Flow-type metal-air battery

Abstract

The present invention provides a flow-type metal-air battery that can suppress the accumulation of solid matter contained in the slurry. [Solution] The flow-type metal-air battery comprises a first structure, a flow channel layer located vertically above the first structure and having a flow channel through which a slurry flows, having a first wall surface and a second wall surface that face each other on either side of the flow channel, and having a protrusion that protrudes from the first wall surface, and a second structure located vertically above the flow channel.

Description

[Technical Field]

[0001] This disclosure relates to a flow-type metal-air battery. [Background technology]

[0002] Patent Document 1 discloses a flow-type battery. In this flow-type battery, the positive electrode active material contained in the positive electrode liquid generates aggregates in the positive electrode liquid that inhibit flow, thereby reducing the fluidity of the positive electrode liquid. Similarly, the negative electrode active material contained in the negative electrode liquid generates aggregates in the negative electrode liquid that inhibit flow, thereby reducing the fluidity of the negative electrode liquid.

[0003] In this flow-type battery, the positive electrode reverse flow line causes the positive electrode liquid to flow into the positive electrode liquid outlet of the cell stack and to flow out from the positive electrode liquid inlet of the cell stack. Similarly, the negative electrode reverse flow line causes the negative electrode liquid to flow into the negative electrode liquid outlet of the cell stack and to flow out from the negative electrode liquid inlet of the cell stack.

[0004] As a result, the positive electrode liquid channel within the cell stack is backwashed by the positive electrode liquid, and the negative electrode liquid channel within the cell stack is backwashed by the negative electrode liquid. This removes aggregates that obstruct the flow of the positive electrode liquid, preventing a decrease in the fluidity of the positive electrode liquid. Similarly, it removes aggregates that obstruct the flow of the negative electrode liquid, preventing a decrease in the fluidity of the negative electrode liquid. (Paragraphs 0016, 0021 and 0053-0061). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2018-181797 [Overview of the project] [Problems that the invention aims to solve]

[0006] In a flow-type metal-air battery, the negative electrode fluid is a slurry containing metal particles.

[0007] Patent Document 1 discloses a method for preventing a decrease in the fluidity of the positive electrode liquid and the negative electrode liquid when the positive electrode active material and the negative electrode active material generate aggregates, but it does not disclose a method for preventing a decrease in the fluidity of the negative electrode liquid when the negative electrode active material itself is a solid material such as metal particles.

[0008] One aspect of this disclosure has been made in view of this problem. One aspect of this disclosure aims to provide a flow-type metal-air battery that can suppress the accumulation of solid matter contained in a slurry, for example. [Means for solving the problem]

[0009] A flow-type metal-air battery according to one aspect of this disclosure is: The first structure and A flow channel layer located vertically above the first structure, having a flow channel through which a slurry flows, and having a first wall surface and a second wall surface facing each other on either side of the flow channel, and having a projection extending from the first wall surface, A second structure positioned vertically above the aforementioned flow path, It is equipped with. [Brief explanation of the drawing]

[0010] [Figure 1] This figure schematically illustrates a flow-type metal-air battery according to the first embodiment. [Figure 2] This is an enlarged cross-sectional view schematically illustrating the negative electrode fluid provided in the flow-type metal-air battery of the first embodiment. [Figure 3] This is an enlarged cross-sectional view schematically illustrating the positive electrode fluid provided in the flow-type metal-air battery of the first embodiment. [Figure 4] This is a schematic cross-sectional view illustrating each charging cell, negative electrode liquid, and positive electrode liquid provided in the flow-type metal-air battery of the first embodiment. [Figure 5] This is a schematic perspective view illustrating the negative electrode flow channel layer provided in the flow-type metal-air battery of the first embodiment. [Figure 6]It is a perspective view schematically illustrating a negative electrode flow path layer provided in the flow-type metal-air battery according to the first embodiment. [Figure 7] It is a cross-sectional view schematically illustrating each discharge cell and negative electrode liquid provided in the flow-type metal-air battery according to the first embodiment. [Figure 8] It is an enlarged top view schematically illustrating a portion near a straight section of a flow path of the negative electrode flow path layer, of the negative electrode flow path layer provided in the flow-type metal-air battery according to the first embodiment. [Figure 9] It is an enlarged cross-sectional view schematically illustrating a portion near a straight section of a flow path of the negative electrode flow path layer, of the negative electrode flow path layer, the first structure and the second structure provided in the flow-type metal-air battery according to the first embodiment. [Figure 10] It is an enlarged cross-sectional view schematically illustrating a portion near a straight section of a flow path of the negative electrode flow path layer, of the negative electrode flow path layer, the first structure and the second structure provided in the flow-type metal-air battery according to the first embodiment. [Figure 11] It is an enlarged top view schematically illustrating a portion near a curved section of a flow path of the negative electrode flow path layer, of the negative electrode flow path layer provided in the flow-type metal-air battery according to the first embodiment. [Figure 12] It is an enlarged cross-sectional view schematically illustrating a portion near a curved section of a flow path of the negative electrode flow path layer, of the negative electrode flow path layer, the first structure and the second structure provided in the flow-type metal-air battery according to the first embodiment. [Figure 13] It is an enlarged perspective view schematically illustrating a portion near a straight section of a flow path of the negative electrode flow path layer, of the negative electrode flow path layer provided in the flow-type metal-air battery according to the second embodiment. [Figure 14] It is an enlarged cross-sectional view schematically illustrating a portion near a straight section of a flow path of the negative electrode flow path layer, of the negative electrode flow path layer, the first structure and the second structure provided in the flow-type metal-air battery according to the second embodiment. [Figure 15] It is an enlarged cross-sectional view schematically illustrating a portion near a straight section of a flow path of the negative electrode flow path layer, of the negative electrode flow path layer, the first structure and the second structure provided in the flow-type metal-air battery according to the third embodiment. [Figure 16]This is an enlarged cross-sectional view schematically illustrating the portion of the negative electrode flow channel layer, the first structure, and the second structure provided in the flow-type metal-air battery of the first modification of the third embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 17] This is an enlarged perspective view schematically illustrating the portion of the negative electrode flow channel layer in the flow-type metal-air battery of the fourth embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 18] This is an enlarged cross-sectional view schematically illustrating the portion of the negative electrode flow channel layer, the first structure, and the second structure provided in the flow-type metal-air battery of the fourth embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 19] This is an enlarged perspective view schematically illustrating the portion of the negative electrode flow channel layer in the flow-type metal-air battery of the fifth embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 20] This is an enlarged top view schematically illustrating the portion of the negative electrode flow channel layer in the flow-type metal-air battery of the fifth embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 21] This is an enlarged perspective view schematically illustrating the portion of the negative electrode flow channel layer in the flow-type metal-air battery of the sixth embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 22] This is an enlarged cross-sectional view schematically illustrating the portion of the negative electrode flow channel layer, the first structure, and the second structure provided in the flow-type metal-air battery of the sixth embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 23] This is an enlarged cross-sectional view schematically illustrating the portion of the negative electrode flow channel layer, the first structure, and the second structure provided in the flow-type metal-air battery of the sixth embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 24] This is an enlarged perspective view schematically illustrating the portion of the negative electrode flow channel layer in the flow-type metal-air battery of the seventh embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 25]This is an enlarged cross-sectional view schematically illustrating the portion of the negative electrode flow channel layer, the first structure, and the second structure provided in the flow-type metal-air battery of the seventh embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 26] This is an enlarged perspective view schematically illustrating the portion of the negative electrode flow channel layer in the flow-type metal-air battery of the eighth embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 27] This is an enlarged cross-sectional view schematically illustrating the portion of the negative electrode flow channel layer, the first structure, and the second structure provided in the flow-type metal-air battery of the eighth embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 28] This is an enlarged perspective view schematically illustrating the portion of the negative electrode flow channel layer in the flow-type metal-air battery of the ninth embodiment, near the straight section of the flow channel of the negative electrode flow channel layer. [Figure 29] This figure schematically illustrates a flow-type metal-air battery according to the tenth embodiment. [Modes for carrying out the invention]

[0011] The embodiments of this disclosure will be described below with reference to the drawings. In the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[0012] 1. First Embodiment 1.1 Flow-type metal-air battery Figure 1 is a schematic diagram illustrating a flow-type metal-air battery according to the first embodiment.

[0013] The flow-type metal-air battery 1 of the first embodiment, as illustrated in Figure 1, absorbs oxygen gas OG1 from the surrounding air when discharging. When the flow-type metal-air battery 1 is being charged, it releases oxygen gas OG2 into the surrounding air.

[0014] In the first embodiment, the flow-type metal-air battery 1 is a flow-type zinc-air battery. Therefore, the negative electrode active material in the flow-type metal-air battery 1 is zinc. However, the flow-type metal-air battery 1 may be a flow-type metal-air battery other than a flow-type zinc-air battery. Therefore, the negative electrode active material in the flow-type metal-air battery 1 may be a metal other than zinc. Examples of metals other than zinc include cadmium, lithium, sodium, magnesium, lead, tin, aluminum, or iron. The metal constituting the metal species may consist only of the main component metal, or it may consist of an alloy of the main component metal and minor components. The metal species can be either a metal or an oxide. Whether the metal species becomes a metal or an oxide is determined according to the progress of the discharge reaction or the charge reaction.

[0015] As shown in Figure 1, the flow-type metal-air battery 1 comprises a storage unit 11, a charging unit 12, a discharge unit 13, a negative electrode liquid 14, and a positive electrode liquid 15.

[0016] 1.2 Live parts The negative electrode liquid 14 flows into the charging unit 12 from the storage unit 11. The charging unit 12 involves the incoming negative electrode liquid 14 in a charging reaction that regenerates the negative electrode liquid 14, and then discharges the negative electrode liquid 14 that has been involved in the charging reaction back into the storage unit 11. The charging unit 12 involves the negative electrode active material ions contained in the negative electrode liquid 14 in the charging reaction, reducing the negative electrode active material ions, generating reduced negative electrode active material particles, and producing oxygen gas OG2. The charging unit 12 exhausts the generated oxygen gas OG2 into the air surrounding the charging unit 12.

[0017] As shown in Figure 1, the charging unit 12 includes piping 101, pump 102, piping 103, piping 104, pump 105, piping 106, power supply 107, charging stack 108, piping 109, and piping 110.

[0018] The piping 101 guides the negative electrode liquid 14 from the outlet 11a of the storage unit 11 to the inlet 102a of the pump 102. In this way, the piping 101 allows the negative electrode liquid 14 that has flowed out from the outlet 11a to flow into the inlet 102a.

[0019] Pump 102 causes the negative electrode fluid 14 that has flowed into its inlet 102a to flow out through its outlet 102b. In doing so, pump 102 generates a flow of negative electrode fluid 14. As a result, pump 102 sends the negative electrode fluid 14 from the storage unit 11 to the charging stack 108.

[0020] The piping 103 guides the negative electrode fluid 14 from the outlet 102b of the pump 102 to the inlet 108a of the charging stack 108. In this way, the piping 103 allows the negative electrode fluid 14 that has flowed out from the outlet 102b to flow into the inlet 108a.

[0021] The piping 104 guides the cathode fluid 15 from a supply source (not shown) to the inlet 105a of the pump 105. In this way, the piping 104 allows the cathode fluid 15 that has flowed out of the supply source to flow into the inlet 105a.

[0022] Pump 105 causes the cathode liquid 15 that has flowed into its inlet 105a to flow out through its outlet 105b. In doing so, pump 105 generates a flow of cathode liquid 15. As a result, pump 105 delivers cathode liquid 15 from its supply source to the charging stack 108.

[0023] The piping 106 guides the cathode liquid 15 from the outlet 105b of the pump 105 to the inlet 108b of the charging stack 108. In this way, the piping 106 allows the cathode liquid 15 that has flowed out from the outlet 105b to flow into the inlet 108b.

[0024] Power supply 107 inputs charging power to the charging stack 108.

[0025] The charging stack 108 discharges the negative electrode liquid 14 that has flowed into the inlet 108a of the charging stack 108 from the outlet 108c of the charging stack 108, and discharges the positive electrode liquid 15 that has flowed into the inlet 108b of the charging stack 108 from the outlet 108d of the charging stack 108. At the same time, the charging stack 108 involves the incoming negative electrode liquid 14 and positive electrode liquid 15 in a charging reaction caused by the charging power, discharges the negative electrode liquid 14 that has participated in the charging reaction from the outlet 108c, discharges the positive electrode liquid 15 that has participated in the charging reaction from the outlet 108d, and exhausts the oxygen gas OG2 generated by the charging reaction from the outlet 108d.

[0026] The piping 109 guides the negative electrode fluid 14 from the outlet 108c of the charging stack 108 to the inlet 11b of the storage unit 11. In this way, the piping 109 allows the negative electrode fluid 14 that has flowed out from the outlet 108c to flow into the inlet 11b.

[0027] The piping 110 guides the cathode liquid 15 from the outlet 108d of the charging stack 108 to the source of the cathode liquid 15. In this way, the piping 110 allows the cathode liquid 15 that has flowed out from the outlet 108d to flow into the source of the cathode liquid 15.

[0028] 1.3 Discharge section Oxygen gas OG1 contained in the air surrounding the discharge section 13 flows into the discharge section 13. Negative electrode liquid 14 flows into the discharge section 13 from the storage section 11. The discharge section 13 involves the incoming oxygen gas OG1 and negative electrode liquid 14 in a discharge reaction that generates discharge power, and then discharges the negative electrode liquid 14 that has been involved in the discharge reaction back to the storage section 11. The discharge section 13 involves the reduced negative electrode active material particles contained in the oxygen gas OG1 and negative electrode liquid 14 in the discharge reaction, oxidizing the reduced negative electrode active material particles and generating negative electrode active material ions.

[0029] As shown in Figure 1, the discharge section 13 includes piping 121, a pump 122, piping 123, a discharge stack 124, and piping 125.

[0030] The piping 121 guides the negative electrode liquid 14 from the outlet 11c of the storage unit 11 to the inlet 122a of the pump 122. In this way, the piping 121 allows the negative electrode liquid 14 that has flowed out from the outlet 11c to flow into the inlet 122a.

[0031] Pump 122 causes the negative electrode fluid 14 that has flowed into its inlet 122a to flow out through its outlet 122b. In doing so, pump 122 generates a flow of negative electrode fluid 14. As a result, pump 122 sends the negative electrode fluid 14 from the storage unit 11 to the discharge stack 124.

[0032] The piping 123 guides the negative electrode fluid 14 from the outlet 122b of the pump 122 to the inlet 124a of the discharge stack 124. In this way, the piping 123 allows the negative electrode fluid 14 that has flowed out from the outlet 122b to flow into the inlet 124a.

[0033] The discharge stack 124 discharges the negative electrode liquid 14 that has flowed into the inlet 124a of the discharge stack 124 from the outlet 124c of the discharge stack 124. The discharge stack 124 draws in air from around the discharge section 13 through the intake port 124b of the discharge stack 124, absorbs oxygen gas OG1 contained in the drawn-in air, and exhausts the air that has absorbed oxygen gas OG1 through the exhaust port 124d of the discharge stack 124. At the same time, the discharge stack 124 involves the negative electrode liquid 14 that has flowed into the inlet 124a of the discharge stack 124 and the absorbed oxygen gas OG1 in the discharge reaction, and discharges the negative electrode liquid 14 that has been involved in the discharge reaction from the outlet 124c. The discharge stack 124 outputs the discharge power generated by the discharge reaction.

[0034] The piping 125 guides the negative electrode fluid 14 from the outlet 124c of the discharge stack 124 to the inlet 11d of the storage unit 11. In this way, the piping 125 allows the negative electrode fluid 14 that has flowed out from the outlet 124c to flow into the inlet 11d.

[0035] 1.4 Negative electrode solution Figure 2 is an enlarged cross-sectional view schematically illustrating the negative electrode fluid provided in the flow-type metal-air battery of the first embodiment.

[0036] As shown in Figure 2, the negative electrode solution 14 contains reduced negative electrode active material particles 141, oxidized negative electrode active material particles 142, negative electrode active material ions 143, and an electrolyte 144. The reduced negative electrode active material particles 141 and the oxidized negative electrode active material particles 142 are solid negative electrode active materials.

[0037] As described above, in the first embodiment, the flow-type metal-air battery 1 is a flow-type zinc-air battery. Therefore, the negative electrode active material particles 141 in the reduced state, the negative electrode active material particles 142 in the oxidized state, and the negative electrode active material ions 143 are zinc species. The negative electrode active material particles 141 in the reduced state are metallic zinc (Zn) particles. The negative electrode active material particles 142 in the oxidized state are zinc oxide (ZnO) particles. The negative electrode active material particles 141 in the reduced state and the negative electrode active material particles 142 in the oxidized state are dispersed in the electrolyte 144. Therefore, the negative electrode solution 14 is a slurry. The negative electrode active material particles 141 in the reduced state have a particle size of, for example, several μm. The negative electrode active material particles 142 in the oxidized state have a particle size of, for example, several tens to several hundreds of nm. The negative electrode active material ions 143 are zincate ions (Zn(OH)4) 2- The negative electrode active material ions 143 are dissolved in the electrolyte 144.

[0038] The electrolyte 144 may be either an aqueous solution or a solution other than an aqueous solution, but preferably it is an aqueous solution having high ionic conductivity, and more preferably it is an aqueous potassium hydroxide solution having high ionic conductivity.

[0039] The negative electrode active material ions 143 are reactants of the charging reaction occurring in the charging stack 108 and products of the discharge reaction occurring in the discharge stack 124. The reduced negative electrode active material particles 141 are products of the charging reaction occurring in the charging stack 108 and reactants of the discharge reaction occurring in the charging stack 108.

[0040] 1.5 Positive electrode solution Figure 3 is an enlarged cross-sectional view schematically illustrating the cathode solution provided in the flow-type metal-air battery of the first embodiment.

[0041] As illustrated in Figure 3, the positive electrode liquid 15 contains an electrolyte solution 161.

[0042] The electrolyte solution 161 may be either an aqueous solution or a solution other than an aqueous solution, but is preferably an aqueous solution having high ionic conductivity, and more preferably an aqueous potassium hydroxide solution having high ionic conductivity.

[0043] 1.6 Charging Reaction At the negative electrode of the charging stack 108, negative electrode reactions represented by formula (1) and formula (2) occur.

[0044] ZnO+H2O+2OH - →Zn(OH)4 2- (1) Zn(OH)4 2- +2e - →Zn+4OH - (2)

[0045] At the positive electrode of the charging stack 108, a positive electrode reaction represented by formula (3) occurs.

[0046] 4OH - →O2+2H2O+4e - (3)

[0047] Due to the negative electrode reactions represented by formula (1) and formula (2) and the positive electrode reaction represented by formula (3), a charging reaction represented by formula (4) occurs in the charging stack 108.

[0048] 2ZnO→2Zn+O2(4)

[0049] 1.7 Discharging Reaction At the negative electrode of the discharging stack 124, negative electrode reactions represented by formula (5) and formula (6) occur.

[0050] Zn+4OH - →Zn(OH)4 2- +2e - (5) Zn(OH)4 2-→ZnO+H2O+2OH - (6)

[0051] At the positive electrode of the discharge stack 124, the positive electrode reaction represented by equation (7) occurs.

[0052] O2 + 2H2O + 4e - →4OH - (7)

[0053] Due to the negative electrode reactions represented by equations (5) and (6), and the positive electrode reaction represented by equation (7), a discharge reaction represented by equation (8) occurs in the discharge stack 124.

[0054] 2Zn + O2 → 2ZnO (8)

[0055] 1.8 rechargeable cells The charging stack 108 comprises multiple charging cells. The multiple charging cells are stacked. The charging stack 108 may be replaced with a single charging cell.

[0056] Figure 4 is a schematic cross-sectional view illustrating each charging cell, negative electrode fluid, and positive electrode fluid provided in the flow-type metal-air battery of the first embodiment. Figures 5 and 6 are schematic perspective views illustrating the negative electrode flow channel layer provided in the flow-type metal-air battery of the first embodiment.

[0057] As shown in Figures 4 to 6, each charging cell 201 provided in the charging stack 108 comprises an insulating member 221, a sealing portion 222, a negative electrode 223, a sealing portion 224, a negative electrode flow channel layer 225, a sealing portion 226, a separator 227, a sealing portion 228, a positive electrode flow channel layer 229, a sealing portion 230, and a positive electrode 231.

[0058] The insulating member 221 has a frame-like shape. Therefore, an opening 221a is formed in the insulating member 221. The opening 221a is formed in the center of the insulating member 221. The opening 221a has a first recess 221b, a second recess 221c, and a third recess 221d. The insulating member 221 has a first main surface 221i and a second main surface 221j. The first main surface 221i and the second main surface 221j are on opposite sides. The first recess 221b is formed on the side of the first main surface 221i. The second recess 221c is formed on the side of the second main surface 221j. The first recess 221b and the second recess 221c are connected to each other between the first main surface 221i and the second main surface 221j. The first recess 221b has a planar shape smaller than the planar shape of the second recess 221c. The insulating member 221 has a facing surface 221k on the outer edge of the first recess 221b. The facing surface 221k faces the edge of the back surface 223j of the negative electrode 223. The third recess 221d is formed on the facing surface 221k. The first recess 221b has a shape that conforms to the shape of the positive electrode 231. The second recess 221c has a shape that conforms to the shape of the negative electrode 223. The third recess 221d has a shape that conforms to the shape of the sealing portion 222. The third recess 221d is a groove with an annular shape.

[0059] The insulating member 221 is made of an insulator.

[0060] The sealing portion 222 has an annular shape. The sealing portion 222 fits into the third recess 221d. The sealing portion 222 is sandwiched between the insulating member 221 and the negative electrode 223. The sealing portion 222 is made of an elastic material such as rubber. As a result, the sealing portion 222 seals the space between the insulating member 221 and the negative electrode 223.

[0061] The sealing portion 222 is made of an insulator.

[0062] The negative electrode 223 has a plate-like shape. The negative electrode 223 has a negative electrode surface 223i and a back surface 223j. The negative electrode surface 223i and the back surface 223j are main surfaces on opposite sides.

[0063] The negative electrode 223 is fitted into the second recess 221c of the insulating member 221.

[0064] The negative electrode 93 is made of a conductor, such as a magnesium alloy or carbon.

[0065] The sealing portion 224 has the same planar shape as the negative electrode flow channel layer 225.

[0066] The sealing portion 224 is sandwiched between the composite of the insulating member 221, the sealing portion 222, and the negative electrode 223, and the negative electrode flow channel layer 225. The sealing portion 224 has a sheet-like shape. The sealing portion 224 is made of an elastic material such as rubber. As a result, the sealing portion 224 seals the space between the composite and the negative electrode flow channel layer 225.

[0067] The sealing portion 224 is made of an insulator.

[0068] The negative electrode channel layer 225 has a perforated plate shape. The negative electrode channel layer 225 has a first main surface 225i and a second main surface 225j. The first main surface 225i and the second main surface 225j are on opposite sides to each other.

[0069] A channel 225a is formed in the negative electrode channel layer 225. The channel 225a has an inlet channel 225b, a negative electrode chamber 225c, and an outlet channel 225d.

[0070] One end of the inflow channel 225b is connected to the inlet 108a of the charging stack 108 via the manifold of the charging stack 108. The other end of the inflow channel 225b is connected to one end of the negative electrode chamber 225c. As a result, the negative electrode fluid 14 flowing into the negative electrode chamber 225c flows through the inflow channel 225b. The other end of the negative electrode chamber 225c is connected to one end of the outflow channel 225d. The other end of the outflow channel 225d is connected to the outlet 108c of the charging stack 108 via the manifold of the charging stack 108. As a result, the negative electrode fluid 14 flowing out from the negative electrode chamber 225c flows through the outflow channel 225d. As a result, the negative electrode liquid 14 flows into one end of the inflow channel 225b, flows through the inflow channel 225b from one end to the other end, flows through the negative electrode chamber 225c from one end to the other end, flows through the outflow channel 225d from one end to the other end, and flows out from the other end of the outflow channel 225d.

[0071] The flow path 225a has a straight section 225p, a curved section 225q, a straight section 225r, a curved section 225s, a curved section 225t, and a straight section 225u.

[0072] The straight section 225p and the curved section 225q are located in the inflow channel 225b. The curved section 225q connects the end of the straight section 225p and the beginning of the first straight section 225r included in the multiple straight sections 225r, and bends at 90°. The multiple straight sections 225r and the multiple curved sections 225s are located in the negative electrode chamber 225c. The multiple straight sections 225r are parallel to each other. Each curved section 225s included in the multiple curved sections 225s connects the end of one straight section 225r included in the multiple straight sections 225r and the beginning of another straight section 225r included in the multiple straight sections 225r that is adjacent to that one straight section 225r, and bends at 180°. Therefore, the negative electrode chamber 225c has a zigzag shape. The curved section 225t and the straight section 225u are located in the outflow channel 225d. The curved section 225t connects the end of the last straight section 225r and the beginning of the straight section 225u, which are included in a group of straight sections 225r, and makes a 90° turn.

[0073] As shown in Figures 5 and 6, the negative electrode channel layer 225 comprises a negative electrode channel layer body 241 and a plurality of raised sections 242.

[0074] Multiple risers 242 are positioned near curved sections 225q, 225s, and 225t, and are located below the vertical DV of the flow path 225a. The multiple risers 242 locally narrow the flow path 225a. Minimum power generation is possible even when the flow-type metal-air battery 1 is tilted at 90°. For this reason, the configuration is not limited to the multiple risers 242 being positioned below the vertical DV of the flow path 225a.

[0075] The negative electrode channel layer 225 is made of an insulator.

[0076] The sealing portion 226 is sandwiched between the negative electrode flow channel layer 225 and the separator 227. The sealing portion 226 has a sheet-like shape. The sealing portion 226 is made of an elastic material such as rubber. As a result, the sealing portion 226 seals the space between the negative electrode flow channel layer 225 and the separator 227.

[0077] The sealing portion 226 is made of an insulator.

[0078] The separator 227 has a sheet-like shape. The separator 227 is sandwiched between the sealing portion 226 and the sealing portion 228 and is positioned between the negative electrode flow channel layer 225 and the positive electrode flow channel layer 229. The separator 227 separates the negative electrode chamber 225c of the negative electrode flow channel layer 225 from the positive electrode chamber 229c of the positive electrode flow channel layer 229. The separator 227 faces the negative electrode 223 across the negative electrode chamber 225c and faces the positive electrode 231 across the positive electrode chamber 229c.

[0079] The separator 227 suppresses the permeation of reduced negative electrode active material particles 141, oxidized negative electrode active material particles 142, and negative electrode active material ions 143. As a result, the separator 227 suppresses the movement of reduced negative electrode active material particles 141, oxidized negative electrode active material particles 142, and negative electrode active material ions 143 from the negative electrode liquid 14 to the positive electrode liquid 15.

[0080] Separator 227 contains hydroxide ions (OH). - It allows the hydroxide ions OH to pass through. As a result, separator 227 is able to pass them through. - This allows the liquid to move from the negative electrode liquid 14 to the positive electrode liquid 15.

[0081] The sealing portion 228 is sandwiched between the separator 227 and the positive electrode flow channel layer 229. The sealing portion 228 has a sheet-like shape. The sealing portion 228 is made of an elastic material such as rubber. As a result, the sealing portion 228 seals the space between the separator 227 and the positive electrode flow channel layer 229.

[0082] The sealing portion 228 is made of an insulator.

[0083] The positive electrode channel layer 229 has a perforated plate-like shape.

[0084] A positive electrode chamber 229c is formed in the positive electrode channel layer 229.

[0085] The positive electrode channel layer 229 is made of an insulator.

[0086] The sealing portion 230 is sandwiched between the positive electrode flow channel layer 229 and the positive electrode 231. The sealing portion 230 has a sheet-like shape. The sealing portion 230 is made of an elastic material such as rubber. As a result, the sealing portion 230 seals the space between the positive electrode flow channel layer 229 and the positive electrode 231.

[0087] The positive electrode 231 has a plate-like shape.

[0088] The positive electrode 231 is made of a conductor, such as carbon or nickel.

[0089] The positive electrode 231 is positioned in the first recess 221b of the insulating member 221 provided in the adjacent charging cell 201 if there is an adjacent charging cell 201 located vertically above the charging cell 201 in the DV direction.

[0090] Each charging cell 201 may have a structure different from the structure shown in Figure 4.

[0091] 1.9 Discharge Cell The discharge stack 124 comprises multiple discharge cells. The multiple discharge cells are stacked. The discharge stack may be replaced with a single discharge cell.

[0092] Figure 7 is a schematic cross-sectional view illustrating each discharge cell and negative electrode fluid provided in the flow-type metal-air battery of the first embodiment.

[0093] As shown in Figure 7, each discharge cell 301 provided in the discharge stack 124 has a structure in which the sealing portion 228, positive electrode flow channel layer 229, sealing portion 230, and positive electrode 231 provided in each charging cell 201 are replaced with a positive electrode 321, sealing portion 322, and positive electrode flow channel layer 323.

[0094] Each discharge cell 301 is provided with a negative electrode 223 made of a conductor, such as carbon, titanium, or nickel.

[0095] The positive electrode 321 has a plate-like shape.

[0096] The positive electrode 321 faces the negative electrode chamber 225c of the negative electrode flow channel layer 225 via the separator 227.

[0097] The positive electrode 321 includes a catalytic material and a conductive material. The catalytic material promotes the oxygen reduction reaction. The catalytic material is manganese dioxide, etc. The conductive material has conductivity. The conductive material is carbon, etc.

[0098] The sealing portion 322 is sandwiched between the combined separator 227 and positive electrode 321 and the positive electrode flow channel layer 323. The sealing portion 322 has a sheet-like shape. The sealing portion 322 is made of an elastic material such as rubber. As a result, the sealing portion 322 seals the space between the combined separator 227 and positive electrode 321 and the positive electrode flow channel layer 323.

[0099] The sealing portion 322 is made of an insulator.

[0100] The positive electrode channel layer 323 has a plate-like shape.

[0101] A positive electrode chamber 323c is formed in the positive electrode flow channel layer 323.

[0102] The positive electrode channel layer 323 is made of a conductor.

[0103] Each discharge cell 301 may have a structure different from the structure shown in Figure 7.

[0104] 1.10 Protruding parts in straight sections Figure 8 is an enlarged top view schematically illustrating the portion of the negative electrode channel layer in the flow-type metal-air battery of the first embodiment, near the straight section of the channel. Figures 9 and 10 are enlarged cross-sectional views schematically illustrating the portions of the negative electrode channel layer, the first structure, and the second structure in the flow-type metal-air battery of the first embodiment, near the straight section of the channel. Figure 9 shows a cross-section at the position of the cutting line IX-IX drawn in Figure 8. Figure 10 shows a cross-section at the position of the cutting line XX drawn in Figure 8.

[0105] The first structure 401 and the second structure 402, as shown in Figures 9 and 10, are separated from each other in the vertical direction DV and face each other across the flow path 225a. The first structure 401 is located below the vertical direction DV. The second structure 402 is located above the vertical direction DV. Therefore, the flow path 225a is above the vertical direction DV of the first structure 401. The second structure 402 is above the vertical direction DV of the flow path 225a.

[0106] In the straight sections 225p and 225u, the first structure 401 is an insulating member 221, and the second structure 402 is a sealing portion 226. In the straight section 225r, the first structure 401 is a negative electrode 223, and the second structure 402 is a separator 227. If the sealing portion 226, separator 227, and sealing portion 228 are cut along the flow path 225a, the second structure 402 may be a positive electrode flow path layer 402.

[0107] As shown in Figures 8 to 10, the negative electrode channel layer 225 has walls 421 and 422.

[0108] The flow path 225a is demarcated by wall surface 421, wall surface 422, the upper surface of the first structure 401, and the lower surface of the second structure 402. The flow path 225a extends in the flow direction DF. The flow direction DF is parallel to the horizontal direction and parallel to the spreading direction of the negative electrode flow path layer 225. The negative electrode liquid 14 flowing through the flow path 225a flows from the upstream side of the flow direction DF to the downstream side of the flow direction DF. Wall surfaces 421 and 422 are parallel to each other, perpendicular to the horizontal direction, and separated from each other in the horizontal direction. Wall surfaces 421 and 422 are separated from each other in the width direction DW of the flow path 225a. The upper surface of the first structure 401 and the lower surface of the second structure 402 are parallel to each other, perpendicular to the vertical direction DV, and separated from each other in the vertical direction DV.

[0109] The negative electrode liquid 14 contains solid negative electrode active material. Therefore, when the negative electrode liquid 14 flows through the channel 225a, deposits consisting of solid negative electrode active material may accumulate in the channel 225a. These deposits tend to accumulate near the walls 421 and 422, and also tend to accumulate on the upper surface of the first structure 401.

[0110] As shown in Figures 5, 6 and 8 through 10, in the straight sections 225p, 225r, and 225u, the negative electrode flow channel layer 225 is provided with a plurality of first protrusions 441 and a plurality of second protrusions 442.

[0111] The multiple first protrusions 441 are arranged in the flow direction DF and are spaced apart from each other in the flow direction DF.

[0112] Each of the multiple first protrusions 441 has a plate-like shape. Therefore, each first protrusion 441 has a first surface 441a and a second surface 441b. The first surface 441a and the second surface 441b are main surfaces on opposite sides. The first surface 441a and the second surface 441b face the upstream and downstream sides, respectively, of the flow direction DF. The first surface 441a and the second surface 441b have a normal direction parallel to the horizontal direction.

[0113] The plate end of each first projection 441 is connected to the wall surface 421. Each first projection 441 protrudes from the wall surface 421. Each first projection 441 protrudes horizontally from the wall surface 421 and protrudes perpendicular to the wall surface 421. Therefore, each first projection 441 protrudes from the wall surface 421 in a direction perpendicular to the flow path direction DF.

[0114] The multiple second protrusions 442 are arranged in the flow direction DF and are spaced apart from each other in the flow direction DF.

[0115] Each of the multiple second projections 442 has a plate-like shape. Therefore, each second projection 442 has a first surface 442a and a second surface 442b. The first surface 442a and the second surface 442b are main surfaces on opposite sides. The first surface 442a and the second surface 442b face the upstream and downstream sides, respectively, of the flow direction DF. The first surface 442a and the second surface 442b have a normal direction parallel to the horizontal direction.

[0116] The plate end of each second projection 442 is connected to the wall surface 422. Each second projection 442 protrudes from the wall surface 422. Each second projection 442 protrudes horizontally from the wall surface 422 and protrudes perpendicular to the wall surface 422. Therefore, each second projection 442 protrudes from the wall surface 422 in a direction perpendicular to the flow path direction DF. Each second projection 442 protrudes in the opposite direction to the direction in which each first projection 441 protrudes.

[0117] The negative electrode fluid 14 flowing through the channel 225a strikes each of the first protrusions 441 and each of the second protrusions 442. This creates a flow FL of negative electrode fluid 14 from the vicinity of the wall surfaces 421 and 422 toward the center of the channel 225a in the width direction DW. In addition, a vortex VR is formed along the wall surfaces 421 and 422 by the flow FL of negative electrode fluid 14. This allows the deposits accumulated near the wall surfaces 421 and 422 to be moved toward the center of the channel 225a in the width direction DW. This effectively removes the deposits. This prevents the channel 225a from being blocked by the deposits. In addition, a flow FL of negative electrode fluid 14 that dips downwards is also formed. This prevents deposits from accumulating near the base of each of the first protrusions 441 and each of the second protrusions 442.

[0118] The multiple first protrusions 441 and the multiple second protrusions 442 are arranged symmetrically with respect to a plane that is parallel to the wall surfaces 421 and 422 and is the same distance away from the wall surfaces 421 and 422. Therefore, the multiple second protrusions 442 are each arranged in the same position as the multiple first protrusions 441 with respect to the flow path direction DF. When the first protrusions 441 and the second protrusions 442 are arranged in the same position in this way, the flow path 225a can be narrowed locally by the first protrusions 441 and the second protrusions 442 compared to when the first protrusions 441 and the second protrusions 442 are arranged in different positions. This greatly increases the effect of changing the flow FL of the negative electrode liquid 14.

[0119] The first protrusion 441 and the second protrusion 442, which are located at the same position in the flow direction DF, are spaced apart from each other in the width direction DW of the flow path 225a.

[0120] The first structure 401 and each first protrusion 441 are separated from each other in the vertical direction DV. This creates a first gap 481 between the first structure 401 and each first protrusion 441. This creates a flow FL of negative electrode liquid 14 passing through the first gap 481 toward the upper surface of the first structure 401, and the formed flow FL creates a vortex VR. This effectively removes the deposits accumulated on the upper surface of the first structure 401. This prevents the flow path 225a from being blocked by the deposits.

[0121] The first structure 401 and each second protrusion 442 are separated from each other in the vertical direction DV. This creates a second gap 482 between the first structure 401 and each second protrusion 442. This creates a flow FL of negative electrode liquid 14 passing through the second gap 482 toward the upper surface of the first structure 401, and the formed flow FL creates a vortex VR. This effectively removes the deposits accumulated on the upper surface of the first structure 401. This prevents the flow path 225a from being blocked by the deposits.

[0122] The bottom of each first projection 441 faces the first structure 401. The distance in the vertical direction DV between the bottom of each first projection 441 and the first structure 401 is constant.

[0123] The bottom of each second projection 442 faces the first structure 401. The distance in the vertical direction DV between the bottom of each first projection 441 and the first structure 401 is constant.

[0124] Each first projection 441 contacts the second structure 402. Therefore, no gap is formed between each first projection 441 and the second structure 402.

[0125] Each second projection 442 contacts the second structure 402. Therefore, no gap is formed between each second projection 442 and the second structure 402.

[0126] 1.11 Protruding parts in curved sections Figure 11 is an enlarged top view schematically illustrating the portion of the negative electrode channel layer in the flow-type metal-air battery of the first embodiment, near the curved section of the channel. Figure 12 is an enlarged cross-sectional view schematically illustrating the portions of the negative electrode channel layer, the first structure, and the second structure in the flow-type metal-air battery of the first embodiment, near the curved section of the channel.

[0127] The following explains how the portions of the negative electrode flow channel layer 225 near curved sections 225q, 225t, and 225s differ from the portions of the negative electrode flow channel layer 225 near straight sections 225p, 225r, and 225u.

[0128] In curved sections 225q and 225t, the first structure 401 is an insulating member 221 or a raised section 242, and the second structure 402 is a sealing section 226. In curved section 225s, the first structure 401 is a negative electrode 223, and the second structure 402 is a separator 227.

[0129] In curved sections 225q, 225s, and 225t, as shown in Figure 11, the first wall surface, which is one of the wall surfaces 421 and 422, is the outer periphery wall surface, and the second wall surface, which is the other of the wall surfaces 421 and 422, is the inner periphery wall surface.

[0130] As shown in Figure 11, in curved sections 225q, 225s, and 225t, the negative electrode flow channel layer 225 has a plurality of first protrusions 441 that protrude from the first wall surface, which is one of the wall surfaces 421 and 422, but does not have any protrusions that protrude from the second wall surface, which is the other of the wall surfaces 421 and 422. This prevents the protrusions that protrude from the inner circumferential wall surface from becoming too dense. By preventing excessive density, it is possible to prevent stagnation of the negative electrode liquid 14 flow. If the protrusions are too dense, vortices VR will not be formed properly, and the protrusions will simply become flow resistance, which may slow down the flow velocity and promote deposition. Also, since the flow is fast on the inside, even a low density of protrusions is sufficient to suppress deposition.

[0131] 1.12 Size of the protruding part When the flow rate of the negative electrode liquid 14 was 50 mL / min, the effect of removing sediment was obtained even when the thickness t of each first protrusion 441 and each second protrusion 442 (see Figure 8) was varied within the range of 1.0 to 1.5 mm. Furthermore, when the protrusion length L of each first protrusion 441 and each second protrusion 442 (see Figure 8) was set to 2 mm, the effect of removing sediment was sometimes not obtained, but when the protrusion length L was set to 3 mm, the effect of removing sediment was obtained. In addition, when the spacing Δ between multiple first protrusions 441 and multiple second protrusions 442 (see Figure 8) was 10 mm or more, the effect of removing sediment tended to decrease. However, the spacing Δ at which the effect of removing sediment tended to decrease depended on the flow rate of the negative electrode liquid 14. Furthermore, when the thickness of the negative electrode channel layer 225 was set to 4 mm, the effect of removing deposits was obtained even when the depth D of each first protrusion 441 and the depth D of each second protrusion 442 (see Figure 9) were varied within the range of 2.5 to 3.0 mm. From these findings, it can be understood that the protrusion length L of each first protrusion 441 and the protrusion length L of each second protrusion 442 have a significant impact on the effect of removing deposits. From this, it can be understood that it is important to guide the supernatant of the negative electrode liquid 14 toward the solid negative electrode active material sliding on the first structure 401.

[0132] 2. Second Embodiment The following describes the differences between the second embodiment and the first embodiment. For aspects not described, the same configuration as that used in the first embodiment is employed in the second embodiment.

[0133] Figure 13 is an enlarged perspective view schematically illustrating the portion of the negative electrode channel layer in the flow-type metal-air battery of the second embodiment, near the straight section of the channel. Figure 14 is an enlarged cross-sectional view schematically illustrating the portions of the negative electrode channel layer, the first structure, and the second structure in the flow-type metal-air battery of the second embodiment, near the straight section of the channel.

[0134] In the flow-type metal-air battery of the second embodiment, as shown in Figures 13 and 14, the first protrusion 441 and the second protrusion 442 are connected to each other and constitute a single unit 501. This increases the strength of the first protrusion 441 and the second protrusion 442. This prevents the first protrusion 441 and the second protrusion 442 from being deformed or destroyed by the resistance of the negative electrode liquid 14, etc. When the first protrusion 441 and the second protrusion 442 are integrated, the recess 401a described later may not be necessary.

[0135] 3. Third Embodiment The differences between the third embodiment and the first embodiment will be explained below. For aspects not explained, the same configuration as that used in the first embodiment will be used in the third embodiment.

[0136] Figure 15 is an enlarged cross-sectional view schematically illustrating the portion of the negative electrode flow channel layer, the first structure, and the second structure provided in the flow-type metal-air battery of the third embodiment, near the straight section of the flow channel of the negative electrode flow channel layer.

[0137] In the flow-type metal-air battery of the third embodiment, as shown in Figure 15, a recess 401a is formed in the first structure 401. The recess 401a is located vertically DV below the flow path 225a. The recess 401a is connected to the flow path 225a. Therefore, the recess 401a and the flow path 225a constitute a path through which the negative electrode liquid 14 flows. By forming the recess 401a in the first structure 401, deposits accumulated near the wall surfaces 421 and 422 can be guided into the recess 401a. This prevents the flow path 225a from being blocked by the deposits. In addition, the contact area between the negative electrode liquid 14 and the negative electrode 223 can be increased. This improves the efficiency of charging and discharging. The bottom surface of the first structure 401, which is parallel to the width direction DW of the flow path 225a, and the vertical side surface DV of the wall surface 421 face the recess 401a.

[0138] The first projection 441 reaches the lower end of the wall surface 421 in the vertical direction DV. The second projection 442 reaches the lower end of the wall surface 422 in the vertical direction DV. If a recess 401a is formed in the first structure 401, even if the first projection 441 and the second projection 442 reach the lower ends of the wall surfaces 421 and 422, the first structure 401 and the first projection 441 can be separated from each other in the vertical direction DV, and the first structure 401 and the second projection 442 can be separated from each other in the vertical direction DV. For this reason, the wall surfaces 421 and 422 do not have to face the flow path 225a at the position in the flow path direction DF where the first projection 441 and the second projection 442 are arranged.

[0139] Figure 16 is an enlarged cross-sectional view schematically illustrating the portion of the negative electrode flow channel layer, the first structure, and the second structure provided in the first modified flow-type metal-air battery of the third embodiment, near the straight section of the flow channel of the negative electrode flow channel layer.

[0140] In the first modified example of the third embodiment, as shown in Figure 16, the arcuate surface faces the recess 401a.

[0141] 4. Fourth Embodiment The following describes the differences between the fourth embodiment and the first embodiment. For aspects not described, the fourth embodiment employs the same configuration as that used in the first embodiment.

[0142] Figure 17 is an enlarged perspective view schematically illustrating the portion of the negative electrode channel layer in the flow-type metal-air battery of the fourth embodiment, near the straight section of the channel. Figure 18 is an enlarged cross-sectional view schematically illustrating the portions of the negative electrode channel layer, the first structure, and the second structure in the flow-type metal-air battery of the fourth embodiment, near the straight section of the channel.

[0143] In the flow-type metal-air battery of the fourth embodiment, as shown in Figures 17 and 18, the corners on the lower side of the vertical DV at the tip of the first projection 441 and the corners on the lower side of the vertical DV at the tip of the second projection 442 are chamfered. As a result, a portion of the surface of the first projection 441 faces the first structure 401 and moves away from the first structure 401 as it moves away from the wall surface 421. A portion of the surface of the second projection 442 faces the first structure 401 and moves away from the first structure 401 as it moves away from the wall surface 422.

[0144] This creates a large opening in the center of the widthwise DW of the channel 225a. As a result, the flow FL of the negative electrode liquid 14 is more easily concentrated in the center of the widthwise DW of the channel 225a. This suppresses the accumulation of deposits near the walls 421 and 422.

[0145] 5. Fifth Embodiment The differences between the fifth embodiment and the fourth embodiment will be explained below. For aspects not explained, the same configuration as that used in the fourth embodiment will be used in the fifth embodiment.

[0146] Figure 19 is an enlarged perspective view schematically illustrating the portion of the negative electrode channel layer in the flow-type metal-air battery of the fifth embodiment, near the straight section of the channel. Figure 20 is an enlarged top view schematically illustrating the portion of the negative electrode channel layer in the flow-type metal-air battery of the fifth embodiment, near the straight section of the channel.

[0147] In the flow-type metal-air battery of the fifth embodiment, as shown in Figures 19 and 20, each first protrusion 441 protrudes in a direction inclined upstream of the flow direction DF from a direction perpendicular to the wall surface 421 of the negative electrode flow channel layer 225. Similarly, each second protrusion 442 protrudes in a direction inclined upstream of the flow direction DF from a direction perpendicular to the wall surface 422 of the negative electrode flow channel layer 225. As a result, when the negative electrode liquid 14 flows through the flow channel 225a, the pressure of the negative electrode liquid 14 increases near the base of the first protrusion 441 and the base of the second protrusion 442. This increases the flow rate FL of the negative electrode liquid 14 near the wall surfaces 421 and 422, and strengthens the vortex VR formed by the flow rate FL. This effectively removes deposits accumulated near the wall surfaces 421 and 422. Furthermore, as the flow progresses from the upstream side of the flow direction DF to the downstream side of the flow direction DF, a twisted flow FL of the negative electrode liquid 14 is formed, starting from the center of the width direction DW of the flow path 225a, approaching the walls 421 and 422 of the flow path 225a, and then moving from the walls 421 and 422 towards the center of the width direction DW of the flow path 225a. As a result, the solid negative electrode active material contained in the negative electrode liquid 14 is pushed towards the center of the width direction DW of the flow path 225a. This suppresses the accumulation of solid negative electrode active material near the walls 421 and 422.

[0148] The angle between each first protrusion 441 and the wall surface 421 of the negative electrode flow channel layer 225 is preferably 15° to 75°, more preferably 20° to 60°, and particularly preferably 30° to 45°. The angle between each second protrusion 442 and the wall surface 422 of the negative electrode flow channel layer 225 is also preferably 15° to 75°, more preferably 20° to 60°, and particularly preferably 30° to 45°. When the angle between each first protrusion 441 and each second protrusion 442 and the wall surface 421 of the negative electrode flow channel layer 225 is less than 90 degrees, it is desirable in that it does not obstruct the flow and generates stronger vortices than when the angle is 90 degrees or more. For example, if the angle between each first protrusion 441 and each second protrusion 442 and the wall surface 421 of the negative electrode flow channel layer 225 is 90 degrees, most of the flow will be lost to pressure. Note that the desirable range may vary depending on conditions such as the viscosity of the negative electrode fluid 14 being flowed.

[0149] 6. Sixth Embodiment The following describes the differences between the sixth embodiment and the fifth embodiment. For aspects not described, the sixth embodiment employs the same configuration as that used in the fifth embodiment.

[0150] Figure 21 is an enlarged perspective view schematically illustrating the portion of the negative electrode channel layer in the flow-type metal-air battery of the sixth embodiment, near the straight section of the channel. Figures 22 and 23 are enlarged cross-sectional views schematically illustrating the portions of the negative electrode channel layer, the first structure, and the second structure in the flow-type metal-air battery of the sixth embodiment, near the straight section of the channel.

[0151] In the flow-type metal-air battery of the sixth embodiment, as shown in Figures 21 to 23, the first surface 441a of each first projection 441 faces the upstream side of the flow path direction DF and has a normal direction that is inclined downward from the horizontal direction to the vertical direction DV. Also, the first surface 442a of each second projection 442 faces the upstream side of the flow path direction DF and has a normal direction that is inclined downward from the horizontal direction to the vertical direction DV.

[0152] If the first surface 441a of each first projection 441 has a normal direction parallel to the horizontal direction, the flow FL of the negative electrode fluid 14 will be significantly bent when it strikes the first surface 441a of each first projection 441. Similarly, if the first surface 442a of each second projection 442 has a normal direction parallel to the horizontal direction, the flow FL of the negative electrode fluid 14 will be significantly bent when it strikes the first surface 442a of each second projection 442. As a result, the pressure loss in the flow path 225a tends to increase, and stagnation of the negative electrode fluid 14 is likely to occur.

[0153] In contrast, if the first surface 441a of each first projection 441 has a normal direction inclined from the horizontal, it is possible to suppress the significant bending of the negative electrode fluid flow FL when it hits the first surface 441a of each first projection 441. Also, if the first surface 442a of each second projection 442 has a normal direction inclined from the horizontal, it is possible to suppress the significant bending of the negative electrode fluid flow FL when it hits the first surface 442a of each second projection 442. As a result, it is possible to suppress the pressure loss in the flow path 225a and to suppress the occurrence of stagnation of the negative electrode fluid 14.

[0154] 7 Seventh Embodiment The following describes the differences between the seventh embodiment and the sixth embodiment. For aspects not described, the seventh embodiment employs the same configuration as that used in the sixth embodiment.

[0155] Figure 24 is an enlarged perspective view schematically illustrating the portion of the negative electrode channel layer in the flow-type metal-air battery of the seventh embodiment, near the straight section of the channel. Figure 25 is an enlarged cross-sectional view schematically illustrating the portions of the negative electrode channel layer, the first structure, and the second structure in the flow-type metal-air battery of the seventh embodiment, near the straight section of the channel.

[0156] In the flow-type metal-air battery of the seventh embodiment, as shown in Figures 25 and 26, each first protrusion 441 and the second structure 402 are separated from each other in the vertical direction DV. As a result, a first gap 521 is formed between each first protrusion 441 and the second structure 402. Furthermore, each second protrusion 442 and the second structure 402 are separated from each other in the vertical direction DV. As a result, a second gap 522 is formed between each second protrusion 442 and the second structure 402.

[0157] When the first gap 521 and the second gap 522 are formed, bubbles that are mixed into the negative electrode liquid 14 and move along the lower surface of the second structure 402 can pass through the first gap 521 and the second gap 522. This prevents bubbles from accumulating in the flow path 225a.

[0158] The first gap 521 and the second gap 522 are close to the minimum size that allows bubbles to pass through. This makes it possible to suppress the accumulation of bubbles in the channel 225a while maintaining the effect of suppressing the accumulation of sediment on each of the first protrusions 441 and each of the second protrusions 442.

[0159] In the flow-type metal-air battery of the seventh embodiment, the entire top portion of each first protrusion 441 is separated from the second structure 402. Also, the entire second portion of each second protrusion 442 is separated from the second structure 402.

[0160] 8. Eighth Embodiment The differences between the eighth embodiment and the seventh embodiment will be explained below. For aspects not explained, the eighth embodiment employs the same configuration as that used in the seventh embodiment.

[0161] Figure 26 is an enlarged perspective view schematically illustrating the portion of the negative electrode channel layer in the flow-type metal-air battery of the eighth embodiment, near the straight section of the channel. Figure 27 is an enlarged cross-sectional view schematically illustrating the portions of the negative electrode channel layer, the first structure, and the second structure in the flow-type metal-air battery of the eighth embodiment, near the straight section of the channel.

[0162] In the flow-type metal-air battery of the eighth embodiment, as shown in Figures 26 and 27, only a portion of the top of each first protrusion 441 is separated from the second structure 402. Similarly, only a portion of the top of each second protrusion 442 is separated from the second structure 402. The portion of the top of each first protrusion 441 that is separated from the second structure 402 is located at the base of each first protrusion 441. The portion of the top of each second protrusion 442 that is separated from the second structure 402 is located at the base of each second protrusion 442.

[0163] 9. Ninth Embodiment The differences between the ninth embodiment and the eighth embodiment will be explained below. For aspects not explained, the ninth embodiment employs the same configuration as that used in the eighth embodiment.

[0164] Figure 28 is an enlarged perspective view schematically illustrating the portion of the negative electrode flow channel layer in the flow-type metal-air battery of the ninth embodiment, near the straight section of the flow channel in the negative electrode flow channel layer.

[0165] In the flow-type metal-air battery of the ninth embodiment, as shown in Figure 28, the first protrusion 441 and the second protrusion 442 are connected to each other and constitute a single unit 501. This increases the strength of the first protrusion 441 and the second protrusion 442. This prevents the first protrusion 441 and the second protrusion 442 from being deformed or destroyed by the resistance of the negative electrode liquid 14, etc.

[0166] Tenth Embodiment The differences between the tenth embodiment and the first embodiment will be explained below. For aspects not explained, the tenth embodiment employs the same configuration as that used in the first embodiment.

[0167] Figure 29 is a schematic diagram illustrating a flow-type metal-air battery according to the tenth embodiment.

[0168] The flow-type metal-air battery 10 of the tenth embodiment, shown in Figure 29, includes a controller 561.

[0169] The controller 561 can control pumps 102 and 122 to reverse the direction in which the negative electrode fluid 14 is delivered. Therefore, the controller 561, pumps 102 and 122 constitute a mechanism that can reverse the direction of flow of the negative electrode fluid 14 in the flow path 225a. This mechanism may be composed of elements other than the controller 561, pumps 102 and 122. For example, this mechanism may be composed of a four-way valve or the like.

[0170] If the flow direction of the negative electrode liquid 14 is reversed, the positions where vortices VR are formed will also be reversed, with each of the first protrusions 441 and each of the second protrusions 442 in between. Therefore, the accumulation of sediment can be suppressed more effectively.

[0171] This disclosure is not limited to the embodiments described above, and may be replaced with configurations that are substantially the same as those shown in the embodiments, configurations that produce the same effects, or configurations that can achieve the same purpose. [Explanation of Symbols]

[0172] 1. Flow-type metal-air battery 10 Flow-type metal-air batteries 11 Storage section 11a,11c Outlet 11b,11d Inlet 12 Live parts 13 Discharge section 14. Negative electrode solution 15 Positive electrode solution 101 Piping 102 pump 102a Inlet 102b Outlet 103,104 Piping 105 pump 105a Inlet 105b Outlet 106 Piping 107 Power supply 108 charging stack 108a,108b Inlet 108c,108d Outlet 108n Second manifold 109 Piping 110 Piping 121 Piping 122 pumps 122a Inlet 122b Outlet 123 Piping 124 Discharge Stack 124a Inlet 124c Outlet 124b Air intake 124d Exhaust port 125 Piping 141 Reduced state negative electrode active material particles 142 Anode active material particles in an oxidized state 143 Negative electrode active material ions 144 Electrolyte 161 Electrolyte 201 rechargeable cells 221 Insulating material 221a aperture 221b First recess 221c Second recess 221d Third recess 221i First principal surface 221j Second main surface 221k Opposite side 222 Sealing section 223 Negative electrode 223i negative side 223j back side 224 Sealing section 225 Negative electrode channel layer 225a Flow channel 225b Inflow channel 225c negative electrode chamber 225d Outlet channel 225i First main surface 225j Second main surface 225p, 225r, 225u straight section 225q, 225s, 225t curved section 226 Sealing part 227 Separator 228 Sealing section 229 Positive electrode channel layer 229c Positive electrode chamber 230 Sealing part 231 Positive electrode 241 Negative electrode channel layer body 242 Multiple raised sections 301 Each discharge cell 321 Positive electrode 322 Sealing part 323 Positive electrode channel layer 323c positive electrode chamber 401 First structure 401a Recess 402 Second structure 421,422 Wall surfaces 441 First projection 441a First surface 441b Second side 442 Second projection 442a First surface 442b Second side 481 The first gap 482 The second gap 501 One-piece 521 The first gap 522 The second gap 541 The First Heavenly Being 542 The Second Heavenly Being 561 Controller FL flow VR Vortex OG1, OG2 Oxygen Gas

Claims

1. The first structure and A flow channel layer located vertically above the first structure, having a flow channel through which a slurry flows, and having a first wall surface and a second wall surface facing each other on either side of the flow channel, and having a projection extending from the first wall surface, A second structure positioned vertically above the aforementioned flow path, A flow-type metal-air battery equipped with the following features.

2. The first structure and the protruding portion are separated from each other in the vertical direction. The flow-type metal-air battery according to claim 1.

3. A recess is formed in the first structure below the vertical DV of the flow path. The flow-type metal-air battery according to claim 2.

4. The protruding portion reaches the lower vertical end of the first wall surface. The flow-type metal-air battery according to claim 3.

5. The aforementioned protrusion is a first protrusion, The flow channel layer includes a second projection that protrudes from the second wall surface. The flow-type metal-air battery according to claim 1.

6. The first protrusion and the second protrusion constitute a single integrated object. The flow-type metal-air battery according to claim 5.

7. The part of the aforementioned integrated structure and the second structure are separated from each other in the vertical direction. The flow-type metal-air battery according to claim 6.

8. The second projection is positioned in the same location as the first projection in the flow direction. The flow-type metal-air battery according to claim 5.

9. A portion of the surface of the protruding part faces the first structure and moves away from the first wall surface as it moves away from the first structure. The flow-type metal-air battery according to claim 1.

10. The aforementioned protrusion extends in a direction that is inclined upstream of the flow path direction, from a direction perpendicular to the flow path direction. The flow-type metal-air battery according to claim 1.

11. The first wall surface and the protruding portion form an angle of 15° to 75°. The flow-type metal-air battery according to claim 10.

12. The first wall surface and the protruding portion form an angle of 20° to 60°. The flow-type metal-air battery according to claim 10.

13. The first wall surface and the protruding portion form an angle of 30° to 45°. The flow-type metal-air battery according to claim 10.

14. The aforementioned protruding portion faces the upstream side in the flow path direction and has a surface having a normal direction that is inclined downward from the horizontal direction in the vertical direction DV. The flow-type metal-air battery according to claim 1.

15. A portion of the surface of the protruding part faces the first structure and moves away from the first wall surface, and moves away from the first structure as it moves away from the first wall surface. The aforementioned protrusion extends in a direction that is inclined upstream of the flow path direction, from a direction perpendicular to the flow path direction. The flow-type metal-air battery according to claim 1.

16. A portion of the surface of the protruding part faces the first structure and moves away from the first wall surface, and moves away from the first structure as it moves away from the first wall surface. The aforementioned protruding portion extends in a direction inclined upstream of the flow path direction from a direction perpendicular to the flow path direction. The aforementioned protruding portion has a surface facing the upstream side in the flow path direction and having a normal direction that is inclined downward from the horizontal direction in the vertical direction DV. The flow-type metal-air battery according to claim 1.

17. The protruding portion and the second structure are separated from each other in the vertical direction. The flow-type metal-air battery according to claim 1.

18. The second structure is an insulator. The flow-type metal-air battery according to claim 1.

19. The second structure is a separator. The flow-type metal-air battery according to claim 1.

20. The first structure is a conductor. The flow-type metal-air battery according to claim 1.

21. The first structure is the negative electrode, The aforementioned flow path is a negative electrode chamber. The flow-type metal-air battery according to claim 1.

22. A negative electrode chamber is formed in the flow channel layer. The first structure is an insulator, The aforementioned flow path is either an inflow path through which slurry flows into the negative electrode chamber or an outflow path through which slurry flows out of the negative electrode chamber. The flow-type metal-air battery according to claim 1.

23. The flow channel layer includes the protruding portion and comprises a plurality of protruding portions that protrude from the first wall surface and are spaced apart from each other in the flow channel direction. The flow-type metal-air battery according to claim 1.

24. A mechanism for reversing the flow direction of the slurry. A flow-type metal-air battery according to any one of claims 1 to 23, comprising:

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