The Trilogy of "100 Questions on Solid-State Batteries: Decoding the Next Generation Battery Revolution" Part One: The Fundamental Logic]

SMM September 19 News:

Introduction to "100 Questions on the Solid-State Battery Industry - Decoding the Next-Generation Battery Revolution"
After lithium-ion batteries powered the first wave of the global new energy industry, the race for "next-generation battery technology" has become the core arena for reshaping the industrial landscape — and solid-state batteries are the most watched "game-changer" in this competition. With their essential innovation of "no liquid electrolyte," they resolve the core contradiction between safety and energy density in traditional lithium batteries. Not only do they carry the user expectation for EVs to achieve a driving range over 1,000 kilometers and fast charging within ten minutes, but they also pertain to the energy form upgrades in fields such as ESS, consumer electronics, and aerospace, profoundly impacting the global layout of lithium resources and the carbon neutrality process.
However, the current solid-state battery industry is at a critical period where "a profusion of technologies coexists with the fog of industrialisation": sulphide, oxide, and polymer routes each have their pros and cons, and there are various opinions on the industrialisation periods for semi-solid and fully solid states. Real challenges such as material costs, equipment compatibility, and standard setting need to be clarified. From the laboratory to the production line, from the policy end to the consumer end, different participants still have information gaps and biases in their understanding of solid-state batteries. The market urgently needs a reference text that combines systematic, practical, and timely content to bridge the gap between "technical language" and "market language." There are many questions and expectations about its market recognition: when will it become widespread? What changes will it bring to the industry chain? How will it reshape our production and lifestyle?
To systematically address these market concerns, SMM, with deep insights into the new energy field and extensive exchanges with academia, research, and industry, has compiled this "100 Questions on the Solid-State Battery Industry" by gathering the views of many experts. This book is divided into ten chapters, covering basic knowledge, technical principles, material systems, enterprise layouts, cost analysis, policies and standards, application scenarios, and future outlooks. It aims to comprehensively and multi-dimensionally analyze the current development and future trends of the solid-state battery industry through one hundred key questions.
This "100 Questions on the Solid-State Battery Industry" is not merely a technical manual or a list of data: it starts with the basic understanding of "what is a solid-state battery," delves into the technical core such as interface impedance and electrolyte route selection, extends to key industrialization issues like production line investment, patent layout, and recycling systems, and ultimately focuses on the market scale and social transformation by 2030. Whether you are a "beginner" just getting acquainted with solid-state batteries or a "practitioner" deeply involved in the industry, you can find relevant information here: perhaps a comparative reference for technical routes, a basis for judging cost trends, or a panoramic view of enterprise layouts.
Table of Contents for "100 Questions on the Solid-State Battery Industry - Decoding the Next-Generation Battery Revolution"
I. 100 Questions on the Solid-State Battery Industry: Basic Knowledge
II. 100 Questions on the Solid-State Battery Industry: Technical Principles
III. 100 Questions on the Solid-State Battery Industry: Material Systems
IV. 100 Questions on the Solid-State Battery Industry: Enterprise Layouts
V. 100 Questions on the Solid-State Battery Industry: Industry Chain and Costs
VI. 100 Questions on the Solid-State Battery Industry: Policies and Standards
VII. 100 Questions on the Solid-State Battery Industry: Challenges and Trends
VIII. 100 Questions on the Solid-State Battery Industry: Application Scenarios
IX. 100 Questions on the Solid-State Battery Industry: Recycling and Environmental Protection
X. 100 Questions on the Solid-State Battery Industry: Future OutlookChapters 1–3: Technological Core—Deciphering the Underlying Logic of Solid-State Batteries
Chapters 4–6: Industrial Ecosystem—Outlining the Commercialization Path of Solid-State Batteries
Chapters 7–10: Future Prospects—Exploring the Applications and Ultimate Form of Solid-State Batteries

Trilogy of "100 Questions on Solid-State Batteries: Decoding the Next Generation Battery Revolution" Part One: The Underlying Logic—Technical Core · Decrypting the Fundamental Principles of Solid-State Batteries
I. Basic Knowledge: One Hundred Questions on the Solid-State Battery Industry (Part 1)
Q1: What is a solid-state battery?
A: An all-solid-state battery (ASSB) is a type of battery that uses a solid electrolyte to replace the traditional liquid electrolyte, relying on solid materials to conduct ions. Its core advantages are high safety and great potential for energy density.

Q2: What is the fundamental difference between solid-state batteries and liquid lithium batteries? What are the advantages of all-solid-state batteries?
A: The most critical difference lies in the form of the electrolyte. Liquid batteries use a liquid electrolyte, while solid-state batteries use a solid electrolyte. This brings three major advantages: significantly improved safety, substantially increased energy density, and extended cycle life. The latest data show that the theoretical energy density of all-solid-state batteries can reach 500 Wh/kg, more than twice that of current top-tier lithium batteries. The main advantages of all-solid-state batteries include higher safety, energy density, and cycle life, as well as a broader operating temperature range.

Q3: Does "solid-state" in solid-state batteries mean absolutely no liquid?
A: Strictly speaking, "all-solid-state" means completely free of liquid electrolyte, but the industry also has "semi-solid-state" batteries, depending on the specific technical route.

Q4: How is the "high safety" of solid-state batteries demonstrated?
A: Liquid electrolytes are flammable, while most solid electrolytes are non-flammable, greatly reducing the risk of thermal runaway and offering greater stability in scenarios such as punctures or high temperatures.

Q5: How high can the energy density of solid-state batteries reach?
A: Theoretically, the energy density of all-solid-state batteries can exceed 500 Wh/kg, far above the upper limit of around 300 Wh/kg for liquid lithium batteries, enabling EVs to easily achieve a driving range of over 1,000 kilometers.

Q6: Are solid-state batteries only lithium-based?
A: No, there are also solid-state sodium batteries, solid-state zinc batteries, and others. However, current industrialisation efforts focus mainly on solid-state lithium batteries due to the higher efficiency of lithium-ion migration.

Q7: When will solid-state batteries be commercially available on a large scale?Answer: In two steps: semi-solid-state batteries and all-solid-state batteries. Some enterprises have already applied semi-solid-state batteries in small batches, and more car models may be equipped with them by 2025-2026. All-solid-state batteries are still in the R&D and pilot production stage. Top-tier enterprises are committed to building demonstration production lines at the megawatt hour level, mainly focusing on the oxide electrolyte route; all-solid-state batteries using sulphide systems have not yet been installed in vehicles and are currently only at the small-capacity laboratory sample stage. It is expected that all-solid-state batteries will achieve small-scale mass production and be used in vehicles by 2027-2028, and large-scale commercial application will be realized around 2030. In terms of production lines, the total capacity in 2025 is about 0.6Gwh, and it is expected to reach 1.2Gwh by 2025.

Q8: What characteristics of solid-state batteries should consumers pay most attention to?
Answer: Ordinary users can focus on "safety + driving range + charging speed". Solid-state batteries theoretically address these three pain points simultaneously.

Q9: Are solid-state batteries in the same category as "blade batteries" and "Qilin batteries"?
Answer: No, blade and Qilin represent structural innovations in liquid lithium batteries, belonging to an "upgrade of liquid batteries"; solid-state batteries are a "revolution in technology routes", with completely different electrolyte systems.

Q10: How long has the R&D history of solid-state batteries been?
Answer: Basic research dates back to the 1970s, but due to material and process limitations, industrialisation breakthroughs have only occurred in the past decade.

II. Solid-State Battery Industry 100 Questions - Technology Principles
Q11: How do solid-state batteries conduct electricity?
Answer: By ion migration within the solid electrolyte, while electrons are conducted through the external circuit. The principle is the same as for liquid batteries, except the ion transmission medium changes from liquid to solid.

Q12: Is the ionic conductivity of solid electrolytes sufficient?
Answer: Early oxide electrolytes had low conductivity, but the room temperature conductivity of sulphide electrolytes now approaches that of liquid electrolytes, meeting practical needs.

Q13: Why can solid-state batteries improve energy density?
Answer: First, they can use lithium metal anodes, and second, the thinner solid electrolytes can reduce the "ineffective space" inside the battery. Q14: How Is the Cycle Life of Solid-State Batteries?
A: In the laboratory, some all-solid-state batteries have achieved over 3,000 cycle times. However, interface stability issues must be resolved before mass production. Currently, the cycle life of semi-solid-state batteries is close to that of liquid batteries.

Q15: Do Solid-State Batteries Charge Quickly?
A: Theoretically, the ion migration properties of solid electrolytes support high C-rate charging, with the potential to achieve "80% charge in 10 minutes" in the future. However, this still requires matching with positive and negative electrode materials.

Q16: Is Interface Impedance a Core Challenge for Solid-State Batteries?
A: Yes. The interface contact between solid electrolytes and positive/negative electrodes is not as "tight" as with liquid electrolytes, which can easily lead to impedance, capacity decay, and affect battery performance and stability. This is currently a major focus of research.

Q17: How to Address the Interface Impedance Issue?
A: There are many methods, such as applying buffer layers at the interface, using in-situ polymerization technology to improve contact, and developing composite electrolytes. Different enterprises are pursuing various technical routes.

Q18: Do Solid-State Batteries Require Special Production Equipment?
A: Yes. Equipment such as dry electrode preparation and hot-press encapsulation are needed, which differ significantly from liquid battery production lines. This is also one of the cost barriers to industrialisation.

Q19: How Is the Low-Temperature Performance of Solid-State Batteries?
A: The ion migration in solid electrolytes is less affected by temperature compared to liquid electrolytes, theoretically resulting in better low-temperature performance. Capacity retention at -20°C could be more than 20% higher than that of liquid batteries.

Q20: Will Solid-State Batteries Have a "Lithium Dendrite" Problem?
A: Yes, but the mechanical strength of solid electrolytes can suppress lithium dendrite penetration, making them safer than liquid batteries. However, precautions are still needed under extreme conditions.

III. Solid-State Battery Industry 100 Questions - Material Systems
Q21: What Are the Main Types of Solid Electrolytes?
A: There are three major types: oxide, sulphide, and polymer, as well as emerging types like halides.

Q22: Which Electrolyte Has the Most Industrialisation Potential?
A: Sulphide electrolytes have the highest conductivity and are easy to thin, making them the mainstream direction for all-solid-state batteries. Oxides offer good stability and are suitable for semi-solid-state or specific applications. Polymers are low-cost and flexible. Q23: What are the advantages and disadvantages of sulphide solid electrolytes, and what are the core technical challenges?
A: Sulphide solid electrolytes are highly regarded for their extremely high ionic conductivity and good interfacial chemical stability. However, they are sensitive to moisture and prone to releasing toxic gases, requiring strict environmental control during production and use, which increases process difficulty and cost.
The current core challenge lies in how to form them into high-density, high-conductivity, and structurally stable electrolyte membranes through effective compaction processes. Conventional rolling and cutting techniques struggle to meet their mechanical and electrochemical performance requirements.

Q24: What are the representative materials for oxide solid electrolytes?
A: A typical example is garnet-type LLZO, which offers good chemical stability but relatively low room-temperature conductivity. It is often used in composite form with other materials.

Q25: Are the cathode materials for solid-state batteries the same as those for liquid batteries?
A: Most are reused, such as NCM, NCA, and LFP. Due to its limited theoretical energy density (industry estimates suggest it is difficult to exceed 250 Wh/kg), LFP is only used in semi-solid-state batteries, while all-solid-state batteries typically employ high-nickel ternary cathode materials to achieve higher energy density. To match high voltage and high energy density, nickel-rich, cobalt-free, and even sulfur-based cathodes are also under development.

Q26: Can lithium metal be used as the anode in solid-state batteries? What other anode materials are available?
A: Yes, this is key to improving energy density. Liquid batteries rarely use lithium metal due to the risk of lithium dendrites, but solid-state batteries can safely utilize it. Other anode materials include graphite and silicon-based anodes.

Q27: Are there solid-state batteries that do not use lithium?
A: Yes, for example, solid-state sodium-ion batteries, which use sodium metal anodes and sodium-ion conductor electrolytes. These are suitable for low-cost energy storage scenarios and are also under concurrent R&D.

Q28: Is the cost of solid electrolytes high?
A: Currently, it is very high. The cost of sulphide solid electrolytes is 5–10 times that of liquid electrolytes. However, costs are expected to decrease with mass production; for instance, a production line with an annual capacity of 100,000 mt could reduce costs by 60%.

Q29: Do solid-state batteries require separators?Answer: All-solid-state batteries do not require traditional separators, as the solid electrolyte itself serves the dual function of "ion conduction and electron insulation" as a separator.
Question 30: What is the role of new materials such as LiFSI in solid-state batteries?
Answer: LiFSI is often used as an additive or auxiliary electrolyte in semi-solid-state batteries to help improve interface performance, and it is also employed in the synthesis and modification of solid electrolytes.

**Note:** For further details or inquiries regarding solid-state battery development, please contact:
Phone: 021-20707860 (or WeChat: 13585549799)

Contact: Chaoxing Yang. Thank you!