While the demand for Lithium batteries has soared, particularly for energy storage, and the cost of producing these batteries has plummeted in recent years, a start-up battery maker has created a new zinc-based battery that may be able to outperform lithium cells for up to 50% cheaper.
Eos Energy, located in Edison, New Jersey, manufactures battery energy storage systems (BESS) for electrical grids that balance the variable output of wind and solar farms. Their zinc-halide batteries are nonflammable, easily recyclable, and do not require rare earth or conflict materials
to manufacture. This is important to US consumers as zinc is the fourth most produced metal in the world - globally mined and refined in 50 countries - making its supply more secure, conflict-free, and not dependent on China for rare earth minerals.
The US Department of Energy has recognized and rewarded the advancements that EOS has made by making a "conditional commitment" of a $400 million loan to help further develop this alternative to lithium-ion cells (the conditions include reaching certain technical, commercial, and financial milestones).
An Old Technology with a New Life
Zinc batteries aren't a new invention. Researchers at Exxon patented the first zinc-bromine flow batteries in the 1970s. Eos has altered the technology over the past decade to improve battery performance. The result is longer energy storage at a lower cost.
"In the 90s, there was so much research going into lithium that zinc-based batteries were considered an old technology," says Josef Daniel-Ivad, manager of the newly established, global Zinc Battery Initiative, "But now things are different."
Manufacturers like Eos have resolved performance issues that once plagued zinc-based batteries, such as shape change and dendrite formation, which could cause system failure. Now, they "have a wide operating temperature range [of] between -40 and 167 degrees Fahrenheit and an estimated life expectancy of 20 years," according to Daniel-Ivad.
This is good news as Lithium batteries last between 200–300 cycles, while zinc-ion batteries can last up to 20,000 cycles. Experts believe the US grid alone will require between 225 and 460 gigawatts of long-duration energy storage capacity by 2050 - a fivefold increase over current needs. Zinc-based batteries are poised to more efficiently address these needs.
Safer Storage for Commercial and Residential Use
Eos hopes to quickly commercialize this zinc-based technology to enable electricity storage for hours or even days at a lower cost to businesses and homeowners. Some additional advantages include:
A more consistent supply of electricity for the grid
Reduced climate impact
A longer lifespan of 20 years over lithium's 10–15 years
Fewer required safety measures such as active temperature control
Water-based electrolyte structure makes them more stable and nonflammable
Improvements are Still Needed
One of the current zinc-based battery limitations is their relatively low efficiency. This means more energy is lost during charging and discharging than with lithium-ion batteries. Kara Rodby, technical principal at Volta Energy Technologies, says these technical challenges are largely addressable, though, and the bigger challenge will be manufacturing at large scales.
Eos' factory in Pennsylvania isn't operating a full capacity today, but the DOE loan will provide much-needed capital to build its manufacturing capacity, according to EOS CFO Nathan Kroeker. THE DOE funding will support up to four additional, fully automated lines in the existing factory which could produce eight gigawatt-hours worth of batteries by 2026. This is enough to meet the daily needs of up to 130,000 homes.
EOS isn't the only company developing zinc-based batteries, so look for even further advancements in energy storage that will be safer and better for our environment in the decades to come.
Sources: Iceberg Research, MIT Technology Review, NREL.gov, PV Magazine