A recent article in Nature on battery technology discussed a result which may seem surprising to those not used to working in the field. Studies have shown that asking different teams to make the same battery, i.e. a battery made from the same commercially available materials arranged in the same way, can result in very different results – sometimes batteries having a more than five-fold difference in performance. This is a striking difference for nominally the same battery. The study highlights the lack of standardisation in the field and the issues faced in reproducing research from other parties. These are issues from a technical perspective, but they highlight a common difficulty faced from a legal perspective when seeking patent protection in this field, and perhaps also give insight into a direction of travel for battery intellectual property.

The common difficulty arises because when trying to secure a patent protecting a new type of battery or a new type of battery material, it can be very useful to show to a patent examiner that your new battery / battery material is better than the state of the art – showing an improvement is key in demonstrating that there was an inventive step [1]. However, showing an improvement requires a comparison, typically hard data proving that the invention is better than what came before. But if battery technology is difficult to reproduce, then arriving at a fair comparison can be hard to do.

In many other fields, a prior art document would give results characterising the state of the art and it would be reasonable to compare those results with results generated in the inventor’s lab on their new invention. However, for battery technology, the prior art may be missing key information on exactly how the battery / battery material was tested, which could have impacted the results (e.g. what was the thickness of the current collector or lithium foil? What load was used during calendaring? What purity of starting material was used? and so on). Without standardisation it can be difficult to fill in the gaps, and so difficult to know if a direct comparison with prior art results is valid – like comparing apples with pears.

These challenges are not insurmountable if properly addressed when drafting a patent application. One approach is for the technical team to prepare comparative examples representing the key teaching of the state of the art and to test these using identical methodology as the inventive examples – apples with apples. This approach does, however, require additional experimental work. Another approach is to focus on the results the prior art is saying are important. If the invention betters these results then, provided that there is sufficient technical justification to show that this improvement is linked to the core of the invention, and not due to other differences in how the batteries were made and tested, this may be sufficient to convince a patent examiner that there is an inventive step – comparing apples with pears can sometimes be valid, particularly if the prior art did not give sufficient detail to allow a proper reproduction. Improving an innovator’s case here requires careful thought on how much detail is appropriate to put in the patent application.

There are efforts to improve standardisation in the battery sector. If these efforts reach a point where specific patented battery technologies are held to represent a technical standard, then it could be that the battery sector reaches a stage where some patents are held to be Standard Essential Patents (SEPs). After all, if the successive generations of mobile network technology underlying our phones (3G, 4G, 5G, etc.) are protected by SEPs, then why should successive generations in battery technology powering those phones not be protected by SEPs?

It could be, though, that battery manufacturers prefer not to share their internally standardised methodology, perhaps not sharing those precise settings of the equipment on the cell line which just seem to make better batteries. Indeed, given the difficulties of reproducibility in the battery sector, confidential information of this sort can be valuable intellectual property of its own, and possibly more valuable if kept as a trade secret and never patented. This shows the importance of well-rounded IP strategy, taking advantage of all the forms available. At Carpmaels & Ransford, our multi-disciplinary Energy team is well-placed to advise on these matters and can assist in gaining broad and robust patent protection in this area, as well as advising on knowledge supply agreements and the like involving patent rights and trade secrets.

Footnotes

[1] Although it should be emphasised that there is no absolute need to show any sort of improvement for a patent to be granted – non-obvious alternatives can be patentable.