LK-99: Patenting an ambient superconductor
Does patentability hinge on whether the claim of superconductivity is correct?

LK-99 was claimed to be an ambient superconductor – a claim which seems to have been debunked by the wider scientific community. We discuss how far it matters, for patenting LK-99, whether the claim is real or not. No prior knowledge of patent law required for the reader!

In July 2023, a group of scientists released two academic papers[1] claiming to have observed superconductivity under ambient conditions (room temperature and atmospheric pressure) in a material they termed LK-99, having the chemical formula Pb10-xCux(PO4)6O. Rarely does a story cut across the scientific community like this. Achieving ambient superconductivity would be a monumental discovery – “an obvious instant Nobel prize”, according to some commentators. Was the discovery real?

Before announcing their discovery, the scientists had the good business sense to file a patent application with a view to protecting their invention. After all, if they were right that LK-99 is an ambient superconductor, then that patent application could be the foundation of a multi-billion-dollar industry; without it, they might have given away the invention for free (albeit with the comfort of looking forward to that expected Nobel prize). An international patent application[2] was published in March 2023, titled “Room temperature and normal pressure superconducting ceramic compound, and method for manufacturing same”, with the inventors named as the same scientists who’d authored the two papers. The patent application refers to LK-99 by name, and claims patent protection for a general formula which encompasses it[3]. Published together with the patent application was a preliminary opinion from the Korean patent office on whether a patent should be granted. Good news for the scientists/inventors, as the opinion was entirely positive – all the patentability requirements seem to be met.

Although the patent application had been published a few months earlier, it took the publication of the academic papers for the international scientific community to take note of LK-99 and the bold claim of ambient superconductivity. Teams around the world swung into action trying to make LK-99 themselves, seeking to verify whether it did indeed behave as promised. Unfortunately, almost as quickly as the excitement had spread across the globe, it began to dissipate as those teams debunked the claims. More mundane explanations arose for the properties the original scientists had ascribed to ambient superconductivity. Perhaps ferromagnetism – the property behind everyday magnets – was the reason for the magnetic levitation of LK-99 which had been taken as a tell-tale sign of superconductivity. Perhaps Cu2S impurities were the cause of the electrical properties.

So, it may be that the dream of ambient superconductivity is dead, at least for LK-99. However, the patent application seeking to protect LK‑99 is still alive. This poses the question: how far does it matter for the validity of that application that LK-99 might not be an ambient superconductor after all? Can a patent still be granted to protect LK-99, despite that it might not perform as originally claimed? There are a number of requirements for a patent to be granted, so we will take a look at whether these might or might not be met depending on whether LK-99 is an ambient superconductor[4].

A first requirement for getting a patent is that the invention to be protected must be novel, which means that the invention must not have been available to the public before the patent application was filed. For LK-99, whether it is an ambient superconductor should not affect this requirement. If the invention is the lump of material which is LK-99, defined by the chemical formula, and if no one has published before the same ratio of lead : copper : phosphorus : oxygen of the formula, then the novelty requirement should be met regardless of whether LK-99 is a superconductor[5].

A second requirement is that the invention must show an inventive step, which means that it would not have been obvious to a skilled person in the relevant technical field. The skilled person is a legal fiction of someone who is aware of all the knowledge in their field, can perform routine experiments, and can follow detailed instructions and technical teachings, but who has no inventive nature or tendency for lateral thinking whatsoever. The requirement of showing an inventive step is a complex and highly nuanced legal battleground. However, at a simplistic level, an invention is more likely to be found to show an inventive step if it is achieving something unexpected. If LK-99 is an ambient superconductor then this was surely very unexpected, and thus a very strong sign that an inventive step is present. However, the converse is not necessarily the case – a failure to achieve ambient superconductivity does not inherently mean that there is no inventive step. It depends on what else has been achieved by LK-99. For instance, if LK-99 is still a superconductor but only at temperatures well below room temperature then, provided that there was nothing to suggest to the skilled person that the chemical formula would be expected to at least be a low-temperature superconductor, the invention of LK-99 may still show an inventive step. As long as LK-99 achieves something that the skilled person would not have expected, even if that thing is not as groundbreaking as ambient superconductivity, then the inventive step requirement might be met.

What if LK-99 is not a superconductor at all, not under any temperature or pressure? In that event the case for an inventive step would be weaker. If LK-99 has no useful properties then, from an inventive step perspective, it would effectively be seen as an arbitrary combination of lead, copper, phosphorus, and oxygen. It could be argued that this combination would have been obvious to the skilled person – as equally obvious as any arbitrary combination of elements – and so there would be no inventive step.

A third requirement is that the patent application must provide sufficient teaching to enable the skilled person to perform the invention (a requirement typically known as “sufficiency” or “enablement”). To understand whether achieving this requirement is affected by whether LK‑99 is an ambient superconductor, a brief dive into a more detailed level of patent law is needed. What is protected by a patent is what is written in the “claims” of a patent. It is completely up to the patent applicant (typically working closely together with their patent attorney) to decide how the claims are written. For a material like LK-99, the claims would typically include a general chemical formula which encompasses the specific formula of LK-99. However, in addition to the formula, the patent applicant could choose to write in their claim that the chemical formula is of a superconductor, or even of an ambient superconductor. If they did, this would mean that the invention is only present when the chemical formula is present and when the material is a superconductor. This is relevant because the claims of the LK-99 patent application define the chemical formula as “a superconductive ceramic compound”,  i.e. requiring superconductivity but not necessarily ambient superconductivity.

If the claims include a requirement for an ambient superconductor, and if LK-99 is not so, then the skilled person cannot perform the invention and the enablement requirement would not be met, which means that no patent should be granted. If the claims include a requirement for superconductivity without specifying the conditions then, as long as LK-99 is a superconductor under some conditions which could reasonably be achieved by the skilled person, then the enablement requirement should be met. If the claims do not include any requirement for superconductivity at all, e.g. if they just recite a chemical formula, then it does not matter whether LK-99 is an ambient superconductor – the enablement requirement is met simply if the skilled person can reproduce the chemical formula based on the teaching of the patent application[6].

A fourth requirement for getting a patent is that the invention must be industrially applicable, which means that the invention must be useful in some way. It might sound like whether LK-99 is an ambient superconductor is highly relevant to this requirement – if it isn’t then does it have any practical use? –  but that is not the case. The requirement for industrial applicability is a very low bar. As long as an invention can be used in effectively any way, then it is deemed to be industrially applicable. So, even if LK-99 does not superconduct under any conditions, perhaps it could be used instead as an unusually expensive form of shipping ballast. That would be enough for it to be industrially applicable.

You might be wondering what the point is of the industrial applicability requirement, given that it is such a low bar. On a practical level, the point is that it gives patent offices a way of rejecting patent applications which contravene the laws of physics (e.g. perpetual motion machines), without needing to come up with reasons under the other patentability requirements why no patent should be granted (reasons which, for something like a perpetual motion machine, can be difficult to formulate sensibly).

In summary, whether LK-99 is an ambient superconductor might not be determinative of whether it can be patented. If its chemical formula is novel, if it achieves something unexpected (ambient superconductivity or something else), and if the claims do not include a requirement for ambient superconductivity (and perhaps do not require superconductivity at all), then it could be patented.

It will be interesting to see the fate of the LK-99 patent application, which is still in its early stages. It might be abandoned, given the general scepticism over whether LK-99 is of any use at all, or it could nonetheless be maintained and used to seek patents worldwide to protect LK‑99. If it is maintained – and given the possible rewards if ultimately it turns out that the inventors are right and the rest of the world is wrong, it may well make sense to do so – it will be interesting to see how patent offices approach the examination of the patentability requirements. The experimental data in the patent application purports to show ambient superconductivity[7], so will patent offices take that at face value, as they might have done for a less ambitious claim which was not scrutinised so heavily by the international community? Or will patent offices refer to the numerous failed attempts at reproducing the ambient superconductivity and refuse to grant a patent? We will be monitoring the progress of the application with interest.


[1] here and here
[2] Publication number WO2023/027536A1.
[3] Claim 1 is (machine translation):
A superconductive ceramic compound comprising a ceramic compound according to Chemical Formula 1:
AaBb(EO4)cXd [Formula 1]
A: (s-, p-block metals) Ca, Ba, Sr, Sn, Pb, (lanthanides, etc.) Y, La, Ce or combinations thereof
B: (d-block metal) Cu, Cd, Zn, Mn, Fe, Ni, Ag or a combination thereof
E: P, As, V, Si, B, S or a combination thereof
X: F, Cl, OH, 0, S, Se, Te or a combination thereof
(a: 0 to 10, b: 0 to 10, c: 0 to 6, d: 0 to 4).
[4] A disclaimer – this article is not a considered legal opinion on the patentability of LK-99 or the related patent application WO2023/027536A1.
[5] Although, given that the “99” in LK-99 is said in some articles to signify the year (1999) of the discovery of the material, it could perhaps be questioned whether the formula has really been kept secret since then.
[6] You may be wondering why the claims would want to include a requirement for superconductivity at all, when this only seems to make it harder to achieve the enablement requirement, seemingly with no upside. If you are, then consider a career as a patent attorney. In brief, it could be advantageous for the claims to require superconductivity when it comes to other patentability requirements (e.g. novelty and inventive step), but explaining why is beyond the scope of this article.
[7] The patent application concludes that “all evidence and explanations show that LK-99 is the first room temperature and ambient pressure superconductor”.