Graphene is the most extensively researched nanomaterial in recent years, owing to its exceptional properties. Despite its promise, the widespread application of graphene is impeded by the absence of high-quality and cost-effective mass-production methods.
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Challenges in Mass Producing Graphene
Scalability of Production Methods
The methodologies employed for mass production must align with the requirements for industrial-scale testing, typically involving quantities such as a kilogram of powder or suspension containing graphene flakes (typically micrometer-scale) or a thousand pieces for continuous graphene films (normally larger than millimeter size).1
Cost-Effectiveness
For industrial-scale applications, a delicate balance must exist between graphene quality and production cost. As diverse applications demand varied graphene properties, customizing graphene films to suit specific applications becomes essential.
Conversely, the demand for cost-effective graphene production with tailored properties also propels market growth across various applications.2
Quality and Consistency
Quality control is crucial to graphene mass production, ensuring uniformity and reproducibility across large surface areas and between production batches.
The structural attributes of graphene films dictate critical properties, with the number of graphene layers and domain size emerging as crucial factors. As a result, achieving uniform layers and consistent domain sizes in graphene growth becomes imperative.3
Current Methods for Graphene Production
Chemical Vapor Deposition
Among various methods, graphene films synthesized via Chemical Vapor Deposition (CVD) exhibit superior overall performance, meeting the criteria of high quality, large size, and reasonable cost.
However, the presence of prevalent structural imperfections, such as grain boundaries, point defects, and wrinkles, offsets the advantageous properties of CVD-grown samples compared to mechanically exfoliated samples.4,5
These challenges become more pronounced in large-scale graphene synthesis.
Liquid-phase Exfoliation
Owing to its affordability and abundance, graphite is a promising exfoliation resource. The challenge lies in overcoming the van der Waals interaction between graphene layers while preserving the size of graphene platelets.
Early methods involved simple sonication of graphite in organic solvents or water with surfactants.6 Recently, the efficacy of this method has seen partial enhancement through shear exfoliation instead of sonication.7
Graphite Oxide Reduction
The graphite oxide route is the predominant wet chemical method for producing graphene materials, specifically graphene oxide (GO) and reduced graphene oxide (rGO).8
This method’s popularity stems from its potential scalability, high yield, and, most notably, its excellent dispersibility in various solvents, facilitating processability for numerous applications.
Recent Advances from Research
Tour and colleagues revealed a groundbreaking discovery wherein various amorphous carbon materials were rapidly transformed into highly crystalline graphene within a single second through flash Joule heating (FJH).
The process was simple: a carbon source with inherent conductivity was compressed between two electrodes within a quartz or ceramic tube.9
Graphene is also synthesized through FJH, utilizing an electric current to generate high-quality turbostratic flash graphene (tFG). Compatible with waste rubber feedstocks, this process offers a more cost-effective alternative to conventional synthetic techniques.10
Another study proposes combining ball milling with shear-mixing in supercritical CO2 for large-scale graphene production. A continuous exfoliation system has been developed comprising a ball-milling subset driven by a mixer in series with a shear-mixing subset in supercritical CO2.11
Addressing limitations posed by conventional ball milling, the study employed regularly applied shear load feasible for industrial-scale application. The innovative approach uses involute gear teeth profiles instead of spherical surfaces of balls to exfoliate LT-EG/Di-methyl formamide (liquid phase) within the gear contact zone under regularly applied shear load and low temperatures.12
An ultrafast and scalable strategy has been developed for directly exfoliating graphite into high-quality graphene, which strongly favors the formation of single layers and eliminates the need for intercalants, chemicals, or solvents. Graphite exfoliation was achieved using a DC plasma spray setup integrated with a custom-designed inert atmosphere shroud.2
Industrial Advancements
Various efforts have been made to leverage the extraordinary properties of graphene, initially spearheaded by small companies exploring commercial applications of this ground-breaking material.
Today, large consortiums, such as the Graphene Flagship, provide substantial funding and support for bringing graphene products to market.13
Renowned companies have entered the market with graphene-powered supercapacitors, presenting high energy density, low internal resistance, and prolonged application lifetimes.
Skeltontec, a Germany-based company, utilizes its patented Curved Graphene carbon material, which is mass-produced for supercapacitors that surpass industry standards in power and energy density.
Volta-xplore, a leading energy materials company from Canada, employs its SiG graphene-enhanced Silicon anode active material to shape the future of energy storage.14,15
First Graphene, based in the UK, specializes in producing graphene from graphite using the electrochemical exfoliation method. This process involves applying a voltage that drives specific ions to intercalate into the carbon layers of graphite, causing the layers to expand and separate.
The resulting graphene is then utilized in concrete applications, offering promising potential in reducing the cement industry’s carbon footprint by up to 20 % through reduced cement content.16
Graphene manufacturing group (GMG) is also exploring applications in aluminium-ion batteries, heat transfer enhancement, and lubricants using an instant, scalable graphene made from natural gas (methane).17
Companies like Applied Graphene Materials are actively working on graphene dispersions and paints, using bottom-up processes to mass-produce graphene nanoplatelets.18
Graphene Mass Production: Challenges and Innovations
Graphene’s commercialization journey will unfold in distinct phases.
In the short term (within five years), applications in the materials sector, such as composites, inks, and coatings, will dominate.
Moving into the mid-term (five to ten years), advancements in the energy sector and optoelectronics are expected, including batteries, solar cells, and sensor technologies.
Over the subsequent five to fifteen years, these applications will expand into various markets, impacting construction materials, water purification membranes, supercapacitor electrodes, flexible solar cells, and autonomous driving systems.
In the long term (fifteen to thirty years), graphene’s properties will be harnessed in medical devices, while layered materials will play a pivotal role in quantum technology endeavors.19
More from AZoNano: What is a Graphene Semiconductor?
References and Further Reading
- Zhu, Yanwu., et al. (2018). Mass production and industrial applications of graphene materials. National Science Review. doi.org/10.1093/nsr/nwx055
- Islam, A., et al. (2021). Ultra-fast, chemical-free, mass production of high quality exfoliated graphene. ACS Nano. doi.org/10.1021/acsnano.0c09451
- Kong, W., et al. (2019). Path towards graphene commercialization from lab to market. Nature Nanotechnology. doi.org/10.1038/s41565-019-0555-2
- Jia, K., et al. (2021). Toward the commercialization of chemical vapor deposition graphene films. Applied Physics Reviews. doi.org/10.1063/5.0056413
- Ciesielski, A., Samorì, P. (2014). Graphene via sonication assisted liquid-phase exfoliation. Chemical Society Reviews. doi.org/10.1039/C3CS60217F
- Li, X, et al. (2009). Large-area synthesis of high-quality and uniform graphene films on copper foils. Science. doi.org/10.1126/science.1171245
- Paton, KR., et al. (2014). Scalable production of large quantities of defect-free few-layer graphene by shear exfoliation in liquids. Nature Materials. doi.org/10.1038/nmat3944
- Sharif, A., et al. (2023). Extensive reduction of graphene oxide on thin polymer substrates by ultrafast laser for robust flexible sensor applications. Applied Surface Science. doi.org/10.1016/j.apsusc.2022.156067
- Luong, DX., et al. (2020). Gram-scale bottom-up flash graphene synthesis. Nature. doi.org/10.1038/s41586-020-1938-0
- Advincula, PA., et al. (2021). Flash graphene from rubber waste. Carbon. doi.org/10.1016/j.carbon.2021.03.020
- Tan, H., et al. (2022). Scalable massive production of defect-free few-layer graphene by ball-milling in series with shearing exfoliation in supercritical CO2. The Journal of Supercritical Fluids. doi.org/10.1016/j.supflu.2021.105496
- Yousef, S., Mohamed, A., Tatariants, M. (2018). Mass production of graphene nanosheets by multi-roll milling technique. Tribology International. doi.org/10.1016/j.triboint.2018.01.040
- Graphene Flagship. (no date). What is the Graphene Flagship?. [Online] Graphene Flagship. Available at: https://graphene-flagship.eu/
- Skelton Technologies. (no date). Skelton Materials. [Online] Skelton Technologies. Available at: https://www.skeletontech.com/ultracapacitor-technology
- Voltaxplore. (no date). Product. [Online] Voltaxplore. Available at: https://voltaxplore.com/?page_id=2
- First Graphene. (2022). Graphene a key driver in race for green cement and concrete. [Online] First Graphene. Available at: https://firstgraphene.net/graphene-a-key-driver-in-race-for-green-cement-and-concrete/
- GMG. (no date). Graphene Aluminium-Ion Battery. [Online]. GMG. Available at: https://graphenemg.com/graphene-products/
- Applied Graphene Materials. (no date). Products. [Online]. Applied Graphene Materials. Available at: https://www.appliedgraphenematerials.com/
- Reiß, T., Hjelt, K., Ferrari, AC. (2019). Graphene is on track to deliver on its promises. Nature Nanotechnology. doi.org/10.1038/s41565-019-0557-0
