What is Copper Carbon Nanotube?
Copper carbon nanotube (CNT) composites are a new type of material that has carbon nanotubes inserted in a copper matrix for an optimum mechanical strength, weight reduction, and current carrying capacity. These composites are electrically and mechanically more robust than pure copper and can be used for demanding applications in electric cars, power electronics and industrial systems.
What is the Characteristic of Copper Carbon Nanotube?
Carbon nanotubes drastically increase copper's mechanical and electrical properties. Copper-CNT composites, for example, have up to 14% higher current carrying capacity and 20% higher mechanical performance than pure copper.
Detailed properties are summarized in the table below:
| Property | Copper-CNT Composite | Pure Copper | Improvement |
| Electrical Conductivity (S/cm) | ~2.3 - 4.7×105 | ~5.96×105 | Comparable, up to 82% IACS |
| Current Carrying Capacity | 14% higher | Baseline | 14% |
| Maximum Vickers Hardness (HV) | 1.3 GPa | ~0.52 GPa | 150% |
| Yield Strength (MPa) | 142.2 MPa | ~60 MPa | 150% |
What is the Technology for Fabricating Copper Carbon Nanotubes?
The good conductivity of copper-carbon nanotube composites is due to the way that their fabrication methods improve the dispersion of carbon nanotubes and their attachment to the copper substrate.
- Magnetron Sputtering
We developed a process for depositing and positioning carbon nanotubes on copper, and the copper film was deposited by magnetron sputtering. Vacuum furnace annealing produces a dense uniform copper-carbon nanotube network that increases the current capacity and mechanical properties by 14% and 20%, respectively.
- Hydrogen Etching
In this method, carbon nanotubes are first acid-treated and then ball-milled with copper powder to form a composite powder. The mixture is then hydrogen etched and discharge plasma sintered to produce a bulk composite. This method increases the interfacial area between the carbon nanotubes and the copper matrix, which facilitates load transfer and results in excellent mechanical properties.
- Thermal acid Mixing Process
The researchers used a hot-mix acid process to functionalize the CNT surface and optimize its dispersion in the copper powder. The process combines vacuum hot pressing with controlled sintering parameters (700 ℃, 30 minutes, 30 MPa pressure, and 10-3 Pa vacuum). The method produces composites with customized properties based on the CNT surface treatment, such as copper or nickel plating.
Fig.1 There are two main methods for preparing CNT/Cu: powder processing and Cu electrodeposition[1].
What is Copper Carbon Nanotube Used for?
Copper-CNT composites find extensive use in industries demanding high-performance materials.
Electric Vehicles (EVs)
These composites are utilized in traction motors, busbars, and connectors to enhance the efficiency, power density, and longevity of EV systems. Oak Ridge National Laboratory's advancements in composite copper-CNT materials have enabled their use in high-efficiency traction motors, boosting their current capacity by 14% and reducing costs.
Power Electronics
The material is pivotal in manufacturing advanced motor systems and compact power inverters. Improved electrical and mechanical performance allows for smaller and more efficient components, essential for next-generation electronics.
Industrial and Energy Systems
Collaborations between the International Copper Association and leading universities have focused on copper-CNT wires for reducing power losses in industrial motors and electrical grids. These wires could lower power losses by up to 50%, achieving substantial energy savings and carbon emission reductions.
The continued development of copper-CNT composites is expected to address critical challenges, such as achieving uniform CNT dispersion and robust interfacial bonding. Ongoing research into novel synthesis methods and surface functionalization techniques will further enhance their application potential, particularly in emerging fields like renewable energy and aerospace.
Conclusion
Copper carbon nanotube composites represent a transformative advancement in materials science, combining the electrical excellence of copper with the extraordinary mechanical properties of carbon nanotubes. Their integration into high-demand applications is set to revolutionize industries by enabling unprecedented performance improvements, energy efficiency, and environmental sustainability.
Reference
- Sundaram RM., et al. Copper/carbon Nanotube Composites: Research Trends and Outlook. Royal Society Open Science (2018).
