Electric vehicles (EVs) are always evolving, and so are the batteries that power them. Traditionally, EVs use lithium-ion batteries as a power source. However, a new solid-state battery could replace them, though we may still be some time away from that.

Auto manufacturers are testing the batteries, with some further along than others. Importantly, the batteries are still in trial phases, but auto manufacturers are eager to equip EVs with solid-state batteries because of the potential benefits.

What Are Solid-State Batteries?

Solid-state battery
Solid-state battery; Photo: Mercedes-Benz Group

The key to understanding a solid-state battery is knowing the difference between it and lithium-ion batteries. One major difference is the separator in each battery, which separates the anode and cathode (negative pole and positive pole). A current lithium battery’s separator is submerged in the liquid electrolyte, a medium through which the ions move. A solid-state’s separator is not submerged in liquid. Instead, it’s usually made of ceramic or solid polymer, hence the name solid-state.

In short, this provides the potential benefits of the solid-state battery, including greater energy density, a longer life, and greater safety in a smaller size. Additionally, studies have shown that it charges six times faster than available technology. According to an overview from Flash Battery, some people say that because it doesn’t require a liquid state, it allows for quicker production.

Much like an anode and cathode, the positives come with negatives.

The solid-state separator can only operate under high temperatures. For example, when the battery is not hot, its performance declines “considerably.” In addition, Flash Battery’s overview states that the life cycle is still shorter than that of other lithium-ion technologies, with some surpassing 4,000 charges. Currently, production costs are very high.

Testing the New Technology

Solid-state batteries have great potential in the electric vehicle sector. In February, Mercedes-Benz started road tests with the all-electric EQS after previously modifying the vehicle to fit the solid-state battery. According to a report from Autocar, BMW says that there is “a long way to go” with lithium-ion batteries before the industry starts testing new technology. The report says that BMW’s Vice President of Next-Generation Battery Tech, Martin Schuster, estimates that BMW is eight years away from needing solid-state batteries in its vehicles.

In February, it seemed like Hyundai was ready to launch a pilot test of the new technology in March. However, Elektrek reports that Hyundai doesn’t expect to have the technology ready for Kia electric vehicles until 2030.

Despite the uncertain timeline for official solid-state battery production, auto manufacturers are heavily researching and studying the technology. In addition to the companies mentioned above, Toyota, Nissan, and Volkswagon are also investing in and attempting to industrialize the technology.