Solid-State Battery | A Complete Guide to Understanding Solid-State Batteries in One Article
1. Background of the Shift to Solid-State Energy Storage Technology
The evolution of energy storage technologies has played a crucial role in driving modern technological advancements and has made significant contributions to the development of sustainable energy systems. Historically, energy storage has undergone several stages of innovation, with each phase bringing improvements in efficiency, safety, and environmental impact.
Figure 1.(a) The Leyden jar storing electrostatic charge (1745); (b) and (c) Voltaic cell (1800) and lead-acid battery (1859), generating electricity through chemical conversion reactions;(d) Lithium-ion intercalation reaction for power generation (1991).
Currently, the field of energy storage is undergoing a significant transformation toward solid-state energy storage, exemplified by the development of solid-state batteries (SSBs). This shift is driven by two main factors:
First, lithium-ion batteries using liquid electrolytes face inherent safety and performance limitations. These include the flammability of liquid organic electrolytes, risks of thermal runaway, the formation of lithium dendrites during charging, and the temperature-dependent nature of ionic conductivity—all of which negatively impact battery performance and lifespan.
Second, there have been major advancements in materials science. Batteries using solid-state electrolytes offer higher energy density, which is critical for a wide range of applications, from consumer electronics to electric vehicles. At the same time, they mitigate many of the safety risks associated with liquid electrolytes.
Given these limitations, there is an urgent need to explore alternatives like solid-state batteries to enable the development of next-generation, high-performance energy storage systems.
2. Differences Between All-Solid-State Batteries and LIBs
All-solid-state batteries (ASSBs) differ from traditional lithium-ion batteries (LIBs) primarily in the type of electrolyte used. While conventional LIBs rely on liquid electrolytes to transport ions between electrodes, ASSBs use solid-state electrolytes, which offer numerous advantages over their liquid counterparts.
As illustrated in Figure 2, traditional lithium-ion batteries utilize a liquid electrolyte that facilitates ion transport between the anode and cathode. A separator layer is placed between the electrodes to allow ionic movement while preventing direct electrical contact.
In contrast, solid-state batteries eliminate the need for a separator by using a solid electrolyte to separate the electrodes. This solid medium not only enables ion conduction but also serves as a physical barrier to prevent short circuits.
Under certain conditions, all-solid-state batteries may also offer faster charging speeds compared to conventional lithium-ion batteries.
Figure 2. Differences Between All-Solid-State Batteries and Traditional Lithium-Ion Batteries
3. Components of Solid-State Batteries
3.1 Anode
For solid-state lithium batteries, the ideal anode material is lithium metal (Li), as lithium possesses a high specific capacity (3860 mAh/g) and a low electrochemical potential (–3.04 V versus the standard hydrogen electrode). However, the lithium anode faces numerous challenges that limit its practical application, including the formation of lithium dendrites during charge and discharge cycles, which can lead to internal short circuits, capacity fade, and safety risks.
Lithium metal tends to undergo volume expansion during cycling, which exacerbates the above issues, shortens cycle life, and affects the structural integrity of the anode. The increased overpotential and capacity degradation caused by these factors are major obstacles to improving the long-term stability of lithium-based solid-state batteries.
To address these issues, various alternative anode materials have been explored for solid-state batteries, each with its own advantages and disadvantages. Intercalation-type anode materials, such as graphite, have been widely used in lithium-ion batteries, but they offer lower specific capacity compared to lithium metal. However, graphite’s well-established cycling performance and stability make it a viable choice for solid-state battery anodes.
Materials like tin (Sn) offer higher specific capacity than graphite but undergo significant volume expansion during charge and discharge cycles, which can lead to mechanical degradation and poor long-term performance.
Alloy-type anode materials, such as lithium–silicon (Li–Si), lithium–tin (Li–Sn), and lithium titanate (Li₄Ti₅O₁₂), have emerged as promising candidates for solid-state batteries due to their ability to form alloys with lithium, enabling higher specific capacities. Among them, Li–Si is particularly attractive because of its high specific capacity (4.2 Ah/g).
However, Li–Si undergoes significant volume expansion and contraction (up to 300%) during charge and discharge cycles, making it prone to capacity fade and cracking. Similarly, Li–Sn offers better cycling stability compared to Li–Si, but at the cost of lower specific capacity.
Conversion-type anode materials, represented by lithium metal oxides (such as LiCoO₂) and hydrides (such as LiAlH₄), exhibit a different electrochemical mechanism in which lithium ions do not simply intercalate into the electrode but instead react with the material to form new compounds. Although these materials can offer high specific capacities, the large volume changes associated with the conversion reactions often make it difficult for them to maintain structural integrity over long-term cycling.
Recent anode research has also focused on sodium metal (Na). Compared to lithium, sodium offers several advantages, including greater abundance and lower cost. Its low redox potential (2.7 V versus the standard hydrogen electrode) and relatively high specific capacity (1165.8 mAh/g) make it a highly attractive alternative material.
However, sodium metal anodes also face challenges such as dendrite formation and limited cycling stability, although these issues are generally less severe than in lithium-based systems. The development of sodium-ion-based materials is still ongoing, and the future of sodium-based solid-state batteries largely depends on overcoming dendrite growth and achieving stable cycling performance.
In addition, a simple mechanical embossing method can be used to pattern graphite anodes, which helps reduce the diffusion length at the electrode/electrolyte interface.
Figure 3. Classification of Anode Materials for Solid-State Batteries
3.2 Cathode
Similar to liquid lithium-ion batteries, the most commonly used cathode materials in solid-state batteries are lithium metal oxides, such as lithium cobalt oxide (LCO), lithium nickel cobalt aluminum oxide (NCA), lithium nickel manganese cobalt oxide (NMC), lithium manganese oxide (LMO), and lithium iron phosphate (LFP), as shown in Figure 4 below.
Figure 4. Classification of Cathode Materials for Solid-State Batteries
3.3 Solid Electrolyte: The Core of Solid-State Batteries
The primary difference between current lithium-ion batteries and solid-state batteries lies in the physical state of the electrolyte used. Although the room-temperature ionic conductivity of solid electrolytes is generally lower than that of liquid electrolytes, they offer advantages in terms of thermal stability, non-flammability, durability, and simplified battery design.
Solid electrolytes can be categorized into the following types:
Oxide electrolytes: such as LIPON, NASICON, and garnet-type
Sulfide electrolytes: such as LPS and argyrodite-type
Polymer electrolytes
Halide electrolytes
Composite electrolytes
Hybrid solid-liquid electrolytes
Among these, the first three types are currently recognized as the mainstream solid electrolyte routes. There is no definitive consensus on which technology route will dominate, as each has its own strengths and weaknesses. Most companies entering the solid-state battery space are investing in multiple directions simultaneously.
Oxide-based solid electrolytes offer good chemical stability and mechanical strength but relatively low ionic conductivity. Their ionic conductivity can be effectively enhanced through doping, structural modification, and nanostructuring techniques.
Sulfide-based solid electrolytes provide high ionic conductivity and excellent flexibility but have lower chemical stability and higher synthesis costs. Techniques such as wet-chemical synthesis and mechanical ball milling can help reduce production costs to some extent.
Polymer-based solid electrolytes possess good flexibility and processability but tend to have lower ionic conductivity and poorer thermal stability. Their performance can be significantly improved by incorporating inorganic fillers or optimizing polymer molecular structures.
As shown in Figure 5, polymer solid electrolytes offer the best interfacial compatibility, oxide solid electrolytes provide the highest chemical stability, while sulfide solid electrolytes exhibit the highest ionic conductivity.
Figure 5. Comparison of (a) Polymer Solid Electrolytes; (b) Oxide Solid Electrolytes; and (c) Sulfide Solid Electrolytes
3.3.1 Oxide Electrolytes
Common oxide electrolytes include LIPON, NASICON, and garnet-type solid electrolytes. LIPON is composed of lithium (Li), phosphorus (P), oxygen (O), and nitrogen (N), with the general chemical formula LixPOyNz. Its development began in the 1970s and it is typically prepared in an amorphous glass form via RF magnetron sputtering. However, this process is time- and energy-intensive, making it suitable only for thin-film applications. LIPON is used in microbatteries, often paired with LiCoO₂ cathodes and lithium metal anodes, and is suitable for low-power applications. It offers a wide electrochemical window (0–5.5 V vs. Li⁺/Li), room-temperature ionic conductivity of approximately 2 × 10⁻⁶ S/cm, extremely low electronic conductivity (~8 × 10⁻¹⁴ S/cm), compatibility with various electrode materials, and excellent mechanical properties that help maintain structural integrity.
However, LIPON has a low effective cathode loading and high production costs for thin-film microbatteries.
NASICON was first reported by Goodenough and others in 1976. The general structural formula of NASICON is LiX₂(PO₄)₃, where X is typically Ge, Zr, or Ti. Through doping with trivalent ions such as Al³⁺, derivative materials like Li₁₊ₓAlₓTi₂₋ₓ(PO₄)₃ (LATP) and Li₁₊ₓAlₓGe₂₋ₓ(PO₄)₃ (LAGP) can be obtained. These materials exhibit room-temperature ionic conductivities up to 10⁻³ S/cm. LATP is stable in ambient air, has high ionic conductivity, and a relatively low sintering temperature.
However, LATP faces challenges in its interaction with lithium metal anodes, and most improvement efforts have focused on introducing interlayers.
Garnet-type solid electrolytes such as Li₇La₃Zr₂O₁₂ (LLZO) are considered promising candidates for solid-state batteries due to their high ionic conductivity and electrochemical stability. Recent research on LLZO has explored the effects of varying lithium content, polymorphism, and dopants. Key advantages of LLZO include high lithium-ion conductivity, a wide electrochemical stability window, and chemical stability with lithium metal. However, LLZO relies on lanthanum, and its synthesis requires high temperatures, leading to increased costs and limited compatibility with certain cathode active materials.
3.3.2 Sulfide Electrolytes
In 2011, a research team led by Professor Kanno at the Tokyo Institute of Technology in Japan successfully developed sulfide-based solid electrolytes, a breakthrough that caused a sensation in the field of all-solid-state battery research. Since then, the team has progressively increased the ionic conductivity of sulfide solid electrolytes to 25 mS/cm, and by 2023, they achieved a new record with a maximum ionic conductivity of 32 mS/cm. Thanks to this outstanding characteristic, sulfide solid electrolytes offer significantly faster charge and discharge capabilities.
Sulfide solid electrolytes include a series of compounds primarily composed of lithium and sulfur, and may also incorporate additional elements such as phosphorus, silicon, germanium, or various halides. These materials are highly regarded in the field of solid-state ceramic electrolytes due to their excellent ionic conductivity—often comparable to, or even exceeding, that of traditional organic liquid electrolytes.
Sulfide-based electrolytes also exhibit remarkable ductility and toughness, making them well-suited for cold-press processing methods, thereby avoiding the need for expensive high-temperature sintering. Under high pressure, these materials can form highly dense layers with minimal grain boundary resistance. This property enhances the electrode–electrolyte contact and reduces the likelihood of lithium dendrite formation.
Overall, sulfide-based electrolytes demonstrate promising characteristics, including effective ionic conductivity, low interfacial resistance with electrodes, and relatively low manufacturing costs. These advantages make them leading candidates in the field of inorganic solid electrolytes. Sulfide electrolytes are currently the preferred technology route for many mainstream companies.
3.3.3 Polymer Electrolytes
Polymer solid electrolytes represent a transitional technology between liquid and solid electrolytes. Polymer chains can facilitate the movement of lithium ions (Li⁺) within a solid structure. Polymer electrolytes are semi-crystalline or completely amorphous at room temperature, similar to liquid electrolytes, making them suitable for battery applications.
Polymer electrolytes are composed of three main components: an organic polymer matrix, lithium salt, and various additives (including inorganic functional materials). The matrix plays a key role in maintaining the structural and mechanical integrity of the electrolyte system. Essential properties of the polymer matrix include mechanical strength, ionic conductivity, thermal and chemical stability, and the ability to dissolve lithium salts. Because different polymers exhibit varying mechanical, thermal, and chemical behaviors, selecting the appropriate polymer matrix is crucial.
Commonly used polymers include polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), and polyethyleneimine (PEI). In PEO-based electrolytes, the preferred lithium salt is lithium bis(trifluoromethanesulfonyl)imide (LiN(CF₃SO₂)₂), also known as LiTFSI. This salt is favored for its ability to reduce the crystallinity of PEO, thereby enhancing ionic conductivity in the polymer–salt matrix. Important characteristics of lithium salts include low lattice energy (to promote ion pair dissociation), as well as chemical and thermal stability and cost-effectiveness. Some newly developed lithium salts, when used with PEO at room temperature, can achieve conductivities greater than 1 mS/cm.
Additives in polymer electrolytes are used to enhance mechanical properties or suppress the crystallinity of the polymer–salt matrix, particularly at lower temperatures, thereby promoting higher ionic conductivity. For example, nanofillers can increase the degree of salt dissociation, reduce anion mobility, and enhance interfacial stability with lithium metal. Active nanofillers such as γ-LiAlO₂ assist lithium ion conduction, while inert fillers like Al₂O₃, SiO₂, or carbon particles serve various functional roles.
Polymer materials offer several advantages, including low flammability, ease of processing, and electrochemical stability. Compared to liquid alternatives, they provide better mechanical flexibility to accommodate electrode deformation, and compared to other solid-state options, they offer more adaptable interfacial contact with electrodes. Despite these benefits, certain critical aspects still require improvement—such as increasing lithium ion conductivity (by raising the lithium ion transference number) to offset polarization caused by anion migration, and enhancing mechanical strength to prevent the formation of lithium metal dendrites.
3.3.4 Halide Electrolytes
Halide solid electrolytes are considered promising materials for advancing all-solid-state battery technology, primarily due to the unique chemical properties of halide anions. A major advantage lies in the relatively weak Coulombic interactions between monovalent halide anions and lithium ions, which leads to faster lithium-ion transport and higher ionic conductivity. In addition, the larger ionic radii of halide anions result in longer ionic bond lengths, which are expected to enhance ion mobility and deformability.
Another benefit is the high electrochemical redox potential of halide anions—particularly fluorine and chlorine—which contributes to improved oxidative stability. Despite these promising characteristics, halide solid electrolytes, which have been studied since the 1930s, initially faced challenges such as low ionic conductivity at room temperature, limiting their widespread application.
Metal halide superionic conductors, typically represented by the general formula Li₃MX₆ (where M is a trivalent rare-earth metal and X is F, Cl, Br, or I), usually exhibit a crystal structure based on a LiX matrix. This structure is achieved through M-element doping and the formation of lithium vacancies. The stability of these structures depends on the close contact between cations and anions, which is influenced by their ionic radii, polarizability, and packing modes. While fluorides offer a wide electrochemical stability window, their room-temperature ionic conductivity is generally lower.
3.3.5 Composite Electrolytes
Composite electrolytes (CEs) combine the advantages of ceramic fast-ion conductors and polymer electrolytes, aiming to overcome the limitations of each. Ceramic conductors exhibit high ionic conductivity but are difficult to process and have poor interfacial properties, while polymer electrolytes are flexible and easy to process but have low ionic conductivity at room temperature. CEs are mainly classified into two types: inorganic nanoparticle/polymer composites (INPCs) and inorganic nanofiber/polymer composites (INFPCs).
INPCs incorporate inorganic nanoparticle fillers such as SiO₂ or Al₂O₃ into a polymer matrix to enhance mechanical strength, ionic conductivity, and interfacial stability. Smaller particles are more favorable for ion transport. INFPCs, on the other hand, use nanofibers instead of nanoparticles, reducing the number of junctions and providing smoother pathways for ion migration. They also inhibit polymer crystallization and enhance ion mobility.
Studies have shown that INPC composites containing active fillers like LATP exhibit superior cation transport properties compared to those with inert fillers. INFPCs, such as LLTO nanowires embedded in PAN–LiClO₄ polymer composites, form a three-dimensional ion conduction network, significantly improving ionic conductivity.
3.3.6 Hybrid Solid-State Electrolyte–Liquid Electrolyte Systems
Solid electrolytes typically exhibit relatively low ionic conductivity at room temperature, which hinders efficient ion transport and consequently weakens the overall performance of the battery. In addition, solid electrolytes often struggle to maintain stable interfacial contact with electrodes. Poor contact can lead to increased resistance and negatively affect battery efficiency. Inadequate interfacial compatibility may result in uneven current distribution and localized material degradation. It can also lead to dendrite formation at the electrolyte–electrode interface, poor mechanical stability, and undesirable chemical reactions.
To address these challenges, researchers have proposed the use of hybrid solid–liquid electrolyte systems. This approach combines the high ionic conductivity of liquid electrolytes with the structural integrity and safety of solid electrolytes. The goal is to create a synergistic effect: the liquid component reduces interfacial resistance and enhances ion transport, while the solid matrix contributes to overall mechanical stability and safety.
This innovative method helps suppress common issues found in traditional electrolytes, such as dendrite formation and poor mechanical stability. Introducing a liquid phase into the solid electrolyte matrix can improve ionic conductivity, especially at lower temperatures. Additionally, such hybridization promotes more efficient interfacial contact with electrodes, ensures more uniform current distribution, and reduces the risk of localized degradation. These systems also exhibit greater mechanical robustness compared to pure liquid electrolytes, significantly lowering the risks of leakage and flammability, making them a promising path forward in the development of safer and more efficient solid-state batteries.
Figure 6. In 2024, the IM L6 was released featuring the first-generation “Lightyear” solid-state battery, which is a hybrid solid–liquid electrolyte battery (also known as a semi-solid-state battery) incorporating an organic separator with an added oxide electrolyte coating.
Although the battery used in the IM L6 is not a fully solid-state battery, it achieves a cell-level energy density of 368 Wh/kg while significantly enhancing overall safety. The vehicle also boasts an impressive range of 1,000 kilometers. In addition, the battery offers excellent fast-charging performance, delivering 400 kilometers of range with just 12 minutes of charging—an outcome that appears to be a well-balanced compromise.
4. Advantages and Technical Challenges of Solid-State Batteries
4.1 Advantages Over Traditional Battery Technologies
Solid-state batteries represent a new era in energy storage, offering a range of advantages over traditional liquid lithium-ion batteries. These benefits are not merely incremental improvements but are transformational in nature. Broadly speaking, the main advantages include:
Enhanced Safety:
The most significant advantage of solid-state batteries is their safety. Since they do not contain flammable liquid electrolytes, the risk of fire and explosion—which has long been a concern with liquid lithium-ion batteries—is greatly reduced.
Higher Energy Density:
Solid-state batteries have the potential to achieve higher energy densities compared to conventional lithium-ion batteries. This is partly due to the use of lithium metal anodes, which offer higher capacity than graphite anodes. Moreover, the compact design of solid-state batteries—without bulky auxiliary components needed for liquid electrolyte management—contributes to a reduction in overall battery size, allowing for more efficient space utilization and increased energy storage per unit volume.
Longer Lifespan:
Solid electrolytes are less prone to degradation compared to liquid electrolytes, which tend to decompose over time and under thermal stress. This inherent stability helps extend the lifespan of solid-state batteries, reducing the frequency of battery replacements and, in the long term, mitigating the environmental and economic impact of battery disposal.
Operational Stability Under Extreme Temperatures:
Solid-state batteries exhibit exceptional performance stability across a wide temperature range. Unlike liquid electrolytes, whose ionic conductivity changes significantly with temperature, solid electrolytes maintain consistent performance in both high and low temperature environments. This feature enhances the reliability of solid-state batteries under various climate conditions, making them suitable for a broader range of applications.
No Leakage or Drying Issues:
The solid nature of the electrolyte inherently eliminates the risk of leakage—a common problem in liquid lithium-ion batteries that can lead to performance degradation and safety hazards. Furthermore, solid electrolytes do not dry out over time, an issue seen in certain types of liquid electrolyte systems, especially under high-temperature conditions.
Design Flexibility:
The absence of liquid components in solid-state batteries allows for greater design flexibility. This opens the door to developing battery shapes and sizes that were previously impractical, enabling integration into a wider variety of products and devices, including wearable electronics and uniquely designed electric vehicles.
Environmental Sustainability:
From an environmental standpoint, solid-state batteries offer a more sustainable solution. They reduce the use of toxic and volatile substances commonly found in traditional liquid electrolytes during production and disposal, thereby lowering environmental risks. In addition, the longer service life of solid-state batteries decreases the frequency of replacements, enhancing their environmental friendliness.
In essence, the advantages of solid-state batteries over traditional technologies stem from their unique structural and material properties, which enable higher safety, greater energy density, longer service life, improved thermal tolerance, design versatility, and environmental sustainability. Collectively, these benefits position solid-state batteries as a key technology in the future of energy storage solutions.
4.2 Technical Challenges of Solid-State Batteries
Despite their significant advantages, solid-state batteries still face several technical challenges that hinder their widespread adoption:
Interfacial Stability:
Instability at the electrode–electrolyte interface is one of the most critical challenges in the development of solid-state batteries. Unlike liquid-electrolyte lithium-ion batteries (LE-LIBs), where the electrolyte easily conforms to the electrode surface, the rigid nature of solid electrolytes in solid-state batteries can result in poor contact, leading to high interfacial resistance. This issue is further exacerbated during charge and discharge cycles, as volume changes in the electrodes can disrupt the interface. Ensuring a stable, low-resistance interface is essential for efficient ion transport and overall battery performance.
Manufacturing Complexity and Scalability:
The production of solid-state batteries involves complex manufacturing processes that are currently difficult to scale. Fabricating thin, dense, defect-free solid electrolyte layers and ensuring perfect contact with the electrodes require precise engineering and control. Scaling these processes to mass production while maintaining quality and consistency remains a major obstacle to commercialization.
Material Selection and Cost:
Finding materials for solid electrolytes that offer high ionic conductivity, mechanical strength, and stability is a major challenge. Many promising solid electrolyte materials are expensive or difficult to synthesize in large quantities, affecting the cost-effectiveness of solid-state batteries. Additionally, identifying compatible electrode materials that work efficiently with these solid electrolytes adds another layer of complexity.
Brittleness of Solid Electrolytes:
Many solid electrolytes, especially ceramic-based ones, are brittle and pose challenges in handling and durability. This brittleness can lead to cracking and mechanical failure, particularly under the stress of repeated charge and discharge cycles. Developing solid electrolytes with sufficient mechanical properties to withstand these stresses is crucial.
Lithium Dendrite Formation:
Although solid-state batteries reduce the risk of lithium dendrite formation compared to liquid-electrolyte systems, the issue is not entirely eliminated—especially when using lithium metal anodes. Dendrite formation can still occur and may lead to short circuits and battery failure. Addressing this requires a deeper understanding of the conditions that promote dendrite growth and the development of strategies to mitigate it.
Thermal Management:
While solid-state batteries are inherently safer and more stable at high temperatures, thermal management remains an issue, particularly in high-power applications such as electric vehicles. Solid electrolytes have lower thermal conductivity than liquid electrolytes. Designing solid-state batteries capable of effectively managing heat during fast charge and discharge cycles is essential for maintaining performance and ensuring longevity.
Limited Understanding of Solid Electrolyte Behavior:
Compared to liquid electrolytes, the behavior of solid electrolytes under various conditions is not yet fully understood. The lack of comprehensive models that accurately predict ion behavior within solid matrices limits innovation and performance optimization. Investing in fundamental research to deepen the understanding of solid electrolyte behavior is critical to advancing solid-state battery technology.
In summary, while solid-state batteries hold great promise for the future of energy storage, overcoming these technical barriers is essential for their successful market adoption. These challenges span materials science, manufacturing processes, and the fundamental understanding of solid-state electrochemistry—each requiring dedicated research and innovation to overcome.
5. Challenges and Opportunities of Solid-State Batteries
Although many issues related to solid-state batteries remain to be resolved, their advantages are clearly evident when compared to the limitations of traditional liquid-based batteries. The current challenges and opportunities associated with solid-state batteries can be summarized as follows:
| Challenges | Opportunities |
|---|---|
Low Ionic Conductivity
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Low Cycle Life
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Degradation of Solid Electrolytes
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Fast-Charging Performance
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Poor Stability
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Manufacturing Scalability
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6. Current Status and Roadmap of Solid-State Batteries
Based on information released on official websites, the current state of research and development, along with future plans of major solid-state battery manufacturers, has been summarized as shown in the table below:
| Manufacturer | Technology Route | R&D Status | Mass Production Timeline |
|---|---|---|---|
|
CATL |
Sulfide-based all-solid-state |
Established a dedicated all-solid-state battery pilot line; focused on high-energy ternary electrodes with sulfide electrolytes; new condensed battery tech to launch in 2024 |
Small-scale production in 2027; large-scale industrialization after 2030 |
|
BYD |
Sulfide-based composite electrolyte |
R&D started in 2013; already completed industrial pilot validation for materials, batteries, and core systems; full-chain development ongoing |
Pilot-scale production in 2027; large-scale commercialization by 2030 |
|
Toyota |
Sulfide-based all-solid-state |
R&D initiated in 2006; accumulated many patents; small-scale production planned for 2026, vehicle installation validation in 2027 |
Large-scale production by 2030 |
|
Gotion High-Tech |
Sulfide-based all-solid-state |
Launched “Golden Battery” with 430Wh/kg in 2024; passed 2000°C oven test and over 3000 cycles of performance testing |
Small-scale production in 2027 |
|
Gotion High-Tech |
Oxide-based semi-solid → all-solid |
First-gen (liquid content 5–15%) already in production; second-gen (liquid <5%) to begin production in 2024 |
Third-gen fully solid-state battery to be installed in vehicles in 2027 |
|
HiNa Battery |
Oxide-based all-solid-state |
First GWh-scale production line began operation in 2024; long-term goal to reach 150GWh capacity |
Semi-solid scaled use in 2025; all-solid mass production by 2030 |
|
WeLion New Energy |
Solid–liquid hybrid battery |
Hybrid solid-liquid battery entered mass production in 2024 (3GWh), with capacity to reach 7GWh; focused on solid-state electrolyte material R&D |
All-solid-state battery scaling in 2027; cost target of ¥0.5/Wh by 2030 |
|
Aviation Lithium Battery |
Sulfide-based all-solid-state |
Launched 430Wh/kg all-solid-state battery; capacity exceeds 50Ah; passed stringent safety tests |
Pilot car installation in 2027; mass production afterward |
|
Samsung SDI |
Sulfide-based all-solid-state |
Developing 900Wh/L energy density full solid-state battery; focusing on fast-charging performance |
Mass production in 2027 |
Table 1. Current Status and Plans of Major Manufacturers
As shown in the table, in terms of technical routes, sulfide-based electrolytes have become the mainstream choice in the solid-state battery field due to their high ionic conductivity (>10⁻³ S/cm). Leading companies such as CATL, Toyota, and BYD are all focusing on this pathway. However, large-scale production processes and interfacial stability remain key challenges to overcome.
At the same time, the industry is currently in a transitional phase toward semi-solid-state technology. Between 2025 and 2027, semi-solid-state batteries (such as CATL’s condensed batteries and QingTao Energy’s second-generation products) are expected to be the first to achieve large-scale deployment. These batteries feature a gradual reduction in liquid electrolyte content to below 5% and offer cost advantages—30% to 50% lower than that of fully solid-state batteries.
In terms of commercialization timelines, semi-solid-state batteries are expected to be widely adopted in vehicles between 2025 and 2027, while fully solid-state batteries will enter the small-scale validation stage (e.g., products from CATL and CALB). Large-scale production of fully solid-state batteries is anticipated after 2030.
