Contemporary Amperex Technology (CATL) unveiled its newly-developed sodium-ion battery at a recent launch event, together with its AB battery pack solution, which enables the integration of sodium-ion cells and lithium-ion cells into one pack.
The sodium-ion battery works on a similar principle to the lithium-ion battery, shuttling sodium ions between the cathode and anode. However, compared with lithium ions, sodium ions have a larger volume and higher requirements regarding structural stability and the kinetic properties of materials. This has become a bottleneck for the industrialization of sodium-ion batteries.
CATL has been researching sodium-ion battery electrode materials for many years. For cathode materials, CATL has applied Prussian white material with a higher specific capacity and redesigned the bulk structure of the material by rearranging the electrons, which solved the problem of rapid capacity fading upon material cycling. In terms of anode materials, CATL has developed a hard carbon material that features a unique porous structure, which enables the abundant storage and fast movement of sodium ions, and also an outstanding cycle performance.
CATL says its sodium-ion battery cell can achieve specific energy of up to 160 Wh/kg, and the battery can charge to 80% SOC in 15 minutes at room temperature. In a low-temperature environment of -20° C, the sodium-ion battery has a capacity retention rate of more than 90%, and its system integration efficiency can reach more than 80%.
CATL’s AB battery system solution allows designers to mix and match sodium-ion and lithium-ion batteries, and integrate them into one battery system, controlling the different systems through a BMS algorithm. The system can compensate for the current energy-density shortage of the sodium-ion battery, and also expand its advantages of high power and performance in low temperatures.
At the launch event, Dr. Qisen Huang, Deputy Dean of the CATL Research Institute, said that sodium-ion battery manufacturing is perfectly compatible with lithium-ion battery production equipment and processes, and that production lines can be rapidly switched to achieve a high production capacity. CATL has started its industrial deployment of sodium-ion batteries, and plans to form a basic industrial chain by 2023.
“It is interesting to see CATL develop an integrated battery management system to accommodate lithium-ion and sodium-ion battery cells under the same battery management system and boost the total energy density of the battery cell,” said Wood Mackenzie Senior Analyst Le Xu. “Sodium-ion batteries could potentially solve cost challenges faced by Chinese renewables developers, bringing energy storage cost down to a new level.”
“Sodium-ion technology has long been touted for commercial battery use due to sodium’s low cost and high abundance relative to lithium, and CATL producing large-scale sodium-ion batteries shows the technology’s appeal is coming to fruition sooner rather than later,” added Research Analyst Max Reid. “The lower energy of the sodium-ion cells suggests that the technology may be more suited for stationary energy storage applications which are less restrictive, while the unveiling of battery packs combining both sodium-ion and lithium-ion cells could point towards compromise in performance for low-cost electric vehicles.”