What is good quality graphene?

Dr Khasha Ghaffarzadeh
What is good quality graphene?
At IDTechEx we have been closely following and analysing the nano-carbon areas including graphene and carbon nanotubes. Our market research report Graphene Markets, Technologies, Opportunities 2014-2024 is the result of our work which has seen us closely engage with innovators, suppliers and end users. We plan on sharing with you insights from our work on a regular basis. Here is a short piece on what constitutes good quality graphene.

Am I better than the guy next door?

It is increasingly common to hear that one graphene is higher quality than another, or that one graphene is really just thin graphite re-branded as graphene to exploit the hype. It has become a point of contention and also differentiation. Clearly, there are many types of graphene on the market. And this is no surprise because the properties of graphene vary depending on the production method, of which there are many.
This argument however misses the point, which is that only benchmarking at the intermediary level is meaningful. End customers want graphene incorporated into an intermediary product, and ultimately only the performance benefits delivered at or via the intermediary matter.
The product quality at this level will reflect the properties of the graphene and the skill of the compounder. The latter is vitally important. This is because dispersing materials with high surface-to-volume ratios is difficult, and materials like graphene are rarely a drop-in replacement for the materials that they seek to replace.
Graphene quality therefore only finds meaning in the context of an intermediary product. The curious consequence is that a so-called low quality graphene platelet, judged roughly on the basis of its deviation from perfect graphene, can perform better if it closely matches the host material system and the compounding conditions. The perfect graphene is the hardest to disperse.
The compounding step does not receive the attention it deserves despite its importance. For example, there is very little comparative data at the intermediary level beyond the work published in academia. We expect this to change as intensifying competition inevitably forces suppliers to prove their quality.

Un-blocking the market

Indeed, this is already happening as graphene suppliers migrate downstream en masse to offer intermediaries. This trend should help un-block the market. It should also help alleviate some of the health and safety concerns that act as brakes in more conservative sectors. This is because graphene is least safe to handle when it is in powder form before incorporation into an intermediary.
We are not advocating that graphene suppliers become global compounders. Graphene suppliers often tend to be small start-ups with localised operations, little capital, and very little revenue. This means that they cannot compete with large compounders. Graphene companies should therefore concentrate on their core competency, which is material production.
Graphene suppliers should however develop dispersion know-how in-house in order to signal to the market that (a) their material can be dispersed, and (b) that their material performs well at the intermediary level. This, of course, will not be easy to do for graphene companies with limited capital and resources. Therefore, suppliers have to narrow their target markets, carefully pick the target applications, and focus on the right intermediaries.
We note here that reproducibility is found wanting today as not all graphene materials do what it says on the tin. This is bad for the industry and will be weeded out as competition intensities and the industries fall off its peak of hype.

Carbon nanotubes

As an aside, it is instructive to consider what happened in the carbon nanotube business. The industry soon categorized CNTs on the basis of their chirality and number of layers. The suppliers increasingly went downstream and offered inks or masterbatches. This was to unblock the markets and mitigate health and safety concerns. Multi-walled CNTs found market success despite their lower quality. This was because (a) they could be produced more economically at volume (higher yield process) and (b) they were easier to disperse and found markets. The high-performing single-walled CNTs remained expensive and hard to disperse. This is why they are today still confined to niche applications, most of which are applied via an ink.
For more information on the report Graphene Markets, Technologies, Opportunities 2014-2024 please visit www.IDTechEx.com/graphene. This report is based on several years of research, many interviews and site visits, and on organising, attending, and presenting at many conferences around the world.
If you want to know more about graphene or carbon nanotubes, or if you have any comments, then please contact me on khasha@IDTechEx.com.
Top image: SEM Image of Graphene Film Grown on Nickel Foam, Graphene Supermarket