Zinc is gaining ground in the battery industry, becoming increasingly key to powering portable and energy-hungry devices.
Although zinc was around in the early days of batteries — Alessandro Volta’s voltaic pile, the predecessor of modern batteries, stacked copper and zinc plates to conduct electrical currents — until recently it has largely given way to lead-acid — and more recently, nickel, cadmium and lithium-ion — batteries.
While zinc never entirely left the market, it has faced competitors constructed of low-cost materials that can reliably and repeatedly hold charges. As a result, zinc has not played a dominant role in supplying the market’s need for cheap and reliable energy storage.
But zinc energy-storage technologies are evolving and picking up where other batteries are falling short.
Lithium-ion batteries — currently the battery of choice for the majority of personal electronics, laptops and electric vehicles — require extensive casings because of their high volatility when exposed to water or air. This volatility limits their size and charge capacity, making them less capable of adapting to evolving energy-storage demands.
Further, the ability to source cheap and plentiful lithium has led to a lag in battery technology that has forced designers to conform to their battery’s restrictions.
But zinc is helping to change this situation.
Existing and emerging zinc batteries
In the face of this growing need for new battery options, a number of zinc battery designs are offering two specific selling points.
The first is flexibility. New designs and methods of construction, such as those used to make Imprint Energy’s recently released Zinc Poly™ batteries, are providing practical options for wearable battery technology, according to Bloomberg. Using the type technology that is used to print graphics on T-shirts, the Zinc Poly™ battery is designed to be flexible, small and capable of being molded into almost any shape.
Further, as zinc is less toxic and can be safely exposed to water or air, it is much more adaptable and less dangerous for harvesting electrolytes. Zinc as a metal is a less significant risk than materials like lead or lithium, and thus creates fewer concerns for applications that are placed on, or even inside, the body.
Hearing aids, internal heart, blood or organ monitors and wearable gadgets like Nike’s FuelBand bracelets or temperature-responsive clothing are all products that could make use of the flexibility of new zinc technology.
The second selling point is zinc batteries’ ability to quickly recharge. As batteries grow larger in capacity, they take longer to charge.
Zinc battery technology uses zinc as the anode combined with an electrolyte and a cathode made of a metal oxide. Zinc ions travel from the anode to the cathode through the electrolyte, creating a chemical reaction that allows electrons to be collected along the way.
The Zinc Poly™ battery’s use of a solid electrolyte source, in contrast to the air or liquid solution options used in many other batteries, helps prevent the development of dendrites (whiskers) that develop and reduce a battery’s ability to recharge.
The stable, more clean design allows the battery to adapt to the emerging, more intimate and delicate uses for energy storage.
Zinc demand and batteries
While the Zinc Poly™ model is only one specific development for zinc-based batteries, zinc’s use in other areas is also growing.
Zinc’s abundance and low cost, relative to other battery materials, will be a key factor that makes it an attractive material for battery design over the long term.
Currently, 21 months of global zinc production would be sufficient to produce 1 billion 10-kWh zinc-air batteries. That’s compared to the more than 180 months of lithium production that would be required to produce the same number of lithium-ion batteries.
Large-scale energy storage for electric vehicles and renewable energy sources (such as wind and solar) desperately rely upon ensuring that energy production is stored and dispensed for constant and stable consumption.
The impact of zinc-based batteries on zinc’s overall demand and price will not likely be significant. Currently two-thirds of zinc production is used for galvanizing or alloying use. However, zinc’s role in energy storage is likely to grow and will result in increasing reliance on the metal.
Securities Disclosure: I, James Wellstead, hold no direct investment interest in any company mentioned in this article.