The Open Vanadium Redox Battery (VRB) aims to develop a working residential scaled VRB in a public space using open tools and technologies.
VRB's are unlike traditional battery technologies in that they separate the chemical to electrical conversion from the energy storage. The chemical to electrical conversion (and visa versa) occurs in a cell stack which the storage chemicals are cycled through from storage containers. This allows the storage capacity to be cheaply scaled as the need arises, unlike traditional batteries where to increase storage capacity a whole set of batteries may need to be purchased. Another less explored advantage for off grid users is the ability to charge the battery at any of the cell stack voltages, not just at the final voltage, and in this way VRB's can also act as DC transformers.
VRB's may be one of the easier batteries to manufacture at home, with relatively safe and simple chemistry, with the majority of the problem being the manufacture of leak free cell stacks.
A great impediment to home manufacture is the cost and availability of the membrane. The most common membrane material is Nafion 117, which although being available could be prohibitively expensive to most would be battery makers.
In this project we will focus on using FDM 3D printing technology to print the cell stack, investigating different materials and designs to optimise fluid flow. We will investigate various battery configurations to minimise self discharge and the need for expensive proprietry membranes. Finally the control gear and metrics reporting will be developed.
A VRB is a special case of a redox flow battery, using Vanadium ions in both half cells. What makes an ![test][test]
- Investigate suitable materials
- Trial various flow frames and gaskets for a. Water tightness b. Fluid dispersion into felt c. Maximum flow rate