The race to develop solid-state batteries has gained prominence in recent years, with a focus on electric cars, electronic devices, and energy storage systems. This advancement is seen as the next major leap forward in overcoming the limitations of current lithium-ion batteries, whose technology is beginning to reach its limits in terms of range, safety, and charging capacity.
Technology and automotive companies, along with research centers worldwide, are working against the clock to realize the promises of this technology. However, industrial and security challenges are extending timelines that, according to industry experts, will not allow for its widespread deployment before the next decade.
What do solid-state batteries offer compared to current ones?
Solid-state batteries replace the liquid electrolyte typically found in lithium-ion cells with solid materials, such as polymers or ceramics, improving energy density and providing greater safety against overheating or leaks. Among the most notable advantages are the possibility of achieving ranges exceeding 1.200 or even 1.500 km in electric vehicles, significantly shorter charging times, reduced weight and volume , and the elimination of risks of fire or accelerated degradation under extreme conditions.
An added benefit is that their performance is not diminished in cold environments , a problem with conventional batteries, and they can even remain stable below freezing. Furthermore, a more compact package allows for better use of space inside the vehicle and optimizes weight distribution.
In terms of manufacturing, some advanced solid-state battery designs are compatible with existing lithium-ion production lines, which would facilitate a less costly industrial transition than initially anticipated. Models with multi-layer structures and Cell-to-Body (CTB) designs will allow the battery to be integrated into the structural part of the car, improving both volumetric efficiency and overall vehicle safety.
Research, patents, and expectations: the position of Xiaomi and other brands
Global interest in this technology is reflected in the surge of numerous projects and patents. A prime example is Xiaomi's recent patent detailing an advanced multi-layer structure for the electrodes and an integration of active materials and a solid electrolyte. This system, measuring just 120 mm in height, would achieve a volume efficiency of 77,8% and offer theoretical ranges exceeding 1.200 km, with the ability to recover up to 800 km in just 10 minutes of charging.
This breakthrough, according to the company, would facilitate mass production without completely reinventing the industrial process, given that the battery would be compatible with current manufacturing lines. Furthermore, the Cell-to-Body design is awaiting future commercial applications in the company's new electric models, as a way to reduce dependence on large external suppliers.
The Chinese alliance CASIP , which includes companies such as CATL, EVE Energy, CALB, SVOLT, Gotion High-Tech, and BYD's FinDreams Battery division, reflects the collective effort of the sector in Asia. This is further bolstered by announcements from Toyota and BMW—which are already testing prototypes—and brands like SAIC, NIO, and Changan, which plan to begin small-scale production between 2027 and 2028.
Technical obstacles and the path to solid-state batteries
Despite the potential, the technical challenges for mass deployment are significant . The main one lies in the use of pure metallic lithium in the anode , a necessary condition for achieving high energy densities. This choice requires maintaining the battery at very high pressures, which complicates its manufacturing, increases the risk of structural failure, and can shorten its lifespan. Furthermore, if the casing is damaged, contact between the lithium and ambient humidity can trigger dangerous reactions, such as the generation of toxic lithium hydroxide.
Executives from major companies, such as Robin Zeng—CEO of CATL—warn that the technology is not yet practical or safe for mass production and use , and estimate that its arrival on the market will be delayed by at least a decade. This cautious analysis coincides with the experience of manufacturers who, after years of research and multimillion-dollar investments, continue to face problems with durability, pressure, and cost.
Meanwhile, researchers at the Georgia Institute of Technology have explored mixing lithium and sodium as an electrolyte to reduce the required pressure and improve overall battery stability, showing that small modifications to the composition can be key to resolving some of the critical issues.
Intermediate alternatives and the advancement of semi-solid batteries
While the technical challenges of pure solid-state batteries are being addressed, the industry is working on hybrid solutions , especially so-called semi-solid batteries. These combine the advantages of solid and liquid electrolytes, achieving double the range compared to current batteries , reducing weight and costs, and increasing safety by avoiding pressure problems and dangerous reactions of metallic lithium.
Chinese companies like CATL already have semi-solid battery prototypes in production, while others—such as NIO, SAIC, and Changan—are exploring different chemistries and configurations. Models like the IM L6 and the Nio ET7 are already implementing semi-solid batteries commercially in China. In Europe and Japan, Stellantis, BMW, and Toyota are advancing their testing and development.
Furthermore, sodium-ion batteries are beginning to be considered a viable option for stationary applications in the short to medium term, thanks to the abundance of sodium and the diversification of the supply chain.
Impact on the autonomy, sustainability, and future of electric mobility
The emergence of solid-state batteries has the potential to revolutionize electric mobility: ranges of 1.200 to 1.500 km, ultra-fast charging , and new design opportunities for manufacturers. However, their ultimate success will depend on resolving both technical and economic issues: the cost of materials , manufacturing scalability, and access to critical minerals without generating geopolitical or environmental risks.
Currently, demand for minerals such as lithium, cobalt, and nickel continues to grow, but chemical alternatives such as LFP (lithium iron phosphate) and sodium batteries are also emerging, seeking to reduce dependence on critical materials and move toward more sustainable and affordable electrification.
Solid-state battery technology continues to advance, although it is not yet ready to immediately replace current solutions in the mainstream market. Innovations in multilayer structures, optimization of ion transport, and cost reduction predict a promising future, but the transition will depend on both technical achievements and industrial adaptation and consumer acceptance. Meanwhile, intermediate solutions such as semi-solid-state batteries offer answers to current energy challenges and pave the way toward cleaner, safer, and more efficient mobility in the coming years.