One of the major barriers to EV adoption is concern over battery range, with so called ‘range anxiety’ relating to fears over the distance an EV can travel on a single charge. Other EV battery constraints include their safety record, their weight, and their cost.
Consequently, recent data has shown a notable slow-down in BEV (Battery Electric Vehicles) sales, particularly in western markets. In fact, when taking into consideration recent data and future sales projections, ZCA’s latest EV forecasts (published in September 2025) have been lowered compared with our 2024 analysis[i].
While mass EV adoption remains hindered by consumer fears, the market may yet see a substantial boost from next-gen battery technologies. Amongst these, All Solid-State Batteries (ASSBs) stand out as the most promising advancement.
All solid-state batteries are seen by some as the future of EV batteries and a strong alternative to ‘traditional’ lithium-ion. These batteries use solid electrolytes, rather than liquid ones, which makes them less volatile than lithium-ion. In addition, they have the capacity to store more energy and offer better performance at both high and low temperatures. These batteries are cheaper (theoretically if mass-produced), lighter, and faster to charge, as well as offering greater range. However, they are notoriously difficult and expensive to scale-up.
ASSBs offer greater energy density than traditional lithium-ion EV batteries, providing up to 500 watt-hours-per-kilogram (Wh/kg), compared to just 150-250 Wh/kg for lithium-ion batteries. This makes them more energy dense and therefore able to deliver the same level of energy as a traditional EV battery for a fraction of the weight.
Research from the University of California, published in July, found that while today’s standard lithium-ion EV batteries may take 30 to 45 minutes to reach 80% charge, solid-state models can cut that time to just 12 minutes, and in some cases, as little as three. Further, whereas traditional EV batteries show degradation after just 1000 charge/discharge cycles, ASSBs are more durable. The researchers found that after 5000 cycles they can retain 90% of the original battery capacity, due to lessened mechanical strain.
While the technology in ASSBs has existed for decades, having been used in small devices like hearing aids and pacemakers, scaling it for EVs has proven difficult and expensive. However, if manufactured at scale, they could deliver the ideal balance of range, safety, and performance in a compact package.
Given the potential benefits, several major manufacturers have been working on perfecting the technology for larger applications, including Toyota, Stellantis, and BYD. However, it was Mercedes-Benz who recently became the first manufacturer to reveal a working EV powered using a solid-state battery, beating previous industry front-runner Toyota (which has been researching and developing ASSBs since 2012).
Partnering with a US-based company called Factorial Energy, Mercedes-Benz announced its ASSB project ‘Solstice’ in September 2024, before showcasing the EQS solid-state concept car on track in February 2025. The concept car’s battery offers 450 Wh/kg power density, this news from Mercedes-Benz was swiftly followed by BMW confirming that it has started real-world testing for a new version of its i7, a car which will be powered by ASSB technology in collaboration with Solid Power.
Unsurprisingly Chinese manufacturers too are targeting mass-rollout of the technology. Changan aims to have all-solid-state batteries in prototype cars by end of 2025, offering over 1,500 km of range, before starting mass production of all-solid-state batteries by 2027. BYD and CATL are also hoping to produce small batches of ASSBs by 2027.
Source: ZCA
What is driving development forward?
What is holding ASSBs back?
Whilst ASSBs have several hurdles to overcome before we see mass-adoption, in the interim a number of manufacturers are exploring the use of ‘semi-solid-state batteries’ (also termed quasi-solid-state batteries, or QSSBs) with their EVs.
In contrast to ASSBs, these batteries use a gel-like electrolyte that also promises improvements over traditional lithium-ion batteries. The energy density of semi-solid-state batteries typically ranges between 250-350 Wh/kg. QSSB technology is still evolving, with Farasis Energy recently announcing that it’s third-generation semi-solid-state battery, currently under development, has achieved an energy density of 400Wh/kg, and the company anticipates achieving an energy density exceeding 500Wh/kg through further optimisation.
In addition, QSSBs generally offer a longer cycle life than lithium-ion, of between 1,000–2,000 cycles, however this is far lower than solid-state batteries. Presently the market is dominated by Chinese companies, with over 80% of current or planned semi-solid-state battery manufacturing capacity currently situated in China, according to data from BNEF.
EVs with semi-solid-state batteries are already in production in China, though currently in small numbers. Early adopters of the technology here include Nio and the state-backed SAIC Motors. In the West, BMW is testing semi-solid-state batteries, and Stellantis is planning to begin trials next year.
Source: ZCA
What is driving development forward?
What is holding Semi-Solid-State Batteries back?
While ASSBs may not dominate the EV market overnight, their potential to overcome today’s limitations is undeniable. Semi-solid-state batteries are already bridging the gap, offering tangible improvements and paving the way for full solid-state breakthroughs. As manufacturers race to commercialise next-gen battery technology, the road to 2030 could be paved with innovation.
For in-depth analysis of the EV & charging infrastructure industries explore ZCA’s new research Electric vehicles & charging infrastructure 2025-2030
This deep-dive report analyses government policy-including tariffs, EV roll-out targets and deadlines, consumer demand, technological developments, charging types and battery technologies. The research assesses the current market opportunities alongside key recommendations and prospects for both the public and private sector.
Furthermore, the report considers EV charging adoption, such as public charging, home charging, and workplace charging, providing critical insight into how deployments are evolving and the opportunities these offer. Additionally, the research includes the influential ‘ZCA Leaderboard’ product, offering analysis of 12 EV vendors, and 10 EV charging providers.
[ii] Solid-state battery road tests begin | Mercedes-Benz Group > Innovations > Drive systems > Electric
[iii] Farasis to Deliver 400 Wh/kg Solid-State Cells by Year-End - Battery-Tech Network
[iv] Solid Power Inc. - BMW Group and Solid Power are Testing All-Solid-State Battery Cells in a BMW I7
[v] Changan Solid-State Battery Will Unlock Up To 1500 Kilometers Of Range - CleanTechnica
[vi] BYD confirms plans for EVs with all-solid-state batteries in 2027
[vii] QuantumScape snags new partner to aid in solid-state production
Lauren has extensive experience as an analyst and market researcher in the digital technology and travel sectors. She has a background in researching and forecasting emerging technologies, with a particular passion for the Videogames and eSports industries. She joined the Critical Information Group as Head of Reports and Market Research at GRC World Forums, and leads the content and data research team at the Zero Carbon Academy. “What drew me to the academy is the opportunity to add content and commentary around sustainability across a wealth of industries and sectors.”
