CATL and Changan Automobile have presented an electric car equipped with a sodium-ion battery. According to CATL, it retains more than 90% of its capacity at -40°C.
Cold weather can significantly reduce an electric car’s range. In a Norwegian winter test at temperatures down to -32°C, a Tesla Model Y drove almost 43% less far than its advertised range.
Better performance in the cold could be valuable for commuters and delivery fleets facing long, freezing winters.
The technology has been studied since the early 1980s. Today’s development builds on decades of research, with patent applications covering very specific improvements.
One CATL application describes partially closing the microscopic pores in a hard-carbon electrode material to reduce unwanted reactions and improve efficiency during the first charge-discharge cycle.
Another patent application targets better cold-weather performance through the electrolyte’s composition. It helps sodium ions separate more easily from solvent molecules.
There is a trade-off: sodium-ion cells generally store less energy per kilogram than leading lithium-ion cells.
For drivers in cold climates, better winter performance could make that compromise worthwhile.