Lithium-ion EV batteries: What are they and how do they work?

As the “heart” of an electric vehicle, an EV battery distributes electrical energy needed to power the car, but also serves as a storage system for this same energy.

As such, EV batteries need to possess a number of key characteristics; among them are having high voltage and charge storage.

The current drive for “green” energy also requires that these batteries not only have zero to low gas emissions, but also be recyclable so that electronic waste does not end up polluting the environment.

At present, lithium-ion EV batteries meet these high standards. This article serves as your introduction to these batteries, how they work, and how they are produced and eventually recycled.

What is a lithium-ion EV battery?

Lithium-ion EV batteries are considered as an advanced form of battery technology. Most people are familiar with these batteries because they are commonly found in smartphones, laptops, and other electronic devices. 

It is so-named for the lithium ions present in the EV battery components. The electrochemical reaction of these ions generates electricity that powers the vehicle.

How do lithium-ion EV batteries work?

To better answer this question, we need to take a look at the four main components of the lithium-ion EV battery: the cathode, anode, separator, and electrolyte. 

Inside a single EV battery cell, the cathode (positive electrode) is installed apart from the anode (negative electrode) by a micro-permeable separator. These two electrodes both contain lithium ions, although there are more in the cathode when the battery isn’t running. The cathode and anode are immersed in an electrolyte solution, through which the lithium ions will flow.

When you turn the EV on, the battery is in a state of DISCHARGING. A chemical reaction occurs which results in lithium ions flowing from the cathode to the anode. This flow generates the electrical energy distributed throughout the EV.

When you turn off your EV and plug the battery in an electrical outlet, it is now in a state of CHARGING. The chemical reaction now happens in reverse. The lithium ions now flow from the anode to the cathode, where it is stored.

This reverse reaction also occurs when you slow down or step on the brakes (also known as “regenerative braking”). The excess kinetic energy produced by the EV also results in the flow of lithium ions from the anode to the cathode, so that more energy is stored.

How are lithium-ion EV batteries manufactured?

Most people erroneously believe that their cars contain a single battery. However, an electric vehicle needs a large number of batteries to power it.

The battery’s manufacturing follows a strict design to ensure high voltage, high storage capacity, and safety.

This design begins with the individual cell. As mentioned earlier, a single cell is assembled so that you have the anode and cathode apart from each other by means of a separator and then immersed in an electrolyte solution. Most commonly used in EV battery current collectors assembly are copper and aluminum. 

This is then encased in a metal housing. Tests are done to check for electrolyte leaks and prevention of moisture seepage within the battery.

These EV battery cells are then assembled into modules, which have their own sturdy metal housing to protect the cells from external shocks. Modules are then placed inside the large battery pack and installed in an electric vehicle.

What are busbars?

Busbars are among the types of EV battery components that can be put in to improve the battery’s overall performance. It is a conductor, enabling the flow of current through an electric vehicle’s subsystems.

Meanwhile, laminated busbars are multi-layered and composite structures connected with a platoon. They are used as the electric current distribution system to the main parts of an EV.

These are highly customizable, quickly installed, helps reduce overall system costs and improves performance reliability in EV batteries.

How long does a lithium-ion EV battery last?

The lifespan of lithium-ion EV batteries makes it ideal for electric vehicles. On average, this type of EV battery is built to last for 10 to 20 years with proper usage and care.

Much like the lithium-ion batteries in your electronic gadgets, these batteries should not undergo extreme charging cycles (i.e., depleting the battery to 0, then charging it to 100%). It is best to maintain the battery’s state of charge (SOC) at 20 to 80%.

Are lithium-ion EV batteries sustainable?

The U.S. Environmental Protection Agency defines “sustainability” as being able to meet present needs without compromising next generations’ ability to meet their needs.

This entails taking action necessary to protect the environment in economically viable, socially just, and humanly beneficial ways.

So, are lithium-ion EV batteries sustainable? To answer this, we need to take a look at the lithium EV battery components. 

The most important chemical components in these EV batteries are found in the cathode, namely lithium, manganese, nickel, and cobalt.

While lithium and manganese are abundant (current reserves of lithium stand at 21 million tonnes) and can support the projected ambitious conversion to EVs from 2030s to 2050s, lithium mining requires large amounts of energy to extract from rock and large volumes of water to extract from brine.

More problematic are nickel and cobalt, two-thirds of which are being mined in the Democratic Republic of Congo. Cobalt is a highly toxic heavy metal. As the demand for these metals increases, there is a danger of experiencing shortages for EV battery manufacturing.

Future EV battery technology is currently focused on eliminating cobalt and/or nickel from cathodes without compromising battery performance. One way is by using small quantities of other metals while maintaining the integrity of the cathode’s crystal structure that is the same as cobalt-oxide. Another method is the use of disordered lithium-rich rock salts that allow for easy flow of lithium ions with repeated charging, even in the absence of nickel or cobalt.

Recycling lithium-ion EV batteries

In light of the potential shortage of these batteries, recycling plays a big role in possibly addressing these deficits.

The umbrella term used to describe the processes for recycling lithium-ion batteries is “destructive dismantling”.

Whether it’s smelting, direct recovery, or intermediate processes between the two previous procedures, recycling involves destroying the batteries themselves to recover the valuable metals and other elements, which can be reused in new batteries or for other purposes. 

The latest technologies in EV batteries material recycling, particularly wet-chemistry extraction, allows for more efficient recovery of lithium and other valuable materials. These technologies are vital now as more EVs are reaching their end-of-life. The US Department of Energy projects that “recycled material could potentially provide one-third of United States cathode material needs for lithium-ion batteries by 2030.”