Electrolytic element for alkaline water electrolysis and alkaline water electrolysis cell

Abstract

An electrolytic element for alkaline water electrolysis comprises: a conductive partition wall having a first surface and a second surface; an anode for generating oxygen; a cathode for generating hydrogen; a first connecting mechanism, which fixes the anode to the partition wall in a manner that the anode and the first surface of the partition wall are opposite to each other with a first gap therebetween, and electrically connects the anode to the partition wall; a conductive elastomer, which supports the cathode; and a cathode collector, which supports the elastomer, the cathode collector being fixed to the partition wall in a manner that the cathode and the second surface of the partition wall are opposite to each other with a second gap therebetween, and electrically connected to the partition wall, the first connecting mechanism comprising a conductive bolt having at least a rod portion, and the anode is detachably fixed to the partition wall by means of the conductive bolt.

Description

Technical Field

[0001] The present invention relates to an electrolytic element and an electrolytic cell, and more particularly, to an electrolytic element and an electrolytic cell that can be suitably used for electrolysis of alkaline water. Background Art

[0002] As a method for producing hydrogen and oxygen, an alkaline water electrolysis method is known. In the alkaline water electrolysis method, water is electrolyzed by using an alkaline aqueous solution (alkaline water) in which an alkali metal hydroxide (such as NaOH, KOH, etc.) is dissolved as an electrolyte, thereby generating hydrogen from the cathode and oxygen from the anode. As an electrolytic cell for alkaline water electrolysis, the following electrolytic cell is known, which has an anode chamber and a cathode chamber divided by an ion-permeable diaphragm, and an anode is arranged in the anode chamber and a cathode is arranged in the cathode chamber. In addition, in order to reduce energy loss, an electrolytic cell having a zero-gap structure (zero-gap type electrolytic cell) in which the anode and the cathode are maintained in direct contact with the diaphragm, respectively, has been proposed.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2001-262387

[0006] Patent Document 2: Japanese Patent Application Publication No. 2013-104090

[0007] Patent Document 3: Japanese Patent Application Publication No. 2013-108150

[0008] Patent Document 4: International Publication No. 2018 / 139616

[0009] Patent Document 5: Japanese Patent Application Publication No. 2015-117407

[0010] Patent Document 6: International Publication No. 2013 / 191140

[0011] Patent Document 7: Japanese Patent No. 4453973

[0012] Patent Document 8: Japanese Patent No. 6093351

[0013] Patent Document 9: Japanese Patent Application Publication No. 2015-117417

[0014] Patent Document 10: International Publication No. 2019 / 111832

[0015] Patent Document 11: Japanese Patent Application Laid-Open No. 56-102586 Summary of the invention

[0016] Problem that the invention aims to solve

[0017] Figure 1 1 is a partial cross-sectional view of a conventional zero-gap alkaline water electrolyzer 9000 schematically illustrating one embodiment. The zero-gap electrolyzer 9000 comprises: electrode chamber units 9010, 9010, ..., each comprising a conductive partition wall 9011 and a flange 9012 separating an anode chamber A from a cathode chamber C; an ion-permeable diaphragm 9020 disposed between adjacent electrode chamber units 9010, 9010; and gaskets 9030, 9030 disposed between the diaphragm 9020 and the flange 9012 of the electrode chamber unit 9010, and sandwiching the diaphragm 9020. The peripheral portion of the cathode 9070 and the peripheral portion of the conductive elastic body 9060 are fixed to the peripheral portion of the current collector 9050. In the zero-gap electrolytic cell 9000, the soft cathode 9070 is pressed toward the diaphragm 9020 and the anode 9040 by the conductive elastic body 9060, so that the diaphragm 9020 is sandwiched between the adjacent cathode 9070 and the anode 9040. As a result, the diaphragm 9020 and the anode 9040 are in direct contact with each other, and the diaphragm 9020 and the cathode 9070 are in direct contact (ie, zero gap), so the solution resistance between the anode 9040 and the cathode 9070 is reduced, thereby reducing energy loss.

[0018] In the previous zero gap alkaline water electrolyzer 9000, the conductive elastomer 9060 presses the soft cathode 9070 toward the diaphragm 9020 and the rigid anode 9040, and the rigid anode 9040 is welded to the conductive rib 9013, and the conductive rib 9013 is welded to the partition wall 9011. This structure can be said to be reasonable in the alkaline water electrolysis process where the pressure on the cathode chamber side of the hydrogen is maintained higher than the pressure on the anode chamber side of the oxygen. That is, as the ion permeable diaphragm 9020 of the alkaline water electrolyzer, a cheap porous membrane is usually used instead of the expensive ion exchange membrane used in the electrolyzer of the alkali metal salt. Different from the ion exchange membrane, the diaphragm 9020 as a porous membrane also has a certain degree of permeability for gas. Therefore, from the viewpoint of improving the purity of the hydrogen recovered from the cathode chamber, it is advantageous to maintain the pressure in the cathode chamber of the hydrogen generation to be higher than the pressure in the anode chamber of the oxygen generation to carry out electrolysis. When the pressure in the cathode chamber is higher than the pressure in the anode chamber, the diaphragm 9020 is pressed toward the anode 9040 due to the pressure difference (differential pressure) between the two-electrode chamber. As in the above-mentioned alkaline water electrolyzer 9000, in the structure where the conductive elastomer 9060 presses the soft cathode 9070 toward the rigid anode 9040, the direction in which the conductive elastomer 9060 presses the cathode 9070 is the same direction as the force of the differential pressure between the two-electrode chambers pressing the diaphragm 9020, so even if the reaction force of the conductive elastomer 9060 is low, the zero gap state can be stably maintained. This can also be said to be advantageous in terms of extending the renewal interval of the elastomer 9060 and reducing the wear of the diaphragm 9020 caused by the pressure fluctuation during operation. In addition, the conductive rib 9013 that holds the anode 9040 is welded and fixed to the partition wall 9011, which can also be said to be advantageous in terms of improving mechanical strength and reducing resistance.

[0019] However, oxygen is generated in the anode 9040 of the alkaline water electrolyzer, so the bound electrons flow out from the anode 9040, and the anode 9040 is placed under oxidation conditions. The anode 9040 usually has a conductive substrate and a catalyst supported on the surface of the substrate. In the anode 9040 placed under oxidation conditions as described above, the catalyst and the conductive substrate are easily ionized or oxidized, so the catalyst is easily detached from the electrode surface, and as a result, the anode 9040 tends to reach the end of its service life earlier than the cathode 9070. The anode 9040 whose service life has expired needs to be replaced with a new anode, and for this purpose, it is necessary to (1) mechanically separate the anode 9040 from the conductive rib 9013 (for example, by melting, etc.), (2) after adjusting the height of the end of the conductive rib 9013 (for example, by grinding, etc.), (3) weld the new anode 9040 to the conductive rib 9013. When performing such a replacement operation, dedicated equipment is required, so it is difficult to perform the replacement operation of the anode 9040 at the site where the electrolytic cell is installed and operated. Therefore, the pole chamber unit 9010 whose service life of the anode 9040 has expired is sent to a factory capable of replacing the anode 9040. After the factory replaces the anode 9040, the pole chamber unit 9010 that has completed the replacement of the anode 9040 is sent back from the factory to the installation and operation site of the electrolyzer. In this way, in the previous zero-gap alkaline water electrolyzer, the renewal of the anode requires a high cost.

[0020] The present invention aims to provide an electrolytic element which can be used in a zero-gap alkaline water electrolysis cell and in which the anode can be easily replaced, and an alkaline water electrolysis cell having the electrolytic element.

[0021] Solutions for solving problems

[0022] The present invention includes the following technical solutions [1] to

[25] .

[0023] [1] An electrolytic element for alkaline water electrolysis, characterized in that:

[0024] The electrolytic element for alkaline water electrolysis comprises:

[0025] A conductive partition wall having a first surface and a second surface;

[0026] an anode for generating oxygen;

[0027] a cathode for producing hydrogen;

[0028] a first connecting mechanism for fixing the anode to the partition wall so that the anode faces the first surface of the partition wall with a first gap therebetween and for electrically connecting the anode to the partition wall;

[0029] a conductive elastomer supporting the cathode; and

[0030] a cathode current collector supporting the elastic body,

[0031] The cathode current collector is fixed to the partition wall so as to face the second surface of the partition wall with a second gap therebetween and is electrically connected to the partition wall.

[0032] The first connection mechanism includes a conductive first bolt, the first bolt having at least a rod portion.

[0033] The anode is detachably fixed to the partition wall by the first bolt.

[0034] [2] The electrolytic element according to [1], wherein:

[0035] The first connecting mechanism further comprises:

[0036] a first through hole provided in the partition wall and capable of allowing the shank of the first bolt to pass therethrough; and

[0037] A first nut is threadably engaged with the first bolt.

[0038] [3] The electrolytic element according to [2], wherein:

[0039] The first connection mechanism further includes a first conductive structural element,

[0040] The first structural element includes: a first spacer extending from the anode toward the first surface of the partition wall in a direction intersecting the first surface of the partition wall; and a first plate-shaped portion extending continuously with the first spacer in a direction parallel to the first surface of the partition wall.

[0041] The first spacer has an end portion fixed to the anode,

[0042] The first plate-shaped portion includes a second through hole through which the shank of the first bolt can pass.

[0043] The shank portion of the first bolt passes through the first through hole and the second through hole and is threadedly engaged with the first nut, whereby the first structural element is fixed to the partition wall.

[0044] [4] The electrolytic element according to [3], wherein:

[0045] The second through hole is provided continuously from the first plate-shaped portion to at least a portion of the first spacer portion.

[0046] [5] The electrolytic element according to [3] or [4], wherein:

[0047] The first bolt further includes a head, which is provided at the end of the rod.

[0048] The shank of the first bolt is inserted through the first through hole and the second through hole in a direction in which the head of the first bolt presses the first plate-shaped portion of the first structural element toward the partition wall.

[0049] The first structural element further includes a rotation restricting portion that contacts a side surface of the head of the first bolt to restrict rotation of the first bolt when the shank of the first bolt is inserted into the second through hole and the head of the first bolt contacts the first plate-shaped portion.

[0050] [6] The electrolytic element according to any one of [3] to [5], wherein

[0051] The first connection mechanism further includes a second nut capable of being threadedly engaged with the first bolt.

[0052] The second nut is screwed with the rod of the first bolt inserted into the second through hole in such a manner that the head of the first bolt and the second nut sandwich the first plate-shaped portion of the first structural element, thereby fixing the first bolt to the first plate-shaped portion of the first structural element.

[0053] The shank portion of the first bolt fixed to the first plate-shaped portion of the first structural element passes through the first through hole of the partition wall and is screwed into the first nut, whereby the first bolt is fixed to the partition wall.

[0054] [7] The electrolytic element according to any one of [3] to [6], wherein

[0055] The cathode current collector includes a third through hole at a position facing the first through hole of the partition wall, and the third through hole has a shape and a size that allows the first nut to pass therethrough.

[0056] [8] The electrolytic element according to [7], wherein:

[0057] The electrolytic element also has

[0058] a detachable conductive first cover member, the first cover member blocking at least a portion of the third through hole of the cathode current collector,

[0059] When the first cover member is attached so as to block at least a portion of the third through hole of the cathode current collector, the first cover member is electrically connected to the cathode current collector.

[0060] [9] The electrolytic element according to [1], wherein

[0061] The first connection mechanism further includes a first threaded hole that opens on the first surface of the partition wall and can be threadably engaged with the first bolt.

[0062]

[10] The electrolytic element according to [9], wherein:

[0063] The first connection mechanism further includes a first conductive structural element,

[0064] The first structural element includes: a first spacer extending from the anode toward the first surface of the partition wall in a direction intersecting the first surface of the partition wall; and a first plate-shaped portion extending continuously with the first spacer in a direction parallel to the first surface of the partition wall.

[0065] The first spacer has an end portion fixed to the anode,

[0066] The first plate-shaped portion includes a second through hole through which the shank of the first bolt can pass.

[0067] The shank portion of the first bolt is inserted into the second through hole and screwed into the first threaded hole of the partition wall, whereby the first structural element is fixed to the partition wall.

[0068]

[11] The electrolytic element according to

[10] , wherein:

[0069] The anode includes a fourth through hole at a position facing the second through hole, and the fourth through hole has a shape and a size that allows the first bolt to pass therethrough.

[0070]

[12] The electrolytic element according to

[11] , wherein

[0071] The electrolytic element also has:

[0072] a second cover member made of the same material as the anode and blocking at least a portion of the fourth through hole of the anode; and

[0073] a conductive second bolt fixed to the second cover member,

[0074] The head of the first bolt has a second threaded hole capable of being threadedly engaged with the second bolt.

[0075] The second bolt is screwed into the second threaded hole, whereby the second cover member is detachably fixed to the first bolt and electrically connected to the first bolt, and the second cover member closes at least a portion of the fourth through hole of the anode.

[0076]

[13] The electrolytic element according to [9], wherein:

[0077] The first bolt is a stud bolt having a first end and a second end.

[0078] The first connecting mechanism further comprises:

[0079] a first conductive structural element, comprising a first spacer and a first plate-shaped portion, the first spacer extending from the anode toward the first surface of the partition wall in a direction intersecting the first surface of the partition wall, the first plate-shaped portion and the first spacer extending continuously in a direction parallel to the first surface of the partition wall; and

[0080] a first nut capable of being threadedly engaged with the stud bolt,

[0081] The first spacer has an end portion fixed to the anode,

[0082] The first plate-shaped portion includes a second through hole through which the first bolt can pass.

[0083] The stud bolt is screwed into the first threaded hole of the partition wall, whereby the first end of the stud bolt is fixed to the partition wall.

[0084] The stud bolt fixed to the partition wall is inserted into the second through hole and the first nut is screwed into the stud bolt from the second end portion, whereby the first structural element is fixed to the partition wall.

[0085]

[14] The electrolytic element according to

[13] , wherein:

[0086] The anode includes a fourth through hole at a position facing the second through hole, and the fourth through hole has a shape and a size that allows the first nut to pass therethrough.

[0087]

[15] The electrolytic element according to

[14] , wherein:

[0088] The electrolytic element also has:

[0089] a second cover member made of the same material as the anode and blocking at least a portion of the fourth opening of the anode; and

[0090] a conductive second bolt fixed to the second cover member,

[0091] The second end of the stud bolt has a second threaded hole capable of being threadedly engaged with the second bolt.

[0092] The second bolt is screwed into the second threaded hole, whereby the second cover member is detachably fixed to the stud bolt and electrically connected to the stud bolt, and the second cover member closes at least a portion of the fourth through hole of the anode.

[0093]

[16] The electrolytic element according to any one of [1] to

[15] , wherein

[0094] The electrolytic element further comprises a second connecting mechanism, and a first plate-shaped portion fixes the cathode current collector to the partition wall in a manner that the cathode current collector and the second surface of the partition wall face each other with the second gap therebetween, and electrically connects the cathode current collector to the partition wall.

[0095] The second connection mechanism includes a conductive second structural element, the second structural element including a second spacer extending between the cathode current collector and the second surface of the partition wall in a direction intersecting the second surface of the partition wall,

[0096] The second structural element includes an end portion fixed to the cathode current collector and an end portion fixed to the second surface of the partition wall.

[0097]

[17] An electrolytic element for alkaline water electrolysis, characterized in that:

[0098] The electrolytic element for alkaline water electrolysis comprises:

[0099] a partition wall having a first surface and a second surface;

[0100] an anode for generating oxygen;

[0101] a cathode for producing hydrogen;

[0102] a conductive elastomer supporting the cathode;

[0103] a cathode current collector supporting the elastic body; and

[0104] a third connecting mechanism that fixes the anode and the cathode current collector to the partition wall in such a manner that the anode faces the first surface of the partition wall and the cathode current collector faces the second surface of the partition wall, and electrically connects the anode and the cathode current collector,

[0105] The third connection mechanism comprises:

[0106] A conductive first bolt having at least a stem portion;

[0107] a first through hole provided in the partition wall and capable of allowing the shank of the first bolt to pass therethrough; and

[0108] a first nut capable of being threadedly engaged with the first bolt,

[0109] The anode has:

[0110] A first flat portion extending in two dimensions;

[0111] a first cup-shaped portion, which projects from the first flat portion toward the first surface of the partition wall in a tapered shape;

[0112] a fifth through hole, which is provided at the bottom of the first cup-shaped portion and through which the rod of the first bolt can pass;

[0113] The cathode current collector comprises:

[0114] A second flat portion extending in two dimensions;

[0115] a second cup-shaped portion that projects from the second flat portion toward the second surface of the partition wall in a tapered shape; and

[0116] a sixth through hole, which is provided at the bottom of the second cup-shaped portion and through which the rod of the first bolt can pass;

[0117] The shank of the first bolt passes through the first through hole, the fifth through hole, and the sixth through hole and is threadedly engaged with the first nut, whereby the anode and the cathode current collector are detachably fixed to the partition wall by the first bolt.

[0118]

[18] The electrolytic element according to

[17] , wherein:

[0119] The first bolt further includes a head, which is provided at the end of the rod.

[0120] The anode, the partition wall, and the cathode current collector are sandwiched and fastened by the head of the first bolt and the first nut.

[0121]

[19] The electrolytic element according to

[18] , wherein:

[0122] The electrolytic element also has:

[0123] a second cover member made of the same material as the anode and having a two-dimensionally extending shape capable of blocking at least a portion of an opening of the first cup-shaped portion of the anode; and

[0124] a conductive second bolt having a head portion fixed to the second cover member and a rod portion fixed to the head portion,

[0125] The head of the first bolt has a threaded hole capable of being threadedly engaged with the second bolt.

[0126] The second bolt is screwed into the threaded hole, whereby the second cover member is detachably fixed to the first bolt and electrically connected to the first bolt, and the second cover member closes at least a portion of the opening of the first cup-shaped portion of the anode.

[0127]

[20] The electrolytic element according to

[17] ,

[0128] The electrolytic element further includes a second cover member, the second cover member being made of the same material as the anode and having a two-dimensionally extending shape capable of blocking at least a portion of an opening of the first cup-shaped portion of the anode.

[0129] The first bolt further includes a head, which is provided at the end of the rod.

[0130] The second cover member is fixed to the head of the first bolt and is electrically connected to the first bolt.

[0131] The third connection mechanism further includes a second nut capable of being threadedly engaged with the first bolt.

[0132] The rod of the first bolt passes through the first through hole, the fifth through hole and the sixth through hole and is threadedly engaged with the first nut and the second nut, thereby clamping and fastening the anode, the partition wall and the cathode collector by the first nut and the second nut, and the anode, the second cover member and the cathode collector are detachably fixed to the partition wall by means of the first bolt, and the second cover member blocks at least a portion of the opening of the first cup-shaped portion of the anode.

[0133]

[21] The electrolytic element according to any one of [1] to

[20] , wherein

[0134] The electrolytic element further includes a flange portion provided on an outer peripheral portion of the partition wall and extending toward both sides of the partition wall in a direction intersecting the first surface and the second surface of the partition wall.

[0135]

[22] An alkaline water electrolyzer, wherein:

[0136] The alkaline water electrolyzer has a stacked structure, which includes:

[0137] multiple ion-permeable membranes; and

[0138] The electrolytic element according to any one of [1] to

[21] , wherein each of the electrolytic elements is disposed between adjacent ion-permeable membranes.

[0139] The adjacent electrolytic elements are arranged such that the anode of one electrolytic element and the cathode of the other electrolytic element face each other via the ion-permeable membrane.

[0140]

[23] The alkaline water electrolyzer according to

[22] , wherein:

[0141] The alkaline water electrolyzer also has:

[0142] a first terminal element disposed so as to face the cathode of the first electrolytic element disposed at one end of the stacked structure with the ion-permeable diaphragm interposed therebetween; and

[0143] a second terminal element disposed so as to face the anode of the second electrolytic element disposed at the other end of the stacked structure with the ion-permeable diaphragm interposed therebetween;

[0144] The first terminal element comprises:

[0145] a conductive first partition wall; and

[0146] a first anode electrically connected to the first partition wall,

[0147] The second terminal element comprises:

[0148] a conductive second partition wall; and

[0149] A second cathode is electrically connected to the second partition wall.

[0150]

[24] The alkaline water electrolyzer according to

[22] , wherein:

[0151] The alkaline water electrolyzer also has:

[0152] a spacer that holds the peripheral edge of each of the ion-permeable diaphragms;

[0153] an electrically insulating frame-shaped protective member that holds the peripheral edge of each of the ion-permeable diaphragms via the spacer; and

[0154] sealing members are respectively arranged between the partition wall and the protection member, between the first partition wall and the protection member, and between the second partition wall and the protection member,

[0155] The electrolytic elements are the electrolytic elements described in any one of [1] to

[20] .

[0156]

[25] The alkaline water electrolyzer according to

[23] , wherein:

[0157] The electrolytic elements are respectively the electrolytic elements described in

[21] ,

[0158] The first terminal element further comprises a first flange portion, which is provided on the outer peripheral portion of the first conductive partition wall and extends toward the flange portion of the first electrolytic element.

[0159] The second terminal element further includes a second flange portion provided on an outer peripheral portion of the conductive second partition wall and extending toward the flange portion of the second electrolytic element.

[0160] Effects of the Invention

[0161] According to the electrolytic element for alkaline water electrolysis of the first aspect of the present invention, the anode is detachably fixed to the partition wall by the conductive bolts, and thus the anode can be easily replaced, thereby reducing the time and cost required for the renewal of the anode.

[0162] According to the alkaline water electrolysis cell of the second aspect of the present invention, since it includes the electrolysis element of the first aspect of the present invention, the anode can be easily replaced, and thus the time and cost required for the renewal of the anode can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0163] Figure 1 This is a partial cross-sectional view schematically illustrating a conventional zero-gap electrolytic cell 9000 according to one embodiment.

[0164] Figure 2 (A) is a cross-sectional view schematically illustrating an electrolytic element 100 according to an embodiment of the present invention. Figure 2 (B) schematically illustrates the Figure 2 (A) is an exploded cross-sectional view of the electrolytic element 100 in an exploded state.

[0165] Figure 3 It is a perspective view schematically illustrating the first structural element 43 .

[0166] Figure 4 (A) is a cross-sectional view schematically illustrating an electrolytic element 200 according to another embodiment of the present invention. Figure 4 (B) schematically illustrates the Figure 4 (A) is an exploded cross-sectional view of the electrolytic element 200 in an exploded state.

[0167] Figure 5 (A) is a top view of the cathode current collector 60 . Figure 5 (B) means Figure 5 (A) is a plan view showing a state where first cover members 61, 61, ... are mounted in third through holes 60h, 60h, ... of cathode current collector 60. Figure 5 (C) is Figure 5 (B) CC view.

[0168] Figure 6 (A) is a plan view schematically illustrating the first cover member 61 . Figure 6 (B) is Figure 6 (A) is the front view and left and right side views.

[0169] Figure 7 (A) is a cross-sectional view schematically illustrating an electrolytic element 300 according to another embodiment of the present invention. Figure 7 (B) schematically illustrates the Figure 7 (A) is an exploded cross-sectional view of the electrolytic element 300 in an exploded state.

[0170] Figure 8 (A) is a cross-sectional view schematically illustrating an electrolytic element 400 according to another embodiment of the present invention. Figure 8 (B) schematically illustrates the Figure 8 (A) is an exploded cross-sectional view of the electrolytic element 400 in an exploded state.

[0171] Fig. 9 (A) is a perspective view schematically illustrating the first structural element 443. Fig. 9 (B) is from Fig. 9 (A) is viewed from the upper side of the paper. Fig. 9 FIG. 1 is a plan view of an example in which the rod portion 41 a of the first bolt 41 is inserted into the second through hole 43 bh of the first structural element 443 of FIG. Fig. 9 (C) is from Fig. 9 (A) is viewed from the upper side of the paper. Fig. 9 FIG. 1 is a plan view of another example in which the second through hole 43bh of the first structural element 443 of FIG. 1 is penetrated by the rod portion 41a of the first bolt 41. FIG.

[0172] Fig.10 (A) is a perspective view schematically illustrating a first structural element 443 ′ according to another embodiment. Fig.10 (B) is from Fig.10 (A) is viewed from the upper side of the paper. Fig.10 FIG. 1 is a plan view showing a state in which the rod portion 41 a of the first bolt 41 is inserted into the second through hole 43 bh of the first structural element 443 ′ in FIG.

[0173] Fig.11 (A) is a perspective view schematically illustrating a first structural element 443" according to another embodiment. Fig.11 (B) is from Fig.11 (A) is viewed from the upper side of the paper. Fig.11FIG. 4 is a top view showing a state in which the rod portion 41a of the first bolt 41 is penetrated through the second through hole 43bh of the first structural element 443″ in FIG.

[0174] Fig.12 (A) is a cross-sectional view schematically illustrating an electrolytic element 500 according to another embodiment of the present invention. Fig.12 (B) schematically illustrates the Fig.12 (A) is an exploded cross-sectional view of the electrolytic element 500 in an exploded state.

[0175] Fig.13 (A) is a perspective view schematically illustrating a first structural element 443''' according to another embodiment. Fig.13 (B) is from Fig.13 (A) is viewed from the upper side of the paper. Fig.13 FIG. 1 is a plan view of an example in which the second through hole 443 ″′ bh of the first structural element 443 ″′ is penetrated by the rod portion 41 a of the first bolt 41 .

[0176] Fig.14 (A) is a cross-sectional view schematically illustrating an electrolytic element 600 according to another embodiment of the present invention. Fig.14 (B) schematically illustrates the Fig.14 (A) is an exploded cross-sectional view of the electrolytic element 600 in an exploded state.

[0177] Fig.15 (A) is a cross-sectional view schematically illustrating an electrolytic element 700 according to another embodiment of the present invention. Fig.15 (B) schematically illustrates the Fig.15 (A) is an exploded cross-sectional view of the electrolytic element 700 in an exploded state.

[0178] Fig.16 (A) is a cross-sectional view schematically illustrating an electrolytic element 800 according to another embodiment of the present invention. Fig.16 (B) schematically illustrates the Fig.16 (A) is an exploded cross-sectional view of the electrolytic element 800 in an exploded state.

[0179] Fig.17 (A) is a cross-sectional view schematically illustrating an electrolytic element 900 according to another embodiment of the present invention. Fig.17 (B) schematically illustrates the Fig.17 (A) is an exploded cross-sectional view of the electrolytic element 900 in an exploded state.

[0180] Fig.18 (A) is a top view schematically illustrating the anode 920 . Fig.18 (B) is Fig.18BB cross-sectional view of (A).

[0181] Fig.19 (A) is a top view schematically illustrating the cathode current collector 960 . Fig.19 (B) is Fig.19 BB cross-sectional view of (A).

[0182] Fig. 20 (A) is a cross-sectional view schematically illustrating an electrolytic element 1000 according to another embodiment of the present invention. Fig. 20 (B) schematically illustrates the Fig. 20 (A) is an exploded cross-sectional view of the electrolytic element 1000 in an exploded state.

[0183] Fig.21 (A) is a cross-sectional view schematically illustrating an electrolytic element 1100 according to another embodiment of the present invention. Fig.21 (B) schematically illustrates the Fig.21 (A) is an exploded cross-sectional view of the electrolytic element 1100 in an exploded state.

[0184] Fig. 22 (A) is a cross-sectional view schematically illustrating an electrolytic element 1200 according to another embodiment of the present invention. Fig. 22 (B) schematically illustrates the Fig. 22 (A) is an exploded cross-sectional view of the electrolytic element 1200 in an exploded state.

[0185] Fig.23 It is a cross-sectional view schematically illustrating an alkaline water electrolysis cell 10000 according to one embodiment of the present invention.

[0186] Fig.24 yes Fig.23 Exploded diagram of .

[0187] Fig.25 (A) is a plan view schematically illustrating the protection member 110 holding the diaphragm 80 and the gasket 90 . Fig.25 (B) is Fig.25 (A) is a cross-sectional view taken along the line BB. Fig.25 (C) means Fig.25 (B) is a cross-sectional view showing a state where the protection member 110 is disassembled. Fig.25 (D) means Fig.25 (B) is a cross-sectional view showing a state where the protection member 110 is disassembled.

[0188] Fig.26 (A) is a cross-sectional view schematically illustrating the first terminal element 1300 . Fig.26 (B) schematically illustrates the Fig.26(A) is an exploded cross-sectional view of the first terminal element 1300 in an exploded state.

[0189] Fig. 27 (A) is a cross-sectional view schematically illustrating a first terminal element 1300 ′ according to another embodiment. Fig. 27 (B) schematically illustrates the Fig. 27 (A) is an exploded cross-sectional view of a first terminal element 1300' in an exploded state.

[0190] Fig.28 It is a cross-sectional view schematically illustrating an alkaline water electrolysis cell 20000 according to another embodiment of the present invention.

[0191] Fig.29 yes Fig.28 Exploded diagram of .

[0192] Fig.30 (A) is a cross-sectional view schematically illustrating the first terminal element 21300 . Fig.30 (B) schematically illustrates the Fig.30 (A) is an exploded cross-sectional view of the first terminal element 21300 in an exploded state.

[0193] Fig.31 (A) is a cross-sectional view schematically illustrating the second terminal element 21400 . Fig.31 (B) schematically illustrates the Fig.31 (A) is an exploded cross-sectional view of the second terminal element 21400 in a disassembled state. DETAILED DESCRIPTION

[0194] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to these embodiments. In addition, the drawings may not necessarily reflect accurate dimensions. In addition, in the drawings, some of the figure marks are sometimes omitted. In this specification, regarding the numerical values ​​A and B, unless otherwise specified, the expression "A to B" means "greater than or equal to A and less than or equal to B". In the case where only the numerical value B is accompanied by a unit in the expression, the unit is also applied to the numerical value A. In addition, the words "or" and "or" mean logical OR unless otherwise specified. In addition, regarding the element E 1 and E 2 , "E 1 and / or E 2 "This expression means "E 1 or E 2 , or a combination thereof", relevant element E 1 ,…,E N (N is an integer greater than 3), "E 1 ,…,EN-1 , and / or E N "This expression means "E 1 ,…,E N-1 , or E N , or a combination thereof".

[0195] <1. Electrolytic Components>

[0196] Figure 2 (A) is a cross-sectional view schematically illustrating an electrolytic element 100 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 100”) according to one embodiment. Figure 2 As shown, the electrolytic element 100 includes: a conductive partition wall 10 having a first surface 10a and a second surface 10b; an anode 20 for generating oxygen; a cathode 30 for generating hydrogen; a first connecting mechanism 40 that fixes the anode 20 to the partition wall 10 so that the anode 20 faces the first surface 10a of the partition wall 10 with a first gap d1 therebetween, and electrically connects the anode 20 to the partition wall 10; a conductive elastic body 50 that supports the cathode 30; and a cathode current collector 60 that supports the elastic body 50. The cathode current collector 60 is fixed to the partition wall 10 so that the cathode 20 faces the second surface 10b of the partition wall with a second gap d2 therebetween, and is electrically connected to the partition wall 10.

[0197] The first connection mechanism 40 includes: conductive first bolts 41, 41, ... (hereinafter sometimes referred to as "first bolts 41" only), which have at least a rod portion 41a; first through holes 10h, 10h, ... (hereinafter sometimes referred to as "first through holes 10h" only), which are provided in the partition wall 10 and through which the rod portion 41a of the first bolt 41 can pass; first nuts 42, 42, ... (hereinafter sometimes referred to as "first nuts 42" only), which can be screwed with the first bolt 41; and conductive first structural elements 43, 43, ... (hereinafter sometimes referred to as "first structural elements 43" only). The first bolt 41 includes a rod portion 41a and a head portion 41b provided at one end of the rod portion 41a. An external thread is cut at least a portion of the rod portion 41a.

[0198] The first structural element 43 includes: a first spacer 43a extending from the anode 20 toward the first surface 10a of the partition wall 10 in a direction intersecting the first surface 10a of the partition wall 10; and a first plate-shaped portion 43b extending continuously with the first spacer 43a in a direction parallel to the first surface 10a of the partition wall 10. The first spacer 43a has an end 43ae fixed to the anode 20. The first plate-shaped portion 43b has a second through hole 43bh through which the rod 41a of the first bolt 41 can pass.

[0199] The electrolytic element 100 further includes a second connecting mechanism 70, which fixes the cathode current collector 60 to the partition wall 10 in a manner that the cathode current collector 60 and the second surface 10b of the partition wall 10 are opposite to each other with a second interval d2, and electrically connects the cathode current collector 60 and the partition wall 10. The second connecting mechanism 70 includes a conductive second structural element 71. The second structural element 71 includes a second spacer 71a extending between the cathode current collector 60 and the second surface 10b of the partition wall 10 in a direction intersecting the second surface 10b of the partition wall 10. In addition, the second structural element 71 includes an end 71ec fixed to the cathode current collector and an end 71ew fixed to the second surface 10b of the partition wall 10.

[0200] Figure 2 (B) schematically illustrates the Figure 2 1 is an exploded cross-sectional view of the electrolytic element 100 of (A) in which the first structural element 43 of the first connecting mechanism 40 is released from the partition wall 10, and the cathode current collector 60 is released from the elastic body 50 and the cathode 30. In the electrolytic element 100, the first structural element 43 is detachably fixed to the partition wall 10 by passing the rod portion 41b of the first bolt 41 through the first through hole 10h provided in the partition wall 10 and the second through hole 43bh provided in the first plate-like portion 43b and screwing with the first nut 42. That is, the first structural element 43 is connected to the partition wall 10 by the tightening force of the first bolt 41 and the first nut 42. Thus, the anode 20 is detachably fixed to the partition wall 10 by means of the first bolt 41.

[0201] The cathode current collector 60 has third through holes 60h, 60h, ... (hereinafter sometimes simply referred to as "third through hole 60h") having a shape and size that can allow the first nut 42 to pass through, at a position opposite to the first through holes 10h, 10h, ... of the partition wall 10. In the electrolytic element 100, the operation of arranging the first nut 42 at a position to be screwed with the first bolt 41 and the operation of bolting the first structural element 43 to the partition wall 10 by the tightening force of the first bolt 41 and the first nut 42 can be performed through the third through hole 60h (see arrow X). In addition, the operation of removing the first structural element 43 from the partition wall 10 by releasing the tightening of the first bolt 41 and the first nut 42 can also be performed through the third through hole 60h. That is, in the electrolytic element 100, the third through hole 60h functions as an opening for access. Since the conductive elastic body 50 is present between the cathode current collector 60 and the cathode 30 , even if the third through hole 60 h is provided in the cathode current collector 60 , it does not prevent the electrolytic element 100 from being used to form a zero-gap electrolytic cell.

[0202] As the material of the partition wall 10, a rigid conductive material with alkali resistance can be used. Examples of such materials include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metal materials plated with nickel.

[0203] As the anode 20, a known anode for producing oxygen used in a zero-gap electrolyzer for alkaline water electrolysis can be used. The anode 20 is generally provided with a conductive substrate and a catalyst layer covering the surface of the substrate. The catalyst layer is preferably porous. As the conductive substrate of the anode 20, for example, nickel, iron, vanadium, molybdenum, copper, silver, manganese, platinum group elements, graphite, or chromium or a combination thereof can be used. A conductive substrate composed of nickel can be preferably used in the anode 20. The catalyst layer contains nickel as an element. The catalyst layer preferably contains nickel oxide, metallic nickel, or nickel hydroxide, or a combination thereof, and may also contain an alloy of nickel and one or more other metals. The catalyst layer is particularly preferably composed of metallic nickel. In addition, the catalyst layer may also contain chromium, molybdenum, cobalt, tantalum, zirconium, aluminum, zinc, platinum group elements, or rare earth elements, or a combination thereof. Rhodium, palladium, iridium, or ruthenium, or a combination thereof, may also be further loaded on the surface of the catalyst layer as an additional catalyst. Anode 20 can be, for example, a porous plate with flexibility, or, for example, a rigid porous plate, preferably a rigid porous plate. As anode 20 that is a rigid porous plate, a porous plate having a conductive substrate with rigidity (e.g., a porous metal mesh, etc.) and the above-mentioned catalyst layer can be used. In addition, as anode 20 that is a flexible porous plate, a porous plate having a conductive substrate with flexibility (e.g., a metal mesh woven (or braided) by metal wire, a thin perforated metal, etc.) and the above-mentioned catalyst layer can be used.

[0204] As the cathode 30, a known cathode for producing hydrogen used in a zero-gap electrolyzer for alkaline water electrolysis can be used. The cathode 30 usually has a conductive substrate and a catalyst layer covering the surface of the substrate. As the conductive substrate of the cathode 30, for example, nickel, nickel alloy, stainless steel, mild steel, or a substrate having a nickel plating applied to the surface of stainless steel or mild steel can be preferably used. As the catalyst layer of the cathode 30, a coating of precious metal oxides, nickel, cobalt, molybdenum, or manganese, or their oxides, or a coating composed of precious metal oxides can be preferably used. The cathode 30 can be, for example, a flexible porous plate, and can also be, for example, a rigid porous plate, but preferably a flexible porous plate. As a cathode 30 that is a rigid porous plate, a porous plate having a rigid conductive substrate (such as a porous metal mesh, etc.) and the above-mentioned catalyst layer can be used. As the cathode 30 which is a flexible porous plate, a porous plate including a flexible conductive substrate (for example, a metal mesh woven (or braided) from metal wires, a thin perforated metal, etc.) and the above-mentioned catalyst layer can be used.

[0205] As the first bolt 41, it is preferred to use a conductive bolt having a rod 41a and a head 41b provided at the end of the rod, and the length of the rod 41a is longer than the total thickness of the partition wall 10, the first plate-shaped portion 43b and the first nut 42. It is sufficient to cut a thread on the portion of the rod 41a that is to be screwed with the first nut 42, and it is not necessary to cut a thread on the entire rod 41a. The shape of the head 41b is not particularly limited as long as its outer diameter is larger than the second through hole 43bh provided in the first plate-shaped portion 43b (that is, the head 41b cannot pass through the second through hole 43bh). As such a first bolt 41, for example, a known conductive bolt such as a hexagonal bolt can be used. As the material of the first bolt 41, a rigid conductive material having alkali resistance can be used. Examples of such materials include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metal materials obtained by plating them with nickel.

[0206] As the first nut 42, a conductive nut that can be screwed with the first bolt 41 and has an outer diameter larger than the first through hole 10h provided in the partition wall 10 (i.e., the nut cannot pass through the first through hole 10h) can be used. As such a first nut 42, for example, a well-known conductive nut such as a hexagonal nut can be used. As the material of the first nut 42, a rigid conductive material having alkali resistance can be used. Examples of such a material include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metal materials obtained by plating them with nickel.

[0207] Figure 3 4 is a perspective view schematically illustrating the first structural element 43. Figure 3 Sometimes, Figure 2 The elements already shown in the Figure 2 , and the description thereof is omitted. As described above, the first structural element 43 includes a first spacer 43a and a first plate-shaped portion 43b. The first spacer 43a extends from the anode 20 toward the first surface 10a of the partition wall 10 in a direction intersecting the first surface 10a of the partition wall 10. The first plate-shaped portion 43b extends continuously with the first spacer 43a in a direction parallel to the first surface 10a of the partition wall 10. A second through hole 43bh through which the rod 41a of the first bolt 41 can pass is provided in the first plate-shaped portion 43b. In addition, the first spacer 43a has an end 43ae fixed to the anode 20. As the material of the first structural element 43, a rigid conductive material having alkali resistance can be used, and examples of such materials include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metal materials obtained by plating these with nickel. In the electrolytic element 100, the end 43ae of the first spacer 43a is fixed to the anode 20 by welding, but it can also be fixed by other methods.

[0208] As the second structural element 71 having the second spacer 71a, a known conductive structural element used as a conductive rib in an alkaline water electrolysis cell can be used. In the electrolytic element 100, the second structural element 71 is set upright from the second surface 10b of the partition wall 10, one end 71ew is fixed to the second surface 10b of the partition wall 10, and the other end 71ec is fixed to the collector 60. As long as the second structural element 71 can fix and hold the collector 60 relative to the partition wall 10, the shape, number and configuration of the second structural element 71 are not particularly limited. As the material of the second structural element 71, a rigid conductive material with alkali resistance can be used without particular limitation. As examples of such materials, single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, SUS316L; and materials such as metals on which nickel plating is implemented. In the electrolytic element 100 , the second structural element 71 manufactured separately from the partition wall 10 may be fixed to the partition wall 10 by welding or the like, or the partition wall 10 and the second structural element 71 may be formed integrally.

[0209] The first interval d1 and the second interval d2 are not particularly limited, and can be appropriately selected to be other than 0 in consideration of the thickness of the anode chamber and the cathode chamber in the electrolytic cell constituted by the electrolytic element 100. However, the first interval d1 is set to be greater than the total thickness of the thickness of the head 41b of the first bolt 41 and the thickness of the first plate-shaped portion 43b of the first structural element 43. The first interval d1 and the second interval d2 are each generally 10 mm or more, preferably 30 mm or more.

[0210] As the elastic body 50, a known conductive elastic body used in an alkaline water electrolyzer can be used, for example, an elastic pad, a coil spring, a leaf spring, etc., which are composed of a collection of metal wires made of an alkali-resistant conductive material, can be preferably used. Examples of the material of the elastic body 50 include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metals plated with nickel. When the elastic body 50 is held on the collector 60, a known method such as welding, pin fixing, and bolt fixing can be used without particular limitation.

[0211] As the cathode current collector 60, a known current collector used in an alkaline water electrolyzer can be used, for example, a porous metal mesh, a perforated metal, etc. made of a rigid conductive material having alkali resistance can be preferably used. Examples of the material of the current collector 60 include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metals plated with nickel. When the current collector 60 is held at the end 71ec of the second spacer 71a, a known method such as welding or pin fixing can be used without particular limitation.

[0212] Refer again Figure 2 (A) and Figure 2The operation of installing the anode 20 on the partition wall 10 can be performed, for example, by the following steps in the following order: (a) inserting the rod portion 41a of the first bolt 41 through the second through hole 43bh provided in the first structural element 43 joined to the anode 20; (b) further inserting the rod portion 41a of the first bolt 41 through the through hole 10h of the partition wall 10; and (c) screwing the rod portion 41a of the first bolt 41 into the first nut 42 inserted from the through hole 60h of the collector 60. In addition, when the length of the first bolt 41 is longer than the interval between the anode 20 and the first plate-like portion 43b, the rod 41a of the first bolt 41 cannot be inserted into the second through hole 43bh of the first plate-like portion 43b when the anode 20 and the first structural element 43 are engaged, but in such a case, the above-mentioned step (a) can also be performed by the following steps in the following order: (a1) when the first structural element 43 is not fixed to the anode 20, the rod 41a of the first bolt 41 is inserted into the second through hole 43bh of the first plate-like portion 43b; and (a2) fixing the end 43ae of the first structural element 43 to the anode 20. In addition, the operation of removing the anode 20 from the electrolytic element 100 can be performed, for example, by the following steps in the following order: (d) removing the cathode 30 and the elastic body 50 from the cathode current collector 60; (e) inserting a jig or the like from the through hole 60h of the current collector 60 to remove the first nut 42 from the rod portion 41a of the first bolt 41; and (f) pulling and removing the anode 20 and the first structural element 43 joined to the anode 20 from the partition wall 10. In addition, in order to prevent the first bolt 41 and the first nut 42 from rotating together, a step of fixing the head 41b of the first bolt 41 to the first plate-shaped portion 43b of the first structural element 43 by a known method such as welding or brazing may be further performed in the step (a). In this way, the electrolytic element 100 can easily perform the replacement operation of the anode 20, so that the time and cost required for the renewal of the anode 20 can be reduced.

[0213] In the above description of the present invention, the electrolytic element 100 is taken as an example in which the first connection mechanism 40 includes two sets of the first structural element 43, the first bolt 41, and the first nut 42, but the present invention is not limited to this embodiment. The number of sets of the first structural element 43, the first bolt 41, and the first nut 42 included in the first connection mechanism 40 is arbitrary.

[0214] In the above description of the present invention, the electrolytic element 100 is taken as an example in which only one second through hole 43bh is provided in the first plate-shaped portion 43b of the first structural element 43, but the present invention is not limited to this embodiment. For example, the electrolytic element may also be provided with a plurality of second through holes in the first plate-shaped portion of the first structural element.

[0215] In the above description of the present invention, the electrolytic element 100 in which the first structural element 43 has a single first spacer 43a and a single first plate-like portion 43b is cited as an example, but the present invention is not limited to this embodiment. For example, it is also possible to have an electrolytic element in which a first structural element is provided in a manner that a plurality of first plate-like portions separated from each other are continuously provided with a single first spacer. In addition, for example, it is also possible to have an electrolytic element in which a first structural element is provided in a manner that a single first plate-like portion is continuously provided with a plurality of first spacers separated from each other.

[0216] In the above description of the present invention, the electrolytic element 100 is taken as an example in which the elastic body 50 is supported on the cathode current collector 60 without blocking the third through hole 60h provided in the cathode current collector 60, but the present invention is not limited to this method. For example, the electrolytic element may also be provided with a detachable cover member that blocks at least a portion of the third through hole 60h provided in the cathode current collector 60. Figure 4 (A) is a cross-sectional view schematically illustrating an electrolytic element 200 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 200”) according to another embodiment of the present invention. Figure 2 The corresponding figure of (A). Figure 4 Sometimes, Figure 2-Figure 3 The elements already shown in the Figure 2-Figure 3 The same reference numerals as those in the figure are used and the description thereof is omitted. Figure 2 ) is different from the cathode current collector 60 in that it also has a detachable conductive first cover member 61, 61, ... (hereinafter sometimes simply referred to as "first cover member 61").

[0217] Figure 4 (B) schematically illustrates the Figure 4 The electrolytic element 200 of (A) is an exploded cross-sectional view of the state in which the first structural element 43 of the first connecting mechanism 40 is disconnected from the partition wall 10, the cathode current collector 60 is disconnected from the elastic body 50 and the cathode 30, and the first cover member 61 is removed from the third through hole 60h. Figure 2 The first cover member 61 has a shape corresponding to the third through hole 60h of the cathode current collector 60, and can be assembled to the cathode current collector 60 in a manner that blocks at least a portion of the third through hole 60h. When the first cover member 61 is assembled to the cathode current collector 60 in a manner that blocks at least a portion of the third through hole 60h, the first cover member 61 is electrically connected to the cathode current collector 60.

[0218] Figure 5 and Figure 6 It is a diagram schematically illustrating the cathode current collector 60 and the first cover member 61 . Figure 5 (A) is a top view of the cathode current collector 60. Figure 5 As shown in (A), the cathode current collector 60 includes third through holes 60h, 60h, ... The cathode current collector 60 is a porous plate made of an expanded metal. Figure 5 (B) means Figure 5 (A) is a plan view showing a state where the third through holes 60h, 60h, ... of the cathode current collector 60 are equipped with the first cover members 61, 61, ..., Figure 5 (C) is Figure 5 (B) is the CC view. In addition, Figure 6 (A) is a top view schematically illustrating the first cover member 61. Figure 6 (B) is Figure 6 (A) is the front view and the left and right side views. Figure 6 (A) and Figure 6 As shown in (B), the first cover member 61 has: a conductive plane portion 61a having a shape corresponding to the third through hole 60h; and L-shaped metal needle portions 61w, 61w, ... (hereinafter sometimes simply referred to as "metal needle portions 61w"), which are joined to the plane portion 61a. The plane portion 61a can be made of, for example, a porous metal mesh similar to the cathode current collector 60, or can be made of, for example, a metal plate. Figure 5 (B) and Figure 5 As shown in (C), by inserting the planar portion 61a of the first cover member 61 into the third through hole 60h of the cathode collector 60, and inserting the metal needle portion 61w joined to the planar portion 61a into the hole of the porous metal mesh constituting the cathode collector 60, the first cover member 61 is detachably assembled to the cathode collector 60, and the cathode collector 60 is electrically connected to the planar portion 61a of the first cover member 61.

[0219] As the plane portion 61a of the first cover member 61, for example, a porous metal mesh, a perforated metal, a metal plate, etc. made of a rigid conductive material having alkali resistance can be preferably used. Examples of the material of the plane portion 61a include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metals obtained by plating these with nickel.

[0220] As the metal needle portion 61w of the first cover member 61, a metal wire made of a rigid conductive material having alkali resistance can be used. Examples of the material of the metal needle portion 61w include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metals plated with nickel. When the metal needle portion 61w is joined to the flat portion 61a, a known method such as welding or brazing can be used without particular limitation.

[0221] With such an electrolytic element 200, at least a portion of the portion corresponding to the third through hole 60h among the portions where the elastic body 50 contacts the cathode current collector 60 is blocked by the first cover member 61, so that the uniformity of the force supporting the elastic body 50 from behind can be improved. Thus, in a zero-gap electrolytic cell having the electrolytic element 200, the uniformity of the force of the elastic body 50 pressing the cathode 30 toward the diaphragm and the anode can be improved. In addition, similarly to the above description of the electrolytic element 100, with such an electrolytic element 200, the anode 20 can be easily replaced, so the time and cost required for the renewal of the anode 20 can be reduced.

[0222] In the above description of the present invention, an electrolytic element 200 is cited as an example in which the first cover member 61 has a flat portion 61a having a shape corresponding to the third through hole 60h of the cathode current collector 60, and when the first cover member 61 is assembled in a manner to block at least a portion of the third through hole 60h of the cathode current collector, the flat portion 61a is embedded in the third through hole 60h, but the present invention is not limited to this manner. For example, an electrolytic element may also be an electrolytic element in which the first cover member has a flat portion larger than the third through hole 60h, and when the first cover member is assembled in a manner to block the entire third through hole 60h of the cathode current collector, the flat portion of the first cover member is supported by the peripheral portion of the third through hole 60h. In addition, for example, an electrolytic element may also be an electrolytic element in which the first cover member only blocks a portion of the third through hole 60h of the cathode current collector 60. For example, when the first cover member is attached to the cathode current collector 60 , a gap may be present between the outer peripheral portion of the flat surface portion of the first cover member and the inner peripheral portion of the third through hole 60 h of the cathode current collector 60 .

[0223] In the above description of the present invention, the first cover member 61 has a conductive flat surface portion 61a and a metal needle portion 61w in the shape of an L letter joined to the flat surface portion 61a, and the first cover member 61 is assembled to the cathode collector 60 by inserting the flat surface portion 61a of the first cover member 61 into the third through hole 60h of the cathode collector 60, and the metal needle portion 61w joined to the flat surface portion 61a is inserted into the hole of the porous metal mesh constituting the cathode collector 60, and the cathode collector 60 and the flat surface portion 61a of the first cover member 61 are electrically connected. However, the present invention is not limited to this method. For example, the first cover member may have a screw member erected from the flat surface portion, and a threaded hole is provided at the end of the first bolt 41, and the screw member of the first cover member is screwed into the threaded hole, thereby fixing the first cover member. Figure 7 is a cross-sectional view schematically illustrating an electrolytic element 300 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 300”) according to another embodiment of the present invention. Figure 2 (A) and Figure 4 The corresponding figure of (A). Figure 7 Sometimes, Figure 2 to Figure 6 The elements already shown in the Figure 2 to Figure 6 The same reference numerals as those in the figure are used and the description thereof is omitted. Figures 4 to 6 ) is different in that a first cover member 361 is provided instead of the first cover member 61, and a first connection mechanism 340 is provided instead of the first connection mechanism 40.

[0224] Figure 7 (B) schematically illustrates the Figure 7 The electrolytic element 300 of (A) is an exploded cross-sectional view of the state in which the first structural element 43 of the first connecting mechanism 340 is disconnected from the partition wall 10, the cathode current collector 60 is disconnected from the elastic body 50 and the cathode 30, and the first cover member 61 is removed from the third through hole 60h. Figure 2 (B) and Figure 4 (B) The corresponding figure.

[0225] The first cover member 361 and the first cover member 61 ( Figures 4 to 6 ) is different in that, instead of the metal needle portion 61w, there is an extension shaft 361b erected from the plane portion 61a and a cover member fixing screw 361c provided at the end of the extension shaft 361b (the end on the side opposite to the plane portion 61a).

[0226] The first connection mechanism 340 is different from the first connection mechanism 40 in that it includes a first bolt 341 instead of the first bolt 41. The first bolt 341 is different from the first bolt 41 in that it includes a rod 341a instead of the rod 41a. The rod 341a is different from the rod 41a in that a bolt end threaded hole 341h is provided at the end on the side opposite to the head 41b. The bolt end threaded hole 341h is a threaded hole that can be screwed with the cover member fixing screw 361c.

[0227] The first cover member 361 has a shape (e.g., a shape corresponding to the third through hole 60h) capable of blocking at least a portion of the third through hole 60h of the cathode current collector 60, and can be assembled to the cathode current collector 60 in a manner of blocking the third through hole 60h. In the electrolytic element 300, the first cover member 361 is detachably fixed to the first bolt 341 by screwing the cover member fixing screw 361c with the bolt end threaded hole 341h, and is assembled to the cathode current collector 60 in a manner of blocking at least a portion of the third through hole 60h. When the first cover member 361 is assembled to the cathode current collector 60 in a manner of blocking at least a portion of the third through hole 60h, the first cover member 361 is electrically connected to the cathode current collector 60 via the first bolt 341, the partition wall 10, and the second structural element 71.

[0228] As the material of the extension shaft 361b and the cover member fixing screw 361c, a rigid conductive material with alkali resistance can be used, and examples thereof include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metals plated with nickel. The extension shaft 361b and the cover member fixing screw 361c can be formed integrally or joined, for example, by welding. In addition, when joining the extension shaft 361b to the flat portion 61a, a known method such as welding or brazing can be used without particular limitation.

[0229] With such an electrolytic element 300, at least a portion of the portion corresponding to the third through hole 60h among the portions where the elastic body 50 contacts the cathode current collector 60 is blocked by the first cover member 361, so that the uniformity of the force supporting the elastic body 50 from behind can be improved. Thus, in a zero-gap electrolytic cell having the electrolytic element 300, the uniformity of the force of the elastic body 50 pressing the cathode 30 toward the diaphragm and the anode can be improved. In addition, similarly to the above description of the electrolytic element 100, with such an electrolytic element 300, the anode 20 can be easily replaced, so the time and cost required for the renewal of the anode 20 can be reduced.

[0230] In the above description of the present invention, an electrolytic element 300 is cited as an example of a first cover member 361 having an extension shaft 361b fixed to the plane portion 61a and a cover member fixing screw 361c provided at the end of the extension shaft 361b, but the present invention is not limited to this method. For example, an electrolytic element may be provided with a first cover member in which the cover member fixing screw 361c is directly fixed to the plane portion 61a. In addition, for example, an electrolytic element may be provided with a first cover member in which a plane portion is fixed to the head portion provided at the end of the cover member fixing screw.

[0231] In the above description of the present invention, the electrolytic elements 100, 200, and 300 in which the first structural element 43 is composed of the spacer 43a and the first plate-shaped portion 43b are cited as examples, but the present invention is not limited to this embodiment. For example, the electrolytic element may be in the following embodiment: the first structural element further includes a rotation restricting portion, which contacts the side surface of the head 41b of the first bolt 41 to restrict the rotation of the first bolt 41 when the rod 41a of the first bolt 41 is inserted into the second through hole 43bh and the head 41b of the first bolt 41 contacts the first plate-shaped portion 34b. Figure 8 (A) is a cross-sectional view schematically illustrating an electrolytic element 400 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 400”) according to another embodiment of the present invention. Figure 2 (A) Corresponding figure. Figure 8 Sometimes, Figure 2 to Figure 7 The elements already shown in the Figure 2 to Figure 7 The electrolytic element 400 is different from the electrolytic element 100 in that it includes a first connecting mechanism 440 instead of the first connecting mechanism 40. The first connecting mechanism 440 is different from the first connecting mechanism 40 in that it includes a first structural element 443 instead of the first structural element 43. Figure 8 (B) schematically illustrates the Figure 8 The electrolytic element 400 of (A) is an exploded cross-sectional view showing a state where the first structural element 443 of the first connecting mechanism 440 is disconnected from the partition wall 10, and the cathode current collector 60 is disconnected from the elastic body 50 and the cathode 30. Figure 2 (B) The corresponding figure.

[0232] Fig. 9 (A) is a stereoscopic diagram schematically illustrating the first structural element 443, which is similar to Figure 3 The corresponding figure. Fig. 9 Sometimes, Figure 2 to Figure 8 The elements already shown in the Figure 2 to Figure 8The first structural element 443 and the first structural element 43 ( Figure 3 ) is that, in addition to the first spacer portion 43a and the first plate-like portion 43b, it also includes a rotation limiting portion 443c. The rotation limiting portion 443c is a plate-like component that is erected from the first plate-like portion 43b. As the material of the rotation limiting portion 443c, a rigid conductive material with alkali resistance can be used. Examples of such materials include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metal materials that are nickel-plated thereon, and it is preferred that the same material as the first plate-like portion 43b be used. The rotation limiting portion 443c can be formed integrally with the first plate-like portion 43b, or can be joined to the first plate-like portion by welding or the like.

[0233] Fig. 9 (B) is from Fig. 9 (A) is viewed from the upper side of the paper. Fig. 9 FIG. 4 is a top view of an example of a case where the second through hole 43bh of the first structural element 443 of FIG. 4 is penetrated by the rod portion 41a of the first bolt 41. Fig. 9 In (B), the head 41b of the first bolt 41 is shown together with the end 43ae of the spacer 43a, the first plate-shaped portion 43b, and the rotation limiting portion 443c. In the electrolytic element 400, the first bolt 41 is a hexagonal bolt. Fig. 9 As shown in (B), when the rod portion 41a of the first bolt 41 passes through the second through hole 43bh of the first structural element 443 and the head portion 41b of the first bolt 41 contacts the first plate-shaped portion 43b, the rotation limiting portion 443c contacts the side surface (peripheral portion) of the head portion 41b to limit the rotation of the first bolt 41. Fig. 9 As shown in (B), the rotation limiting portion 443c "contacts the side of the head 41b to limit the rotation of the first bolt 41" means limiting the free rotation of the first bolt 41, and does not require completely limiting the rotation of the first bolt 41. In the first structural element 443, when the first bolt 41 rotates, the free rotation of the first bolt 41 is limited by the corner 41be existing on the side of the head 41b of the first bolt 41 contacting the rotation limiting portion 443c. In addition, the rotation limiting portion 443c "contacts the side of the head 41b to limit the rotation of the first bolt 41" does not require that the rotation limiting portion 443c always contacts the side of the head 41b of the first bolt 41. Fig. 9 (C) is from Fig. 9 (A) is viewed from the upper side of the paper. Fig. 9FIG. 4 is a top view of another example of a case where the second through hole 43bh of the first structural element 443 of FIG. 4 is penetrated by the rod portion 41a of the first bolt 41. Fig. 9 As shown in (C), when one of the planes forming the side surface of the head 41b of the first bolt 41 is parallel to the rotation restricting portion 443c, a gap may exist between the rotation restricting portion 443c and the head 41b of the first bolt 41.

[0234] Since the first structural element 443c is provided with such a rotation restricting portion 443c, the first bolt 41 and the first nut 42 are prevented from rotating together when the rod portion of the first bolt 41 is screwed into the first nut 42. Therefore, the electrolytic element 400 makes it easier to attach and detach the anode 20. As described above with respect to the electrolytic element 100, the electrolytic element 400 can also easily replace the anode 20, thereby reducing the time and cost required for updating the anode 20.

[0235] In the above description of the present invention, an electrolytic element 400 having a first structural element 443 having a plate-shaped member erected from the first plate-shaped portion 43b as a rotation limiting portion 443c is cited as an example, but the present invention is not limited to this embodiment. As long as the rotation limiting portion can limit the rotation of the first bolt by contacting the head of the first bolt, its structure is not particularly limited. For example, it is also possible to have an electrolytic element having a first structural element formed by casting, stamping, or cutting to limit the rotation of the first bolt by contacting the head of the first bolt. As an example of such a structure, a structure in which a recessed portion having a shape corresponding to the head 41b of the first bolt 41 is formed around the second through hole 43bh of the first plate-shaped portion 43b can be cited. Fig.10 (A) is a perspective view schematically illustrating a first structural element 443' of another embodiment as shown in FIG. Fig. 9 The corresponding figure of (A). Fig.10 Sometimes, Figure 2 to Figure 9 The elements already shown in the Figure 2 to Figure 9 The same reference numerals as those in the figure are used and their descriptions are omitted. Fig.10 As shown in (A), in the first structural element 443', a recess 443'c having a shape corresponding to the head 41b of the first bolt 41 as a hexagonal bolt is provided around the second through hole 43bh of the plate-shaped portion 43b, and the recess 443'c functions as a rotation restricting portion. Fig.10 (B) is from Fig.10 (A) is viewed from the upper side of the paper. Fig.10FIG. 4 is a top view showing a state where the rod portion 41a of the first bolt 41 is passed through the second through hole 43bh of the first structural element 443'. Fig.10 In (B), the head 41b of the first bolt 41 is shown together with the end 43ae of the spacer 43a, the first plate-shaped portion 43b, and the rotation restricting portion 443'c. Fig.10 As shown in (B), when the rod portion 41a of the first bolt 41 passes through the second through hole 43bh of the first structural element 443' and the head portion 41b of the first bolt 41 contacts the first plate-shaped portion 43b, the side surface of the recessed portion 443'c as the rotation limiting portion contacts the side surface (peripheral portion) of the head portion 41b (i.e., the peripheral portion of the head portion 41b of the first bolt 41 contacts the side surface of the recessed portion 443'c (i.e., the rotation limiting portion) from the inside), thereby limiting the rotation of the first bolt 41. By using such a rotation limiting portion 443'c as a recessed portion, the same effect as the rotation limiting portion 443c described above can be obtained. In addition, in the above description, the first structural element 443' having a hexagonal recessed portion 443'c as the rotation limiting portion is illustrated corresponding to the shape of the head portion 41b of the first bolt 41 as a hexagonal bolt, but the present invention is not limited to this mode. The first structural element may include, for example, a polygonal (for example, hexagonal) recessed portion with rounded vertices as the rotation restricting portion.

[0236] In addition, for example, the electrolytic element may be configured in the following manner: the second through hole 43bh is arranged at a position close to the first spacer 43a, and the side surface of the head 41b of the first bolt 41 passing through the second through hole 43bh contacts the first spacer 43a, thereby limiting the rotation of the head 41b, that is, the first spacer 43a functions as a rotation limiting portion. Fig.11 (A) is a perspective view schematically illustrating a first structural element 443" of another embodiment as described above. Fig. 9 The corresponding figure of (A). Fig.11 Sometimes, Figure 2 to Figure 10 The elements already shown in the Figure 2 to Figure 10 The same reference numerals as those in the figure are used and their descriptions are omitted. Fig.11 As shown in (A), in the first structural element 443", the second through hole 43bh of the plate-like portion 43b is provided close to the spacer portion 43a, and the spacer portion 43a also serves as a rotation restricting portion 443"c. Fig.11 (B) is from Fig.11 (A) is viewed from the upper side of the paper. Fig.11 A top view of the first structural element 443″ in FIG. 4A shows a state where the rod portion 41a of the first bolt 41 is passed through the second through hole 43bh of the first structural element 443″. Fig.11In (B), the head 41b of the first bolt 41 is shown together with the end 43ae of the spacer 43a and the first plate-shaped portion 43b. Fig.11 As shown in (B), when the rod portion 41a of the first bolt 41 passes through the second through hole 43bh of the first structural element 443", and the head 41b of the first bolt 41 contacts the first plate-shaped portion 43b, the spacer portion 43a serving as a rotation limiting portion contacts the side surface (peripheral portion) of the head 41b, thereby limiting the rotation of the first bolt 41. In this way, by utilizing the spacer portion serving as a rotation limiting portion, the same effect as the rotation limiting portion 443c described above can be obtained.

[0237] In the above description of the present invention, the electrolytic elements 100, 200, 300, and 400 are cited as examples in which the first bolt 41 or 341, the first structural member 43 or 443, and the partition wall 10 are fixed to each other by the tightening force of the first bolt 41 or 341 and the first nut 42, but the present invention is not limited to this method. For example, the electrolytic element may also be provided with a method in which the first bolt and the second nut for fixing the first structural member are further provided. Fig.12 (A) is a cross-sectional view schematically illustrating an electrolytic element 500 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 500”) according to another embodiment of the present invention. Figure 8 The corresponding figure of (A). Fig.12 Sometimes, Figure 2 to Figure 11 The elements already shown in the Figure 2 to Figure 11 The electrolytic element 500 is different from the electrolytic element 400 ( Figure 8 to Figure 11 )different.

[0238] Fig.12 (B) schematically illustrates the Fig.12 The electrolytic element 500 of (A) is an exploded cross-sectional view of the state in which the first structural element 443 of the first connecting mechanism 540 is disconnected from the partition wall 10, the cathode current collector 60 is disconnected from the elastic body 50 and the cathode 30, and the first structural element 443 is disconnected from the first bolt 41. Figure 8 (B) The corresponding figure.

[0239] The first connection mechanism 540 is different from the first connection mechanism 440 in that it further includes second nuts 44, 44, ... (hereinafter sometimes simply referred to as "second nuts 44") that can be threadedly engaged with the first bolts 41, 41, .... Fig.12In (B), after the rod 41a of the first bolt 41 is inserted into the second through hole 43bh of the first plate-shaped portion 43b, the second nut 44 is screwed with the rod 41a of the first bolt 41 in such a manner that the head 41b of the first bolt 41 and the second nut 44 sandwich the first plate-shaped portion 43b, thereby fixing the first bolt 41 to the first plate-shaped portion 43b. Thereafter, the rod 41a of the first bolt 41 fixed to the first plate-shaped portion 43b is inserted into the through hole 10h of the partition wall 10 and screwed with the first nut 42, thereby fixing the first bolt 41 to the partition wall 10 ( Fig.12 (A)).

[0240] As the second nut 44, a conductive nut that can be screwed with the first bolt 41 can be used, and the nut is a nut whose outer diameter is larger than the first through hole 10h provided in the partition wall 10 and the second through hole 43bh provided in the first plate-shaped portion 43b (that is, it cannot pass through the first through hole 10h and the second through hole 43bh). As such a second nut 44, for example, a well-known conductive nut such as a hexagonal nut can be used. As the material of the second nut 44, a rigid conductive material with alkali resistance can be used. Examples of such materials include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metal materials obtained by plating them with nickel.

[0241] With such an electrolytic element 500, in order to attach the anode 20 to the partition wall 10, the rod portion 41a of the first bolt 41 inserted through the second through hole 43bh of the first plate-shaped portion 43b can be inserted through the first through hole 10h of the partition wall 10 while the first bolt 41 is already fixed to the first plate-shaped portion. Thus, since the first bolt 41 is prevented from swinging and coming out of the second through hole 43bh during this operation, the operation of attaching the anode 20 to the partition wall 10 can be performed more easily. In addition, as with the above description of the electrolytic element 100, with such an electrolytic element 500, the operation of replacing the anode 20 can be easily performed, so the time and cost required for replacing the anode 20 can be reduced.

[0242] In the above description of the present invention, the electrolytic element 500 having the first structural element 443 having the rotation restricting portion 443c is cited as an example, but the present invention is not limited to this embodiment. Fig.12 ) can also replace the first structural element 443 ( Fig. 9 ) and has a first structural element 43 ( Figure 3) in the manner of an electrolytic element. The electrolytic element 500 having the first structural element 443 having the rotation limiting portion 443c is preferably used because the rotation limiting portion 443c prevents the first bolt 41 and the first nut 41 from rotating together when the rod portion 41b of the first bolt 41 is screwed into the first nut 41. On the other hand, even in the case where the first structural element does not have the rotation limiting portion, the first plate-shaped portion 43b is tightened by the first bolt 41 and the second nut 44, so that the rotation of the first bolt 41 is suppressed to a certain extent. Therefore, when the rod portion 41b of the first bolt 41 is screwed into the first nut 42, the situation where the first bolt 41 and the first nut 42 rotate together is suppressed to a certain extent, so that sufficient tightening can be performed.

[0243] In the above description of the present invention, the electrolytic elements 400 and 500 are exemplified as the embodiments in which the first cover member that blocks at least a portion of the third through hole 60h of the cathode current collector 60 is not provided, but the present invention is not limited to this embodiment. Figures 4 to 6 ) and electrolytic element 300( Figure 7 ), as described above, the electrolytic element may further include a first cover member that blocks at least a portion of the third through hole 60h of the cathode current collector 60.

[0244] In the above description of the present invention, the electrolytic element 100, 200, 300, 400, 500 having the first structural element 43, 443, 443', or 443" in which the second through hole 43bh having a circular cross-section is provided in the first plate-like portion 43b is cited as an example, but the present invention is not limited to this embodiment. For example, it is also possible to have an electrolytic element in which the second through hole is continuously provided from the first plate-like portion to at least a part of the first spacer. Fig.13 (A) is a perspective view schematically illustrating a first structural element 443"' of another embodiment as shown in FIG. Fig.10 The corresponding figure of (A). Fig.13 Sometimes, Figure 2 to Figure 12 The elements already shown in the Figure 2 to Figure 12 The same reference numerals as those in the figure are used and their descriptions are omitted. Fig.13 As shown in (A), the first structural element 443'" is different from the first structural element 443' ( Fig.10 The second through hole 443"'bh is different from the second through hole 43b provided only in the first plate-shaped portion 43b in that it is provided continuously from the first plate-shaped portion 43b to at least a portion of the first spacer 43a. Fig.13 (B) is from Fig.13(A) is viewed from the upper side of the paper. Fig.13 FIG. 1 is a top view of an example of a case where the second through hole 443″′bh of the first structural element 443″′ passes through the rod portion 41a of the first bolt 41. Fig.13 In (B), the head 41b of the first bolt 41 is shown together with the end 43ae of the spacer 43a, the first plate-shaped portion 43b, the rotation limiting portion 443c, and the second through hole 443"'bh. By using such a first structural element 443"', when the rod 41a of the first bolt 41 is inserted into the second through hole 443"'bh, the rod 41a of the first bolt 41 is inserted into the portion of the spacer 43a in the second through hole 443"'bh ( Fig.13 Then, the direction of the first bolt is changed, so that Fig.13 As shown in (B), the first bolt 41 is arranged so that the head 41b of the first bolt 41 contacts the first plate-shaped portion 43b. Figure 3 )、443( Fig. 9 )、443'( Fig.10 ), or 443”( Fig.11 ), when the height of the spacer 43a (the distance from the first plate-shaped portion 43b to the anode 20) is shorter than the length of the first bolt 41, it is necessary to connect the first structural element to the anode 20 by welding or the like after the first bolt 41 is inserted into the second through hole 43b. In contrast, the first structural element 443"'( Fig.13 ) electrolytic element, even when the height of the spacer 43a (the distance from the first plate-shaped portion 43b to the anode 20) is shorter than the length of the first bolt 41, the rod 41a of the first bolt 41 can be inserted into the second through hole 443"'bh when the first structural element 443"' is already engaged with the anode 20. Therefore, even when the interval d1 from the partition wall 10 to the anode 20 is short, the anode 20 can be more easily installed on the partition wall 10. In addition, Fig.13 , the first structural element 443"' is shown in which a concave portion corresponding to the head 41b of the first bolt 41 as a hexagonal bolt is provided around the second through hole 443"'bh, that is, a rotation limiting portion 443'c. However, the first structural element may also have a rotation limiting portion of other forms or may not have a rotation limiting portion. For example, the rotation limiting portion 443'c ( Fig. 9However, from the viewpoint of making it easier to position the first bolt 41, it is preferable to adopt a first structural element 443'" in which a recessed portion, i.e., a rotation limiting portion 443'c, having a shape corresponding to the head 41b of the first bolt 41 (e.g., a polygonal shape or a polygonal shape with rounded vertices) is provided around the second through hole 443'"bh.

[0245] In the above description of the present invention, the electrolytic elements 100, 200, 300, 400, and 500 in which the partition wall 10 has the through hole 10h are cited as examples, but the present invention is not limited to this embodiment. For example, the electrolytic element may also be an electrolytic element in which the partition wall has a threaded hole opening on the first surface instead of the through hole. Fig.14 (A) is a cross-sectional view schematically illustrating an electrolytic element 600 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 600”) according to another embodiment of the present invention. Figure 2 The corresponding figure of (A). Fig.14 Sometimes, Figure 2 to Figure 13 The elements already shown in the Figure 2 to Figure 13 The same reference numerals as those in the figure are used and their description is omitted. Figure 2 ) is different in that a partition wall 610 is provided instead of the partition wall 10, an anode 620 is provided instead of the anode 20, a cathode collector 660 is provided instead of the cathode collector 60, and a first connecting mechanism 640 is provided instead of the first connecting mechanism 40. The cathode collector 660 is different from the cathode collector 60 in that it does not have the third through hole 60h.

[0246] Fig.14 (B) schematically illustrates the Fig.14 In the electrolytic element 600 of (A), the exploded cross-sectional view of the state where the first structural element 43 of the first connecting mechanism 640 and the partition wall 610 are released is similar to Figure 2 (B) The corresponding figure.

[0247] The partition wall 610 is different from the partition wall 10 in that first threaded holes 610h, 610h, ... (hereinafter sometimes simply referred to as "first threaded holes 610h") are provided instead of the first through holes 10h, 10h, .... Figure 2 ) is different from the first bolt 41, 41, ... in that a first bolt 641, 641, ... (hereinafter sometimes simply referred to as "first bolt 641") is provided instead of the first bolt 41, 41, ..., and the first threaded hole 610h is provided instead of the first through hole 10h. On the other hand, the first nut 42 is not provided.

[0248] The first bolt 641 is thicker than the first bolt 41 ( Figure 2) is a bolt shorter than the first bolt 41. The first bolt 641 is different from the first bolt 41 in that a rod portion 641a shorter than the rod portion 41a is provided instead of the rod portion 41a. The first threaded hole 610h provided in the partition wall 610 is a threaded hole that can be screwed with the first bolt 641. The length of the rod portion 641a of the first bolt 641 is preferably shorter than the sum of the thickness of the first plate-like portion 43b and the depth of the first threaded hole 610h provided in the partition wall 610. As the material of the first bolt 641, the same conductive material as the material described above in connection with the first bolt 41 can be used, and the preferred method thereof is also the same as described above.

[0249] Anode 620 and anode 20 ( Figure 2 ) is that fourth through holes 620h, 620h, ... (hereinafter sometimes simply referred to as "fourth through hole 620h") are provided at positions opposite to the second through hole 43bh provided in the first plate-shaped portion 43b of the first structural element 43. The fourth through hole 620h has a shape and size that allows the first bolt 641 to pass therethrough.

[0250] In the electrolytic element 600, the operation of attaching the anode 620 to the partition wall 610 can be performed, for example, by the following steps in the following order: (a) inserting the rod portion 641a of the first bolt 641 through the second through hole 43bh provided in the first structural element 43 joined to the anode 620; and (b) screwing the rod portion 641a of the first bolt 641 into the first threaded hole 610h of the partition wall 610. In addition, the operation of removing the anode 620 from the electrolytic element 600 can be performed, for example, by the following steps in the following order: (c) inserting a jig or the like from the fourth through hole 620h of the anode 620 to remove the first bolt 641 from the first threaded hole 610h of the partition wall 610; and (d) pulling and removing the anode 620 and the first structural element 43 joined to the anode 620 from the partition wall 610. By using such an electrolytic element 600, the anode 620 can be easily replaced, so the time and cost required for the renewal of the anode 620 can be reduced. In addition, in the electrolytic element 600, the anode 620 is fixed to the partition wall 610 not by the screwing of the first bolt 41 and the first nut 42, but by the screwing of the first bolt 641 and the first threaded hole 610h provided in the partition wall 610, so there is no need for a countermeasure for the common rotation of the first nut and the first bolt. In addition, by using the electrolytic element 600, the partition wall does not have a through hole but has a threaded hole, so the polar liquid does not move between the anode chamber and the cathode chamber through the contact portion between the through hole provided in the partition wall and the first bolt.

[0251] In the above description of the present invention, the electrolytic element 600 in which the fourth through hole 620h provided in the anode 620 is not blocked is cited as an example, but the present invention is not limited to this embodiment. For example, the electrolytic element may also be provided with a second cover member made of the same material as the anode 620 and blocking at least a portion of the fourth through hole 620h provided in the anode 620. Fig.15 (A) is a cross-sectional view schematically illustrating an electrolytic element 700 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 700”) according to another embodiment of the present invention. Fig.14 The corresponding figure of (A). Fig.15 Sometimes, Figure 2 to Figure 14 The elements already shown in the Figure 2 to Figure 14 The same reference numerals as those in the figure are used and the description thereof is omitted. Fig.14 ) is different from the first connection mechanism 640 in that it further includes a detachable conductive second cover member 721, 721, ... (hereinafter sometimes simply referred to as "second cover member 721") that blocks at least a portion of each of the fourth through holes 620h, 620h, ... of the anode 620, and a conductive second bolt 722 fixed to each second cover member 721, and includes a first connection mechanism 740 instead of the first connection mechanism 640. The first connection mechanism 740 is different from the first connection mechanism 640 in that it includes a first bolt 741, 741, ... (hereinafter sometimes simply referred to as "first bolt 741") instead of the first bolt 641, 641, ...

[0252] Fig.15 (B) schematically illustrates the Fig.15 The exploded cross-sectional view of the electrolytic element 700 of (A) is similar to the one shown in FIG. 1 , in which the first structural element 43 of the first connecting mechanism 740 and the partition wall 610 are disconnected and the second cover member 721 is removed from the fourth through hole 620h. Fig.14 (B) The corresponding figure.

[0253] The second cover member 721 is made of the same material as the anode 620 and has a shape (e.g., a shape corresponding to the fourth through hole 620h) that can block at least a portion of the fourth through hole 620h of the anode 620. In the electrolytic element 700, the anode 620 and the second cover member 721 are rigid porous plates having a rigid conductive substrate made of a porous metal mesh and the same catalyst supported on the surface of the conductive substrate.

[0254] The second bolt 722 includes an extension shaft 722a erected from the second cover member 721 and a cover member fixing screw 722b provided at the end of the extension shaft 722a (the end on the side opposite to the second cover member 721). As the material of the second bolt 722, a rigid conductive material with alkali resistance can be used, and examples thereof include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metals plated with nickel. The extension shaft 722a and the cover member fixing screw 722b can be formed integrally, and can also be joined by welding, etc., for example. In addition, when joining the second bolt 722 to the second cover member 721, a known method such as welding and brazing can be used without particular restrictions.

[0255] The first bolt 741 is different from the first bolt 641 in that it includes a head 741b instead of the head 641b. The head 741b is different from the head 641b in that it includes a second screw hole 741bh that can be screwed with the second bolt 722 (the cover member fixing screw 722b).

[0256] The second cover member 721 has a shape (e.g., a shape corresponding to the fourth through hole 620h) that can block at least a portion of the fourth through hole 620h of the anode 620, and can be assembled to the anode 620 in a manner that blocks at least a portion of the fourth through hole 620h. In the electrolytic element 700, the second cover member 721 is detachably fixed to the first bolt 741 by screwing the second bolt 722 (the cover member fixing screw 722b thereof) into the second threaded hole 741bh, blocking at least a portion of the fourth through hole 620h of the anode 620, and is electrically connected to the first bolt 741 via the second bolt 722. Thus, the second cover member 721 is electrically connected to the anode 620 via the second bolt 722, the first bolt 741, and the first structural element 43.

[0257] By using such an electrolytic element 700, it is also possible to obtain the same Fig.14 ) has the same effect as described above. Moreover, by using the electrolytic element 700 with the second cover member 721, the anode area reduced by the fourth through hole is supplemented by the second cover member 721, so that the uniformity of current distribution can be improved and energy loss can be further reduced.

[0258] In the above description of the present invention, an electrolytic element 700 is cited as an example in which the second bolt 722 has an extension shaft 722a provided upright from the second cover member 721 and a cover member fixing screw 722b provided at the end of the extension shaft 722a, but the present invention is not limited to this method. For example, an electrolytic element may also be provided with a second bolt consisting of a cover member fixing screw 722b directly fixed to the second cover member 721. In addition, for example, an electrolytic element may also be provided in which the second bolt has a cover member fixing screw 722b and a head provided at the end of the cover member fixing screw 722b, and the second cover member 721 is fixed to the head of the second bolt.

[0259] In the above description of the present invention, the electrolytic elements 600 and 700 are exemplified as the first bolt 641 having the head 641b or the first bolt 741 having the head 741b being screwed into the first threaded hole 610h provided in the partition wall 610, but the present invention is not limited to this embodiment. For example, the electrolytic element may be an electrolytic element in which the first bolt is a stud bolt without a head. Fig.16 (A) is a cross-sectional view schematically illustrating an electrolytic element 800 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 800”) according to another embodiment of the present invention. Fig.15 The corresponding figure of (A). Fig.16 Sometimes, Figure 2 to Figure 15 The elements already shown in the Figure 2 to Figure 15 The electrolytic element 800 is different from the electrolytic element 700 ( Fig.15 The first connection mechanism 840 is different from the first connection mechanism 740 in that, instead of the first bolts 741, 741, ... having the head 741b, first bolts 841, 841, ... (hereinafter sometimes simply referred to as "first bolts 841" or "stud bolts 841") are provided as stud bolts, and first nuts 842, 842, ... (hereinafter sometimes simply referred to as "first nuts 842") that can be screwed together with the first bolts 841 as stud bolts are provided. Fig.16 (B) schematically illustrates the Fig.16 The electrolytic element 800 of (A) is an exploded cross-sectional view showing a state in which the first structural element 43 of the first connecting mechanism 840 and the partition wall 610 are disconnected, and the second cover member 721 and the first bolt 841 as the stud bolt are disconnected. Fig.15 (B) The corresponding figure.

[0260] The first bolt 841 is a stud bolt, that is, a bolt having no head at the end of the rod. The stud bolt 841 has a first end 841e1 and a second end 841e2. The first end 841e1 of the stud bolt 841 is fixed to the partition wall 610 by screwing the stud bolt 841 from the first end 841e1 into the first threaded hole 610h provided in the partition wall 610. The stud bolt 841 fixed to the partition wall passes through the second through hole 43bh provided in the first plate-shaped portion 43b of the first structural element 43 and screws the stud bolt 841 from the second end 841e2 into the first nut 842, thereby fixing the first structural element 43 to the partition wall 610. As the material of the stud bolt 841 and the first nut 842, the conductive material described above in connection with the first bolt 41 and the first nut 42 can be used, and the preferred mode thereof is also the same as described above.

[0261] A second threaded hole 841bh capable of being screwed with the second bolt 722 (the cover member fixing screw 722b) is provided at the second end 841e2 of the stud bolt 841. The second bolt 722 is screwed with the second threaded hole 841bh, so that the second cover member 721 is detachably fixed to the stud bolt 841 by means of the second bolt 722, the second cover member 721 blocks at least a portion of the fourth through hole 620h of the anode 620, and the second cover member 721 is electrically connected to the stud bolt 841. Thus, the second cover member 721 is electrically connected to the anode 620 via the second bolt 722, the stud bolt 841, the first nut 842, and the first structural element 43.

[0262] Such an electrolytic element 800 can also provide the same effects as those of the electrolytic element 700 described above.

[0263] In the above description of the present invention, an electrolytic element 800 is cited as an example in which the second bolt 722 has an extension shaft 722a provided upright from the second cover member 721 and a cover member fixing screw 722b provided at the end of the extension shaft 722a, but the present invention is not limited to this method. For example, an electrolytic element may be provided with a second bolt consisting of a cover member fixing screw 722b directly fixed to the second cover member 721. In addition, for example, an electrolytic element may be provided with a cover member fixing screw 722b and a head provided at the end of the cover member fixing screw 722b, and a second cover member 721 may be fixed to the head of the second bolt. In addition, for example, an electrolytic element may be provided without the second cover member 721 and the second bolt 722.

[0264] In the above description of the present invention, the electrolytic elements 100, 200, 300, 400, 500, 600, 700 and 800 in which the anode is fixed to the partition wall by the first bolt are cited as examples, but the present invention is not limited to this method. For example, the electrolytic element may also be a method in which both the anode and cathode current collectors are fixed to the partition wall by one bolt. Fig.17 (A) is a cross-sectional view schematically illustrating an electrolytic element 900 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 900”) according to another embodiment of the present invention. Figure 2 The corresponding figure of (A). Fig.17 Sometimes, Figure 2 to Figure 16 The elements already shown in the Figure 2 to Figure 16 The electrolytic element 900 is the same as the electrolytic element 100 ( Figure 2 ) is different in that an anode 920 is provided instead of the anode 20, a cathode collector 960 is provided instead of the cathode collector 60, and a third connecting mechanism 940 is provided instead of the first connecting mechanism 40 and the second connecting mechanism 70. Fig.17 (B) schematically illustrates the Fig.17 The exploded cross-sectional view of the electrolytic element 900 of (A) is a view showing the state where the anode 920, the partition wall 10, and the cathode current collector 960 are disconnected. Figure 2 (B) The corresponding figure.

[0265] The third connection mechanism 940 includes: first bolts 41, 41, ...; first through holes 10h, 10h, ..., which are provided in the partition wall 10 and through which the rod portion 41a of the first bolt 41 can pass; and first nuts 42, 42, ..., which can be screwed with the first bolt 41. The third connection mechanism fixes the anode 920 and the cathode collector 960 to the partition wall 10 in a manner that the anode 920 faces the first surface 10a of the partition wall 10 and the cathode collector 960 faces the second surface 10b of the partition wall 10, and electrically connects the anode 920 and the cathode collector 960.

[0266] Fig.18 (A) is a top view schematically illustrating the anode 920, Fig.18 (B) is Fig.18 BB section view of (A). Fig.18 (A) and Fig.18As shown in (B), the anode 920 includes: a first flat portion 920a extending in two dimensions; first cup-shaped portions 920b, 920b, ... (hereinafter sometimes referred to as "first cup-shaped portion 920b"), which protrude from the first flat portion 920a toward the first surface 10a of the partition wall 10 in a tapered shape; and a fifth through hole 920h, which is provided at the bottom 920c of each first cup-shaped portion 920b and can allow the rod portion 41a of the first bolt 41 to pass through. Fig.17 (A) and Fig.17 (B) and Fig.18 As can be understood from (B), the anode 920 has openings 920d, 920d, ... (hereinafter sometimes simply referred to as "opening 920d") corresponding to the first cup-shaped portions 920b, 920b, .... As the material of the anode 920, the anode 20 ( Figure 2 ) and the same conductive substrate and catalyst, and the preferred mode is the same as above. In the electrolytic element 900, as the anode 920, for example, an anode having a rigid conductive substrate and a catalyst supported on the surface of the conductive substrate can be used, and the conductive substrate is composed of a porous metal mesh, and a shape corresponding to the first cup-shaped portion 920b and the fifth through hole 920h is given by stamping and punching.

[0267] Fig.19 (A) is a top view schematically illustrating the cathode current collector 960, Fig.19 (B) is Fig.19 BB section view of (A). Fig.19 (A) and Fig.19 As shown in (B), the cathode current collector 960 includes: a second flat portion 960a extending in two dimensions; second cup-shaped portions 960b, 960b, ... (hereinafter sometimes referred to as "second cup-shaped portion 960b"), which protrude from the second flat portion 960a toward the second surface 10b of the partition wall 10 in a tapered shape; and a sixth through hole 960h, which is provided at the bottom 960c of each second cup-shaped portion 960b and can allow the rod portion 41a of the first bolt 41 to pass through. Fig.17 (A) and Fig.17 (B) and Fig.19 As can be understood from (B), the cathode current collector 960 has openings 960d, 960d, ... (hereinafter sometimes simply referred to as "opening 960d") corresponding to the second cup-shaped portions 960b, 960b, .... As the material of the cathode current collector 960, the cathode current collector 60 ( Figure 2) and the preferred method is the same as above. In the electrolytic element 900, as the cathode current collector 960, for example, a rigid cathode current collector composed of a porous metal mesh to which the second cup-shaped portion 960b and the sixth through hole 960h are given by stamping and punching can be used.

[0268] Refer again Fig.17 (A) and Fig.17 (B). In the electrolytic element 900, the rod portion 41a of the first bolt 41 passes through the first through hole 10h of the partition wall 10, the fifth through hole 920h of the anode 920, and the sixth through hole 960h of the cathode current collector 960, and is screwed with the first nut 42, thereby clamping and fastening the anode 920, the partition wall 10, and the cathode current collector 960 by the head 41b of the first bolt 41 and the first nut 42. Thus, the anode 920 and the cathode current collector 960 are detachably fixed to the partition wall 10 by means of the first bolt 41 and the first nut 42. Accompanying this, the anode 920, the cathode current collector 960, and the partition wall 10 are electrically connected via the first bolt 41 and the first nut 42.

[0269] In the electrolytic element 900, the operation of installing the anode 920 and the cathode collector 960 on the partition wall 10 can be performed, for example, through the following steps in the following order: (a) inserting the rod 41a of the first bolt 41 into the fifth through hole 920h of the anode 920; (b) further inserting the rod 41a of the first bolt 41 into the through hole 10h of the partition wall 10; (c) further inserting the rod 41a of the first bolt 41 into the sixth through hole 960h of the cathode collector 960; and (d) screwing the rod 41a of the first bolt 41 into the first nut 42. In addition, the operation of removing the anode 920 and the cathode current collector 960 from the electrolytic element 900 can be performed, for example, through the following steps: (e) removing the cathode 30 and the elastic body 50 from the cathode current collector 960; (f) removing the first nut 42 from the rod 41a of the first bolt 41; (g) pulling and removing the anode 920 from the partition wall 10; and (h) pulling out the rod 41a of the first bolt 41 from the fifth through hole 920h of the anode 920, the first through hole 10h of the partition wall 10, and the sixth through hole 960h of the cathode current collector 960. In this way, the electrolytic element 900 can also easily perform the replacement operation of the anode 920, so that the time and cost required for the renewal of the anode 920 can be reduced.

[0270] In the above description of the present invention, an electrolytic element 900 is cited as an example in which the first bolt 41 passes through the fifth through hole 920h, the first through hole 10h, and the sixth through hole 960h from the side where the anode 920 is located, and is screwed with the first nut 42 on the side where the cathode current collector 960 is located, but the present invention is not limited to this method. For example, an electrolytic element may also be an electrolytic element in which the first bolt 41 passes through the sixth through hole 960h, the first through hole 10h, and the fifth through hole 920h from the side where the cathode current collector 960 is located, and is screwed with the first nut 42 on the side where the anode 920 is located.

[0271] In the above description of the present invention, the electrolytic element 900 in which the anode 920 and the cathode current collector 960 are detachably fixed to the partition wall 10 by means of the first bolt 41 and the first nut 42, and the anode 920, the cathode current collector 960 and the partition wall 10 are electrically connected via the first bolt 41 and the first nut 42 is cited as an example, but the present invention is not limited to this embodiment. For example, the electrolytic element in which the anode 920 and the cathode current collector 960 are detachably fixed to the partition wall 10 by means of the first bolt 41 and the first nut 42, and the anode 920 and the cathode current collector 960 are electrically connected via the first bolt 41 and the first nut 42, but the partition wall 10 is not electrically connected to the anode 920 and the cathode current collector 960 may also be used. In addition, in the above description of the present invention, the electrolytic element 900 in which the conductive partition wall 10 is provided is cited as an example, but the present invention is not limited to this embodiment. For example, it is also possible to be an electrolytic element in the following manner: a non-conductive partition wall is provided instead of the conductive partition wall 10, and the anode 920 and the cathode current collector 960 are detachably fixed to the non-conductive partition wall by means of the first bolt 41 and the first nut 42, and the anode 920 and the cathode current collector 960 are electrically connected via the first bolt 41 and the first nut 42. This is because, even if the partition wall is non-conductive, as long as the anode and cathode current collectors arranged with the partition wall sandwiched are electrically connected, the function of the electrolytic element can be exerted. As the material of such a non-conductive partition wall, a resin material having alkali resistance and strength capable of supporting the anode and cathode current collector can be preferably used. As a preferred example of such a resin material, hard vinyl chloride resin, polypropylene resin, polyethylene resin, polyetherimide resin, polyphenylene sulfide resin, polybenzimidazole resin, polytetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene-ethylene copolymer resin, etc. can be cited.

[0272] In the above description of the present invention, the electrolytic element 900 in which the anode 920 has four fifth through holes 920h corresponding to the number of the first cup-shaped portion 920b, the cathode current collector 960 has four sixth through holes 960h corresponding to the number of the second cup-shaped portion 960b, and the partition wall 10 has four first through holes 10h is cited as an example, but the present invention is not limited to this method. The number of the fifth through hole provided in the anode, the sixth through hole provided in the cathode current collector, and the first through hole provided in the partition wall, and the shape and arrangement of the first cup-shaped portion provided in the anode and the second cup-shaped portion provided in the cathode current collector corresponding thereto are arbitrary as long as the anode and the cathode current collector can be detachably fixed to the partition wall by means of the first bolt. However, since the fifth through hole, the sixth through hole, and the first through hole are provided at corresponding positions, if the arrangement of the first through hole is determined, the arrangement of the first cup-shaped portion and the second cup-shaped portion corresponding thereto is also determined.

[0273] In the above description of the present invention, an electrolytic element 900 in which the opening 960d corresponding to the second cup-shaped portion 960b of the cathode current collector 960 is not blocked is cited as an example, but the present invention is not limited to this embodiment. For example, an electrolytic element in which a first cover member is further provided to block at least a portion of the opening 960d of the cathode current collector 960 is also possible. Such a first cover member can be assembled in a manner to block at least a portion of the opening 960d corresponding to the second cup-shaped portion 960b, for example, by the same method as the first cover member 61 described above in connection with the electrolytic element 200 or by the same method as the first cover member 361 described above in connection with the electrolytic element 300, and can be electrically connected to the cathode current collector 960.

[0274] In the above description of the present invention, an electrolytic element 900 in which the opening 920d corresponding to the first cup-shaped portion 920b of the anode 920 is not blocked is cited as an example, but the present invention is not limited to this embodiment. For example, an electrolytic element in which a second cover member is further provided to block at least a portion of the opening 920d of the anode 920 may be provided. Fig. 20 (A) schematically illustrates an electrolytic element 1000 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 1000”) according to another embodiment of the present invention. Fig.17 The corresponding figure of (A). Fig. 20 Sometimes, Figures 2 to 19 The elements already shown in the Figures 2 to 19 The same reference numerals as those in the figure are used and their description is omitted. Fig.17) is different from the anode 920 in that it further includes detachable second cover members 1021, 1021, ... (hereinafter sometimes referred to as "second cover members 1021") which are made of the same material as the anode 920 and block at least a portion of the openings 920d, 920d, ... of the first cup-shaped portions 920b, 920b, ... of the anode 920, and conductive second bolts 1022 fixed to the second cover members 1021, and a third connection mechanism 1040 is provided instead of the third connection mechanism 940. The third connection mechanism 1040 is different from the third connection mechanism 940 in that it includes first bolts 1041, 1041, ... (hereinafter sometimes referred to as "first bolts 1041") instead of the first bolts 41, 41, .... The first bolt 1041 is different from the first bolt 41 in that it includes a head 1041b instead of the head 41b. Fig. 20 (B) schematically illustrates the Fig. 20 The electrolytic element 1000 of (A) is an exploded cross-sectional view showing a state where the anode 920, the partition wall 10, and the cathode current collector 960 are disconnected and the second cover member 1021 is removed from the opening 920d of the first cup-shaped portion 920b. Fig.17 (B) The corresponding figure.

[0275] The second cover member 1021 is made of the same material as the anode 920, and has a two-dimensionally extending shape that can block at least a portion of the opening 920d of the first cup-shaped portion 920b of the anode 920 (e.g., corresponding to the shape of the opening 920d). In the electrolytic element 1000, the anode 920 and the second cover member 1021 are rigid porous plates having a rigid conductive substrate composed of a porous metal mesh and the same catalyst supported on the surface of the conductive substrate. The second cover member 1021 and the opening 920d of the first cup-shaped portion 920b of the anode 920 (see Fig.18 . ) correspondingly has a disc-like shape.

[0276] The second bolt 1022 is a conductive bolt having a head 1022b fixed to the second cover member 1021 and a rod 1022a fixed to the head 1022b. As the material of the second bolt 1022, a rigid conductive material having alkali resistance can be used, and examples thereof include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metals plated with nickel. When the head 1022b of the second bolt 1022 is joined to the second cover member 1021, a known method such as welding or brazing can be used without particular limitation.

[0277] The first bolt 1041 is different from the first bolt 41 (see Figure 2 and Fig.17 The head portion 1041b of the first bolt 1041 is different from the head portion 41b of the first bolt 41 in that it includes a threaded hole 1041bh that can be threadably engaged with (the stem portion 1022a of) the second bolt 1022.

[0278] In the electrolytic element 1000, the second bolt 1022 (the stem 1022a thereof) fixed to the second cover member 1021 is screwed into the threaded hole 1041bh of the head of the first bolt 1041, so that the second cover member 1021 is detachably fixed to the first bolt 1041, and the second cover member 1021 blocks at least a portion of the opening 920d of the first cup-shaped portion 920b of the anode 920. In conjunction with this, the second cover member 1021 is electrically connected to the anode 920 via the second bolt 1022 and the first bolt 1041.

[0279] By using such an electrolytic element 1000, it is also possible to obtain the electrolytic element 900 ( Fig.17 Furthermore, by using the electrolytic element 1000 having the second cover member 1021, the anode area reduced by the opening 920d of the first cup-shaped portion 920b is supplemented by the second cover member 1021, thereby improving the uniformity of current distribution and further reducing energy loss.

[0280] In the above description of the present invention, an electrolytic element 1000 is cited as an example in which the anode 920 and the cathode current collector 960 are detachably fixed to the partition wall 10 by means of the first bolt 1041 and the first nut 42, and the anode 920, the cathode current collector 960 and the partition wall 10 are electrically connected via the first bolt 1041 and the first nut 42, but the present invention is not limited to this embodiment. For example, an electrolytic element in which the anode 920 and the cathode current collector 960 are detachably fixed to the partition wall 10 by means of the first bolt 1041 and the first nut 42, and the anode 920 and the cathode current collector 960 are electrically connected via the first bolt 1041 and the first nut 42, but the partition wall 10 is not electrically connected to the anode 920 and the cathode current collector 960. In addition, in the above description of the present invention, the electrolytic element 1000 having the conductive partition wall 10 is cited as an example, but the present invention is not limited to this mode. For example, it is also possible to be an electrolytic element in the following mode: a non-conductive partition wall is provided instead of the conductive partition wall 10, and the anode 920 and the cathode collector 960 are detachably fixed to the non-conductive partition wall by means of the first bolt 1041 and the first nut 42, and the anode 920 and the cathode collector 960 are electrically connected via the first bolt 1041 and the first nut 42. This is because, even if the partition wall is not conductive, as long as the anode and cathode collectors arranged with the partition wall are electrically connected, the function of the electrolytic element can be exerted. As the material of the non-conductive partition wall, a resin material having alkali resistance and strength capable of supporting the anode and cathode collectors can be preferably used. Preferred examples of such resin materials include rigid vinyl chloride resin, polypropylene resin, polyethylene resin, polyetherimide resin, polyphenylene sulfide resin, polybenzimidazole resin, polytetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene-ethylene copolymer resin, and the like.

[0281] In the above description of the present invention, the electrolytic elements 900 and 1000 are cited as examples in which the anode 920, the partition wall 10, and the cathode current collector 960 are clamped and fastened by the head of the first bolt 41 or 1041 and the first nut 42, but the present invention is not limited to this method. For example, the electrolytic element may be a method in which the anode 920, the partition wall 10, and the cathode current collector 960 are clamped and fastened by two nuts screwed to the same bolt. Fig.21 (A) is a cross-sectional view schematically illustrating an electrolytic element 1100 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 1100”) according to another embodiment of the present invention. Fig.17 (A) and Fig. 20 The corresponding figure of (A). Fig.21 Sometimes, Figure 2 to Figure 20The elements already shown in the Figure 2 to Figure 20 The same reference numerals as those in the figure are used and the description thereof is omitted. Fig. 20 ) is different from the third connection mechanism 1040 in that it does not include the conductive second bolt 1022 fixed to the second cover member 1021, and includes the third connection mechanism 1140 instead of the third connection mechanism 1040. The third connection mechanism 1140 is different from the third connection mechanism 1040 in that it includes the first bolts 1141, 1141, ... (hereinafter sometimes simply referred to as "the first bolt 1141") instead of the first bolts 1041, 1041, ..., and also includes the second nuts 1144, 1144, ... (hereinafter sometimes simply referred to as "the second nut 1144") that can be screwed with the first bolts 1141, 1141, .... Fig.21 (B) schematically illustrates the Fig.21 The electrolytic element 1100 of (A) is an exploded cross-sectional view showing a state where the anode 920, the partition wall 10, and the cathode current collector 960 are disconnected and the second cover member 1021 is removed from the opening 920d of the first cup-shaped portion 920b. Fig.17 (B) and Fig. 20 (B) The corresponding figure.

[0282] The first bolt 1141 is different from the first bolt 41 in that a rod 1141a longer than the rod 41a is provided instead of the rod 41a. As the material of the first bolt 1141, the same material as the first bolt 41 ( Figure 2 ) and the preferred method thereof is the same as described above. As the second nut 1144, a nut having the same conductivity as the first nut 42 can be used. The first bolt 1141 includes a rod 1141a and a head 41b provided at the end of the rod 1141a. The second cover member 1021 is fixed to the head 41b of the first bolt 1141 and is electrically connected to the first bolt 1141.

[0283] In the electrolytic element 1100, the shank 1141a of the first bolt 1141 screwed with the second nut 1144 passes through the fifth through hole 920h of the anode 920, the first through hole 10h of the partition wall 10, and the sixth through hole 960h of the cathode current collector 960, and is screwed with the first nut 42, so that the anode 920, the partition wall 10, and the cathode current collector 960 are sandwiched and fastened by the first nut 42 and the second nut 1144. Thus, the anode 920, the second cover member 1021, and the cathode current collector 960 are detachably fixed to the partition wall 10 by the first bolt 1141, the first nut 42, and the second nut 1144, and the second cover member 1021 blocks at least a portion of the opening 920d of the first cup-shaped portion 920b of the anode 920. Along with this, the anode 920 , the cathode current collector 960 , and the partition wall 10 are electrically connected via the first bolt 1141 , the first nut 42 , and the second nut 1144 , and the second cover member 1021 is electrically connected to the anode 920 via the first bolt 1141 and the second nut 1144 .

[0284] By using such an electrolytic element 1100, it is also possible to obtain the electrolytic element 900 ( Fig.17 Furthermore, by using the electrolytic element 1100 having the second cover member 1021, the anode area reduced by the opening 920d of the first cup-shaped portion 920b is supplemented by the second cover member 1021, thereby improving the uniformity of current distribution and further reducing energy loss.

[0285] In the above description of the present invention, the electrolytic element 1100 is cited as an example in which the anode 920 and the cathode current collector 960 are detachably fixed to the partition wall 10 by means of the first bolt 1141, the first nut 42, and the second nut 1144, and the anode 920, the cathode current collector 960, and the partition wall 10 are electrically connected via the first bolt 1141 and the first nut 42, but the present invention is not limited to this embodiment. For example, the electrolytic element may be an electrolytic element in which the anode 920 and the cathode current collector 960 are detachably fixed to the partition wall 10 by means of the first bolt 1141, the first nut 42, and the second nut 1144, and the anode 920 and the cathode current collector 960 are electrically connected via the first bolt 1141, the first nut 42, and the second nut 1144, but the partition wall 10 is not electrically connected to the anode 920 and the cathode current collector 960. In addition, in the above description of the present invention, the electrolytic element 1100 in the form of the conductive partition wall 10 is cited as an example, but the present invention is not limited to this form. For example, it is also possible to be an electrolytic element in the following form: a non-conductive partition wall is provided instead of the conductive partition wall 10, and the anode 920 and the cathode collector 960 are detachably fixed to the non-conductive partition wall by means of the first bolt 1141, the first nut 42 and the second nut 1144, and the anode 920 and the cathode collector 960 are electrically connected via the first bolt 1141, the first nut 42, and the second nut 1144. This is because, even if the partition wall is not conductive, as long as the anode and cathode collectors arranged with the partition wall are electrically connected, the function of the electrolytic element can be exerted. As the material of the non-conductive partition wall like that, a resin material having alkali resistance and strength capable of supporting the anode and cathode collectors can be preferably used. Preferred examples of such resin materials include rigid vinyl chloride resin, polypropylene resin, polyethylene resin, polyetherimide resin, polyphenylene sulfide resin, polybenzimidazole resin, polytetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene-ethylene copolymer resin, and the like.

[0286] In the above description of the present invention, the electrolytic elements 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 and 1100 in which no flange is provided on the outer periphery of the partition wall are cited as examples, but the present invention is not limited to this embodiment. For example, the electrolytic element may also include a flange provided on the outer periphery of the partition wall. Fig. 22 (A) is a cross-sectional view schematically illustrating an electrolytic element 1200 for alkaline water electrolysis (hereinafter sometimes referred to as “electrolytic element 1200”) according to another embodiment of the present invention. Fig.17 The corresponding figure of (A). Fig. 22 Sometimes, Figure 2 to Figure 21 The elements already shown in the Figure 2 to Figure 21 The same reference numerals as those in the figure are used and the description thereof is omitted. Fig.17 ) is different in that it also has a flange portion 11, which is provided on the outer periphery of the partition wall 10 and extends toward both sides of the partition wall 10 along a direction intersecting the first surface 10a and the second surface 10b of the partition wall 10.

[0287] The flange portion 11 is watertightly connected to the outer periphery of the partition wall 10. Fig. 22 Although not shown in the figure, the flange portion 11 is provided with: an anolyte supply flow path for supplying anolyte to the anode chamber where the anode 920 is arranged; an anolyte recovery flow path for recovering anolyte and gas generated at the anode from the anode chamber; a cathode liquid supply flow path for supplying cathode liquid to the cathode chamber where the cathode 30 is arranged; and a cathode liquid recovery flow path for recovering cathode liquid and gas generated at the cathode from the cathode chamber. As the material of the flange portion 11, a rigid material having alkali resistance can be used without particular limitation. Examples of such materials include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metal materials obtained by nickel plating these; and non-metallic materials such as reinforced plastics. The partition wall 10 and the flange portion 11 can be joined by welding, bonding, etc., or can be formed integrally from the same material.

[0288] Fig. 22 (B) schematically illustrates the Fig. 22 The electrolytic element 1200 of (A) is an exploded cross-sectional view showing the state where the anode 920, the partition wall 10, and the cathode current collector 960 are disconnected. Fig.17 In the electrolytic element 1200 having the flange portion 11, the electrolytic element 900 ( Fig.17 ) Similarly, the anode 920 can be easily replaced, thereby reducing the time and cost required for updating the anode 920.

[0289] In the above description of the present invention, the electrolytic element 900 ( Fig.17 ) is taken as an example, but the present invention is not limited to this embodiment. For example, the electrolytic element 100 ( Figure 2 )、200( Figure 4 )、300( Figure 7 )、400( Figure 8 )、500( Fig.12 )、600( Fig.14 )、700( Fig.15 )、800( Fig.16 )、1000( Fig. 20 ) or 1100( Fig.21 ) is an electrolytic element in which a flange portion is further provided on the outer periphery of the partition wall 10 or 610.

[0290] In the above description of the present invention, the electrolytic element 1200 in which the anode 920 and the cathode current collector 960 are detachably fixed to the partition wall 10 by the first bolt 41 and the first nut 42, and the anode 920, the cathode current collector 960 and the partition wall 10 are electrically connected via the first bolt 41 and the first nut 42 is cited as an example, but the present invention is not limited to this embodiment. For example, the electrolytic element in which the anode 920 and the cathode current collector 960 are detachably fixed to the partition wall 10 by the first bolt 41 and the first nut 42, and the anode 920 and the cathode current collector 960 are electrically connected via the first bolt 41 and the first nut 42, but the partition wall 10 is not electrically connected to the anode 920 and the cathode current collector 960 may also be used. In addition, in the above description of the present invention, the electrolytic element 1200 in which the conductive partition wall 10 is provided is cited as an example, but the present invention is not limited to this embodiment. For example, it is also possible to have an electrolytic element in the following manner: a non-conductive partition wall is provided instead of the conductive partition wall 10, and the anode 920 and the cathode current collector 960 are detachably fixed to the non-conductive partition wall by means of the first bolt 41 and the first nut 42, and the anode 920 and the cathode current collector 960 are electrically connected via the first bolt 41 and the first nut 42. This is because, even if the partition wall is non-conductive, as long as the anode and cathode current collectors arranged with the partition wall sandwiched are electrically connected, the function of the electrolytic element can be exerted. As the material of such a non-conductive partition wall, a resin material having alkali resistance and strength capable of supporting the anode and cathode current collector can be preferably used. As a preferred example of such a resin material, hard vinyl chloride resin, polypropylene resin, polyethylene resin, polyetherimide resin, polyphenylene sulfide resin, polybenzimidazole resin, polytetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene-ethylene copolymer resin, etc. can be cited.

[0291] <2. Alkaline water electrolyzer>

[0292] Fig.23 is a cross-sectional view schematically illustrating an alkaline water electrolysis cell 10000 (hereinafter sometimes referred to as “electrolysis cell 10000”) according to one embodiment. Fig.24 yes Fig.23 Exploded view of the Fig.23 and Fig.24 Sometimes, Figure 2 to Figure 22The elements already shown in the Figure 2 to Figure 22 The electrolytic cell 10000 includes a plurality of ion-permeable diaphragms 80, 80, ... (hereinafter sometimes simply referred to as "diaphragms 80") and electrolytic elements 900, 900, ... ( Fig.17 ) stacked structure. Adjacent electrolytic elements 900, 900 are arranged in a manner that the anode 920 of one electrolytic element 900 is opposite to the cathode 30 of the other electrolytic element 900 via the diaphragm 80. The electrolytic cell 10000 also includes a first terminal element 1300 and a second terminal element 1400. The first terminal element 1300 is arranged in a manner that it is opposite to the cathode 30 of the first electrolytic element 900a arranged at one end of the above-mentioned stacked structure via the diaphragm 80. The second terminal element 1400 is arranged in a manner that it is opposite to the anode 920 of the second electrolytic element 900b arranged at the other end of the above-mentioned stacked structure via the diaphragm 80. The first terminal element 1300 includes a conductive first partition wall 1310 and a first anode 920 electrically connected to the first partition wall 1310. The second terminal element 1400 includes a conductive second partition wall 1410 and a second cathode 30 electrically connected to the second partition wall 1410 .

[0293] The electrolytic cell 10000 also includes: gaskets 90, 90, ... (hereinafter sometimes simply referred to as "gaskets 90"), which hold the peripheral portions of each diaphragm 80; an electrically insulating frame-shaped protective member 110, which holds the peripheral portions of each diaphragm 80 via the gasket 90; and a sealing member 120, which is respectively arranged between the partition wall 10 and the protective member 110, between the first partition wall 1310 and the protective member 110, and between the second partition wall 1410 and the protective member 110.

[0294] Fig.25 (A) is a top view schematically illustrating a protective member 110 holding a diaphragm 80 and a gasket 90, Fig.25 (B) is Fig.25 (A) is a cross-sectional view from the BB direction. Fig.25 (C) and Fig.25 (D) means Fig.25 (B) is a cross-sectional view showing the protective member 110 being disassembled. Fig.25 Sometimes, Figure 2 to Figure 24 The elements already shown in the Figure 2 to Figure 24The same reference numerals as those in the figure are used and their descriptions are omitted. As described above, the peripheral portion of the diaphragm 80 is retained by the gasket 90, and the gasket 90 is retained by the frame-shaped protective member 110. The protective member 110 includes a frame-shaped base 111 and a frame-shaped cover member 112. The base 111 includes: a housing portion 111a, which is provided on the inner peripheral side of the base 111 and accommodates the gasket 90 (retaining the diaphragm 80) and the cover member 112; and a supporting portion 111b, which protrudes and extends from the housing portion 111a toward the inner peripheral side of the base 111, in a direction intersecting the main surface of the diaphragm 80 ( Fig.25 (B)~ Fig.25 The left-right direction of the paper (D). Hereinafter, it is sometimes referred to as the "stacking direction". The gasket 90 ( Fig.25 (D)).

[0295] Fig.25 (C) is a cross-sectional view showing a state where the gasket 90 is accommodated in the accommodation portion 111a of the base 111 and supported by the support portion 111b in a direction intersecting the main surface of the diaphragm 80. The depth of the accommodation portion 111a in the stacking direction is deeper than the thickness of the gasket 90 holding the peripheral portion of the diaphragm 80 in the stacking direction. Therefore, when the gasket 90 holding the diaphragm 80 is accommodated in the accommodation portion 111a and supported by the support portion 111b in the stacking direction, a step is generated between the surface 90a of the gasket 90 accommodated in the accommodation portion 111a on the side opposite to the support portion 111b and the surface 111c of the base 111 on the side opposite to the support portion 111b ( Fig.25 (C)). The cover member 112 has a size that can be accommodated in the step between the surface 111c of the base 111 that accommodates the gasket 90 in the accommodating portion 111a and the surface 90a of the gasket. That is, the outer peripheral portion of the cover member 112 has a size that is substantially the same as the inner peripheral portion of the accommodating portion 111a of the base 111, the inner peripheral portion of the cover member 112 has a size that is substantially the same as the inner peripheral portion of the supporting portion 111b of the base 111, and the thickness of the cover member 112 in the stacking direction is set to be: the sum of the thickness of the gasket 90 holding the diaphragm 80 in the stacking direction and the thickness of the cover member 112 in the stacking direction is substantially the same as the depth of the accommodating portion 111a of the base 111 in the stacking direction. Fig.25 (B) means Fig.25 1 is a cross-sectional view showing a state where the step between the surface 111c of the base 111 and the surface 90a of the gasket 90 accommodates the cover member 112. Fig.25 As shown in FIG. 1B , the gasket 90 and the cover member 112 are accommodated in the accommodation portion 111 a of the base 111 , so that the gasket 90 is sandwiched and held between the support portion 111 b of the base 111 and the cover member 112 .

[0296] As the diaphragm 80, an ion permeable diaphragm that can be used in an electrolytic cell for alkaline water electrolysis can be used without particular limitation. It is desirable that the diaphragm 80 has low gas permeability, low electrical conductivity, and high strength. As examples of the diaphragm 80, porous diaphragms such as a porous membrane consisting of asbestos or modified asbestos, a porous diaphragm using a polysulfone polymer, a cloth using polyphenylene sulfide fiber, a fluorine-based porous membrane, and a porous membrane using a mixed material comprising both an inorganic material and an organic material can be cited. In addition, in addition to these porous diaphragms, ion exchange membranes such as fluorine-based ion exchange membranes can also be used as the diaphragm 80.

[0297] As the gasket 90, any gasket that can be used in an electrolytic cell for alkaline water electrolysis can be used without particular limitation. Fig.25 , a cross section of the gasket 90 is shown in FIG. The gasket 90 has a flat shape, holds the peripheral portion of the diaphragm 80, and on the other hand, is sandwiched and held between the support portion 111b of the base 111 and the cover member 112 in the accommodating portion 111a of the base 111. The gasket 90 is preferably formed of an elastomer having alkali resistance. Examples of materials for the gasket 90 include elastomers such as natural rubber (NR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPT), ethylene-propylene-diene rubber (EPDM), isobutylene-isoprene rubber (IIR), and chlorosulfonated polyethylene rubber (CSM). In addition, when using a gasket material that does not have alkali resistance, a layer of alkali-resistant material can also be provided on the surface of the gasket material by covering or the like.

[0298] The substrate 111 is preferably electrically insulating with respect to the voltage applied from the outside. In one embodiment, the substrate 111 is formed of an electrically insulating material. As an electrically insulating material forming the substrate 111, a resin material having alkali resistance and strength to withstand the extrusion force applied along the stacking direction can be preferably used. As preferred examples of such resin materials, hard vinyl chloride resin, polypropylene resin, polyethylene resin, polyetherimide resin, polyphenylene sulfide resin, polybenzimidazole resin, polytetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene-ethylene copolymer resin, etc. can be cited. In other embodiments, the substrate 111 is a core material composed of a metal material and a covering layer of an electrically insulating material covering the surface of the core material. As examples of metal materials forming the core material of the substrate 111, for example, rigid metal materials such as single metals such as iron and stainless steels such as SUS304 can be cited. In addition, as a preferred example of an electrically insulating material forming the covering layer of the substrate 111, in addition to the above-mentioned electrically insulating resin material, an elastomer having electrical insulation and alkali resistance can also be cited. As a preferred example of such an elastomer, natural rubber (NR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPT), ethylene-propylene-diene rubber (EPDM), isobutylene-isoprene rubber (IIR), chlorosulfonated polyethylene rubber (CSM), etc. can be cited. In addition, when using an elastomer that does not have alkali resistance, a layer of an alkali-resistant material can also be provided on the surface of the elastomer by covering or the like.

[0299] The cover member 112 may be made of metal or may be formed of an electrically insulating material. As an example of a metal material forming the cover member 112, the same metal material as the material described above in relation to the substrate 111 can be cited. In one embodiment, the cover member 112 is formed of an electrically insulating material. As a preferred example of an electrically insulating material forming the cover member 112, the same resin material as the material described above in relation to the substrate 111 can be cited. In another embodiment, the cover member 112 is formed of a core material composed of a metal material and a covering layer of an electrically insulating material covering the surface of the core material. As an example of a metal material forming the core material of the cover member 112, the same rigid metal material as the material described above in relation to the core material of the substrate 111 can be cited. In addition, as a preferred example of an electrically insulating material forming the covering layer of the cover member 112, the same resin material and elastomer as the material described above in relation to the covering layer of the substrate 111 can be cited.

[0300] In the electrolytic cell 10000, anode chambers (A1, A2, A3) for accommodating the anode 920 are defined between the first surface 10a of the partition wall 10 of the electrolytic element 900 and the diaphragm 80 facing the first surface 10a, and between the first partition wall 1310 of the first terminal element 1300 and the diaphragm 80 facing the first partition wall 1310. In addition, cathode chambers (C1, C2, C3) for accommodating the cathode 30 are defined between the second surface 10b of the partition wall 10 of the electrolytic element 900 and the diaphragm 80 facing the second surface 10b, and between the second partition wall 1410 of the second terminal element 1400 and the diaphragm 80 facing the second partition wall 1410. The first terminal element 1300 defines only the anode chamber (A1), and a positive terminal is connected to the first partition wall 1310 thereof, and the positive terminal is connected to the positive electrode of a DC power supply. The second terminal element 1400 only divides the cathode chamber (C3), and a negative terminal is connected to the second partition wall 1410 thereof, and the negative terminal is connected to the negative electrode of the DC power supply. In addition, the electrolytic cell 10000 also includes: an anolyte supply flow path (not shown) that supplies anolyte to each anolyte chamber (A1, A2, A3); an anolyte / gas recovery flow path (not shown) that recovers anolyte and gas from each anolyte chamber; a catholyte supply flow path (not shown) that supplies catholyte to each cathode chamber (C1, C2, C3); and a catholyte / gas recovery flow path (not shown) that recovers catholyte and gas from each cathode chamber.

[0301] Fig.26 (A) is a cross-sectional view schematically illustrating the first terminal element 1300, which is similar to Fig.17 The corresponding figure of (A). Fig.26 Sometimes, Figure 2 to Figure 25 The elements already shown in the Figure 2 to Figure 25 The same reference numerals as in the figure are used and description thereof is omitted. Fig.26 (B) schematically illustrates the Fig.26 The exploded cross-sectional view of the case where the anode 920 and the first partition wall 1310 are released in (A) is similar to Fig.17 The first terminal element 1310 includes a conductive first partition wall 1310 , an anode 920 electrically connected to the first partition wall 1310 , and a conductive first bolt 1341 fixing the anode 920 to the partition wall 1310 .

[0302] The first partition wall 1310 is different from the partition wall 10 in that a threaded hole 1310h capable of being screwed with the first bolt 1341 is provided instead of the first through hole 10h. As the material of the first partition wall 1310, the same conductive material as the partition wall 10 described above can be used, and the preferred mode thereof is also the same as described above. The first bolt 1341 is different from the bolt 41 in that a shorter rod 1341a is provided instead of the rod 41a. As the material of the first bolt 1341, the same conductive material as the bolt 41 described above can be used, and the preferred mode thereof is also the same as described above. The length of the rod 1341a is preferably shorter than the sum of the thickness of the bottom 920c of the first cup-shaped portion 920b of the anode 920 and the depth of the threaded hole 1310h. In the first terminal element 1300, the rod portion 1341a of the first bolt 1341 passes through the fifth through hole 920h of the bottom 920c of the first cup-shaped portion 920b of the anode 920, and is screwed into the threaded hole 1310h of the first partition wall 1310. The anode 920 is threadedly fixed to the first partition wall 1310 by the first bolt 1341, and the anode 920 is electrically connected to the first partition wall 1310.

[0303] like Fig.24 As shown, the second terminal element 1400 includes a conductive second partition wall 1410, a conductive rib 1470 erected from the second partition wall 1410, and a cathode current collector 660 (see Fig.14 ), a conductive elastic body 50 supported on a cathode current collector 660, and a cathode 30 supported on the elastic body 50.

[0304] As the conductive rib 1470, a known conductive rib used in an alkaline water electrolyzer can be used without particular restrictions. In the second terminal element 1400, the conductive rib 1470 is erected from the second partition wall 1410. As long as the conductive rib 1470 can fix and hold the cathode collector 660 relative to the second partition wall 1410, the connection method, shape, number and configuration of the conductive rib 1470 are not particularly limited. As the material of the conductive rib 1470, a rigid conductive material with alkali resistance can be used without particular restrictions, for example, single metals such as nickel and iron; metal materials such as stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L can be preferably used. These metal materials can also be nickel-plated for use in order to improve corrosion resistance and conductivity.

[0305] The sealing member 120 is clamped between the frame-shaped protection member 110 and the partition wall 10, 1310, 1410, and is subjected to a squeeze force between the protection member 110 and the partition wall 10, 1310 or 1410, thereby preventing the electrolyte or gas from leaking out from between the protection member 110 and the partition wall 10, 1310, 1410 due to the internal pressure of each pole chamber. The sealing member 120 is preferably formed by an elastomer with alkali resistance. As examples of the material of the sealing member 120, elastomers such as natural rubber (NR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPT), ethylene-propylene-diene rubber (EPDM), isobutylene-isoprene rubber (IIR), and chlorosulfonated polyethylene rubber (CSM) can be cited. In addition, when the sealing member 120 uses an elastomer that does not have alkali resistance, a layer of an alkali-resistant material can be provided on the surface of the core material having the elastomer by covering or the like. The sealing member 120 can also be a flat gasket, but is preferably an O-ring. By using an O-ring as a sealing member, the pressure resistance of the electrolytic cell 10000 can be further improved.

[0306] The electrolytic cell 10000 includes the electrolytic element 900 of the present invention as an electrolytic element, so that the anode 920 can be easily replaced, thereby reducing the time and cost required for updating the anode 920. In addition, in the first terminal element 1300, the anode 920 is fixed to the first partition wall 1310 by threaded fixing with the first bolt 1341, so the anode 920 of the first terminal element 1300 can also be easily replaced.

[0307] In the above description of the present invention, the electrolytic cell 10000 having the electrolytic element 900 is cited as an example, but the present invention is not limited to this embodiment. For example, it is also possible to replace the electrolytic element 900 with another electrolytic element 100 ( Figure 2 )、200( Figure 4 )、300( Figure 7 )、400( Figure 8 )、500( Fig.12 )、600( Fig.14 )、700( Fig.15 )、800( Fig.16 )、1000( Fig. 20 ) or 1100( Fig.21 ) method of electrolyzer.

[0308] In the above description of the present invention, the electrolytic cell 10000 is taken as an example in which the opening 920d of the first cup-shaped portion 920b of the anode 920 is not blocked in the first terminal element 1300, but the present invention is not limited to this embodiment. For example, the electrolytic cell may be an electrolytic cell in which the first terminal element has a cover member that blocks at least a portion of the opening 920d of the first cup-shaped portion 920b of the anode 920. Fig. 27 (A) is a cross-sectional view schematically illustrating a first terminal element 1300' according to another embodiment of the present invention. Fig.26 (A) and Fig. 20 The first connection terminal element 1300' and the first connection terminal element 1300 ( Fig.26 ) is different from the anode 920 in that it further comprises a detachable second cover member 1021, 1021, ... which is made of the same material as the anode 920 and blocks at least a portion of the opening 920d of the first cup-shaped portion 920b, 920b, ... of the anode 920 (see Fig. 20 ) and the conductive second bolts 1022 fixed to each second cover member 1021 (see Fig. 20 ), and first bolts 1341', 1341', ... (hereinafter sometimes referred to as "first bolts 1341'") are provided in place of the first bolts 1341, 1341, .... The first bolt 1341' has a head 1041b (see Fig. 20 ) This point is different from the first bolt 1341. Fig. 27 (B) schematically illustrates the Fig. 27 The exploded cross-sectional view of the first terminal element 1300' in (A) is a view in which the anode 920 and the first partition wall 1310 are released from each other and the cover member 1021 is removed from the opening 920d of the first cup-shaped portion 920b. Fig.26 (B) and Fig. 20 (B) The corresponding figure.

[0309] In the first terminal element 1300', the second bolt 1022 (the stem 1022a) fixed to the second cover member 1021 is screwed into the threaded hole 1041bh provided in the head 1041b of the first bolt 1341', so that the second cover member 1021 is detachably fixed to the first bolt 1341' and is electrically connected to the first bolt 1341' via the second bolt 1022, and the second cover member 1021 blocks at least a part of the opening 920d of the first cup-shaped portion 920b of the anode 920. Thus, the second cover member 1021 is electrically connected to the anode 920 via the second bolt 1022 and the first bolt 1341'.

[0310] By using such an electrolytic cell in the form of the first terminal element 1300', it is possible to obtain the electrolytic cell 10000 ( Fig.23 ) The same effect is achieved. Furthermore, by using an electrolytic cell having a first terminal element 1300' having a second cover member 1021, in the first terminal element 1300', the anode area reduced by the opening 920d of the first cup-shaped portion 920b is supplemented by the second cover member 1021, thereby improving the uniformity of current distribution and further reducing energy loss.

[0311] In the above description of the present invention, an electrolytic cell 10000 having an electrolytic element 900 without a flange portion on the outer periphery of the partition wall 10 is cited as an example, but the present invention is not limited to this embodiment. For example, an electrolytic cell having an electrolytic element with a flange portion on the outer periphery of the partition wall 10 may also be used. Fig.28 2 is a cross-sectional view schematically illustrating an alkaline water electrolysis cell 20000 (hereinafter sometimes simply referred to as “electrolysis cell 20000”) according to another embodiment of the present invention. Fig.29 yes Fig.28 Exploded view of the Fig.28 and Fig.29 Sometimes, Figure 2 to Figure 27 The elements already shown in the Figure 2 to Figure 27 The electrolytic cell 20000 includes a plurality of ion-permeable diaphragms 80, 80, ... and electrolytic elements 1200, 1200, ... respectively arranged between adjacent diaphragms 80, 80. Fig. 22 ) stacked structure. Adjacent electrolytic elements 1200, 1200 are arranged in a manner that the anode 920 of one electrolytic element 1200 is opposite to the cathode 30 of the other electrolytic element 1200 via the diaphragm 80. The electrolytic cell 20000 also includes a first terminal element 21300 and a second terminal element 21400. The first terminal element 21300 is arranged in a manner that it is opposite to the cathode 30 of the first electrolytic element 1200a arranged at one end of the above-mentioned stacked structure via the diaphragm 80. The second terminal element 21400 is arranged in a manner that it is opposite to the anode 920 of the second electrolytic element 1200b arranged at the other end of the above-mentioned stacked structure via the diaphragm 80. The first terminal element 21300 includes a conductive first partition wall 1310 and a first anode 920 electrically connected to the first partition wall 1310. The second terminal element 21400 includes a conductive second partition wall 1410 and a second cathode 30 electrically connected to the second partition wall 1410 .

[0312] Fig.30(A) is a cross-sectional view schematically illustrating the first terminal element 21300, which is similar to Fig.26 The corresponding figure of (A). Fig.30 Sometimes, Figure 2 to Figure 29 The elements already shown in the Figure 2 to Figure 29 The same reference numerals as in the figure are used and description thereof is omitted. Fig.30 (B) schematically illustrates the Fig.30 The exploded cross-sectional view of the case where the anode 920 and the first partition wall 1310 are released in (A) is similar to Fig.26 The first connection terminal element 21300 and the first connection terminal element 1300 ( Fig.24 , Fig.26 ) is different in that it further includes a first flange portion 1311 which is provided on the outer periphery of the first conductive partition wall 1310 and extends toward the flange portion 11 of the first electrolytic element 1200a.

[0313] In the first terminal element 21300, the flange 1311 is watertightly connected to the outer periphery of the first partition wall 1310. As the material of the flange 1311, a rigid material having alkali resistance can be used without particular limitation, and examples of such materials include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; metal materials plated with nickel; and non-metallic materials such as reinforced plastics. The partition wall 1310 and the flange 1311 may be joined by welding, bonding, etc., or may be formed integrally from the same material.

[0314] Fig.31 (A) is a cross-sectional view schematically illustrating the second terminal element 21400. Fig.31 Sometimes, Figures 2 to 30 The elements already shown in the Figures 2 to 30 The same reference numerals as in the figure are used and description thereof is omitted. Fig.31 (B) schematically illustrates the Fig.31 21400 is an exploded cross-sectional view of the second terminal element 21400 with the cathode 30 and the elastic body 50 removed. The second terminal element 21400 and the second terminal element 1400 ( Fig.24 ) is different in that it further includes a second flange portion 1411 which is provided on the outer periphery of the second conductive partition wall 1410 and extends toward the flange portion 11 of the second electrolytic element 1200b.

[0315] In the second terminal element 21400, the flange 1411 is watertightly connected to the outer periphery of the second partition wall 1410. As the material of the flange 1411, a rigid material having alkali resistance can be used without particular limitation, and examples of such materials include single metals such as nickel and iron; stainless steels such as SUS304, SUS310, SUS310S, SUS316, and SUS316L; and metal materials plated with nickel; and non-metallic materials such as reinforced plastics. The partition wall 1410 and the flange 1411 may be joined by welding, bonding, etc., or may be formed integrally from the same material.

[0316] In the electrolytic cell 20000, the peripheral edge of each diaphragm 80 is sandwiched by gaskets 90, 90, and the diaphragm 80 is sandwiched between two adjacent flanges (i.e., a group of two adjacent flanges among the flange 11 of the electrolytic element 1200, the flange 1311 of the first terminal element 21300, and the flange 1411 of the second terminal element 21400) with the gasket 90 interposed therebetween. In the cell 20000, anode chambers (A1, A2, A3) for accommodating the anode 920 are defined between the first surface 10a of the partition wall 10 of the electrolytic element 1200 and the diaphragm 80 facing the first surface 10a, and between the first partition wall 1310 of the first terminal element 21300 and the diaphragm 80 facing the first partition wall 1310. In addition, cathode chambers (C1, C2, C3) for accommodating cathodes 30 are defined between the second surface 10b of the partition wall 10 of the electrolytic element 1200 and the diaphragm 80 opposite to the second surface 10b, and between the second partition wall 1410 of the second terminal element 21400 and the diaphragm 80 opposite to the second partition wall 1410. The first terminal element 21300 defines only the anode chamber (A1), and a positive terminal is connected to the first partition wall 1310 thereof, and the positive terminal is connected to the positive electrode of the DC power supply. The second terminal element 21400 defines only the cathode chamber (C3), and a negative terminal is connected to the second partition wall 1410 thereof, and the negative terminal is connected to the negative electrode of the DC power supply. In addition, in the electrolytic cell 20000, the flange portion 11 of each electrolytic element 1200 is provided with: an anolyte supply flow path (not shown) that supplies anolyte to each anode chamber (A1, A2, A3); an anolyte / gas recovery flow path (not shown) that recovers anolyte and gas from each anode chamber; a cathode liquid supply flow path (not shown) that supplies cathode liquid to each cathode chamber (C1, C2, C3); and a cathode liquid / gas recovery flow path (not shown) that recovers cathode liquid and gas from each cathode chamber. The flange portion 1311 of the first terminal element 21300 is provided with an anolyte supply flow path and an anolyte / gas recovery flow path. In addition, the flange portion 1411 of the second terminal element 21400 is provided with a cathode liquid supply flow path and a cathode liquid / gas recovery flow path. Alternatively, the flange portion 1311 of the first terminal element 21300 may further include a cathode liquid supply path and a cathode liquid / gas recovery path, but the cathode liquid supply path and the cathode liquid / gas recovery path are not connected to the anode chamber A1 divided by the first terminal element 23100. Alternatively, the flange portion 1411 of the second terminal element 21400 may further include an anode liquid supply path and an anode liquid / gas recovery path, but the cathode liquid supply path and the anode liquid / gas recovery path are not connected to the cathode chamber C3 divided by the second terminal element.

[0317] The electrolytic cell 20000 includes the electrolytic element 1200 of the present invention as an electrolytic element, so that the anode 920 can be easily replaced, thereby reducing the time and cost required for updating the anode 920. In addition, in the first terminal element 21300, the anode 920 is fixed to the first partition wall 1310 by threaded fixing with the first bolt 1341, so the anode 920 of the first terminal element 21300 can also be easily replaced.

[0318] In the above description of the present invention, the electrolytic cell 20000 having the electrolytic element 1200 is cited as an example, but the present invention is not limited to this embodiment. For example, it is also possible to replace the electrolytic element 1200 with another electrolytic element 100 ( Figure 2 )、200( Figure 4 )、300( Figure 7 )、400( Figure 8 )、500( Fig.12 )、600( Fig.14 )、700( Fig.15 )、800( Fig.16 )、1000( Fig. 20 ) or 1100( Fig.21 ) is an electrolytic cell of an electrolytic element in which a flange portion is provided on the outer peripheral portion of the partition wall.

[0319] In the above description of the present invention, an electrolytic cell 20000 in which the opening 920d of the first cup-shaped portion 920b of the anode 920 is not blocked in the first terminal element 21300 is cited as an example, but the present invention is not limited to this embodiment. For example, an electrolytic cell in which the first terminal element has a cover member that blocks at least a portion of the opening 920d of the first cup-shaped portion 920b of the anode 920 may be used. As such a first terminal element, for example, the first terminal element 1300' described above (see Fig. 27 ) is provided with a flange portion 1311 on the outer periphery of the first partition wall 1310 (see Fig.30 ) method of the first terminal element.

[0320] Description of Reference Numerals

[0321] 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, electrolytic element; 10, 610, partition wall; 10a, first surface; 10b, second surface; 11, 1311, 1411, flange; 20, 620, 920, anode; 620h, fourth through hole; 721, 1021, second cover member; 722, 1022, second bolt; 722a, extension shaft; 722b, cover member fixing screw; 1022a, rod; 1022b, head; 920a, first flat portion; 920b, first cup-shaped portion; 920c, bottom (of first cup-shaped portion); 920d, opening (of first cup-shaped portion) ; 920h, the fifth through hole; 30, cathode; 40, 340, 440, 540, 640, 740, the first connecting mechanism; 41, 341, 641, 741, 841, the first bolt; 41a, 341a, 641a, rod; 841e1, the first end (of the stud bolt); 841e2, the second end (of the stud bolt); 341h, the threaded hole at the end of the bolt; 41b, 741b, head; 741bh, 841h, the second threaded hole; 1041bh, the threaded hole (of the bolt head); 10h, the first through hole; 610h, the first threaded hole; 42, 842, the first nut; 43, 443, the first structural element; 43a, the first spacer; 43ae, the end; 4 3b, 1st plate-shaped portion; 43bh, 2nd through hole; 44, 1144, 2nd nut; 50, elastic body; 60, 660, 960, cathode current collector; 60h, 3rd through hole; 61, 361, 1st cover member; 61a, flat portion; 61w, metal needle portion; 361b, extension shaft; 361c, cover member fixing screw; 960a, 2nd flat portion; 960b, 2nd cup-shaped portion; 960c, bottom (of 2nd cup-shaped portion); 960d, opening (of 2nd cup-shaped portion); 960h, 6th through hole; 70, 2nd connecting mechanism; 71, 2nd structural element; 71a, 2nd spacer; 71ec, end portion; 71ew, end portion; 940, 3rd connecting mechanism; 941, 1st bolt; 941a, rod; 941b, head; 942, first nut; 80, (ion-permeable) diaphragm; 90, gasket; 110, frame-shaped protective member; 120, sealing member; 1300, first terminal element; 1310, first partition wall; 1400, second terminal element; 1410, second partition wall; d1, first interval; d2, second interval; 10000, 20000, alkaline water electrolyzer; 9000, conventional zero-gap alkaline water electrolyzer; 9010, pole chamber unit; 9011, conductive partition wall; 9012, flange; 9013, 9014, conductive rib; 9020, ion-permeable diaphragm; 9030, gasket; 9040, anode;9050, current collector; 9060, conductive elastomer; 9070, cathode; A, A1, A2, A3, anode chamber; C, C1, C2, C3, cathode chamber. ;

Claims

1. An electrolytic element for alkaline water electrolysis, It is characterized in that The electrolytic element for alkaline water electrolysis comprises: A conductive partition wall having a first surface and a second surface; an anode for generating oxygen; a cathode for producing hydrogen; a first connecting mechanism for fixing the anode to the partition wall so that the anode faces the first surface of the partition wall with a first gap therebetween and for electrically connecting the anode to the partition wall; a conductive elastomer supporting the cathode; as well as a cathode current collector supporting the elastic body, The cathode current collector is fixed to the partition wall so as to face the second surface of the partition wall with a second gap therebetween and is electrically connected to the partition wall. The first connection mechanism includes a conductive first bolt, the first bolt having at least a rod portion. The anode is detachably fixed to the partition wall by the first bolt.

2. The electrolytic element according to claim 1, in, The first connecting mechanism further comprises: a first through hole provided in the partition wall and capable of allowing the shank of the first bolt to pass therethrough; and A first nut is threadably engaged with the first bolt.

3. The electrolytic element according to claim 2, in, The first connection mechanism further includes a first conductive structural element, The first structural element includes: a first spacer extending from the anode toward the first surface of the partition wall in a direction intersecting the first surface of the partition wall; and a first plate-shaped portion extending continuously with the first spacer in a direction parallel to the first surface of the partition wall. The first spacer has an end portion fixed to the anode, The first plate-shaped portion includes a second through hole through which the shank of the first bolt can pass. The shank portion of the first bolt passes through the first through hole and the second through hole and is threadedly engaged with the first nut, whereby the first structural element is fixed to the partition wall.

4. The electrolytic element according to claim 3, in, The second through hole is provided continuously from the first plate-shaped portion to at least a portion of the first spacer portion.

5. The electrolytic element according to claim 3 or 4, in, The first bolt further includes a head, which is provided at the end of the rod. The shank of the first bolt is inserted through the first through hole and the second through hole in a direction in which the head of the first bolt presses the first plate-shaped portion of the first structural element toward the partition wall. The first structural element further includes a rotation restricting portion that contacts a side surface of the head of the first bolt to restrict rotation of the first bolt when the shank of the first bolt is inserted into the second through hole and the head of the first bolt contacts the first plate-shaped portion.

6. The electrolytic element according to claim 3 or 4, in, The first connection mechanism further includes a second nut capable of being threadedly engaged with the first bolt. The second nut is screwed with the rod of the first bolt inserted into the second through hole in such a manner that the head of the first bolt and the second nut sandwich the first plate-shaped portion of the first structural element, thereby fixing the first bolt to the first plate-shaped portion of the first structural element. The shank portion of the first bolt fixed to the first plate-shaped portion of the first structural element passes through the first through hole of the partition wall and is screwed into the first nut, whereby the first bolt is fixed to the partition wall.

7. The electrolytic element according to claim 3 or 4, in, The cathode current collector includes a third through hole at a position facing the first through hole of the partition wall, and the third through hole has a shape and a size that allows the first nut to pass therethrough.

8. The electrolytic element according to claim 7, in, The electrolytic element further comprises a detachable conductive first cover member, the first cover member blocking at least a portion of the third through hole of the cathode current collector. When the first cover member is attached so as to block at least a portion of the third through hole of the cathode current collector, the first cover member is electrically connected to the cathode current collector.

9. The electrolytic element according to claim 1, in, The first connection mechanism further includes a first threaded hole that opens on the first surface of the partition wall and can be threadably engaged with the first bolt.

10. The electrolytic element according to claim 9, in, The first connection mechanism further includes a first conductive structural element, The first structural element includes: a first spacer extending from the anode toward the first surface of the partition wall in a direction intersecting the first surface of the partition wall; and a first plate-shaped portion extending continuously with the first spacer in a direction parallel to the first surface of the partition wall. The first spacer has an end portion fixed to the anode, The first plate-shaped portion includes a second through hole through which the shank of the first bolt can pass. The shank portion of the first bolt is inserted into the second through hole and screwed into the first threaded hole of the partition wall, whereby the first structural element is fixed to the partition wall.

11. The electrolytic element according to claim 10, in, The anode includes a fourth through hole at a position facing the second through hole, and the fourth through hole has a shape and a size that allows the first bolt to pass therethrough.

12. The electrolytic element according to claim 11, in, The electrolytic element also has: a second cover member made of the same material as the anode and blocking at least a portion of the fourth through hole of the anode; and a conductive second bolt fixed to the second cover member, The head of the first bolt has a second threaded hole capable of being threadedly engaged with the second bolt. The second bolt is screwed into the second threaded hole, whereby the second cover member is detachably fixed to the first bolt and electrically connected to the first bolt, and the second cover member closes at least a portion of the fourth through hole of the anode.

13. The electrolytic element according to claim 9, in, The first bolt is a stud bolt having a first end and a second end. The first connecting mechanism further comprises: a first conductive structural element, comprising a first spacer and a first plate-shaped portion, the first spacer extending from the anode toward the first surface of the partition wall in a direction intersecting the first surface of the partition wall, the first plate-shaped portion and the first spacer extending continuously in a direction parallel to the first surface of the partition wall; and a first nut capable of being threadedly engaged with the stud bolt, The first spacer has an end portion fixed to the anode, The first plate-shaped portion includes a second through hole through which the first bolt can pass. The stud bolt is screwed into the first threaded hole of the partition wall, whereby the first end of the stud bolt is fixed to the partition wall. The stud bolt fixed to the partition wall is inserted into the second through hole and the first nut is screwed into the stud bolt from the second end portion, whereby the first structural element is fixed to the partition wall.

14. The electrolytic element according to claim 13, in, The anode includes a fourth through hole at a position facing the second through hole, and the fourth through hole has a shape and a size that allows the first nut to pass therethrough.

15. The electrolytic element according to claim 14, in, The electrolytic element also has: a second cover member made of the same material as the anode and blocking at least a portion of the fourth through hole of the anode; and a conductive second bolt fixed to the second cover member, The second end of the stud bolt has a second threaded hole capable of being threadedly engaged with the second bolt. The second bolt is screwed into the second threaded hole, whereby the second cover member is detachably fixed to the stud bolt and electrically connected to the stud bolt, and the second cover member closes at least a portion of the fourth through hole of the anode.

16. The electrolytic element according to any one of claims 1 to 4, in, The electrolytic element further comprises a second connecting mechanism for fixing the cathode current collector to the partition wall so that the cathode current collector and the second surface of the partition wall face each other with the second gap therebetween, and for electrically connecting the cathode current collector and the partition wall. The second connection mechanism includes a conductive second structural element, the second structural element including a second spacer extending between the cathode current collector and the second surface of the partition wall in a direction intersecting the second surface of the partition wall, The second structural element includes an end portion fixed to the cathode current collector and an end portion fixed to the second surface of the partition wall.

17. An electrolytic element for alkaline water electrolysis, It is characterized in that The electrolytic element for alkaline water electrolysis comprises: a partition wall having a first surface and a second surface; an anode for generating oxygen; a cathode for producing hydrogen; a conductive elastomer supporting the cathode; a cathode current collector supporting the elastic body; as well as a third connecting mechanism that fixes the anode and the cathode current collector to the partition wall and electrically connects the anode and the cathode current collector in such a manner that the anode faces the first surface of the partition wall and the cathode current collector faces the second surface of the partition wall, The third connection mechanism comprises: A conductive first bolt having at least a stem portion; a first through hole provided in the partition wall and capable of allowing the shank of the first bolt to pass therethrough; and a first nut capable of being threadedly engaged with the first bolt, The anode has: A first flat portion extending in two dimensions; a first cup-shaped portion, which projects from the first flat portion toward the first surface of the partition wall in a tapered shape; as well as a fifth through hole, which is provided at the bottom of the first cup-shaped portion and through which the rod of the first bolt can pass; The cathode current collector comprises: A second flat portion extending in two dimensions; a second cup-shaped portion, which projects from the second flat portion toward the second surface of the partition wall in a tapered shape; as well as a sixth through hole, which is provided at the bottom of the second cup-shaped portion and through which the rod of the first bolt can pass; The shank of the first bolt passes through the first through hole, the fifth through hole, and the sixth through hole and is threadedly engaged with the first nut, whereby the anode and the cathode current collector are detachably fixed to the partition wall by the first bolt.

18. The electrolytic element according to claim 17, in, The first bolt further includes a head, which is provided at the end of the rod. The anode, the partition wall, and the cathode current collector are sandwiched and fastened by the head of the first bolt and the first nut.

19. The electrolytic element according to claim 18, in, The electrolytic element also has: a second cover member made of the same material as the anode and having a two-dimensionally extending shape capable of blocking at least a portion of an opening of the first cup-shaped portion of the anode; and a conductive second bolt having a head portion fixed to the second cover member and a rod portion fixed to the head portion, The head of the first bolt has a threaded hole capable of being threadedly engaged with the second bolt. The second bolt is screwed into the threaded hole, whereby the second cover member is detachably fixed to the first bolt and electrically connected to the first bolt, and the second cover member closes at least a portion of the opening of the first cup-shaped portion of the anode.

20. The electrolytic element according to claim 17, in, The electrolytic element further includes a second cover member, the second cover member being made of the same material as the anode and having a two-dimensionally extending shape capable of blocking at least a portion of an opening of the first cup-shaped portion of the anode. The first bolt further includes a head, which is provided at the end of the rod. The second cover member is fixed to the head of the first bolt and is electrically connected to the first bolt. The third connection mechanism further includes a second nut capable of being threadedly engaged with the first bolt. The rod of the first bolt passes through the first through hole, the fifth through hole and the sixth through hole and is threadedly engaged with the first nut and the second nut, thereby clamping and fastening the anode, the partition wall and the cathode collector by the first nut and the second nut, and the anode, the second cover member and the cathode collector are detachably fixed to the partition wall by means of the first bolt, and the second cover member blocks at least a portion of the opening of the first cup-shaped portion of the anode.

21. The electrolytic element according to any one of claims 1 to 4 and 17 to 20, in, The electrolytic element further includes a flange portion provided on an outer peripheral portion of the partition wall and extending toward both sides of the partition wall in a direction intersecting the first surface and the second surface of the partition wall.

22. An alkaline water electrolyzer, in, The alkaline water electrolyzer has a stacked structure, which includes: multiple ion-permeable membranes; and The electrolytic element according to any one of claims 1 to 21, which is disposed between adjacent ion-permeable diaphragms. The adjacent electrolytic elements are arranged such that the anode of one electrolytic element and the cathode of the other electrolytic element face each other via the ion-permeable membrane.

23. The alkaline water electrolyzer according to claim 22, in, The alkaline water electrolyzer also has: a first terminal element disposed so as to face the cathode of the first electrolytic element disposed at one end of the stacked structure with the ion-permeable diaphragm interposed therebetween; as well as a second terminal element disposed so as to face the anode of the second electrolytic element disposed at the other end of the stacked structure with the ion-permeable diaphragm interposed therebetween; The first terminal element comprises: a conductive first partition wall; and a first anode electrically connected to the first partition wall, The second terminal element comprises: a conductive second partition wall; and A second cathode is electrically connected to the second partition wall.

24. The alkaline water electrolyzer according to claim 23, in, The alkaline water electrolyzer also has: a spacer that holds the peripheral edge of each of the ion-permeable diaphragms; an electrically insulating frame-shaped protective member that holds the peripheral edge of each of the ion-permeable diaphragms via the spacer; as well as sealing members are respectively arranged between the partition wall and the protection member, between the first partition wall and the protection member, and between the second partition wall and the protection member, The electrolytic element is the electrolytic element according to any one of claims 1 to 20.

25. The alkaline water electrolyzer according to claim 23, in, The electrolytic elements are respectively the electrolytic elements according to claim 21, The first terminal element further comprises a first flange portion, which is provided on the outer peripheral portion of the first partition wall and extends toward the flange portion of the first electrolytic element. The second terminal element further includes a second flange portion provided on an outer peripheral portion of the second partition wall and extending toward the flange portion of the second electrolytic element.

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