Sodium-ion batteries are not new. The concept emerged around the same time as lithium-ion batteries, as both types have a similar principle of operation.
“Sodium ions also shuttle between the cathode and the anode. However, compared to lithium ions, sodium ions have a larger volume and higher demands on the structural stability and kinetic properties of materials. This has become a bottleneck for the industrialization of sodium-ion batteries. . ”
The lower energy density of sodium-ion batteries has limited interest in this type over the years, but it could return as this chemistry has its own specific advantages. CATL had been working on this chemistry for a long time.
Here’s how the company describes cells:
“CATL has been engaged in the research and development of sodium-ion battery electrode materials for many years. In terms of cathode materials, CATL applied Prussian white material with higher specific capacity and redesigned the bulk structure of the material by rearranging the electrons. , which solved the worldwide problem of rapid capacity fading during material cycling. In terms of anode materials, CATL has developed a hard carbon material which features a unique porous structure, which enables abundant storage and rapid movement of sodium ions, as well as excellent bicycle performance. ”
The first generation model should offer decent energy density, very fast charging capacity and particularly high performance at low temperatures.
- energy density of up to 160 Wh / kg
(the objective for the second generation is 200 Wh/kg)
- fast charge up to 80% SOC in 15 minutes at room temperature
- excellent thermal stability
- excellent low temperature performance
at -20 ° C, the sodium-ion battery has a capacity retention rate of over 90%
- system integration efficiency can reach over 80%
(the cells represent more than 80% of the weight and / or volume of the packaging)
Compared to lithium-ion LFP (lithium iron phosphate) chemistry, sodium ion also contains no cobalt or nickel and is expected to be just as affordable on a large scale.
Sodium ion chemistry actually beats the LFP in low temperature performance, fast charging, lifespan, and system integration efficiency, but is currently less energy dense.
“The first generation of sodium-ion batteries can be used in a variety of transportation electrification scenarios, especially in extremely low temperature regions, where its exceptional advantages become evident. In addition, it can be flexibly adapted to the application needs of all energy scenarios. storage field. ”
According to Chinese media reports, sodium-ion cells are expected to start at CNY 500 ($ 77) per kWh on a small scale, while at a volume scale the cost will be halved to CNY 200-300 (31 – $ 47) per kWh, which potentially would be very competitive.
The specificities of sodium-ion batteries make them perfect for cold climates. On the other hand, they can be used with other types (higher energy density lithium-ion) in a single battery.
CATL offers an AB battery system solution – a hybrid battery pack – with two types of battery cells. In combination with the intelligent BMS, the vehicle could take advantage of the low temperature performance of the sodium-ion battery or the high energy density, as required.
“In terms of battery system innovation, CATL made another breakthrough in battery system integration and developed an AB battery system solution, which involves mixing and matching sodium-ion batteries and batteries. lithium-ion in a certain proportion and integrate them into a single battery system, and control the different battery systems through the precision BMS algorithm.
AB battery system solution can compensate for the current shortage of sodium-ion battery energy density, and also extend its advantages of high power and low temperature performance. Thanks to this innovative structure system, the application scenarios of the lithium-sodium battery system are widened. ”
For example, there would be no limitation on regenerative braking in winter.
One of the most important things is that sodium ion can be produced using the production equipment and processes used for lithium ion cells.
CATL begins industrial deployment and should reach scale by 2023. The company invites partners to support the development of chemicals.
Dr. Qisen Huang, Assistant Dean of CATL Research Institute, said that sodium-ion battery manufacturing is fully compatible with lithium-ion battery production equipment and processes, and production lines can be quickly switched to achieve high production capacity.
As of now, CATL has started its industrial deployment of sodium-ion batteries, and plans to form a basic industrial chain by 2023. CATL invites upstream suppliers and downstream customers, as well as research institutes to accelerate jointly the promotion and development of sodium-ion batteries. ”