Comparing cylindrical cells, square cells and soft-packed cells

Overview

Lithium iron phosphate batteries are widely used at home and abroad, but their appearance is different due to the different application fields. They are cylindrical cells, square cells and  and soft-packed cells, respectively.

Advantages of cylindrical cells

•The maturity of battery technology is very high, standardized, and the level of automation of battery production is higher;

•High battery consistency;

•The energy density of a single cell is higher than that of a square cell;

•Excellent battery cycle performance, fast charging and discharging, and high charging efficiency;

•The energy of the battery cell is small, and the failure is easy to control;

•Large heat dissipation area;

Disadvantages of cylindrical cells

•The space utilization rate is not as good as that of square cells;

•The shell is made of steel or aluminium, which is relatively heavy;

•Small room for energy density increase;

Advantages of square cells

• Higher space utilization;

• High strength, low internal resistance and long life;

• The volume and capacity of the monomer are better than other batteries;

• Can be customized;

• Simple structure, easy to expand capacity;

• The cell has high stability and is not prone to problems;

• The volume and capacity of the monomer are large, indicating that the number of packs is reduced, which means that the BMS requirements are reduced;

Disadvantages of square cells

• There are many models, and the process is difficult to unify;

• It is difficult to dissipate heat;

• The level of production automation is not high;

• There is a large difference between the monomers, and in large-scale applications, there is a problem that the system life is shorter than the life of the monomer;

• Higher space utilization means higher requirements for the cooling system, which means that the design cost of the battery pack needs to be increased;

Advantages of soft-packed cells

• Very high energy density;

• Thinner volume;

• Can be customized;

• Lightweight;

Disadvantages of soft-packed cells

• Poor overall performance;

• Requires additional protection against battery damage and thermal runaway;

Conclusion

Since these three kinds of batteries have their own characteristics and advantages, these three kinds of batteries are used in various fields. Cylindrical cells have been developed for a long time, so the manufacturing process is more mature and the cost is lower. But there is still room for further improvement in terms of energy density. Although the standardized technology of square cells and pouch cells is not as high as that of cylindrical cells, they can be customized according to the needs of different vehicles and application areas.