For the 18650 batteries as a new energy electric vehicle battery technology line, we may first turn to Tesla. Tesla in the development of electric vehicle battery, tested a lot of types of batteries, but the final target locked in the SC30 18650 Battery, then what are the advantages and disadvantages of 18650 batteries? The author of this article is Xiaopeng automotive team engineer, he will analyze this.
SC30 18650 Battery what is good, so that most of the electric cars are using it?
18650 actually refers to the shape of the battery specifications, Japan SONY company was to save costs and set a standard battery model, of which 18 said the diameter of 18mm, 65 said length of 65mm, 0 for the cylindrical battery. SC30 18650 Battery refers to the original nickel-metal hydride batteries and lithium-ion batteries, nickel-metal hydride batteries are now less used, so now refers to the lithium-ion battery. 18650 lithium-ion battery single standard voltage is generally 3.6V or 3.7V; minimum discharge termination voltage is generally 2.5 ~ 2.75V. Common capacity of 1200 ~ 3300mAh.
SC30 18650 Battery is the earliest, most mature, most stable lithium-ion battery, widely used in electronic products. Over the years, the Japanese manufacturers in the SC30 18650 Battery production process has accumulated a lot of experience, making the output of the SC30 18650 Battery consistency, security has reached a very high level.
In contrast, stacked lithium-ion battery is far from mature, common with a square battery, soft battery, and even size, size, ear and so are not unified, the battery manufacturers have the production process can not meet the conditions , Most of the human-based control, the battery consistency of less than SC30 18650 Battery level. If the battery consistency does not meet the requirements, a large number of battery strings, parallel to the formation of the battery management will not be able to make each battery better performance, and 18650 batteries can solve this problem.
In summary, the SC30 18650 Battery has a small capacity and requires a large number of monomers (Model S has 7104), but the consistency is good; the capacity of the stacked battery can be made large (20 Ah to 60 Ah ), The number of monomers can be reduced, but the consistency is poor. In contrast, it is difficult at this stage to invest a lot of manpower and resources together with the battery supplier to improve the production process of laminated batteries. Therefore, in the development of Roadster and Model S, Tesla's only option is to buy batteries from the market, self-developed battery system. The development of a set of more than 6,000 modules to manage a good battery system and the development of a more than 200 series of poor consistency of the battery system, compared to the former technical difficulty should be lower. Even if the number of single cells increases, but if the performance of these batteries is reliable, it is easy to manage some.
Compared to another very successful pure electric vehicles, Nissan LEAF, which uses a stacked lithium-ion battery. This is because Nissan and NEC for many years, in the battery technology has accumulated very deep, in the quality control has considerable skill. LEAF battery from AESC - Nissan and NEC joint venture.
Compared to the United States, Japan, and other different regions of the car manufacturers in the development of electric vehicles and battery manufacturers of vertical and horizontal is a very interesting thing.