On January 13, according to the Financial Associated Press, CATL has been laying out anode-free metal battery technology, and has applied for relevant technical material design and key process patents, or will be used for the next generation of sodium-ion batteries.
On July 29 last year, CATL released the first generation of sodium-ion batteries, with an energy density of 160Wh/kg. Compared with the current common lithium batteries, the advantage of sodium-ion batteries is that they are not susceptible to temperature, which may solve the pain points of the winter electric vehicle endurance plunge. However, the density of only 160Wh/kg is far less than that of ternary lithium batteries, and the winter is very strong, and other seasons are somewhat inferior.
In addition, sodium is a congener of lithium, but lithium is a second-stage element, and sodium is a third-stage element, which is larger in volume. The large atomic volume means that sodium ions cannot travel freely between graphite like lithium ions, and some special electrolytes are needed to help sodium pass, and the cost of sodium-ion batteries at this stage is much higher than that of lithium batteries.
This is why sodium-ion batteries can not be mass-produced commercial reasons, focusing on safety of lithium iron phosphate batteries energy density is generally 140Wh / kg ~ 180Wh / kg, but can be large-scale commercialization, is because of the low production costs. Sodium-ion batteries must solve the problem of too high production costs to have commercial value.
Anode-free metal battery technology is a big weapon to solve the high cost of sodium-ion batteries, and xiaolei briefly explains this technology below. As the name suggests, a metal battery without an anode is a battery without an active material of the negative electrode, and after the first charge is completed, the metal material of the positive electrode will migrate to the theoretical negative electrode region to form a true negative electrode.
Traditional lithium battery anode materials will generally choose graphite, because this material has strong conductivity, strong corrosion resistance, and rich sources, after all, it is carbon, and there are too many on the earth. But the above XiaoLei also said that the sodium ion is too large, can not be like lithium ions in the graphite shuttle, no negative electrode metal battery is to replace the graphite with metal, as a negative electrode material, convenient metal ion shuttle, help ningde era to solve the problem of sodium ion battery production costs.
In fact, fifty years ago, there were companies studying metal batteries, but due to the lack of technology, many safety problems were generated, and even large-scale product fires occurred. After 50 years, the technical reserves of battery companies are becoming more and more abundant, and finally they must collectively challenge metal batteries again. According to the Ningde era, the energy density of the second-generation sodium-ion battery will reach 200Wh/kg, which is close to that of ternary lithium batteries.
It should be noted that the significance of anode-free metal batteries is not limited to sodium-ion batteries, lithium-ion batteries are also available. However, the early cost of metal batteries will be slightly higher, and when the technology matures, the cost may be lower than that of traditional graphite anode batteries.