If you're thinking about buying or servicing an electric vehicle, you may come across some unfamiliar terminology. One of these could be the different types of lithium-ion batteries used in modern electric vehicle applications. This can be confusing at first – what's the difference between them? Is one type better than another at powering electric vehicles?
We'll answer all of these questions and more as we explore the various lithium-ion battery technologies used by manufacturers today. We'll explain the features of each model and discuss the pros and cons associated with each so you can make an informed decision about which option is best for your specific needs.
What's so special about lithium-ion batteries?
Lithium-ion batteries are one of the most commonly used battery types in electric vehicle battery pack designs today. This may be due to their immense ability to have high energy density and lightweight. First developed in the 1970s, lithium-ion batteries are primarily composed of graphite, manganese oxide, cobalt oxide and iron phosphate, among other metals.
Additionally, these batteries have a high expected cycle life, meaning they can be recharged hundreds or thousands of times without significant degradation. For example, a common electric car model has a range of 310 miles, and the battery's life expectancy is about 500 to 800 charge cycles before it really starts to degrade.
Combined with these attributes, lithium-ion batteries offer drivers undeniable value in electric vehicles – further underscoring their continued relevance in the automotive industry.
Different types of battery architecture used in electric vehicles
As electric vehicles become more common, it's important to understand the different types of battery architectures used in them. From lithium-ion and cylindrical cells to pouch designs and larger prismatic modules, there are many types of cells that make up electric vehicle battery packs, each with performance advantages and disadvantages in a range of applications.
Additionally, as technology rapidly develops, batteries may become more efficient in the future. Understanding these battery architectures can help guide decisions when choosing the right electric vehicle based on factors such as cost, range, scalability and efficiency.
Cylindrical battery
Cylindrical batteries are the most common type of battery used in electric vehicles. They consist of a metal container with two electrodes (cathode and anode) containing a lithium-ion electrolyte. The size of these cells can be customized to meet the specific needs of the application, making them highly versatile and ideal for electric vehicle applications.
Advantages and Disadvantages of Cylindrical Batteries
advantage:
Versatility - Can be made in a variety of sizes to suit specific needs.
High Energy Density – These batteries are designed for high energy efficiency, which means longer range per charge.
Cost-effective – Cylindrical cells offer significant cost savings compared to other designs.
shortcoming:
Limited Scalability – Cylindrical cells may not be suitable for large applications.
Low Temperature Performance – These batteries tend to perform poorly in cold temperatures and use in such conditions may require additional insulation.
Reduced Safety Features – While cylindrical batteries are generally safe, their design does not provide the same level of safety features as some other designs.
Inefficient use of space – When multiple cells are packed side by side, cylindrical cells create gaps that reduce the energy density of the battery pack.
Soft pack battery
Pouch batteries are an increasingly popular option for electric vehicles due to their lightweight and flexible design. They consist of two electrodes with a soft pouch between them filled with electrolyte and sealed with a laminated membrane. This allows the battery to be shaped as needed, making it ideal for applications where space is limited, such as electric vehicles.
Advantages and Disadvantages of Soft Pack Batteries
advantage:
Lightweight – Pouch batteries are much lighter than other battery designs, making them ideal for electric vehicles.
Flexible Design – These cells can be bent or shaped as needed to fit into tight spaces.
High Energy Density – Pouch batteries have high energy density due to their thin form factor and flexible design.
shortcoming:
More Expensive – Pouch batteries tend to be more expensive than other designs.
Limited Scalability – Pouch batteries may not be suitable for large applications due to their limited size.
prismatic battery
Prismatic cells are larger and more powerful than cylindrical or pouch cells, making them an excellent choice for large EV battery packs. These batteries consist of a stack of electrodes sealed in an aluminum casing, filled with lithium-ion electrolyte, and then folded into the desired shape. This allows the battery to be customized for any type of space restriction, making it an excellent choice for large battery packs.
Advantages and disadvantages of prismatic batteries
advantage:
High Energy Density – These cells offer higher energy density than other designs.
Versatility – The design of prismatic cells allows customization of size and shape to meet specific needs.
Scalable – These batteries can be expanded to meet the needs of larger electric vehicles.
shortcoming:
More Expensive – Prismatic cells tend to be more expensive than other designs.
Reduced Flexibility – The design of prismatic cells makes them less flexible than cylindrical and pouch cells.
Can you choose lithium-ion battery architecture in electric vehicles?
While it's helpful to understand the different architectures used in today's electric vehicle batteries, it won't impact your choice once you're familiar with a specific vehicle. Manufacturers choose the type of battery architecture during the engineering phase, usually based on the vehicle's intended use.
Safety is of paramount importance to car manufacturers, so any of these designs are thoroughly tested before being deployed into new models. Still, in some cases, failures can occur due to manufacturing reasons, and we've seen recalls of battery packs that might have been avoided if a different architecture had been used.
Becoming more familiar with the different battery designs of electric vehicles can help you better understand how they work, which is critical for technicians to understand how to care for, repair, and replace these powerful batteries.
