NEW START-UP COMPANY TO COMMERICALISE

GENERATION 2 VANADIUM FUEL CELL:

 

THE NOVEL VANADIUM BROMIDE REDOX CELL

 

 

 

INTRODUCTION.

 

The original Vanadium Redox Flow Battery patented by UNSW in 1986 (VRB system), employs a 2 M vanadium sulphate solution that provides a specific energy of around 25 Wh/kg. While this energy density is satisfactory for use in stationary applications such as load levelling, renewable energy storage and emergency back-up systems, its use in mobile applications is currently limited to niche markets such as industrial fork-lift trucks and off-road buses and vans. In 2001, a Generation 2 Vanadium Redox Fuel Cell and Battery employing a vanadium bromide electrolyte (the VBr system) was developed by Skyllas-Kazacos and co-workers. The vanadium concentration in the Generation 2 electrolyte can range from 3-4 Molar which means that its increased energy density (30-50 Wh/kg) makes it suitable for use in a much wider range of electric vehicle applications including on-road buses and trucks as well as in delivery vans and vehicles for urban areas. The higher concentration of vanadium in the Generation 2 VBr electrolyte means that much smaller electrolyte volumes and system foot-print areas can be achieved, providing benefits for stationary applications such as wind and solar energy storage systems as well.

 

 

BACKGROUND ON MAGNAM TECHNOLGIES PTY LTD:

 

Magnam Technologies is a new Start-up company that was formed in 2003 by two of the original inventors of the Vanadium Redox Battery Technology (VRB), Professor Maria Skyllas-Kazacos of the School of Chemical Engineering and Industrial Chemistry, UNSW and Mr Michael Kazacos, consultant. Recent negotiations between Magnam Technologies and Unisearch Ltd, the commercial arm of the University of New South Wales, has resulted in agreement to establish a new entity to be called “V-Fuel Pty Ltd”, that will commercialise the new Vanadium Bromide Redox Fuel Cell (VBr) and also manufacture cell stacks for use in the commercial VRB installations by Pinnacle VRB licencees.

 

The extensive expertise and know-how of Magnam Technologies’ key personnel in the area of the VRB technology and stack design, means that V-Fuel will be well placed to capitalise on the growing demand for energy storage systems around the world. With the emergence of the new improved vanadium bromide redox fuel cell technology (VBR) that is owned by the V-Fuel participants, new business opportunities in electric vehicle applications will also be exploited. These new business opportunities have the potential to generate millions of dollars in export earnings for Australia, while also helping to alleviate serious global energy supply and environmental problems.

 

Magnam Technologies Pty Ltd was therefore established to undertake contract R&D in VRB and VBR systems as well as stack design and prototype construction for different redox cell applications

 

The role of V-Fuel will be to offer the following services:

 

-         Stack manufacture and supply to VRB and VBR licencees.

-         Vanadium electrolyte production and supply.

-     Battery control system development for different applications

-     Technical advice and support for commercial installations

-         VRB and VBR system sales, project licences and project management for VRB and VBR installations in Australia and elsewhere

 

It is expected that various joint venture arrangements will be established between V-Fuel and interested parties. One such joint venture arrangement is currently being negotiated with a Chinese bus company to install vanadium redox fuel cells into electric buses along with the installation of recharging/refuelling stations for the Beijing Olympic Games in 2008. The potential market for battery electric buses and Taxis in China is vast with the Government recently appropriating funds to purchase 12,000 battery electric and hybrid electric buses and 50,000 battery electric taxis prior to the opening of the 2008 Olympics.

 

 

THE VANADIUM BROMIDE REDOX FUEL CELL.

 

The energy density of a redox flow battery is related to the concentration of the redox ions in solution, on the cell potential and the number of electrons transferred during discharge per mole of active redox ions. In the case of the all-vanadium redox flow cell, the maximum vanadium ion concentration that can be employed for wide temperature range operation is typically 2 M or less. This concentration is equivalent to an energy density of around 25 Wh/kg and represents the solubility limit of the V(II) and/or V(III) ions in the sulphuric acid supporting electrolyte at temperatures below 5 oC and the stability of the V(V) ions at temperatures above 40 oC.

   

A new V/halide redox flow cell was thus proposed by Skyllas-Kazacos, this employing the VCl2/VCl3 or VBr2 /VBr3  couples in the negative half-cell electrolyte and the Br-/ClBr2- or Cl-/BrCl2- couples in the positive half-cell. A provisional patent application was thus filed in 2001 and a PCT application and several improvement patents filed in 2002 and 2003. The proof-of-concept phase has already been completed with laboratory-scale test cells. The results of the work completed to date has demonstrated that the new V/halide redox flow system is capable of providing energy densities of up to 50 Wh/kg, twice that of the present VRB system.

 

Charge-discharge reactions of V/halide redox flow cells:

 

Negative Half-Cell Reactions:

                                                    discharge

                        VCl2   +   Cl-                                           VCl3   +   e                 

                                                     charge

 

or                                                 discharge

                        VBr2   +   Br-                                          VBr3   +   e                

                                                     charge

 

Positive Half-Cell Reactions:

                                                    

                        BrCl2-   +   2e       discharge              Br-   +   2Cl-

                                                       charge

 

or                     ClBr2-   +   2e       discharge              2Br-   +   Cl-

                                                       charge

 

.

Preliminary experiments with 3-4 M vanadium bromide have already been undertaken by Magnam Technologies and this electrolyte system has been shown to be technically feasible. These solutions provide an energy density of 50 Wh/kg in the V/Br redox flow cell, thus forming the basis of the Generation 2 vanadium battery or fuel cell for electric vehicle applications.

 

By increasing the vanadium concentration in the electrolyte, a very important new market in electric vehicles will open up, this bringing enormous environmental, social and economic benefits to Australia and the world. The new power source will be able to deliver up to 180 km range per charge and be refuelled in five minutes by exchange of electrolyte at a special refuelling station. Electrolyte fuel would be recharged in the refuelling station and recycled an unlimited number of times. The system thus consumes only electrical energy which may be derived from the grid using off peak power or from renewable sources and there are no emissions at point of use.

 

The benefits of the Generation 2 Vanadium Redox Fuel Cell system can be summarised as follows:

·        Simpler, safer, more efficient and much lower cost than gaseous Hydrogen Fuel Cells

·        Refuelling in five minutes by exchange of electrolyte at a specialised refuelling station allows 24 hour operation of buses, taxis, fork-lift trucks and other vehicles (not possible with any other type of battery system).   

·        Electrolyte fuel is recharged in the refuelling station using renewable energy or off-peak grid power and is re-used continually

·        Silent, emission free operation in electric urban vehicles

·        160 – 180 km between refuelling stops – system energy density approximately 50 Wh/kg, twice the Generation 1 VRB energy density

·        Convenient integration into conventional IC engined fleets – refuelling points may be sited alongside diesel or petrol pumps

·        Subject to local market conditions complete Redox fuel systems could be installed for fleet operators and electric fuel could be sold at below equivalent cost for gasoline or diesel

·        Fleet operator studies conducted by the UK-based company, EFuel Techologies Ltd, and based on UK economics show overall cost savings, including capital depreciation, at less than 50% that of gasoline or diesel fuel

 

Comparing the Generation 2 vanadium redox battery with Hydrogen FC systems (Ref E-Fuel Technologies Pty Ltd UK):

·        Efficiency: Round trip efficiency for the Hydrogen electrolysis and FC power generation process is typically 33% compared to 80% for the redox cell.

·        Production cost: of bipolar stack in volume production is projected at $100 to $150 per kW for Redox versus  more than $1000/kW for HFC

·        Fuel distribution and storage: Bottled Hydrogen in metal storage cylinders achieves only 2% weight H2 stored versus container weight. Despite lower ED of 60Wh/kg for Redox versus 250Wh/kg for Hydrogen, Redox range of 150-180 km between refuels is as good or better than bottled H2 at 3000psi.

·        Energy cost: Hydrogen in bottled gas form is expensive – currently quoted $1- $3 per cubic metre in 7000 litre bottles. To produce 1 kWh requires about 20 cents worth of energy

·        Alternatively hydrogen may be generated in a $10k electrolyser but must be compressed to 3000psi and distributed in pressurised bottles. Direct Methanol reformation to Hydrogen is as yet inefficient and releases carbon residues. 

·        Refuelling: Redox liquid refuelling in five minutes is currently faster than exchange of compressed H2 bottles and much faster than re-compression of gas on board the vehicle.