EV Battery Technology: The Next Frontier
November 29, 2022
The world is rapidly shifting to electric, as seen through the influx of newer EV models amongst the world’s top car manufacturers. Although the car industry is still driven primarily by internal combustion engines (ICE), many are slowly shifting towards a more electric future. Driven by pressures from climate change pledges and the allure of generous government subsidies, many car manufacturers are jumping in to support this shift.
However, there are still many challenges ahead for manufacturers and consumers to adopt a fully electric future.
One of which is the battery.
For many 3rd world countries, infrastructure is either non-existent or inadequate, a significant problem that needs to be solved before a full rollout of electric vehicles can be done. While in countries like the U.S. and India, the adoption is much higher simply because the infrastructure is already present and growing.
EVs run on batteries like any other electronic device one may own. This means the need to top up on power and recharge eventually is constant. And just like a mobile phone, an electric vehicle still uses lithium-ion technology, albeit scaled up for electric cars.
What are EV batteries made of?
What powers today’s electric cars? What do most electronics rely on daily? Simple. A battery made out of lithium-ion. A lithium-ion battery boasts a higher energy density than its lead-acid or nickel-cadmium rechargeable counterparts, thus making the size of lithium-ion batteries more space efficient. Lithium-ion batteries are also relatively safer than their counterparts. These batteries are usually manufactured with an integrated battery management system (BMS), which helps the battery charge and operate safely and efficiently.
How does it work?
The interaction between an EV’s battery and the motor is relatively simple. Unlike an internal combustion engine that requires several moving parts to make a car move, an EV powers electric motors to drive the wheels into motion. However, a battery will eventually deplete all its charge as the driver steps on the accelerator, triggering the storm to allow a current to flow into the motors.
A feature of an electric motor is that it can also function as a generator. Meaning when the rotor is moved, a current can be generated instead. Therefore, when the driver takes their foot off the accelerator, the momentum generated by the vehicle allows the forward motion in the wheels to be converted back into electric energy and stored back into the battery. Partner this with regenerative braking technology, where a driver can generate additional power when braking, thus adding a bit more range to an EV.
An EV battery is also typically rated sturdy and may last longer. EV Manufacturers stand by it and even guarantee the batteries for anywhere between 5 to 8 years. For example, the Japanese car manufacturer, Nissan, provides an 8-year warranty or 100,000 miles for its EV battery. A battery’s lifecycle can deteriorate when it goes through several discharging cycles. Despite this, many manufacturers predict that an electric car battery can last nearly two decades before needing replacement.
The EV battery charging challenge
One of the most significant limitations of driving an electric vehicle is its dependence on battery life. A feature that makes it difficult for those longer drives. An electric car will only be helpful for shorter distances without a viable infrastructure to provide charging stations at key locations. How far can one drive on a full charge? A fully electric vehicle or BEV could probably hit a range of 250 miles on a single full charge, while other brands boast of hitting 600 miles (Tesla and Mercedes). A plug-in hybrid or PHEV may drive around 10-15 miles before switching to gasoline. A hybrid, or HEV, will go for about 50-60 miles completely electric before becoming dependent on fuel once again.
For longer drives, planning a journey will now include knowing where the charging stations are to ensure the EV doesn’t run out of juice in the middle of nowhere. That’s not all either, as charging time can easily take between 30 minutes to 12 hours, depending on the battery's size and the charging point's speed. Compare that to the few minutes taken when pumping gas.
To find a solution to this problem, some companies in the U.S. and China have started offering battery-swapping options. Although more viable for fleets than the regular consumer, a driver can change a battery through a specialized swapping station in 3 minutes. In China, local EV manufacturer Nio offers this as a service, while U.S. start-up Ample has also started to offer similar services.
Swapping batteries is a tedious task requiring specialized robots to disconnect, remove and attach a fully charged battery in a few minutes. However, battery swapping may only be temporary since most manufacturers prefer to develop their own battery cells. But what does the future hold for the EV battery?
The battery of the future: Solid-state
All battery manufacturers are always looking for ways to improve the energy density of their batteries. Although the market for portable batteries is now dominated by lithium-ion technology, a new technology is seemingly on the rise that can replace its predecessor. While lithium-ion depends on the chemistry of certain electrolyte liquids to produce a charge, a solid-state battery, on the other hand, uses solid electrolytes instead. Many solid-state battery designs use an anode made of lithium metal, not graphite. Since these are more compact, solid-state batteries offer higher energy densities, faster charging times, and less of a fire hazard.
Unfortunately, it will still take time for the technology to mature and improve, and costs still need to come down to make it more viable. As of today, a solid-state battery could easily cost as much or even more than the car it will power up. What makes these solid-state batteries so expensive? Some difficulties arise in mass-producing solid-state batteries, and a significant one is the formation of dendrites. These small branches of a metal leak from the anode into the electrolyte, which can cause the battery to short out.
Today, automotive companies like Ford and GM have started to invest more in battery research, hoping to edge out companies like Tesla. In an announcement last March, Samsung SDI announced its solid-state pilot production line construction. The U.S.-based company, QuantumScape, aims to mass produce these batteries by 2024 or 2025, seeking to reduce battery costs by 15-20%.
Despite innovations in various technologies, batteries have remained relatively the same over the years. Lithium-ion battery costs may have decreased considerably over the last few decades, but the energy density, charging time, and chemistry have remained somewhat consistent. Could the solid-state battery be the answer to this problem? One thing is for sure, for the future to be electric, innovations in EV batteries will play a major role in how quickly the world can adopt going fully electric.
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