With the increasingly serious global air pollution and the shortage of oil resources, the development of battery energy storage technology has attracted extensive attention all over the world. Fuel cell is the main target of power cell technology development and is considered as the ideal power source for electric vehicles. Vacuum as a gas state below a standard atmospheric pressure can show many new characteristics of the process that cannot occur under atmospheric pressure, and has been applied in many industrial fields. This paper summarizes the application of vacuum system in power battery manufacturing.
Features of power batteries:
1. High energy and power;
2. High energy density;
3. Recycling under the state of high multiplier partial charge;
4. Wide operating temperature range (-30~65);
5. Long service life, 5-10 years;
6. Safe and reliable.
The obstacles to large-scale use of power batteries themselves include battery performance, price and consistency. The key to solve these problems depends on the use and development of advanced technology and means. Vacuum technology and vacuum system equipment play an important role in power battery manufacturing process because of their unique characteristics.
The following highlights list the applications of vacuum technology and vacuum system equipment in various processes of power battery manufacturing, including vacuum mixing, vacuum sintering, vacuum drying, etc.
1. Vacuum mixing
The electrodes are the heart of the battery. The quality of power battery electrode determines the main quality of battery, including capacity, service life, cycle life, safety and so on. The quality of the paste or paste used to make the anode and cathode of the battery determines the quality of the electrode and the battery.
In the vacuum state, the paste or paste used in the mixed production of electrodes is almost inert due to the small number of gas components in the vacuum environment, the surface chemical composition and properties of the paste or paste are not easy to change, and the product is pollution-free. At the same time, it is beneficial to remove the harmful gas carried by slurry or paste and improve production efficiency.
2. Vacuum sintering
The battery electrode is made by sintering process. After sintering, the electrode is required to have high porosity and good uniformity, so that more active substances can be impregnated evenly, and the resulting electrode has high capacity and stable performance.
Due to the lack of hydrogen, nitrogen, oxygen and other gases in the vacuum sintering furnace, it is not easy to occur carburizing, brittle intercalation, oxidation and other surface chemical composition problems, so the combination of grain boundaries will be more firm; At the same time, it can also realize low temperature sintering, fast gasification rate, good heating uniformity, pollution-free, etc., which has become the preferred technology for electrode sintering.
3. Vacuum drying
Compared with atmospheric pressure drying, vacuum drying has a low drying temperature, and the water in the drying materials has internal diffusion, internal evaporation and surface evaporation, which is conducive to the evaporation of water or solvent at low temperature. Good uniformity after drying. General vacuum drying is carried out under low vacuum. In the process of power battery manufacturing, vacuum drying is mainly used in the vacuum drying of electrode manufacturing and the vacuum drying of batteries before liquid injection after assembly.
The development of power battery manufacturing technology is closely related to the development of vacuum technology. Vacuum technology has been shown to play an important role in the manufacture of power batteries because it can produce many unique effects in traditional processes. This paper describes the application of vacuum system in power battery manufacturing, aiming at promoting the improvement and development of power battery manufacturing technology. Through research and analysis, the wide promotion and application of vacuum technology in power battery manufacturing will promote the technical progress and development of power battery manufacturing.