Why Are Lithium Batteries Mostly Cylindrical or Prismatic? Which Is Better: Cylindrical or Prismatic Lithium Batteries?

The shape design of lithium batteries (cylindrical, prismatic, button, etc.) is a comprehensive reflection of their performance, manufacturing processes, and application scenarios. Cylindrical and prismatic lithium batteries have become mainstream because they each have advantages in terms of technological maturity, manufacturing processes, performance, and application scenarios.

1. Why Are Lithium Batteries Mostly Cylindrical or Prismatic?

(1) High Technological Maturity

• Cylindrical Batteries: Cylindrical batteries (such as the 18650) were the first type of lithium batteries to be commercialized on a large scale. They have mature production processes, high levels of automation, and good consistency.

• Prismatic Batteries: Prismatic batteries are widely used in consumer electronics (such as mobile phones and laptops). Their manufacturing processes have been optimized over the years and are technologically mature.

(2) Simple Manufacturing Processes

• Cylindrical Batteries: The winding electrode process for cylindrical batteries is simple, making them suitable for mass production. Additionally, the metal casings are easy to manufacture.

• Prismatic Batteries: Prismatic batteries use flexible stacking or winding electrode processes. They have metal casings that provide stable structures.

(3) Excellent Performance

• Cylindrical Batteries: Cylindrical batteries have high mechanical strength and good heat dissipation, making them suitable for high-power applications.

• Prismatic Batteries: Prismatic batteries have high space utilization and energy density, making them suitable for compact devices.

(4) Wide Range of Applications

• Cylindrical Batteries: Cylindrical batteries are widely used in electric vehicles, power tools, energy storage systems, and other fields.

• Prismatic Batteries: Prismatic batteries hold an important position in consumer electronics, electric vehicles, energy storage systems, and other fields.

2. Cylindrical Lithium Batteries vs. Prismatic Lithium Batteries: Pros and Cons Comparison

(1) Cylindrical Lithium Batteries

• Advantages:

  1. Mature Manufacturing Process: High degree of automation, good consistency, and suitable for mass production.

  2. High Mechanical Strength: The metal casing provides strong resistance to impact and vibration, enhancing safety.

  3. Good Heat Dissipation: The cylindrical design increases the surface area, allowing for even heat distribution and efficient cooling.

  4. Easy to Combine: They can be flexibly arranged in series or parallel to form battery packs, making them suitable for high-power applications.

• Disadvantages:

  1. Low Space Utilization: Gaps between batteries when assembled into packs reduce the overall energy density.

  2. Higher Weight: The metal casing adds weight, which is not ideal for lightweight design.

  3. Shape Limitations: The cylindrical shape may not fit well with the space requirements of certain specialized devices.

(2) Prismatic Lithium Batteries

• Advantages:

  1. High Space Utilization: Prismatic batteries can be closely packed, reducing gaps within the battery pack and increasing overall energy density.

  2. Flexible Design: Dimensions and shapes can be customized to meet specific device requirements, offering strong adaptability.

  3. Stable Structure: The metal casing provides good mechanical strength and thermal management performance.

  4. Easy to Modularize: Suitable for modular design, facilitating the integration of large-scale battery packs.

• Disadvantages:

  1. Complex Manufacturing Process: Higher production process requirements, difficult to ensure consistency, and higher costs.

  2. Poorer Heat Dissipation: Smaller surface area leads to concentrated heat, requiring additional thermal management systems.

  3. Higher Weight: The metal casing adds weight, which has some impact on lightweight design.

3. Cylindrical Lithium Batteries vs. Prismatic Lithium Batteries: Which Is Better?

(1) From the Perspective of Application Scenarios

• Cylindrical Batteries: Suitable for high-power and high-consistency applications, such as electric vehicles, power tools, and energy storage systems.

• Prismatic Batteries: Suitable for space-constrained applications with high energy density requirements, such as consumer electronics, electric vehicles, and energy storage systems.

(2) From the Perspective of Performance

• Cylindrical Batteries: High mechanical strength and good heat dissipation, suitable for high-power output.

• Prismatic Batteries: High energy density and high space utilization, suitable for compact devices.

(3) From the Perspective of Manufacturing Processes

• Cylindrical Batteries: Mature manufacturing processes, suitable for mass production.

• Prismatic Batteries: Complex manufacturing processes, but flexible design, suitable for customized needs.

(4) From the Perspective of Future Trends

• Cylindrical Batteries: Large-format cylindrical batteries (such as the Tesla 4680) combine the high consistency of cylindrical batteries with the high energy density of prismatic batteries and are expected to become mainstream in the future.

• Prismatic Batteries: With the development of CTP (Cell to Pack) technology, the advantages of prismatic batteries in terms of energy density and cost will be further highlighted.

Summary

• Cylindrical Lithium Batteries: Suitable for high-power and high-consistency applications, with mature manufacturing processes and good heat dissipation, but lower space utilization.

• Prismatic Lithium Batteries: Suitable for space-constrained applications with high energy density requirements, with flexible design, but complex manufacturing processes and poorer heat dissipation.

Which is better? There is no absolute superiority or inferiority. The choice between cylindrical and prismatic lithium batteries depends on the specific application scenario and requirements:

• If high-power output and good heat dissipation are required, cylindrical batteries are a better choice.

• If high energy density and compact design are required, prismatic batteries are more advantageous.

In the future, with the development of large-format cylindrical batteries and CTP technology, both cylindrical and prismatic lithium batteries will continue to play important roles in their respective areas of expertise.