5. By only requiring a single element for both storage tanks, these devices eliminate the possibility of cross-contamination degradation, which is often a problem associated with RFBs that involve more than one element. Other types of RFBs often experience this irreversible degradation of the electrolytes as a result of ions of different metals that cross the permeable membrane that exists between the positive and negative sides of the battery, subsequently resulting in a loss of energy of the system.
Most VRBs currently utilize sulfuric acid solutions as their liquid electrolyte to carry vanadium ions, however, they are limited as they become easily oversaturated when these ion levels increase. This limiting factor, combined with the small temperature range in which it functions and its often expensive polymer membrane requirement make it difficult for current VRBs to meet the economic and performance requirements needed for most industrial purposes. To combat this challenge, Researchers from the Office of Electricity Delivery and Energy Reliability’s Energy Storage Program are funding projects that are looking to develop more efficient and less expensive VRBs that will be applicable to operate a wide range of systems5. Such research objectives are looking at utilizing other electrolytes that can achieve higher energy and power densities when combined with vanadium ions, extending the VRBs operative temperature range, and reduce the cost of its membranes.
Dispatchable electricity, which describes a type of energy that can be transmitted upon request of the power grid operators or plant owner, is a desirable quality that industries look towards when deciding on their power source. While fossil fuels and nuclear power plants are known for their dispatchable generation of energy, renewable energy sources must often depend on efficient energy storage options to allow for such a rapid production of energy to occur. Unlike lithium-ion batteries, VRBs are large-scale energy storage systems that can not only release large amounts of electricity at once, but can be repeatedly charged and discharged over an extended period of time. As a leading company in the quest towards ensuring a cleaner and more efficient future, NEXTracker utilize VRB technology to provide their solar energy owners an efficient way to store and utilize their saved energy. With products such as the NX HorizonTM, NX FusionTM, and NX Fusion PlusTM, NEXTracker some of the most advanced solar energy systems currently on the market.
Massachusetts based company, Vionx Energy, has partnered with United Technologies Corporation (UTC) to develop a revolutionary Vanadium Redox Flow technology known as their “Interdigitated Flow Field.6” By improving the way in which the liquid electrolyte solution moves through the power cell of the VRB, this new process improvement generates a power density that is two times greater than traditional batteries. Designed to last at least 20 years, the Vionx Vanadium Battery employs an average runtime of 6-10 hours, which is extremely competitive as compared to tradition VRBs with an average run time of 1-4 hours. This increased power output, combined with a much lower material cost associated with the system, makes the Vionx Vanadium Battery one of the safest and most practical battery options available on the market.
London based company redT Energy has spent the last 15 years to develop a sustainable Vanadium Redox battery that manipulates the multi-valent properties of the liquid electrolyte to enhance the lifetime of the device to 25 years or longer7. By relying on four different oxidation states of vanadium which include V2+, V3+, V4+ and V5+, each of which hold their own unique electrical charge, the redT energy storage systems separates the vanadium ions evenly between the negative and positive side of the cell stack, in which its location within the system is determined by the ion’s charge. As the reduction and oxidation reactions occur, a surplus of electrons is brought to the anode until the system discharges, bringing the electrons to the positive terminal to eventually generate a reproducible electrical current within the system8. With its applications readily available to be combined with renewable energy such as solar and wind options, the redT energy storage system maximizes the efficiency capabilities of VRBs.
References
- “The Element Vanadium” – Jefferson Lab
- “Vanadium – V” – Lenntech
- “Electricity Energy Storage Technology Options” – Electric Power Research Institute
- “Redox Flow Batteries” – Energy Storage Association
- “Vanadium Redox Flow Batteries” – U.S. Department of Energy
- “Technology” – Vionx Energy
- “Who are redT?” – redT Energy Storage
- “How does redT’s patented technology work?” – redT Energy Storage
Image Credit:
Shutterstock.com/Antoine2K
Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.