Battery that works well in the cold

China’s CATL announced that they have made a sodium-ion battery. Production of the new automotive batteries, which are much more cold tolerant than lithium batteries, will start in 2023. One of the biggest backers of electric mobility is the Chinese battery manufacturer CATL (Contemporary Amperex Technology Co., Ltd.). CATL is a partner of Tesla, Daimler, Volkswagen, Toyota, Volvo, Hyundai and many Chinese car manufacturers in the development and production of electric cars.

The company, which is just 10 years old but employs more than 33,000 people, announced in an online press conference that it has developed a new type of energy storage device, the sodium-ion battery, which addresses many of the problems associated with today’s lithium-based batteries. CATL is currently only able to produce sodium-ion batteries with a power density that is not an order of magnitude, if at all, behind lithium-ion or the lithium-iron phosphate batteries that are widely used in China. The announcement is for a 160 Wh/kg battery, but the company is already developing the next generation sodium battery with a target of 200 Wh/kg. (A Tesla battery today has a power density of about 260 Wh/kg.) However, the new battery has some very important advantages.

For example, it works reliably even in very cold conditions. According to CATL, in -20 degrees Celsius their new battery can deliver around 90 percent of its theoretical peak capacity, while lithium batteries can lose up to half their capacity in sub-zero temperatures, and some manufacturers even consider prolonged use in extreme cold to be a warranty voiding factor !

Another advantage of the CATL sodium-ion battery is its fast charging. Today’s CATL cells can draw up to 80% of their full capacity in 15 minutes when discharged. The new battery is also likely to be cheaper to produce than lithium batteries: sodium is a more common, more readily available material than lithium, and the other materials that make up the cells eliminate the rare, expensive and worryingly mined cobalt that is a major focus of today’s lithium battery developments.

CATL is not saying that their new battery will send lithium-based technology to the museum in one fell swoop. Rather, they see lithium and sodium batteries as complementing each other to help spread electric mobility, thereby reducing CO2 emissions from transport and traffic.