With electric vehicles (EVs) becoming a crucial part of sustainable transportation options worldwide, understanding their anatomy—specifically their batteries—is necessary as we transition to cleaner means of transport. This article offers a clear look into EV battery technology, covering everything from its most basic components to operational dynamics.
This blog is an ideal resource for sustainable tech enthusiasts, as it will cover all the details of what makes an EV battery. While we will cover the specific components of an EV battery, for more information about its lifespan and maintenance, check out our article on EV battery longevity here.
What is in an EV battery?
Simply put, an EV battery is a rechargeable battery that powers the electric motor of an electric vehicle. Most batteries use lithium, cobalt, graphite, and other minerals, with lithium being the most popular as it can generate greater energy levels and is relatively lower in cost.
While the minerals can be different, every EV battery build is relatively the same. An EV battery comprises a cell, a module, and a pack. Let’s talk about each of these to better understand how these batteries are built. EV batteries share a lot of similarities with other kinds of batteries but with extra steps that make the layout smarter and stronger.
The cell: The primary unit of energy storage.
EV batteries consist of numerous cells that act as individual power units. As KPA explains in their article, each cell is made of two electrodes that store electric current. One, the anode, holds a positive charge, while the cathode is negatively charged. An electrolyte solution separates these two electrodes and transports positively charged ions between the anode and the cathode. As energy is used, it is released from the anode.
In this image, you can find a detailed diagram of the electrochemical process.
Source: Self-Made Diagram based on EV Electrochemical reaction, Karsten and West 2015
Different types of EV cells.
According to EV Box, EV batteries have different cell styles: cylindrical, prismatic, and pouch cells.
- Cylindrical cells are compact, durable against mechanical shocks, cost-efficient, and easy to make. However, they may offer limited power output.
- Prismatic cells are much larger than cylindrical ones, offering more energy storage, power, and superior heat resistance.
- Pouch cells have a space-efficient design in a soft plastic casing. However, while this design provides higher efficiency, the delicate casing may need additional protection to prevent mechanical damage.
Modules: Scalable energy clusters.
A module is a collection of strategically organized cells. The structure protects the cells against heat and vibration. This modular arrangement simplifies manufacturing and enables scalability. The following image represents how modules are compiled in an EV battery.
Source: EV Modules diagram adapted from (Modules of an EV, O’Shaughnessy, 2022)
The battery management system (BMS).
The BMS is the brain of an EV battery. This intelligent electronic system supervises and controls battery operations. Its primary directive is to take care of the battery. It handles the charging and discharging of the cells, ensuring they perform optimally. By monitoring parameters such as voltage, current, and battery temperature, the BMS preserves the battery from overheating or overcharging, thus extending battery life and protecting the device from sudden disruptions. It also reports on charging and battery status for outside structures, like chargers.
Source: Battery Management System diagram adapted from (Battery Management System (BMS), O’Shaughnessy, 2022)
The cooling system.
The cooling system does what its name suggests. It moves heat away from the battery modules, as EV batteries can generate significant heat during energy discharge. This is the same reason why your phone heats up when it’s working extra hard. The process is similar to antifreeze or cooling systems for combustion engine vehicles and fans and coolants in computers.
The casing.
Finally, the casing protects the cells, modules, and the cooling system from different types of damage, including impacts, chemicals, external vehicle heat, environmental heat, and structural harm.
How the charging process works.
EV batteries recharge through a process known as “intercalation.” As Martinneau R. states in this article, this process involves connecting an electric vehicle to a charger. This charger prompts an external electrical power source that moves lithium into the negative cathode. Then, the lithium-ion moves from the negative cathode to the positive anode, charging the cells. This same process is often applied to handheld devices and mobility devices but on a different scale.
There are also different levels of EV chargers for your battery. Let’s talk about the main differences between the charging levels, their benefits, and their uses.
Charging levels explained.
Level 1 charging is the most basic, using a standard 120 V outlet. It’s slow and doesn’t require special equipment.
Level 2 charging requires a 240 V electrical source and charges much faster, making it suitable for home and public locations.
Level 3 charging, often called direct current fast charging (DCFC), offers the quickest charge. Due to high power demand, it’s primarily used in commercial settings.
When charging, vehicles communicate with the charging equipment via a digital “handshake” —imagine both systems agreeing on what needs to be done. This process ensures that batteries charge safely and efficiently. Chargers, working hand in hand with the batteries’ BMS, consider the batteries’ maximum charge rate, temperature, and other factors. This happens on Ivy chargers as soon as you plug in.
Battery and charging technology is evolving to allow higher energy density in batteries and high-power charging. Reliable, safe, and efficient charging is common throughout this evolution.
Bridging the gap between technology and sustainability with Ivy.
EV batteries power the hearts of electric vehicles and, just like cells in our bodies, each part of an EV battery has its own job. It takes a lot of know-how to assemble these pieces and make them work efficiently and safely.
The shift to EVs is part of our efforts to reduce environmental footprints and move toward a decarbonized world. By ensuring easy access to increasingly efficient charging infrastructures, we can accelerate the adoption of EVs, helping people contribute to a sustainable future while easily accessing charging stations that accommodate their needs.
If you are looking for Level 2 chargers for your home or Level 3 stations across Ontario, Ivy has your back. Whether at home, at work, or on the go, you can always count on our intuitive and reliable electric vehicle charging solutions.
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