Mar 15, 2025
Company News
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- EN
In the dazzling constellation of contemporary materials science, single-walled carbon nanotubes (SWCNTs) undoubtedly stand out as a prominent star. Formed by the perfect rolling of a single layer of graphene, they create a seamless tubular structure with a diameter of only 1-2 nanometers and a length that can reach micrometers or even millimeters. This nearly ultimate one-dimensional nanomaterial, since its discovery, has been hailed as a "super material" due to its extraordinary comprehensive properties, carrying the high hopes of revolutionizing numerous fields such as electronics, energy storage, and advanced manufacturing. Currently, it stands at a critical historical juncture, transitioning from the laboratory to large-scale applications, and a silent yet profound materials revolution is underway.
The exceptional performance of single-walled carbon nanotubes stems from their perfect sp² carbon atom bonding and highly symmetrical one-dimensional hollow structure.
In terms of mechanical properties, their tensile strength can reach approximately 100 gigapascals (GPa), and their Young's modulus is as high as approximately 1.25 terapascal (TPa). This means that its strength is more than 100 times that of high-quality structural steel, while its density is only about one-sixth that of steel. It is no exaggeration to describe it as "stronger than steel, lighter than a feather," providing a fantastic material basis for manufacturing ultra-strong and ultra-light composite materials, space cables, and other applications.
Its electrical properties are even more remarkable. The carrier mobility of single-walled carbon nanotubes can reach up to approximately 7.9×10⁴ cm²/(V·s), nearly three orders of magnitude higher than the typical values of current silicon-based semiconductor materials, indicating the potential to surpass the speed limits of conventional semiconductors. Even more astonishingly, metallic single-walled carbon nanotubes can carry current densities as high as 10⁹ A/cm², 2-3 orders of magnitude greater than traditional good conductors like copper, with almost no electromigration, making them ideal high-performance interconnect materials.
In the field of thermal properties, their theoretical axial thermal conductivity is approximately 6600 W/(m·K), more than ten times that of copper, combining excellent heat conduction with high-temperature stability, offering a novel solution to the heat dissipation challenges of high-power electronic devices.
Additionally, their unique nanoscale tubular structure (with a diameter less than one fifty-thousandth of a human hair) gives them an enormous specific surface area, reaching up to 380 m²/g, which provides significant advantages in adsorption, catalysis, and energy storage.
With this set of "extraordinary" performance parameters, the applications of single-walled carbon nanotubes (SWCNTs) extend into many cutting-edge areas:
New Energy Materials: This is currently the fastest-growing area in terms of industrialization. As a new type of conductive additive for lithium batteries, SWCNTs can form a superconducting three-dimensional network, significantly enhancing the conductivity of both the cathode and anode materials, thereby effectively increasing the battery's energy density, fast-charging performance, and cycle life. Especially in high-energy-density systems such as next-generation solid-state batteries and silicon-carbon composite anodes, their role is almost "essential." Market data shows that by 2025, the shipment volume of SWCNT conductive slurry in China is expected to exceed 3,000 tons, demonstrating strong growth momentum.
Semiconductors and Electronics: This is the sector where single-walled carbon nanotubes have the most disruptive potential. Due to their extremely high mobility and nanoscale size, scientists have successfully fabricated carbon nanotube transistors in the lab that outperform silicon-based devices of the same size. They are considered one of the core candidate materials for continuing Moore's Law and building future carbon-based chips. In the field of flexible electronics, their combination of flexibility and high performance makes them ideal materials for developing foldable displays, electronic skin, and similar devices.
Composites: When used as reinforcements in polymer, ceramic, or metal matrices, they can greatly enhance the material's strength, toughness, electrical, and thermal conductivity, with potential applications in aerospace, automotive lightweighting, and high-end sports equipment.
Other Fields: In photovoltaic and thermoelectric devices, they can improve light absorption and charge collection efficiency. In biomedical applications, owing to their nanoscale size and surface functionalization capabilities, they hold potential for targeted drug delivery, biosensing, and other research areas.
Despite the broad prospects, single-walled carbon nanotubes still face several major hurdles in transforming from a “laboratory treasure” into a widely used “industrial commodity”:
1. Difficulty in controllable structural preparation: Single-walled carbon nanotubes (SWCNTs) can be metallic or semiconducting, with numerous chiralities that determine their electrical properties. Current mainstream preparation methods (such as chemical vapor deposition) struggle to produce large quantities of SWCNTs with a single chirality, especially high-purity semiconducting tubes, which severely limits their application in high-end semiconductor fields.
2. High cost and complex scaling: The large-scale production of high-purity, high-quality SWCNTs involves complex processes with high energy consumption, making their cost far exceed that of many traditional materials (such as carbon black and multi-walled carbon nanotubes). Reducing costs is key to opening up a broader market.
3. Dispersion, purification, and standardization: Carbon nanotubes aggregate easily, and achieving uniform and stable dispersion in various matrices remains a technical challenge. Subsequent purification processes (removing amorphous carbon, residual metal catalysts, etc.) also affect product performance. In addition, the industry lacks unified quality standards and evaluation systems, which hinders downstream application development and market regulation.
4. Lack of integration processes: Particularly in the field of integrated circuits, accurately assembling and integrating billions or even hundreds of billions of carbon nanotube transistors with consistent performance onto wafers, and developing a complete set of compatible front-end and back-end processing technologies, is an extremely large-scale system engineering task that is still in the early research stage.
Looking ahead over the next 3-5 years, the development path of single-walled carbon nanotubes (SWCNTs) is becoming increasingly clear. At the industrial level, the field of lithium battery conductive agents will continue to act as both a 'pioneer' and a 'stabilizing force' for commercialization. With the global boom in electric vehicles and energy storage, especially as the solid-state battery technology roadmap gradually becomes clearer, the demand for high-performance conductive agents is expected to grow exponentially, continuously driving the expansion of SWCNT production capacity and technological iteration, while also promoting cost reduction.
At the technological level, preparation methods will continue to advance. Whether through the design of new catalysts, optimization of reaction engineering, or leveraging advanced separation techniques (such as chromatography and aqueous two-phase extraction), achieving high-selectivity growth or efficient separation of specific chiralities, particularly semiconductor-type carbon nanotubes, will be a key focus of research and development. Once breakthroughs are made, they will open doors for high-end applications such as logic chips and sensors.
Meanwhile, downstream demand will become increasingly strong. Beyond new energy, the high-end semiconductor industry has an urgent demand for new materials that surpass the limits of silicon. Although large-scale commercialization of carbon-based chips faces significant challenges, breakthroughs may first occur in specific applications such as RF devices and flexible display drivers. Additionally, in niche markets like defense aerospace and high-performance composite materials, the pursuit of ultimate performance will provide early application scenarios for SWCNTs.
In summary, single-walled carbon nanotubes are a high-performance, highly promising strategic frontier material. They are steadily progressing along the path from "laboratory to production line": in the field of lithium batteries, their commercial viability has already been successfully demonstrated and is moving into the fast lane; in more precise fields such as semiconductors, while their feasibility has been shown in principle, they still need to traverse a long engineering tunnel. It is foreseeable that, with the continuous maturation of core technologies like fabrication, separation, and integration, as well as the sustained pull from disruptive downstream demands, single-walled carbon nanotubes are expected to truly shed the label of "sample," growing into a new material sector worth hundreds of billions that supports the next industrial revolution, turning the legend of a "super material" into a grand chapter in real-world industry.
