Cylindrical lithium ion batteries are divided into different systems of lithium iron phosphate, lithium cobalt oxide, lithium manganate, cobalt-manganese hybrid, and ternary materials. The outer shell is divided into two types: steel shell and polymer. Batteries of different material systems have different advantages.
(1) Definition of the cylindrical lithium ion battery
Cylindrical lithium ion batteries are divided into different systems of lithium iron phosphate, lithium cobalt oxide, lithium manganate, cobalt-manganese hybrid, and ternary materials. The outer shell is divided into two types: steel shell and polymer. Batteries of different material systems have different advantages. At present, the cylinder types are mainly steel-shell cylindrical lithium iron phosphate batteries, which are characterized by high capacity, high output voltage, good charge and discharge cycle performance, stable output voltage, large current discharge, stable electrochemical performance, safe use, wide operating temperature range, and environmental protection. It is widely used in solar lamps, lawn lamps, back-up energy, power tools, toy models.
(2) The structure of cylindrical lithium ion battery
The structure of a typical cylindrical lithium ion battery includes: shell, cap, positive electrode, negative electrode, separator, electrolyte, PTC element, gasket, safety valve, etc. 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.
Compared with soft packs and square lithium batteries, cylindrical lithium ion batteries have the longest development time, with a higher degree of standardization, a more mature technology, a high yield and a low cost.
(1) Mature production technology, low PACK cost, high battery product yield, and good heat dissipation performance
(2) Cylindrical lithium ion batteries have formed a series of internationally unified standard specifications and models with mature technology, which are suitable for continuous mass production.
(3) The cylinder has a large specific surface area and a good heat dissipation effect.
(4) Cylindrical lithium ion batteries are generally sealed batteries, and there are no maintenance problems during use.
(5) The battery shell has high withstand voltage, and there will be no phenomena such as being square, flexible packaging battery expansion during use.
(1) The technological progress of cylindrical lithium ion battery mainly comes from the progress of innovative research and application of key battery materials. The development of new materials will further improve battery performance, improve quality, reduce costs, and improve safety. In order to meet the requirements of downstream applications for increasing battery specific energy, first of all, materials with high specific capacity can be used, and secondly, high-voltage materials can be used by increasing the charging voltage.
(2) Cylindrical lithium ion batteries have developed from 14500 to Tesla 21700 batteries. In the near and mid-term development, while optimizing the existing system of lithium-ion power battery technology to meet the large-scale development needs of new energy vehicles, manufacturers also focus on developing new lithium-ion power batteries, improving key technologies such as safety, consistency and life, and simultaneously carrying out forward-looking research and development of new system power batteries.
(3) For the mid- to long-term development of cylindrical lithium ion batteries, while continuing to optimize and upgrade new lithium batteries, manufacturers also focus on the research and development of new system power batteries, significantly increasing specific energy, greatly reducing costs, and realizing the practical and large-scale application of new system power batteries.