How powerful is CATL's sodium-ion battery? A 10-minute fast charge is enough to revolutionize the industry

On May 21, at the annual shareholders' meeting of CATL, Chairman Zeng Yuqun revealed that CATL will release sodium batteries around July this year. The news caused heated discussions on the Internet as soon as it was released. On the one hand, CATL has always played an important role in the battery field. Many electric vehicles on the market are now equipped with CATL batteries. On the other hand, compared with lithium-ion batteries, sodium-ion batteries are more suitable as large-scale energy storage devices.

At the same time, the price of raw materials for lithium-ion batteries has been rising since the second half of last year, and 40% of the cost of electric vehicles is in batteries. Tesla's price increase some time ago was more or less due to this reason. In the view of many industry insiders, sodium-ion batteries may become an important supplement to lithium-ion batteries.

What is a sodium-ion battery?

There are two main types of batteries on the market: lithium iron phosphate batteries and ternary lithium batteries. These two types of batteries are further subdivided into blade batteries and magazine batteries, represented by BYD and GAC New Energy respectively. What exactly is a sodium-ion battery?

As the name implies, sodium-ion batteries replace the lithium ions in ordinary lithium-ion batteries with sodium ions. Their working principle is similar to that of lithium-ion batteries, that is, the discharge process is achieved by the movement of sodium ions between electrodes. The difference from lithium-ion batteries is that lithium-ion batteries achieve the discharge process by the movement and conversion of lithium ions between the positive and negative electrodes, while sodium-ion batteries achieve discharge by the insertion and extraction of sodium ions between the positive and negative electrodes.

Strictly speaking, sodium-ion batteries are not a new technology. Research on sodium-ion batteries began as early as the 1970s. my country has already put sodium-ion batteries into practical applications in the field of 5G base stations and low-speed vehicles in 2017. So far, more than 20 companies around the world are conducting research and development in the field of sodium-ion batteries.

Advantages and disadvantages of sodium-ion batteries

Since we are going to develop sodium-ion batteries, they must have their advantages. Compared with lithium-ion batteries, the biggest advantage of sodium-ion batteries is the obvious advantages in cost and charging time. Scarcity makes things valuable. The reason why the raw material cost of lithium-ion batteries is high is mainly because lithium is too rare. The content of lithium in the earth's crust is only 0.0065%, while the content of sodium in the earth's crust is as high as 2.64%. In our daily life, sodium ions are also very common. Our common table salt is sodium chloride. Therefore, the cost of sodium-ion batteries is much lower than that of lithium-ion batteries.

In addition, sodium-ion batteries also have obvious advantages in charging time. Even with the support of DC fast charging, the common ternary lithium batteries on the market usually take 30 minutes to charge from 20% to 80%, and the charging time of lithium iron phosphate batteries is even longer, about 45 minutes. The charging time of sodium-ion batteries only takes 10 minutes, which completely solves the problem of long charging time for electric vehicles.

But even the seemingly perfect sodium-ion battery has a big shortcoming, that is, low energy density. At present, the average energy density of sodium-ion batteries is 90-150Wh/kg, which is far behind the 250Wh/kg of lithium batteries. Low energy density means insufficient mileage. But it is precisely because of the low energy density of sodium-ion batteries that they are safer than ternary lithium batteries.

Why develop sodium-ion batteries?

Since the low energy density of sodium-ion batteries has violated the "bottom line" of electric vehicles, why does CATL still want to develop sodium-ion batteries? In fact, the main reason is the lack of lithium resources. Although my country is the world's fourth largest lithium reserve country, it is also the world's largest lithium resource importer, with 80% of lithium resources relying on imports.

It is precisely because of the excessive reliance on lithium resources that there is a risk of "stuck neck", making it difficult to support the demand and development of both new energy vehicles and large-scale energy storage industries. At the same time, it is difficult to make major breakthroughs in lithium-ion batteries. Not only is the cost out of control, but the price of global lithium resources is also rising, which hinders the popularization of new energy vehicles.

As mentioned above, 40% of the cost of an electric car is spent on batteries. The development of sodium-ion batteries can not only alleviate the problem of limited development of energy storage batteries caused by the shortage and uneven distribution of lithium resources, but also gradually replace lead-acid batteries that seriously pollute the environment, which has important economic value and strategic significance.

In conclusion:

For CATL, although it has captured most of the domestic battery market, the safety of CATL's existing ternary lithium batteries has been questioned, and it is also limited by foreign lithium resources. It has no choice but to develop sodium-ion batteries. At the same time, Zeng Yuqun also said that within 3-5 years, sodium-ion batteries will have a mature industrial chain, but the reality of the low energy density of sodium-ion batteries is also the key to whether sodium-ion batteries can be popularized. How high can the energy density of CATL's sodium-ion batteries be? We have to look forward to the official release around July.