Zinc Bromine Basics

The electrolyte in a ZB battery is an aqueous (dissolved in water) solution of zinc bromide. This is circulated with small pumps over both electrode surfaces, which is why it is referred to as a "flow" battery.

The basic operation can be most simply described as a reversible electroplating process. During charging, zinc is plated onto the conductive plastic electrodes. During discharging, the reverse reaction occurs and zinc is removed as electricity is generated. The ZB battery is designed to offer full 100% discharge with no damage, unlike many other battery systems..

Plastic is used in the construction of the electrodes and most other parts of the battery. These do not corrode or deteriorate over time. Therefore, the ZB battery is a non-perishable battery.
Many other batteries types have limited shelf life because of internal corrosion and other degradation processes that occur whether the batteries have been used or not.
RedFlow's ZB battery can be stored indefinately, moreover, as the chemicals associated with the reaction are separated when the battery is charged, the ZB battery has the potential to maintain its charge indefinitely with no self discharge.

RedFlow's ZB battery modules are sealed systems that do not require any specific regular maintenance procedures. The pumps and control system are fully integrated, making the Redflow module a "set and forget" energy storage system. An annual check of the general installation is recommended.

When compared with many other battery technologies, the ZB battery offers high energy density (the amount of energy contained for a given battery weight or size). This is critical for developing commercially viable energy storage solutions. It also has the benefit of being a repairable product, unlike lead-acid batteries.
In addition it operates at normal ambient temperatures, minimising the need for external heaters or chillers, which add to the cost and reduce the efficiency of other battery systems.

The ZB battery uses many low cost materials and with RedFlow's planned large scale manufacturing, this will result in a high performance battery at low wholesale cost. The battery modules produced by RedFlow are configured for 48 volt operation, ideally matched for high performance inverters to generate AC power at household and light commercial scale and also for telecommunication applications.

The underlying concept of the zinc bromine battery was first developed more than 100 years ago. In the mid 1970s and early 1980s, Exxon and Gould pioneered the initial designs for practical application, but did not have all the advanced materials now available.  Nor was there a sufficiently attractive market application on hand to warrant further development. Like so many good technologies, the full commercialisation of the ZB battery has had to wait for a critical market application to arise. That time is now for the ZB battery, as the world grapples with climate change and the need to develop the "Smart Grid" to improve the economics of supplying electricity to customers.