It’s been a bumpy road on the way to the EV future so far, and automakers around the world are bracing for an “EV winter” of slower demand. Yet there are a few positives making news as well, like the fact that real-world solid-state batteries are inching ever closer to production. What’s the difference between those batteries and typical EV setups? An EV battery cell charges by splitting electrons off lithium atoms at the cathode and allowing the resulting lithium ions to travel through a separator to an anode, where they are reunited with electrons — which, unable to penetrate the separator, followed a different path through the charger circuit to get to the anode. Using that electricity for the motor runs the process in reverse, with the split-off electrons traveling in an external circuit to power a vehicle’s electric motor before rejoining the lithium ions.
In the traditional EV cell, there’s also a liquid or gel electrolyte material surrounding the electrodes and separator, and this is the stuff the ions move through in the cell. A solid-state battery swaps out the surrounding liquid electrolyte for a solid material that also acts as a separator. So the cell is like a slice of three-layer cake consisting of the anode, the electrolyte, and the cathode.
Eliminating the highly flammable liquid, which can be difficult to contain during an accident, is one of the many benefits of solid-state batteries, but they do have challenges of their own. At this stage, engineers are still working out ways to bring down production prices, properly manage battery pack temperatures, maintain an optimum flow of ions, and prevent the lithium being used from causing short circuits in the battery pack. Let’s see how they’re doing.
Solid-state batteries can require even more lithium
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One of the biggest issues affecting solid-state batteries is the same one that’s hampered the production of more traditional EV batteries — the cost of the raw materials needed to make them. Lithium is especially problematic here because — despite eliminating the lithium-containing electrolyte material — solid-state batteries can often use more of it overall. For example, a common way to boost energy density in solid-state batteries is with a solid lithium anode. And according to Dr. Jordan Lindsay of the environmental consulting firm Minviro, as reported in Motor Trend, solid-state batteries could require five to 10 times the lithium necessary for typical EV batteries. Nor will those immediately disappear when solid-state batteries are introduced.
The outcome is that the demand for lithium for solid-state batteries has to be added to the demand for lithium in other EV systems, driving prices up yet further. While EV sales have certainly lost some traction in the United States since the elimination of the federal tax credit, 2025 still saw the second-highest number of annual EV sales in this country ever, according to RMI. Plus, EV sales in China and Europe last year rose 30% and 17%, respectively. Then there’s the fact that lithium mining for EVs may destroy the planet.
As a result of factors like these, experts predict lithium could rise to $28,000 per ton in 2026. That compares to spot prices this summer in China — where the vast majority of the world’s lithium is processed — of about $8,300. New technologies are on the horizon, however, with some claiming the ability to reduce costs by 40% and make extraction more environmentally friendly, too. Companies are working on different battery chemistries, like sodium-sulfur setups.
Lithium can lead to damaging dendrite growth
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Beyond its costs — both financial and otherwise — lithium is a concern because it can form dendrites. They’re a fairly common problem when you mix metals and electricity, as electric current causes atoms of the former to start building up on an EV battery’s anode. During charging, the buildup forms tiny, spiky, sometimes branching structures that grow toward the cathode. True, the separator lies between the two electrodes, and that’s partly to prevent the two from touching and causing a short circuit. But the separator material is specifically designed to filter out the electrons and allow the lithium to pass through as part of the charging/discharging process. The lithium dendrites can grow from one electrode to the point where they pierce through the separator and come into contact with the other — causing a short circuit.
It’s essentially the same as when you get a short circuit in your engine block heater. Electricity follows the path of least resistance, and in an EV battery, that can mean electrons flowing between the electrodes, along the dendrites, instead of following the longer circuit to run the EV motor. The resulting heat from the short circuit can lead to thermal runaway, igniting the liquid electrolyte and causing a hard-to-extinguish fire.
Nor are dendrites limited to lithium setups: Alternatives like sodium-ion solid-state batteries are lithium-free yet still at risk of forming as a natural reaction to the electricity-making process. That said, scientists are making progress on the situation, with tailored production methods that help create a better, more uniform distribution of the sodium atoms, and this can indeed minimize dendrite growth while also resisting corrosion.
Production costs for solid-state batteries can be higher
Solid-state batteries can cost significantly more to produce for reasons other than lithium demand. It’s relatively easy for electrons and ions to move through the electrolyte when they’re essentially surrounded by the material in liquid or gel form, but engineers face some major obstacles with solid materials. Those have to be made to exceedingly tight tolerances to make sure the surfaces of the three layers of a solid-state battery — cathode-electrolyte-anode — are in as close and consistent contact as possible. In addition, even if you could somehow ensure seamless contact, the boundaries between those layers can create areas of high resistance that make it tougher for the lithium ions to get from one side to the other.
On the one hand, assembling solid-state batteries can be much quicker than regular EV batteries, which can take weeks to complete due to the finicky requirements of the liquid electrolyte, and that should save costs. On the other hand, the production of solid-state batteries is still a work in progress that’s likely to be expensive and time-consuming to perfect — and in some cases invent.
Another production hurdle comes from the materials used as separators in solid-state batteries. They’re often made of ceramic, and — as we discovered when looking at the differences between ceramic and steel bearings — that stuff can be exceedingly brittle and require special care to prevent cracks and breakage when the batteries are assembled. Scientists are hard at work on solutions, of course, ranging from separators made from sulfide- and oxide-based materials to the use of tailored additives engineered to reduce the risk of cracking.
Thermal management
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Generally speaking, batteries work best in a certain temperature range. When they’re too cold, the chemical reactions needed to create electricity will slow too much to be effective. Too hot, and the battery components can start to degrade. Automakers have developed a series of increasingly advanced thermal-management systems over the years to help manage both situations, and although that experience should help with fine-tuning the technology for solid-state batteries, not everything will simply carry over.
For example, one disadvantage of eliminating the liquid electrolyte is that solid-state batteries can’t get rid of heat as quickly — and it doesn’t take much heat to start affecting an EV battery. The so-called sweet spot for EVs is between 60 and 80 degrees Fahrenheit, a temperature range not often enjoyed in the United States. When it gets colder, the chemical reactions required for producing electricity slow down, and battery components start degrading more quickly when it gets hotter. There’s the risk of thermal runaway as well — although those dangers can be somewhat mitigated by this “perfectly safe” EV battery ejection system.
Thermal management also plays a particularly important role for solid-state batteries because of the contact problem we discussed above. Like most materials, the components in a solid-state battery can expand and contract as temperatures rise and fall — but because the battery materials are different from each other, the changes don’t occur at the same time or to the same extent. That, in turn, makes it extra difficult to keep the surfaces of the electrodes and separator in proper contact.
