An Australian team is looking to commercialize a large-scale sodium battery technology, despite the chemistry’s long and checkered history.
Sodium-ion battery pack
Researchers at the University of Wollongong (UOW), New South Wales, are developing a 5-kilowatt-hour sodium-ion battery pack that can be used for stationary storage applications, according to the Australian Renewable Energy Agency (ARENA).
A 30-kilowatt-hour battery system is due to be tested alongside solar panels at a Sydney Water sewage pumping station in 2019, said ARENA, which has put AUD $2.7 million (USD $2.1 million) into developing the technology.
Before then, a single 5-kilowatt-hour battery will debut in a UOW sustainable home showcase called the Illawarra Flame House. ARENA’s funding, part of a total project cost of AUD $10.6 million (USD $8.1 million), was announced in April 2016.
At the time, ARENA CEO Ivor Frischknecht called it “a new type of sodium battery that’s modular. The idea is very low-cost storage.”
The agency also said the research is aiming to create a viable alternative to lithium-ion battery chemistries, which face supply-chain concerns.
But it was not the first sodium battery maker to run into problems. In 2015, the digital industrial giant General Electric put the brakes on production of a sodium-ion product called Durathon, which it had bought via a U.K. startup called Beta Research in 2007.
Sodium-based batteries have been relatively successful in other areas. Italy’s FZSoNick (formerly FIAMM), for example, produces sodium-nickel batteries for stationary storage and electric vehicles.
Japanese automotive parts maker NGK, meanwhile, is commercializing a sodium-sulfur battery that has been deployed at scale in projects such as a 34-megawatt, 245-megawatt-hour hybrid wind and storage system in Aomori, Japan.
In Italy, the transmission system operator Terna “has significant capacity” of sodium-sulfur batteries, installed in 2014 and 2015, according to Valts Grintals, an analyst at Delta Energy & Environment.
Overall, though, “it is still a very small part of the market, and in the past two years there has not been [a lot of] interest in this chemistry,” he said.
Today’s sodium batteries can be divided into high-temperature products, which offer high energy capacity and long duration, and low-temperature variants, which are smaller, safer and potentially cheaper.
But both have drawbacks in terms of cost, efficiency and cycling capability, said Grintals. High-temperature batteries also suffer from flammability issues. Furthermore, sodium-based batteries are suffering as customers stampede toward lithium-ion.
As of mid-2017, International Renewable Energy Agency figures showed sodium-sulfur and other sodium-based batteries making up 3 percent and 8 percent, respectively, of the global electrochemical storage market. Lithium-ion, in contrast, represented 59 percent.
“Scarcity of lithium, which is one of the big selling points from a sodium-ion perspective, is not an issue that the industry is too concerned with yet,” Grintals said. “Based on how the market looks, this will not be a driver for uptake of sodium tech.”
The Australian team could face an uphill struggle with sodium-based batteries even if its concept overcomes the drawbacks of previous concoctions. “When it comes to products like the one from Aquion, it has been a tough sell,” said Grintals.
“I don’t see anything in the market indicating that this could change in the future.”