By and large, lithium batteries bring a wide range of different benefits to the table that are difficult - if not impossible - to replicate in any other way. Also commonly referred to as lithium-metal batteries (due to the fact that they use lithium as an anode), they're typically capable of offering a very high-charge density (read: longer lifespan) than other alternatives that are on the market today.
For that reason alone, lithium batteries have a wide range of applications in our daily lives, especially for those critical in nature that we tend not to spend too much time thinking about. Specialized types of lithium batteries are used in pacemakers and other implanted medical devices, for example, because they can often last 15 years (or longer) under the right circumstances. They've even started to replace traditional alkaline batteries in many everyday devices like clocks, digital cameras, watches, portable data assistants, and more, all thanks to that longer lifespan that minimizes the need to replace the battery over time.
But, regardless of the specific application you're looking at, when it comes time to actually select a lithium battery for your own uses, you will have two major options available to you. Cylindrical and prismatic lithium batteries are very common in today's modern, tech-driven world, and each brings with them their own unique sets of advantages and best practices that are certainly worth exploring.
What Are Cylindrical Lithium Batteries?
Cylindrical lithium batteries, as the name suggests, feature electrodes that are encased in a cylindrical cell that is wound very tightly within a specially designed metal casing. This unique makeup helps to minimize the chances that the electrode material inside will break up, even under the heaviest of use conditions.
Example of cylindrical lithium batteries.
Issues like mechanical vibrations, thermal cycling from charging and discharging, and the mechanical expansion of current conductors are all things that can affect a battery's lifespan. Therefore, the design of these cylindrical units is intended to help mitigate risk from these and other factors as much as possible.
On the inside of a cylindrical battery, a series of cells are combined and operate in parallel to one another. This is done to help increase both the voltage and the overall capacity of the battery pack.
For these reasons, cylindrical batteries are usually the kind that are found in the aforementioned medical device systems. Smaller, more specially designed cylindrical cells are also commonly found in portable devices like laptop computers. Notably, Tesla also made headlines recently by selecting cylindrical lithium batteries to power its fleet of popular electric cars.
What Are Prismatic Lithium Batteries?
A prismatic lithium battery, on the other hand, features a cell that has been encased in either aluminum or steel, mainly for the purposes of increased stability. This, in turn, creates several key advantages right out of the gate. Because of this unique construction and makeup, prismatic lithium batteries tend to be very thin, very light and offer an effective use of space.
Example of prismatic lithium batteries.
Because the rectangular shape of your average prismatic Li battery offers far better layering than other options, they typically give engineers a higher level of flexibility when designing products that will one day feature prismatic batteries as power sources. Because of that, it should come as no surprise that prismatic batteries are typically found in smartphones, tablets, and similar types of electronic devices where mobility is a major priority.
Due to these properties, modern day prismatic batteries are also commonly used in larger critical applications like energy storage systems and in electric powertrains.
Cost, Manufacturing, and Automation Considerations
Cylindrical lithium batteries are the most commonly available and widely used type today. When compared to their prismatic counterparts, they can typically be produced much faster and with a lower cost-per-KWh (kilowatt hour). Their design naturally supports automation in manufacturing, which ensures better product consistency and keeps production costs low.
One of the main reasons prismatic cells have gained popularity in recent years is their large capacity. Their rectangular shape allows for easy stacking, making them ideal for high-power applications like energy storage systems and electric powertrains. However, this design comes with drawbacks, particularly when it comes to failure risks—if one cell in a prismatic battery fails, the entire battery pack may become compromised. In contrast, cylindrical cells are connected in series and parallel configurations, reducing this risk.
Heat Management, Design Flexibility, and Cost Trade-Offs
One of the key advantages of cylindrical lithium batteries is their ability to radiate heat efficiently, helping to regulate temperature naturally. Prismatic batteries, on the other hand, pack cells tightly together, which increases capacity but also raises the likelihood of short circuiting and design inconsistencies. Additionally, prismatic cells can be more challenging to integrate into automated production processes due to their larger size.
The thin form factor of prismatic batteries gives product designers more flexibility, but this comes at a cost. Their manufacturing process is more complex and expensive, which often leads to higher consumer prices. Additionally, limited standardization in prismatic battery sizes makes it harder to achieve mass production efficiency. While they cost more upfront, prismatic cells can offer long-term cost savings, depending on the application.
In most cases, cylindrical batteries are considered safer. If internal pressure builds too high, most cylindrical cells are designed to rupture safely, reducing the risk of fires or explosions. This built-in safety feature makes them a preferred choice for applications where reliability and risk mitigation are top priorities.
Summary
None of this is to say that cylindrical lithium batteries are inherently "better" than their prismatic counterparts, or vice versa. As is often the case with these types of situations, there is no "one-size-fits-all" approach to battery selection. Much of your decision will ultimately come down to the eventual application and the amount of risks and potential disadvantages that you're willing to accept as a result. There will be some situations where a prismatic battery absolutely makes the most sense. There will be situations where cylindrical batteries seem like the logical choice.
More often than not, choosing the right type of lithium battery to meet your needs will come down to three factors:
- The amount of money you're willing to pay, the effectiveness of the battery you're trying to unlock, and the safety considerations given the application.
- If space isn't necessarily at a premium and you need to find a cost-effective way to guarantee both performance and longevity, cylindrical batteries offer what you need.
- If cost isn't a factor and you need as much power as possible in an already small space, prismatic is likely the direction you'll want to head in.
Only by trying to learn as much about these options as possible will you be able to make the best decision given your needs in the moment. Ultimately, your ability to do that successfully is all that matters.
Key Takeaways:
- Cylindrical Batteries Offer Cost-Effective Manufacturing & Reliability:
- Cylindrical lithium batteries are widely used due to their lower production costs, automation-friendly design, and safety features that help regulate heat and prevent overcharging.
- Prismatic Batteries Maximize Space & Energy Density:
- Their thin, rectangular shape allows for efficient layering and higher capacity, making them ideal for smartphones, tablets, and energy storage systems where compact, high-power solutions are needed.
- Thermal Management & Safety Vary by Design:
- Cylindrical batteries naturally dissipate heat more effectively, reducing the risk of overheating, while prismatic cells have higher short-circuit risks due to their compact design.
- Cost vs. Long-Term Savings Tradeoff:
- Cylindrical batteries cost less upfront and are easier to replace if a single cell fails, while prismatic batteries may offer long-term cost reductions despite higher initial pricing.
- Application Determines the Best Battery Choice:
- Cylindrical batteries suit applications prioritizing affordability, safety, and longevity (e.g., medical devices, laptops, EVs like Tesla), whereas prismatic batteries are preferred for high-density energy storage in compact spaces (e.g., smartphones, powertrains).
