T 1610/22 - Solution prior to the problem

Key points

• "According to the patent in suit, the problem to be solved is to provide a redox flow battery having a long cycle life (paragraph [0006])."
• "It is proposed to solve the problem using a redox flow battery characterised in that a first permeation preventing unit is disposed adjacent to an outlet for the first electrolytic solution of the first electrolytic solution container."
• "the patent lacks any evidence that the presence of a permeation preventing unit in a set-up as shown in D2 would provide any benefit in the long run. Even if it were accepted that the pellets of D2 would degrade over time, there is still no evidence that the degradation would be such as to clog the porous carbon felt electrode. As indicated by the respondent [proprietor (?)], the degradation of materials in batteries over time is only now becoming the subject of intense research, so this phenomenon was not described and corroborated by evidence in the patent. Therefore, no benefit of a permeation preventing unit in D2 can be discerned.
• Cf. G2/21 hn.2. 
•  "to provide a permeation preventing unit in the set-up of D2 since it does not bring any benefit (see respondent's reply to the appeal, page 17, first full paragraph).  Therefore - as even the respondent acknowledges - including such a unit is a disadvantageous modification which cannot justify an inventive step"
• In Ar-3, the active material is limited to powder, which could leach (in D2, the active material is in the form of the pellets). However, that auxiliary request is not admitted under Art. 13(2).

EPO 

The link to the decision and an extract of it can be found after the jump.

https://www.epo.org/en/boards-of-appeal/decisions/t221610eu1

1.1 The invention relates to a redox flow battery.

1.2 As agreed by the parties, D2 is a possible starting point for assessing inventive step. In particular, Figure 4-1 (page 60) discloses all the features of claim 1 except for a "permeation preventing unit" adjacent to the outlet of the first electrolytic solution container. D2 discloses that the active electrode materials, which are interconnected, immobile and in the form of pellets, as is evident from the text and Figure 4-1 on page 60, "do not flow with the circulation of the electrolyte" (see the paragraph below the cited figure). Under these circumstances, a permeation preventing unit is not necessary.

1.3 According to the patent in suit, the problem to be solved is to provide a redox flow battery having a long cycle life (paragraph [0006]).

1.4 It is proposed to solve the problem using a redox flow battery characterised in that a first permeation preventing unit is disposed adjacent to an outlet for the first electrolytic solution of the first electrolytic solution container.

1.5 It has not been credibly shown that the problem is solved by the feature distinguishing claim 1 from D2. Page 60 of D2 clearly discloses that the pellets are immobile and hence do not leave the reservoir. It is thus impossible for them to clog up the porous carbon felt electrode.

The respondent's argument that powder can be prevented from exiting the electrolytic tank is irrelevant since powder is neither disclosed in D2 nor part of claim 1.

In addition, the patent lacks any evidence that the presence of a permeation preventing unit in a set-up as shown in D2 would provide any benefit in the long run. Even if it were accepted that the pellets of D2 would degrade over time, there is still no evidence that the degradation would be such as to clog the porous carbon felt electrode. As indicated by the respondent, the degradation of materials in batteries over time is only now becoming the subject of intense research, so this phenomenon was not described and corroborated by evidence in the patent. Therefore, no benefit of a permeation preventing unit in D2 can be discerned.

Consequently, the board agrees with the respondent in so far as the skilled person would not have had any motivation to provide a permeation preventing unit in the set-up of D2 since it does not bring any benefit (see respondent's reply to the appeal, page 17, first full paragraph).

1.6 Therefore - as even the respondent acknowledges - including such a unit is a disadvantageous modification which cannot justify an inventive step (Case Law of the Boards of Appeal of the EPO, 10th edition, 2022, I.D.9.21.1).

1.7 The requirements of Article 56 EPC are not met, and so the main request must fail.