DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Status of the Claims
The amendment filed 1-4 and 7 has been entered. Claims 1-4 and 7 have been amended to a method from an apparatus. Claims 1-4 and 7 are currently pending and are examined.
Status of the Rejection
The 35 U.S.C. § 103 rejections of claims 1 and 4 are maintained and modified as necessitated by the amendment. The 35 U.S.C. § 103 rejection of claims 2-3 is withdrawn.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Kurashina et al. (JP 2012153965, cited in IDS 3/4/2026).
Regarding claims 1-3, Kurashina et al. teaches a method of operating a water electrolysis apparatus (12; Fig. 1) that performs water electrolysis in which hydrogen and oxygen (paragraph 1) are obtained by supplying water to water electrolysis cells and applying voltage to the water electrolysis cells, comprising:
providing the water electrolysis apparatus (Fig. 1), the water electrolysis apparatus including comprising:
a water electrolysis stack (i.e., multiple cells stacked together; paragraph 3) in which the water electrolysis cells are stacked;
a water supply side path (i.e., water is circulated and electrolyzed to generate oxygen on the anode side which is circulated out of the electrolysis cell 12; paragraph 12) through which water is supplied to the water electrolysis stack;
a hydrogen side path (i.e., hydrogen is produced on the cathode side which is removed from the electrolysis cell 12; paragraph 12) through which hydrogen generated from the water electrolysis stack is collected;
an electric power source (i.e., power supply 38; Fig. 1) that applies the voltage to the water electrolysis stack; and
a controller (i.e., controller 20) that controls application voltage of the electric power source;
performing water electrolysis by supplying water to the water electrolysis stack (paragraph 12) and applying voltage to the water electrolysis stack from the electric power source (paragraph 12); and
controlling, by the controller, at times of startup and stop of the water electrolysis apparatus, the controller controls the voltage of the electric power source such that an average change rate of a current density is higher
Kurashina et al. further teaches applying a current density with an initial average change rate (i.e., slope in the first portion of the start-map in Fig. 4 as annotated below) that is higher in the first portion than the second portion during the initial start (i.e., start-map phase in Fig. 4) of the electrolysis cell. Kurashina et al. further teaches that the current density is controlled according to Fig. 4 to reliably prevent a rapid increase in cell voltage (paragraph 42).
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Since Fig. 4 of Kurashina et al. does not have scale bars, Kurashina et al. does not explicitly teach whether the change of the current density slope is at the half point of the current density from steady operation of the water electrolysis apparatus.
However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention control the power source to have applied the voltage of the electric power source such that an average change rate of a current density is higher in a region where the current density is equal to or lower than half of a current density at a time of steady operation of the water electrolysis apparatus than in a region where the current density is higher than half of the current density at the time of the steady operation, because Kurashina et al. teaches having a higher change rate of the current density in the first half than the second half as shown in Fig. 4 in order to prevent a rapid increase in cell voltage. Since the average change rate, i.e., slope, of the first portion as shown in Fig. 4 is significantly higher than the change rate of the second portion, one having ordinary skill in the art would recognize that the average change rate of the current density is higher in the first portion than the average change rate in the second portion where the current density is higher than half of the current density at the time of steady operation.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Kurashina et al. in view of Taruya et al. (US 20100230295, cited in IDS 11/3/2023).
Kurashina et al. does not explicitly teach a valve that decreases the hydrogen pressure of the hydrogen side path and actuating the valve before the current density decreases to 0.4 A/cm2.
Taruya et al. teaches a water electrolysis apparatus having a depressurization valve 89 (Fig. 1) connected to the high-pressure hydrogen pipe 88 to reduce the pressure of the hydrogen side of the electrolysis apparatus (paragraph 58). This valve is controlled by controller 22 (paragraph 58). Taruya et al. further teaches that the controller controls the electrolysis power supply 38 to stop applying a preset voltage after the pressure on the hydrogen flow field is reduced (paragraph 59).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention modified the electrolysis apparatus of Kurashina et al. by incorporating the depressurization valve connected to the controller as taught by Taruya et al., because it would allow for the depressurization of the high-pressure hydrogen side of the electrolysis cell. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have further activated the depressurization valve prior to reducing the current density to 0.4 A/cm2 since it would reduce the buildup of pressure while the water electrolysis apparatus is operating.
Allowable Subject Matter
Claims 2, 3, and 7 are objected to as being dependent upon a rejected base claim but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: While Kurashina et al. teaches ramping up current density having a higher average change rate, i.e., steeper slope in the first portion as shown in Fig. 4, than the second portion, Kurashina et al. does not explicitly teach or suggest the transition between the regions at 0.4 A/cm2 (claim 2); the startup reaches 0.4 A/cm2 within 5 seconds and the water electrolysis apparatus reaches a stopped rate within five seconds after the current density reaches 0.4 A/cm2 (claim 3); or average change rate of the current density in the region where the current density is equal to or lower than half of the current density at the time of steady operation is 20 A/(cm2-second) or higher (claim7).
Response to Arguments
Applicant's arguments in the Remarks, filed July 13, 2026, with respect to the 35 35 U.S.C. § 103 rejections have been fully considered. However, applicant’s arguments are moot in view of the new grounds of rejection.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795
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