Why Are Lithium-ion Batteries Used In EVs?
Lithium batteries have been around since the 1970s and have become the default cells used in electric vehicle battery packs. They come in several sizes, but the most common ones used in EVs aren’t that dissimilar from what you’d find in your TV remote.
Electric car battery packs consist of between several hundreds to several thousands of these cylindrical Lithium-ion cells. The mode of operation is simple. Like a regular battery, lithium-ion ones consist of an anode (negative) and a cathode (positive) separated by an electrolyte.
When placed in a closed circuit, the battery’s lithium’s outer electron travels across the circuit from the negative to the positive terminal. The lithium-ions, with one less electron, travel from the anode (inside the battery), through the electrolyte and flow towards the battery’s cathode.
When charging the battery with an external power source, the exact reverse reaction takes place. The electrons flow through the external circuit from the cathode and head towards the anode. The Lithium-ions that have lost said electron, leave the cathode and flows back through the electrolyte to the anode.
Now that we know the basics of how this type of battery works, it’s also important to know the reasons why Lithium-ion batteries are used over other options to power electric vehicles.
High Power Density
These batteries can hold a significantly higher amount of charge compared to similarly sized conventional batteries. Despite being small, they can also offer a high discharge rate, which means they can deliver the power that they have, quickly.
High Voltage
Lithium-ion batteries can deliver high voltage. Voltage is the potential difference measured between two points. It’s the pressure that is exerted on electrons, propelling them forward in a circuit. The higher the voltage, the higher the current flows through the circuit (as long as all other parameters remain equal).
Long Service Life
Lithium-ion batteries can be charged and discharged over several hundred or thousands of cycles without experiencing much degradation. This makes them ideal power sources for electronic devices and electric cars.
Can Be Charged In A Short Time
Lithium-ion batteries can be charged significantly faster than conventional batteries. The rate at which they can reverse the chemical reaction mentioned earlier is far quicker than that of other rechargeable batteries. This is why electric cars can be charged in a few hours or in some cases in under an hour with the right charger.
Low Self-Discharge
They don’t lose much power when not used. That means they can keep their charge for far longer periods than other types of batteries. This is why your smartphone’s battery doesn’t lose much power if you don’t turn on your phone for days or weeks.
We hope this article helped shed some light on why lithium-ion batteries have found their way into most of our electronic devices. That said, Studies are underway to find a replacement for Lithium due to its negative environmental impact. Though it offers many benefits, its use does introduce several drawbacks.
