Analysis of the structural characteristics of cylindrical lithium batteries

Cylindrical batteries are a common way of battery construction. Ni/MH, lithium batteries, etc. all have a cylindrical structure, and the newly developed power lead-acid battery also has a cylindrical structure. Cylindrical batteries have been standardized, from the smallest 0.1Ah AAAA cylindrical battery to the higher capacity M-shaped battery of about 10Ah, forming an internationally consistent series of specifications. 1. Cylindrical battery structure (1) Cylindrical battery is generally used. The structure of cylindrical battery is shown in Figure 3-4, which consists of a shell, a cap, a positive electrode, a negative electrode, a barrier and an electrolyte. Generally, the battery case is the negative electrode of the battery, the cap is the positive electrode of the battery, and the battery case is made of nickel-plated steel plate. (2) The main difference of the power cylindrical battery is the conductive connection structure of the battery, because the power lithium-ion battery generally uses a relatively large current and requires a special high-current structure plan. In order to facilitate the assembly and connection, on the basis of the original cylindrical battery structure, a special connection assembly device is planned, such as the internal threads or studs on the positive and negative electrodes of the battery, and the conductivity is also enhanced. 2. Features of the cylindrical battery Strengths: ① Cylindrical batteries have formed a series of internationally consistent specifications and models. The technology is relatively mature and suitable for continuous processing in large quantities. ②The cylinder has a large specific surface area and is good for heat dissipation. ③ Cylindrical batteries are generally sealed batteries, and there is no protection problem during use. ④The battery shell has high pressure resistance, and there will be no phenomena such as square, flexible packaging battery expansion during use. Disadvantages: ①Batteries are connected in series, usually by spot welding, laser welding and other methods. Generally planned cylindrical batteries have limited conductivity and are used for re-planning the need for power lithium-ion batteries in the conductive connection (contains the conductive connection within the battery of an electric vehicle and the connection between the batteries). ②It is not suitable for large-capacity batteries, and parallel connection is required when manufacturing large-capacity battery packs. The parallel process is complicated and the combined cost is high. ③The pressure resistance of cylindrical batteries is generally relatively high. For example, conventional Ni-MH D-shaped cylindrical batteries, the opening pressure of the safety valve is generally 1~3MPa, so when the battery presents safety problems, the possibility of explosion is greater. ④Battery packs made of cylindrical batteries will have a larger volume. Disclaimer: Some pictures and content of articles published on this site are from the Internet, please contact to delete if there is any infringement.