The world’s largest sodium-ion storage battery, with a capacity of 100 MWh, is reportedly operational in Qianjiang, Hubei Province, China.

Datang Group, a state-owned power generation company, connected the battery to the grid at the end of June.

As the world looks to move away from fossil fuels, battery-based energy storage solutions are critical when using the sun and wind as energy sources. A large-scale renewable energy plant powered by wind turbines or solar panels needs an equally large storage solution to tide over the intermittency of power generation and store it for future use. 

Due to their high storage density, lithium-ion batteries have been the solution of choice for energy storage in electronic devices and electric vehicles. Their usage has also been extended to renewable energy, but large-scale energy storage requires massive battery packs. 

Since renewable energy plants are located in some extreme environments, the battery packs are also exposed to excessive heat, exacerbating the problems of lithium-ion batteries, such as risks of catching fire, less-than-optimal storage performance, and more. 

This is why scientists have been looking for more user-friendly alternatives to lithium-ion storage and have found a scalable one in sodium-ion batteries. 

Advantages of sodium-ion batteries

Compared to lithium-ion batteries, sodium-ion batteries are advantageous on multiple fronts. They are made from sodium, which is abundantly available and easier to source than the extensive mining needed for lithium.

Due to increased demand, lithium prices are at an all-time high, making it difficult to transition to greener energy sources. An alternative from an abundantly available and cheaper source makes the transition easier. 

Moreover, sodium-ion batteries have a better safety record, they work well at extremely low and high temperatures. 

“They can still guarantee 85 percent charge and discharge efficiency at minus 20 degrees Celsius, which is unmatched by other batteries,” Cui Yongle, Datang Hubei Sodium Ion Energy Storage project manager, told ESS News.

“They can also guarantee 1,500 charge and discharge cycles at a high temperature of 60 degrees Celsius.”

A 100 MWh project also demonstrates that the technology is scalable as well. 

World’s largest sodium-ion battery

The world’s largest sodium-ion battery system was built using 185 Ah sodium-ion batteries built by HiNa Battery, a China-based supplier. The system consists of 42 battery storage containers and 21 sets of boost converters. 

Interestingly, with the connection of this system to the electrical grid, HiNa batteries broke its record as the world’s largest sodium-battery system, which it held for a 10 MWh unit located in Nanning in southwest China. The unit became operational in May this year. 

At the Qianjiang facility, the sodium-ion battery system will store up to 100,000 kWh of electricity on a single charge and dispense it to 12,000 households for their daily needs. At this scale, the facility will help avoid equivalent carbon emissions of 13,000 tonnes annually. 

While the Nanning facility is expected to scale up to 100 MWh energy capacity in the future, the Qianjiang facility will also grow to 200 MWh capacity in its next phase, CNEVPost said in its report.

The growing storage capacities of these units show that the sodium-ion batteries are no longer limited to the laboratories and are making their presence felt in the market.