Electric vehicles are driven by batteries, so from the outside, electric trucks on the market are generally powered by multiple battery packs of hundreds of kilograms. Open the outer packaging of the battery pack and you will find that it is actually composed of more small batteries. For example, Tesla's electric car, its battery is composed of more than 7000 batteries the size of AA batteries. of.
The three cell structures of lithium batteries are generally divided into cylindrical, square and soft packs
The battery cell is the smallest unit that constitutes the power battery of an automobile. Generally speaking, the battery of an electric car is composed of hundreds of cells, and the battery cell is the smallest unit that constitutes the power battery of an automobile. For lithium batteries, there are currently three main structures of cells-cylindrical, square and soft. Judging from the installed capacity of electric vehicle batteries in 2018, the most popular one in China is Rechargeable Square Pouch Battery.
Cylindrical batteries are a relatively traditional battery construction technology. In the past, household batteries were basically of this structure. The cylindrical winding type is a very classical battery configuration. Therefore, it has long-term applications and the industry has accumulated a lot of Production design experience. The advantages of this type of battery include the advantages of high production efficiency and good consistency. The disadvantages are low space utilization caused by the cylindrical shape and temperature distribution problems caused by poor radial heat conduction.
Rechargeable Square Pouch Battery is currently the most used lithium battery type in many electric vehicles. Rechargeable Square Pouch Battery generally has the advantages of high space utilization and high production efficiency. However, the design of this type of battery is also the most complicated. There are many design variables that need to be considered and the technical requirements are high. However, the advantages of the Rechargeable Square Pouch Battery are also very obvious.
The Rechargeable Square Pouch Battery has high packaging reliability; the energy efficiency of the system is also high; therefore, it is relatively light in weight and high in energy density; and the battery has a relatively simple structure and relatively convenient expansion. At present, it is an important option to increase the energy density by increasing the monomer capacity; if the monomer capacity is large, the system structure is relatively simple, making it possible to monitor the monomers one by one; another advantage brought by the simple system is relatively good stability.