With electric vehicles becoming so popular that it has become a question of when rather than if they will replace their fossil fuel counterparts, the question for battery raw material suppliers and manufacturers is what will power EVs in the future.

For the last decade, lithium-ion has been the dominant power supply solution driving forward a litany of portable technologies, including mobile phones, laptops, drones, wearable technology and, most notably, electric vehicles.

However, whilst it is an established technology, it is not a completely sustainable one, given that there is a limited amount of not only lithium but also nickel, manganese and cobalt, which are the four main rare metals used in the construction of EVs.

As well as this, its volatility means that extra care needs to be taken during the manufacturing process to ensure that the components are kept within safe operating parameters so they do not swell, overheat, catch fire or even explode.

One solution that has been suggested as a theoretical solution for a long time is solid-state batteries, but could this vision of the future be closer to the present than people expect?

A Future In Solid State

Since the voltaic pile, practically every commercially available usable battery has used a liquid electrolyte, which whilst providing effective energy generation is also relatively heavy and can have issues with volatility given the reactiveness of the materials involved outside of their optimal operating temperatures.

An ideal solution to both of these issues would be a solid-state battery, which opts for a solid electrolyte instead of a gel or liquid.

The concept is far from new; Michael Faraday discovered several early potential solid electrolytes, but problems with design, execution and cost meant that they were essentially impossible to make.

However, with much-improved and more advanced manufacturing techniques and technologies, solid-state batteries went from a theoretical possibility into a small-capacity reality by the 1990s.

However, in 2011, the first solid-state electrolyte that was even comparable to a typical lithium-ion battery was constructed, and that brought the possibility of a rapid technological evolution in electric vehicles.

The first ever car with a solid-state battery was the Bolloré Bluecar, a small electric city car with a range of 160 miles (in city driving conditions, the range is closer to 95 on motorways), with the battery pack itself weighing 300 kg.

It was largely a statement of purpose and potential, and whilst it has only been produced in fairly small numbers, it showed a path that other manufacturers would be hesitant to follow for the next decade.

The issue was a matter of cost; the complex manufacturing processes that solid-state batteries use are often slow to produce, and it took until the 2020s for other manufacturers to start actively pivoting towards solid state alongside other technologies such as sodium-ion.

Part of the reason for this is that it was not until the late 2010s and early 2020s that electric vehicles reached a critical mass of customers and ownership, which galvanised manufacturers to invest more in research and development for solutions that were previously either small-scale or even theoretical.

However, with bigger manufacturers involved, these technologies could start appearing in consumer products as early as 2027, although the likely year of release will likely be closer to 2029.

Samsung was the latest company to announce a proposed date that they will enter mass production, with the view that the initial focus will be on “super-premium” cars with a focus on long-range.

The benefits of solid state are safety, efficiency and improved versatility when it comes to size and form factor.

Electric cars fundamentally need to be designed around their batteries because they are the heaviest components of the car by a significant margin, and a lot of the aerodynamics, weight distribution and other components have to be designed around making this significant bulk feel as light as possible.

This means that the “super premium EVs” that solid-state batteries will be fitted to will not only have longer ranges and may have higher power output, allowing them to go faster, but will also be faster and easier to drive simply by virtue of being lighter.

Once solid state is manufactured at scale, this will make the power packs in general cheaper to produce than typical lithium-ion packs, and so whilst they will only be available at the top end of the market initially, this will change as time progresses.

LG, Samsung’s main Korean rival, is also producing solid-state batteries and aiming for a similar late 2020s production date.