In September 2024, Toyota announced that the Japanese government had approved its plans to build cars with solid-state batteries.
But what makes these batteries so different, and why is Toyota betting on them?
Solid-state batteries could fundamentally change the EV landscape. They use solid electrolytes instead of the liquid ones in conventional lithium-ion batteries, making them safer and reducing the risk of fires. They also boost energy density and longevity, aligning with the industry’s push towards more reliable and durable energy storage solutions.
Toyota plans to start production of its solid-state batteries by 2026, aiming for 9 gigawatt-hours annually. The goal is to have solid-state battery-powered vehicles on the road by 2027. The company has positioned itself at the forefront of EV innovation.
But it took 15+ years for Toyota to reach here.
One and a Half Decade of Research and Development
In the mid-2000s, Toyota’s initial interest in lithium batteries was low, and the company claimed that they would eventually be superseded by fuel cells. While fuel cell work continues, battery activity surged drastically in the 2010s.
Toyota started researching solid-state batteries in 2010 and first announced a four-layer all-solid-state battery in December 2010.
Toyota confirmed that the prototyped all-solid-state battery can be used at 100°C. Existing lithium-ion rechargeable batteries with electrolytes cannot be used at this temperature because their electrolytes boil.
At the same time, Toyota was advancing Eco-Car Development With Electric and Hybrid vehicles. So, a safe and efficient battery was a challenge to overcome.
Toyota’s foresight in recognizing the potential of solid-state batteries to revolutionize electric vehicles (EVs) by offering higher energy densities and safety profiles than traditional lithium-ion batteries is truly impressive. The company’s aim to lead in this transformative area is a testament to its vision and commitment to innovation.
Toyota further sought partnerships with different research entities to speed up the research and development of SSBs. Over the years, the company overcame several challenges with successful partnerships to reach SSB commercialization sooner.
After one year of development, Toyota and its research partners, involving Ryoji Kanno and his associate Masaaki Hirayama from Tokyo Tech, announced a breakthrough in SSBs.
They developed the world’s first lithium superionic conductor, Li10GeP2S12, which demonstrated the capability to conduct lithium ions at room temperature more effectively in the solid state than in liquid. This new material doubled the conductivity of existing lithium-ion conductors and surpassed the ionic conductivity of the organic solvents used in current lithium-ion batteries.
The company devised a plan to commercialize this technology between 2015 and 2020.
As the research intensified, the company made plans to expand its EV market.
Battery technology was even included on MIT’s list of the top 10 breakthrough technologies in 2011, further encouraging other players to join the race.
This was when many startups started to enter this technology to offer solutions to the challenges faced by Li-ion batteries.
In 2011, Toyota and Panasonic made a joint venture for battery development for EV and Hybrid cars.
Over the next two years, the company provided updates on battery chemistry refinement to improve its hybrid vehicles.
In 2014, Toyota researchers announced a battery development and showcased its intentions to research lithium-air batteries.
At the International Meeting on Lithium Batteries in Como, Italy, Dr. Hideki Iba from Toyota’s Battery Research Division and Dr. Chihiro Yada from Toyota Motor Europe’s Advanced Technology Group noted that, while lithium-air batteries may not be commercialized until 2030, solid-state batteries could be ready for the market as soon as 2020.
Source: Chargedevs
By 2014, the company had improved its battery technology 5X in power output compared to 2012. At that time, its solid-state battery had a power density of around 400 Wh/l (watt-hour per liter).
Meanwhile, Toyota also focused on hydrogen fuel cell technology and vehicles as it launched Mirai in Europe in 2015.
As the race for solid-state batteries heated up, patent filings increased yearly. Even companies like Apple filed patents on batteries.
2016 brought another breakthrough for Toyota and its research partners from the Tokyo Institute of Technology. The breakthrough was an improved design from its predecessor that was proven expensive, and some have exhibited problems with electrochemical stability.
The research highlighted lithium superionic conductors that exhibit exceptionally high conductivity (25 mS cm−1) and remarkable stability. These conductors, specifically Li9.54Si1.74P1.44S11.7Cl0.3, demonstrate near-zero voltage against lithium metal, indicating high stability.
In 2017, Toyota claimed to work on new battery types that could hold a higher charge. The improved battery technology would allow the creation of smaller, more lightweight lithium-ion batteries for use in EVs.
In May 2018, Toyota announced a new R&D program with Panasonic, Nissan, and Honda for solid-state battery development. The aim was to develop batteries with a range of upto 500 miles. The Japanese government was also a part of this program.
Despite all this research, the journey wasn’t always fruitful. The company faced several challenges, such as production hell and heating competition.
In 2018, Panasonic’s CEO said the anticipated battery won’t be able to make it to production for another decade. This came from one of its partners and was a surprise.
Meanwhile, other automotive companies invested hundreds of millions in startups to gain a competitive advantage. For example, Volkswagen invested $100 million in Quantumspace, one of the top solid-state battery manufacturers.
In 2019, Toyota announced that it would debut its solid-state battery EV in the Tokyo Olympics, but COVID-19 failed that plan.
In 2020, Toyota established Prime Planet Energy & Solutions, Inc., a joint venture with Panasonic to develop automotive prismatic batteries. The joint venture will supply batteries not only to Toyota but broadly to all customers.
By 2021, Toyota had a portfolio of 1000+ patents in solid-state batteries alone and was leading the technology in patent count.
Toyota further announced an investment of $13.5 billion by 2030 in batteries, including solid-state batteries. It aimed to slash the cost of its batteries by 30% or more by improving the materials used and the structure of the cells.
“We are still searching for the best materials to use,” Chief Technology Officer Masahiko Maeda.
In 2023, Toyota released its battery technology roadmap, which showcases that it won’t be able to release solid-state batteries before 2027.
Source: Toyota
The company further clarified that they will use these batteries on a hybrid vehicle first.
It’s planning to sell 3.5 million EVs annually across 30 different Toyota and Lexus model lines by 2030. Long-range battery packs will provide up to 500 miles of range by 2026 and 620 miles by 2027.
Toyota aims to introduce solid-state batteries in 2027 that are capable of ultra-fast 10-minute recharge times from 10 to 80 percent state of charge.
Major Challenges in Solid-State Batteries
Toyota’s pursuit of solid-state battery technology represents a significant advancement in the electric vehicle (EV) sector, but it is not without its challenges. Solid-state batteries possess several critical issues that must be addressed to ensure their practical application in automotive settings.
One of the primary challenges facing solid-state batteries is the interfacial stability between the solid electrolyte and the electrodes. High interfacial impedance is a significant barrier to the commercialization of SSBs, as it can lead to inefficient ion transport and reduced battery performance (Feng, 2024; Wang et al., 2020).
The solid-solid contact necessary for effective ion conduction often increases resistance, severely limiting the battery’s efficiency. This interfacial challenge is compounded by the mechanical and chemical instability that can occur at the electrode/electrolyte interface, which can lead to rapid capacity decay and failure of the battery (Liu, 2023; Chen et al., 2019).
Moreover, the mechanical properties of solid electrolytes present another hurdle. While solid electrolytes are generally more stable than their liquid counterparts, they can be brittle and susceptible to cracking under stress. This brittleness can lead to the formation of voids and cracks, further exacerbating interfacial issues and resulting in dendrite growth, potentially causing short circuits. Developing flexible and mechanically robust solid electrolytes is essential to mitigate these risks and improve the overall durability of solid-state batteries (Liu et al., 2020; Yang et al., 2021; Chen et al., 2019).
Temperature sensitivity is another significant concern for solid-state batteries. Polymer-based solid electrolytes, while offering some advantages, can suffer from performance degradation at elevated temperatures due to shrinkage and deformation. This sensitivity limits the operational temperature range of solid-state batteries, which is critical for automotive applications that require reliable performance across varying environmental conditions (Hu, 2024; Wang et al., 2020).
Toyota Patents on Solid-State Battery
In the last 10 years, Toyota has filed nearly 2000 patents on solid-state batteries. Although the company claims to have 1000 patents, the analysis shows the number is much higher.
Below is the patent filing trend of Toyota’s patents in SSBs:
The filing chart shows that the filing surge in 2016.
The US received the most patent filings, followed by China, the biggest market for EV batteries.
This huge patent count on solid-state batteries proves Toyota’s intense focus on the tech. These patents solve significant issues in solid-state batteries, such as increasing charging speed, enhancing battery life, improving energy density and safety, etc.
Below are some recent patent examples of how the company solves these issues.
Increase Charging Speed
One of Toyota’s inventions (US20230387412A1) uses graphite particles with a specific crystalline structure and sulfide solid electrolyte to improve charging. Experimental results show reduced ion transport resistance and better charging capabilities.
Another invention (US20220267166A1) improves charging speed in solid-state batteries by developing new lithium-ion electrolytes and electrode materials. The electrolyte composition enhances conductivity and stability at high temperatures while reducing gas generation and hardness. The method uses mixing and heat treatment processes to achieve better ionic conductivity and thermal stability, addressing critical issues in solid-state batteries.
In another patent (US20240021797A1), Toyota discusses a composite particle with a fluorine-based coating film for all-solid-state batteries to reduce resistance increment, especially under high voltage. This technology enhances charging speed by minimizing resistance, with the composite particle produced through a mixture of coating liquid and active material particles. The coating includes fluorine, phosphorus, and a glass network former, with optional metallic elements for further resistance reduction.
Enhance Battery Life
Toyota’s patent (US20240038972A1) discusses an electrode material for all-solid-state batteries that reduces resistance degradation during cycling. The electrode uses a composite particle structure with alternating fluoride and sulfide electrolyte layers, minimizing resistance increment over time. This innovation improves battery longevity by decreasing post-endurance resistance.
This patent (US20230343961A1) showcases a method to reduce resistance in all-solid-state batteries by coating positive electrode particles with a phosphorus-containing film, enhancing adhesion and ion conductivity. The process involves spray drying a coating mixture of active particles and a solution with a lithium-phosphorus ratio. The coated electrode is then formed and rolled at 170°C or higher, achieving a filling rate of 90% or more, improving battery longevity and performance.
Improve Energy Density
Toyota’s patent (US20230299337A1) discusses a solid-state battery design with low restraining pressure, enhancing energy density. The positive electrode layer uses composite particles covered by a sulfide solid electrolyte, preventing contact failure at pressures of 0.5 MPa or less. Critical factors like particle composition and peel strength help maintain battery performance, with tests showing reduced resistance during cycling.
This patent (US20220328815A1) discusses a solid-state battery design with a Si-based anode to reduce resistance increase during cycling. The design balances energy density and resistance by optimizing the anode capacity ratio and fill factor. The Si-based anode prevents cracking during volume expansion, with specific ratios allowing expansion without fracturing. This innovation improves battery performance by managing anode expansion and contact resistance.
Another patent application (US20220200057A1)showcased a method to enhance energy density by enclosing the battery laminate in a metal case and welding the protruding current collector layers to folded margin parts. This design eliminates the need for welding clearance, making the battery more compact. The method involves folding the welded parts inside the case and sealing it with resin, leading to a more efficient and dense battery design. The battery can use various materials like sulfide solid electrolytes and carbon, improving energy density in bipolar and monopolar types.
Market Growth
According to Markets and Markets, the global solid-state battery market is expected to grow from $85 million in 2023 to $963 million in 2030, with a CAGR of 41.5%.
EVs are one of the biggest reasons the SSB market will explode shortly. So, it is not surprising that big automotive companies such as Toyota or Volkswagen are trying to perfect this battery tech.
Besides Toyota, other companies are also leading in solid-state battery manufacturing. Most of them are startups that attract attention and funds from VCs and EV companies. As a result, specialized startups such as QuantumScape, BrightVolt, and Solid Power are now big manufacturers of SSBs.
Universities and Research institutes are participating vigorously in this technology to make it efficient.
A report by Elsevier shows the top universities with the most research papers on solid-state batteries published between 2011 and 2020. In 2011, there were 66 publications on solid-state battery technology, but by 2020, 722 papers were published.
Many startups are born from these institutes, including Ion Storage Systems, founded by Eric Wachsman, a Maryland Energy Innovation Institute Director.
Further, Toyota isn’t the only automaker planning to put solid-state batteries in cars to reap all their benefits. SAIC-owned MG says it will launch its first solid-state-powered production vehicle in 2025. Another SAIC brand, IM Motor, has already revealed the L6, which has a 133 kWh semi-solid-state battery that promises to deliver a range of up to 673 miles on the Chinese CLTC test cycle. Charging it for just 12 minutes adds 249 miles of range.
Toyota’s Partnerships to Develop SSBs
Toyota, a longstanding pioneer in hybrid technology, has strategically positioned itself as a leader in the SSB domain. Recognizing the potential of SSBs to revolutionize the automotive sector, Toyota has been proactive in forming alliances and fostering collaborations.
Toyota’s collaborations span industries and borders, including ties with Panasonic to develop and scale battery production and a notable partnership with Idemitsu. These partnerships leverage mutual strengths in materials science, manufacturing processes, and technological innovation.
Partnership with Tokyo Institute of Technology
Toyota partnered with the Tokyo Institute of Technology before 2010 to research and develop solid-state batteries. Together, they announced a breakthrough in 2011.
A New R&D Program, Libtec
In 2018, Toyota, Honda, and Nissan, with battery maker Panasonic, and the Japanese Govt announced a new R&D program, Libtec, for solid-state battery development. The aim was to develop batteries with a range of upto 500 miles.
Joint Venture with Panasonic
In 2020, Toyota and Panasonic announced a joint venture, Prime Planet Energy & Solutions, Inc., specializing in automotive prismatic batteries. Toyota has 51% ownership in this venture, while Panasonic owns 49%. The number of employees is 5100, including 2400 at a subsidiary in China.
Partnership with Idemitsu
In October 2023, Toyota partnered with Idemitsu, a petroleum company that develops elemental technologies for all-solid-state batteries. They agreed to work together to establish a mass-production technology of solid electrolytes. This will allow both companies to improve productivity and establish a supply chain to mass produce all-solid-state batteries for battery electric vehicles (BEVs).
How will the Success of SSBs impact Toyota?
The successful commercialization of solid-state batteries (SSBs) could be a game-changer for Toyota, altering the company’s market dynamics in several ways.
Enhanced Vehicle Performance
Toyota’s entry into EVs is inevitable now, so it is crucial to have a superior electric vehicle compared to companies with big market shares in EVs.
Toyota’s SSB prototype showcased a record range and charging time. For instance, Toyota has suggested that its SSB technology could enable EVs to charge from zero to full in just 10 minutes.
This enhancement meets another crucial consumer demand—reducing downtime due to battery charging, which currently hampers the practicality of EVs for long-distance travel and quick usage turnaround.
Market Share Growth
By leading in SSB technology, Toyota positions itself at the forefront of the next wave of EV innovation, which could enable it to capture a larger share of the burgeoning EV market.
Toyota’s early adoption and potential mastery of SSB technology could attract a broad customer base, ranging from eco-conscious individuals to tech enthusiasts and typical consumers looking for reliable, advanced, and efficient vehicles.
Competitive Edge
The shift to SSBs could provide Toyota with a significant competitive advantage. While other automakers may be hesitant or slower to move away from the more mature lithium-ion technology, Toyota’s commitment to SSBs could make it a leader in a crucial area of automotive technology.
Toyota enhances its brand reputation by establishing itself as a leader in SSB technology. It sets a high standard for competitors, potentially leading to a scenario where Toyota’s innovations become the benchmark against which other vehicles are measured.
What’s next?
The impact of these dynamics is multifaceted. For Toyota, it could mean stronger sales, a more robust market position, and the influence to shape future industry standards. It could also translate into access to more advanced, reliable, and sustainable consumer vehicles.
Collectively, these factors could dramatically reshape the automotive market, placing Toyota at the vanguard of the next major shift in automotive technology.
This analysis provides an overview of Toyota’s Battery Innovation efforts. However, the in-depth study of its patent portfolio and market research provides a broader view of its research strategy.
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Authored by: Vipin Singh and Shrey Gupta, Marketing Team.
