Comparison of 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: the process limitation of the cylindrical battery welding multi-terminal ear, the rate characteristic is slightly worse than that of the square multi-terminal battery.
3. Discharge platform: The lithium battery adopts the same positive and negative electrode 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 pole piece has a low probability of secondary slitting defects, and the maturity and automation of the winding process are relatively high. The lamination process currently still uses a semi-manual method. The battery quality has an adverse effect.
5. Tab welding: The tabs of cylindrical batteries are easier to weld than square lithium batteries; square lithium batteries are prone to false welding that affects battery quality.
6. PACK into groups: Cylindrical batteries are easier to use, so the PACK technology is simple and the heat dissipation effect is good; the problem of heat dissipation should be solved when the square lithium battery packs.
7. Structural features: The chemical activity at the corners of the square lithium battery is poor, the energy density of the battery is easy to decay after long-term use, and the battery life is short.
5. Comparison of cylindrical lithium battery and soft pack lithium battery
1. The safety performance of the soft pack battery is better. The soft pack battery is packaged with aluminum-plastic film in structure. When a safety problem occurs, the soft pack battery will generally burst and crack, instead of exploding like a steel shell or aluminum shell battery cell. ; It is better than cylindrical lithium battery in safety performance.
2. The weight of the soft pack battery is relatively light, the weight of the soft pack battery is 40% lighter than the steel shell lithium battery of the same capacity, and 20% lighter than the cylindrical aluminum shell lithium battery; the internal resistance of the soft pack battery is smaller than that of the lithium battery , Which can greatly reduce the self-consumption of the battery;
3. The cycle performance of the soft pack battery is good, and the cycle life of the soft pack battery is longer, and the attenuation of 100 cycles is 4% to 7% less than that of the cylindrical aluminum shell battery;
4. The design of the soft pack battery is more flexible, the shape can be changed to any shape, and it can be thinner. It can be customized according to customer needs, and new battery cell models can be developed. The cylindrical lithium battery does not have this condition.
5. Compared with the cylindrical lithium battery, the disadvantages of the soft pack battery are poor consistency, higher cost, and easy leakage. High cost can be solved by large-scale production, and liquid leakage can be solved by improving the quality of aluminum plastic film.
