Solid-State Battery Challenges: Why the 1,000km EV Battery Isn't in Your Car Yet

This is a story of blind faith. In the 1980s, physicist John B. Goodenough and his team were experimenting with materials that everyone believed couldn’t produce high-voltage batteries. And they made a breakthrough. While typical lithium-ion batteries used in EVs have a nominal voltage of 1.5 volts, Goodenough’s experiments led to solid-state batteries capable of 4 to 5 volts.

“We didn’t know that you weren’t supposed to be able to get such a big voltage out of it,” he recalled. “But because I didn’t know that, we went ahead and did it. And it was stable.”

But if these batteries are so promising, why aren’t they in every car yet? And when will they be (if ever)? Read on to find out.

A solid-state battery is an advanced battery technology where the liquid electrolyte used in conventional lithium-ion cells is replaced with a solid material. This difference in design makes the battery safer, allows it to store more energy and enables faster charging. It’s not in mass production yet.

A solid-state battery uses two charged parts (anode and cathode) and a solid electrolyte. The solid electrolyte creates an environment for ions (charged atoms) to move in order to make the battery work. In addition, it physically stops the electrodes from touching, this way preventing a short circuit.

• The anode is where the battery stores energy in a charged state. And that’s what makes the solid-state battery so beautifully different compared to the lithium-ion ones. Solid electrolyte allows the use of much more efficient lithium metal, unlike conventional batteries, which must use graphite.

• The cathode is where the energy goes when the battery is in use. Usually, it’s made from a mix of lithium, nickel, manganese, and cobalt. In solid-state batteries, the cathode is the same as in the traditional ones.

• The solid electrolyte is the middle layer. It lets ions move between the anode and the cathode. It makes the whole thing much safer, as it is non-flammable compared to when a liquid electrolyte is used for the same purpose.

Solid-state batteries use ions to move charge between the electrodes, like Li-ion batteries. However, they replace the liquid with a solid electrolyte. This change allows using a pure lithium metal anode instead of graphite. A lot of the improvements mentioned before become possible thanks to lithium metal.

Graphite, used in lithium-ion batteries, limits how much energy the battery can store. As a result, batteries need to be larger to hold more power. A lithium-metal anode allows storing nearly twice as much energy, so batteries become lighter and driving ranges increase (so far, in theory). A few months ago, Mercedes-Benz demonstrated the potential of solid-state battery technology by driving a modified EQS test vehicle 1,205 km from Stuttgart to Malmö on a single charge.

* Despite the fact that liquid electrolytes are flammable, the fire risk in EVs is around  60 times lower than in cars with combustion engines.

In theory, solid-state batteries could outperform lithium-ion batteries. However, they’re not yet fully developed for mass production. In the future, solid-state batteries may offer longer range and lifespan, faster charging, and better resistance to extreme temperatures compared to lithium-ion batteries.

• Li-ion: Typically 300 - 600 km per full charge in modern EVs, with maximum range potential of 1000+ km

• Solid-state: Potentially 20 - 50% higher energy density, which could translate into a significantly longer range of 1000+ km without increasing battery size or weight

• Li-ion: Typically 500 to 2,000 cycles

• Solid-state: Potential for 5,000+ cycles

• Li-ion: Low temperatures (e.g. -20 °C) can cause a dramatic drop in performance, while high temperatures (e.g. +60 °C) can damage the battery.

• Solid-state: Expected to handle extreme temperatures much better, but early prototypes still see some limitations.

• Li-ion:

AC: Approx. 3 - 12 h

DC: 10 - 80% in 20 - 40 minutes if power delivery and battery design allow

• Solid-state:

AC: Approx. 3 - 12 h

DC: 10 - 80% in 10 - 15 minutes if power delivery and battery design allow

• Li-ion: Affordable, widely available, with a mature supply chain. Economies of scale make them the standard for current EVs.

• Solid-state: Expensive and limited to prototypes; mass production is still a challenge.

Japan is the leader right now, thanks to Toyota, which is aiming to have next-generation batteries capable of a 1,000 km range by 2027 - 2028. In the United States, one startup is focused on ultra-fast-charging battery designs and expects to begin mass production in 2026. China is rapidly scaling semi-solid batteries now and full solid-state ones by 2027 - 2030.

Toyota is primarily developing sulphide-based solid-state batteries, and it has already announced breakthroughs in improving durability. In the meantime, its competitors and researchers are also exploring oxides, polymers, and glass-ceramics as alternative solid electrolytes. The Japanese company is partnering with chemical firm Idemitsu Kosan to establish a small-scale production line for lithium sulphide (a key electrolyte material).

Toyota aims for the world's first practical use of all-solid-state batteries in electric vehicles by 2027 - 2028. The initial batteries are targeted to have an amazing range exceeding 1,000 km.

QuantumScape, a prominent USA startup focused on solid-state lithium-metal batteries, uses an anode-less design and a proprietary solid ceramic separator. This design is intended to boost energy density and reduce 10 - 80% charging times to under 15 minutes.

The company has partnered with Volkswagen’s PowerCo and has already shipped advanced prototype cells (the B1 “Cobra”-based QSE-5) for testing in motorcycles and other vehicles. Mass production of the QSE-5 cell for commercial use is expected as early as 2026.

As always, when it comes to e-mobility and innovation, China isn’t sitting still. Companies like Chery and Sunwoda are pushing high-energy prototypes, up to 600 Wh/kg. They’re also working on semi-solid-state batteries, which are a clever halfway step to solid-state and easier to commercialise now.

Chery has already presented its high-density all-solid-state battery module with a truly impressive target range of over 1,300 km. The company plans to begin initial vehicle testing in 2027. Furthermore, CATL and BYD, the world’s two biggest battery suppliers from China, aim for commercial launches between 2027 and 2030. 

Solid-state batteries still face several challenges, including poor contact between solid components, high manufacturing costs, scaling difficulties, and questions around real-world durability.

Current batteries in vehicles like the VW ID.3 or Fiat 500e use a liquid or gel electrolyte. It easily flows around the solid components (the cathode and anode) to transfer lithium ions back and forth. In contrast, solid-state batteries use a rigid, solid electrolyte. The challenge is that these solid components don’t bond perfectly with each other like liquids that naturally fill gaps much more effectively.

But that’s just half of the issue. When you’re charging your car, microscopic spikes of lithium metal, called dendrites, can grow on the anode, which is totally normal. But because the solid electrolyte is rigid, these spikes are much more dangerous for it. They can pierce right through the electrolyte and cause a short circuit. There is no way for mass production before this gets solved.

You can't just repurpose an old lithium-ion factory and announce that it’s now for solid-state batteries. Companies need to build new facilities. They also need to buy specialised equipment to handle and assemble the new, delicate solid materials. This costs a lot, even for large battery producers, and will naturally drive up the initial cost of the product. Manufacturers are trying to solve this in different ways. For example, Volkswagen is partnering up with QuantumScape to speed up the production of cathode materials for its all-solid-state batteries. 

It’s easy to make a perfect solid-state cell the size of a postage stamp in a research lab. It is exponentially harder to reliably and cost-effectively produce millions of cells the size of a laptop or larger to power an EV. This is also the reason why new partnerships are emerging. Toyota is teaming up with Sumitomo Metal Mining, which will allow them to share R&D costs, secure material supply chains, and make sure there is a buyer and real-world use for the batteries once they are ready.

An electric car battery has to handle a lot over its lifetime. Even careful drivers can’t avoid bumps, heat, or freezing cold. Solid-state batteries need to stay strong and work reliably through all of that. BMW, Solid Power, and Samsung SDI are on it. They have recently formed a three-way partnership, where Solid Power provides the solid electrolyte, Samsung SDI builds the cells, and BMW handles module/pack development and vehicle integration. Together, they can ensure the entire system withstands automotive stress.

Solid-state batteries are expected to start appearing around 2027 to 2028. Major automakers like Toyota and battery makers such as Samsung SDI are aiming to begin mass production and put them into a few high-end EV models.

Widespread use across most EVs and other devices will take longer. For that to happen, production costs need to come down, and factories need to be able to produce them at scale. We expect to see it after 2030.

By 2035, solid-state batteries are forecasted to reach a total capacity of 1,200 GWh and capture a significant part of the global battery market. According to Professor Achim Kampker (PEM), the sales potential could reach 550 billion euros, making even a small share very appealing.

Several battery technologies, including improved versions of today’s lithium-ion chemistry, are evolving to boost range, cut costs, and make EVs more accessible. Here’s a simple look at the most relevant alternatives.

Solid-state isn’t the only way to upgrade EVs. Traditional lithium-ion batteries keep getting better. Manufacturers are improving them through silicon-enhanced anodes, higher-density nickel chemistries, and advanced LFP variants (like LMFP) to improve performance while keeping batteries safe and affordable.

Sodium-ion batteries replace lithium with a more abundant and less expensive sodium. They offer excellent performance in cold conditions and can be fully discharged to zero volts without damage. Yes, they do have low energy density. But they are a solid, low-cost option for grid storage and small city EVs.

These next-gen batteries use a sulphur cathode and a lithium-metal anode. They are great for applications where weight is crucial, like aviation or high-end EVs. Sulphur is cheap and abundant, so no more fretting over cobalt or nickel prices. The problem is that the so-called “polysulphide shuttle effect” makes the battery lose capacity fast. This limits its lifespan to about 300-500 cycles. 

It is possible that in the future, solid-state batteries will become the main choice for electric vehicles. High costs mean they will likely debut in premium models, much like today’s NCA lithium-ion batteries found in high-performance EVs such as the Tesla Model S and Lucid Air. Leading car manufacturers, including BMW and Mercedes, plan to integrate solid-state batteries in their vehicles by 2030.

In the meantime, traditional NMC (great range and performance at a decent price) and LFP (safe, durable, and affordable) batteries will continue to play an important role. They already have an excellent combination of cost, range, and reliability and are constantly being improved. For many drivers, these batteries will remain a practical and trustworthy choice for years to come.