What is the difference between cylindrical lithium battery and square lithium battery?

The structure difference between cylindrical lithium battery and square lithium battery Cylindrical lithium battery is 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. Different materials System batteries have different advantages. At present, the main column is 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, high current discharge, stable electrochemical performance, and use Safe, wide operating temperature range, and environmentally friendly. It is widely used in solar lamps, lawn lamps, back-up energy, power tools, toy models. The structure of a typical cylindrical battery includes: a positive electrode cover, a safety valve, a PTC element, a current cut-off mechanism, a gasket, a positive electrode, a negative electrode, a separator, and a casing. Square lithium battery usually refers to aluminum shell or steel shell square battery. The popularity of square battery is very high in China. With the rise of automobile power lithium-ion batteries in recent years, the contradiction between automobile mileage and battery capacity has become increasingly prominent. Domestic power lithium-ion battery manufacturers mostly use aluminum shell square batteries with higher battery energy density, because the structure of square batteries is relatively simple, unlike cylindrical batteries that use high-strength stainless steel as the shell and accessories such as explosion-proof safety valves. , So the overall attachment weight should be lighter, and the relative energy density is higher. The square battery adopts two different processes: winding and lamination. Comparison of cylindrical lithium batteries and square lithium batteries Battery shape: square lithium batteries can be of any size, so they cannot be compared to cylindrical batteries. Rate characteristics: the process limitation of cylindrical lithium battery welding multi-pole lugs, so the rate characteristics are slightly worse than square. The same positive electrode material, negative electrode material, and electrolyte are used, so theoretically the discharge platform is the same, but the internal resistance of the square battery is slightly superior, so the discharge platform is slightly higher. Product quality: Cylindrical lithium battery technology is very mature, the probability of common secondary slitting defects of the pole piece is low, and the winding process is more mature and automated than the lamination process. The lamination process is currently still using semi-manual methods, so about The quality of the battery has an adverse effect. Tab welding: The tabs of cylindrical lithium batteries are easier to be welded than square lithium batteries, and square batteries are prone to false welding that affects battery quality. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous article: Which kinds of UPS batteries should be paid attention to?