China’s largest electric vehicle (EV) battery producer, CATL, debuted its first sodium-ion battery in late July. This breakthrough in manufacturing means their new battery can charge to near capacity in only 15 minutes.
The $200 billion, Ningde-based company confirmed it would establish a supply chain for the new product by 2023.
Typically CATL EV batteries are composed of elements such as lithium, nickel and cobalt. CATL believes the sodium-ion option will alleviate some of the demand for these elements, which have been skyrocketing since the EV wave hit the automotive industry.
There are very few differences between the mechanics of lithium-ion and sodium-ion cells, so the makeup of CATL’s new battery is not too dissimilar from a standard EV battery unit.
However, a key differentiator is the distinct size difference between sodium and lithium ions. Sodium ions have a significantly larger volume than their lithium counterparts and require a more structurally secure environment to facilitate flow from cathode to anode.
After several years of research and development, the CATL team applied the battery material, Prussian white, to reinforce the cathodes. The company says this breakthrough, along with making alterations to the bulk structure, has solved the problem of ”rapid capacity fading” during material cycles. CATL developed anodes from hard carbon materials that the team says are also porous, allowing for the faster flow of sodium ions within the cell.
While sodium-ion batteries are lower in energy density than the lithium variety, CATL says its new battery can still achieve an impressive 160Wh/Kg (lithium-ion batteries in EVs produce anywhere from 100-265Wh/Kg).
The battery will also be quick to charge. According to Interesting Engineering, CATL’s sodium-ion battery can reach a charge of 80% in fifteen minutes at room temperature. In terms of safety, the new CATL product has thermal stability that exceeds the requirements set by the Chinese government for traction batteries.
The battery manufacturing behemoth also said that it is developing an AB battery pack solution. This pack allows for lithium-ion and sodium-ion cells to be combined in a single battery unit. According to CATL, this compensates for the sodium-ion unit’s lack of energy density, while still maintaining the benefits of the low-temperature performance.
Dr. Qisen Huang, deputy dean of CATL’s research institute, said the sodium-ion battery production methods used are compatible with lithium-ion manufacturing processes, meaning production lines can seamlessly transition from sodium to lithium-ion battery production with minimal fuss.