Cylindrical lithium battery are divided into lithium cobalt oxide, lithium manganese oxide, ternary materials. Three kinds of material system lithium battery have different advantages, the battery is widely used: notebook computers, digital cameras, lighting, toys, power tools, portable energy and other fields. So what is the structural characteristics of cylindrical lithium battery?
Cylindrical lithium battery are a common form of battery structure. Ni / MH, lithium battery are cylindrical structure, and the newly developed power lead-acid batteries also have cylindrical structure. Cylindrical batteries have been standardized, from the smallest 0.1A · h AAAA cylindrical battery, to a higher capacity of about 10A · h M-shaped battery, forming a unified international series of specifications.
1. The structure of cylindrical lithium battery
(1) common cylindrical battery common cylindrical battery structure shown in Figure 3-4, from the shell, cap, positive, negative, diaphragm and electrolyte composition. General battery shell for the battery negative, the cap for the battery cathode, the battery shell with nickel-plated steel.
(2) power-type cylindrical battery is the main difference between the battery conductive connection structure, because the general application of power battery current is relatively large, the need for special high-current structure design.
In order to facilitate the combination of connection, in the original cylindrical battery structure, based on the design of a special connection combination device, such as the positive and negative electrodes in the design of internal thread or stud, the conductivity is also enhanced,
2. Features of cylindrical lithium battery
Advantages: ① cylindrical battery has formed a series of international uniform standard specifications and models, the process is more mature, suitable for large quantities of continuous production. ② cylindrical surface area of large, good heat dissipation. ③ cylindrical battery is generally sealed battery, the use of the process there is no maintenance problems. ④ battery shell pressure is high, the use of the process does not appear, such as square, flexible packaging battery expansion and so on.
Disadvantages: ① battery connected in series, usually by spot welding, laser welding and other methods to connect. Commonly designed cylindrical battery conductivity is limited, for power batteries in the conductive connection (including the electric car battery internal conductive connection and the connection between the battery) need to be redesigned. ② not suitable for large capacity batteries, the production of large capacity battery pack need to be connected in parallel. Parallel process complex, high cost combination. ③ cylindrical battery pressure level is generally high, such as conventional nickel-metal hydride D-shaped cylindrical battery, the safety valve opening pressure is generally 1 ~ 3MPa, so when the battery safety problems, the possibility of its explosion is greater. ④ the use of cylindrical battery battery pack, the volume will be larger.