Because the automation degree of 18650 lithium ion battery with high stability, high interchangeability, the 18650 batteries are unique in the development of the system modularization and standardization of the unique advantage. The utility model can effectively reduce the production cost and save labor force. Removal of the old Tesla, including Porsche and JAC, Thailand, Changan, Guangzhou automobile, etc. have also joined the 18650 battery models R & D team. Insiders said that in the future there will be more models love on the 18650 battery, driving the use of the 18650 battery disruptive changes in the road.
However, everything has its two sides, the pros and cons of things are normal. 18650 in addition to the advantages of the battery, the disadvantages can not be ignored. The biggest defect is that the current 18650 battery single battery capacity which is low, generally around 2~4Ah, so very much the number of electric vehicle battery which is required, such as Tesla Motors requires only 18650 7000-8000 battery reliably connected module. So many of the battery, the battery management more complex, more consistent requirements.
In the field of electric vehicles and many other series, the battery does not affect the use of battery performance, and even bring some security risks.
Lithium ion batteries alone or in small scale parallel use, the basic security issues can be controlled, but when using large scale lithium ion battery group, especially as the electric vehicle battery is used, its security issues will be more prominent, the lithium ion battery group when in use, the monomer quantity, complex structure consistency, screening of the monomer, and the consistency of management more difficult, which makes the battery in the "short board" battery easily over aging, resulting in the use of the process more prone to accidents.
Therefore, to solve the problem of safety of Li ion batteries, in improving battery safety at the same time, starting from the battery system perspective is very necessary and urgent to strengthen the safety of lithium-ion battery group.
There are a variety of sources of inconsistency, the material that makes up the battery itself is not exactly the same, and the manufacturing process of the battery can not be controlled to each battery in any detail is the same. This will lead to inconsistent and capacity voltage inconsistency, inconsistent resistance, life is not consistent. It is difficult to fundamentally solve. It is necessary to detect and select the core before the group.