IEEE Spectrum Article re: Gelion Non-Flow Battery Part 129 Dec 2021 10:13
The article (27 Oct 2021) below is from the www.ieee.org website. Therefore an unbiased honest qualified assessment of Gelion's non-flow battery technology.
Maybe flow batteries aren't always everything they're cracked up to be. A new technology from Australia is certainly raising this prospect, offering a novel approach to stationary energy storage—whose packaging at least harkens back to the old, familiar car battery.
Flow batteries use liquid electrolytes held externally in tanks and which circulate through the cells using pumps and piping. Their capacity is proportional to the size of the tanks, making them easily scalable. In theory, they should be a good choice for applications, such as storing surplus energy from renewables. But their reliance on mechanical components and intricate design presents drawbacks, including highly specialized maintenance needs, while flow batteries' electrolytes can be costly, corrosive or toxic. This has inhibited flow batteries from gaining widespread deployment, despite increasing improvements.
Now, Gelion Technologies, a startup based in Sydney, Australia, has found a way to dispense with the pumps and plumbing, and to eliminate other drawbacks common with conventional flow batteries by creating a non-flow zinc-bromine battery. Gelion founder and inventor of the new technology, Professor Thomas Maschmeyer at the University of Sydney, describes how it works.
"Instead of circulating fluids, the battery uses a proprietary gel, hence the company name gel plus ion." The gel enables molecular encapsulation of the bromine in a manner that is reversible, so that the bromine is still available for electrochemistry. To explain, he uses the analogy of Velcro. The “Velcro"-like gel sticks to the bromine, yet it can separate from it with a little pull when needed. "That pull in the battery is a little bit of its potential," he says.
Gel batteries, say its advocates, deliver robust, durable, non-flammable storage made from materials that are inexpensive, readily sourced, and recyclable.
Equally important, the gel ensures the bromine, which is heavy, stays well-distributed throughout the battery, reducing stratification and the formation of undesirable zinc plating called dendrites, which can cause short-circuits. In turn, fewer dendrites reduce gassing and pH drift (unwanted change in the acidity or alkalinity in the electrolyte).
"By keeping everything homogenous within the gel, it's basically dealing with all the issues addressed by flow so that they don't really arise," says Maschmeyer. Or if they arise, "they can be dealt with in the existing paradigms of battery technology. This makes for a super safe battery."