Cylindrical lithium batteries are divided into different systems such as 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 material systems have different advantages. At present, cylindrical batteries are mainly steel cylindrical lithium iron phosphate batteries, which are characterized by high capacity, high output voltage, good charge-discharge cycle performance, stable output voltage, large discharge current, stable electrochemical performance, safe use, and wide operating temperature range. Environmental protection, widely used in solar lights, lawn lights, backup energy, power tools, toy models.
The prismatic lithium battery usually refers to an aluminum shell or a steel shell prismatic battery. So, what is the difference between a cylindrical lithium battery and a square lithium battery?
Comparison of the difference between cylindrical lithium battery and square lithium battery
1. Battery shape: The square size can be designed arbitrarily, but the cylindrical battery cannot be compared.
2. Rate characteristics: Cylindrical batteries are limited by the process of welding multi-electrode, and the rate characteristics are slightly worse than that of square multi-electrode batteries.
3. Discharge platform: Lithium batteries use the same positive and negative materials and electrolyte. In theory, the discharge platform should be the same, but the discharge platform in the square lithium battery is slightly higher.
4. Product quality: The manufacturing process of the cylindrical battery is relatively mature, the probability of defects in the secondary slitting of the pole piece is low, and the winding process has a high degree of maturity and automation. The lamination process is still semi-manual, which has an adverse effect on the quality of the battery.
5. Tab welding: The tabs of cylindrical batteries are easier to weld than square lithium batteries; square lithium batteries are prone to false welding, which affects the quality of the battery.
6. PACK group: Cylindrical battery has the characteristics of easy use, simple PACK technology, good heat dissipation effect; the heat dissipation problem should be solved when square lithium battery pack.
7. Structural features: The four corners of the square lithium battery have poor chemical activity, the energy density of the battery is easy to decay after long-term use, and the battery life is short.
With the rise of automobile power batteries in recent years, the contradiction between automobile cruising range and battery capacity has become increasingly prominent. Power battery manufacturers mostly use aluminum shell prismatic batteries with higher battery energy density because the structure of prismatic batteries is relatively simple. The cylindrical battery uses high-strength stainless steel as the shell, and other accessories have explosion-proof safety valves, so the overall accessories should be lighter and have a higher relative energy density.