What Are Solid-State Batteries?

Electrification is the trend nowadays, with every manufacturer more or less ditching the old internal combustion engines to transition to electric vehicles. However, at the current time, such a task is difficult and precarious due to the mass and volume of the current batteries, among other matters. That’s where the upcoming solid-state battery comes into play. The question is, what’s this supposed holy grail?


Samsung Electric


How Electric Batteries Work

To understand the difference, we need to delve a little bit into how batteries work. Explained incredibly simplistic, a battery works by transferring a bit of electric charge from a chemical to another chemical through some sort of medium, called an electrolyte. This electricity is produced thanks to a chemical reaction that can go in both directions; that is, the reaction can occur to create electricity, or the reversal can happen and absorb electricity to recreate the initial chemicals. These reactions aren’t perfectly reversible, but enough to be deemed efficient.

Usually, this electrolyte that allows positively charged or negatively charged ions to move is a liquid solution made of salt, acid, or base. The lithium-ion batteries use such a solution, but in this case, the electrolyte is incredibly volatile. They are prone to fires, can’t deal particularly well with overcharging, and the erupted fires are a pain to extinguish. Moreover, this electrolyte makes lithium-ion batteries quite voluminous, all while not supplying a high voltage from a singular cell.

Solid-State Batteries

This is where solid-state batteries come in. The electrolyte found here is, as the name states, solid, found as a glass or a ceramic material and not a liquid solution. This allows the material to be quite a bit denser, reducing the size of the battery. On top of that, a solid material is easier to contain, potentially resulting in a less hazardous battery.

They aren’t new technology by any stretch of the imagination, being discovered in the 19th century, but back then they were next to impossible to manufacture. Nowadays, the situation has changed slightly, but there’s still significant difficulty in producing reliable batteries at a large scale, all the while keeping the price down.

Research Toward Deployment

A myriad of companies and people consider solid-state batteries to be the future. Toyota aims to bring cars on the market equipped with such a battery in 2025. Ford Motor Company and BMW will test and potentially use solid-state batteries produced by a company named Solid Power, located in Louisville, Colorado.

Other major brands that hopped on the train are General Motors and Honda, resulting in a partnership aiming to push solid-state batteries to the market. On the other side of the spectrum, we haven’t heard anything specific regarding solid-state batteries and Tesla, with Elon Musk not saying anything specific regarding them.

Smaller, Lighter Than Lithium-Ion Batteries

However, all of these thus far are just claims. What are the improvements in actuality? Compared to the regular lithium-ion batteries, solid-state batteries should theoretically be 70 percent smaller and 40 percent lighter, with more real and sensible figures being 50 percent smaller and 30 percent lighter at peak development.

The result would be that an 85 kWh Tesla Model S would have an improvement in the range from 265 miles to around 370 miles if the battery had the same weight. A significant improvement, but they are still far from being usable on semi-trucks and other heavier vehicles. A truck has a range of over 1000 miles. That would result in a battery weight of over 4000 lb.

Charging Challenges

Regarding charging, QuantumScape, one of the most promising start-ups that will manufacture solid-state batteries, claims a charge time from 10 to 80 percent in around 15 minutes, done for 400 repeated charging cycles. However, the tests have been made completely in-house, so the results may vary wildly based on the test conditions. Toyota, a much more reputable brand, reported difficulties with repeated charging.

Why would that be an issue? Well, charging cycles put a great strain on the solid electrolyte, so much so that microscopic cracks form on the surface. These cracks are then filled with small lithium dendrites that will, more often than not, short-circuit the battery, rendering it completely useless. Liquid-based lithium-ion batteries don’t have such issues, because these lithium dendrites can’t crack the liquid, they will just suffer a loss of performance. With this in mind, solid-state batteries, especially early on, might turn out to be significantly dodgy.

Future Electrification Solution

As such, solid-state batteries are the next step forward for electricity storage. However, while a significant improvement, similar to the jump from NiMH batteries to lithium-ion batteries, solid-state batteries are still quite far from being the battery of the future. Once manufacturers figure out how to make them as affordable and as reliable as possible, we will reach the next step towards total electrification, being the needed push for some people to make the transition.


References


Verma, P. (2022, May 18). Inside the race for a car battery that charges fast and won’t catch fire. The Washington Post.

(2022, March 10). Solid-state batteries for green mobility understanding challenges and recent developments. EVreporter.

Motavalli, J. (2022, May 10). How Solid-State EV Batteries May Lick the Fast-Charging Degradation Problem. Autoweek.


See AlsoThe Ways Semiconductors Can Help a Vehicle’s Performance


Image copyright Samsung Advanced Institute of Technology

Please follow and like us:
Author: Cristian Puscasu
Cristian Pușcașu started loving cars and wanted to become a “racing driver” thanks to some computer game that lit the fire almost two decades ago. Since then, he came to his senses and decided that becoming an automotive engineer is more sensible, and pursued such a degree in his home country, Romania. Cristian decided to try writing about what he learned, in an attempt to correct certain misconceptions and to use his soon-to-be degree a bit unconventionally.

Leave a Reply

Your email address will not be published.