Lithium-ion batteries have been leading for many years in almost all industries where energy storage is required, writes Interestingengineering. But they can be replaced, at least in the segment of industrial enterprises or households, by a new technology.
We are talking about zinc-bromine batteries, the technology of which was patented in the distant 1885 by a resident of New York, K. S. Bradley. At that time, electrification was only gaining momentum, and no one was particularly interested in large, powerful batteries.
But taking into account modern realities, zinc-bromine batteries will be in great demand. After all, it is not enough to simply get the energy of the Sun or the wind, you also need to store it somewhere in case it is cloudy or windless. This requires large and powerful batteries, and lithium-ion or any other lithium-based batteries are not well suited for this role. They are expensive, explosive and not environmentally friendly (the process of extracting a metric ton of lithium requires the consumption of almost 2 thousand cubic meters of water for production).
How a zinc-bromine battery works
Australian companies Gelion and Redflow presented their Endure zinc-bromine battery, which is an improvement on their ZBM3 model.
Zinc bromine batteries are a type of flow redox battery or RFB. Like any battery, these batteries contain a cathode, an anode, and a separator. The main nuance is the use of reservoirs filled with liquid electrolyte on both sides of the battery: one for the catholyte and one for the anolyte instead of solid components, as in the case of lithium-ion batteries. Each side contains a chemical substance of different oxidation state.
When a zinc-bromine battery is discharged, chemical energy is converted into electrical energy by reduction-oxidation. As the battery charges, this process is reversed. Due to their rather large structure, such batteries are not suitable for small appliances or even electric cars. But they are perfect for a home, office or enterprise, because the blocks of such batteries are very well scaled as needed.
The developers at Gelion and Redflow refined the basic idea and equipped their battery with a plate that is positive for bromide and negative for zinc, and placed a layer of gel in the middle as an electrode.
What are the advantages of zinc-bromine batteries
First, the depth of the discharge. Unlike lithium-ion batteries, they can be constantly discharged to zero, but lithium-ion batteries are not recommended to be discharged below 20% - the battery will quickly begin to degrade.
Secondly, safety. Zinc-bromine batteries are more resistant to high temperatures and do not explode. The developers claim that they heated the battery to a temperature of 700°C and it did not explode.
Thirdly, safety for a person. Although bromine is still a health hazard in electrolyte form due to its carcinogenic nature, doctors say that the rate of evaporation of bromine from a damaged battery is too slow, and it has such an unpleasant odor that a bromine leak can be quickly detected . But other types of batteries are much more toxic and dangerous to health.
And, of course, it is worth noting the cost of energy storage in kWh. On an industrial scale, it ranges from $46 to $52 per kWh for lithium-ion or vanadium batteries. Zinc-bromine will cost at least three times cheaper. The operation of these batteries will also not hit the corporate budget, because their maintenance will be at least 25% cheaper due to the fact that, according to Gelion and Redflow, they do not need air conditioning and fire extinguishing systems.
The production line will not have to be completely redesigned for the production of such batteries. They can be produced at the same capacities as conventional lithium-ion batteries or any other, with minor adjustments.
The charge-discharge cycle also beats all competitors. If for lithium batteries it is an average of 2500 cycles, then for zinc bromine the indicator is 2 times higher. Environmental friendliness is also incomparable with lithium-ion or any other batteries. The zinc bromine battery pack can be easily disposed of in the oil and gas industry, and the battery case is comparable in performance to its lead-acid counterparts and is disposed of in a similar way with the nice bonus of being free of sulfuric acid.
Disadvantages of zinc-bromine batteries
The disadvantages are the large size and average density, in which they are significantly inferior to lithium-ion counterparts. But they are also intended for use in a completely different segment.
Gelion and Redflow hope that the updated and improved 137-year-old technology they have breathed life back into will be very relevant to Australia and the world. Of course, there are always lithium-ion batteries on hand. But why not remember the old recipe? Moreover, it is safer and more profitable.
