CN101577342A - Fuel cell with humidification zone of single cell - Google Patents

Abstract

A fuel cell with a unit cell humidification zone. This kind of fuel cell is composed of multiple monomers, each monomer includes a cathode flow field plate, an anode flow field plate, a seal and a membrane electrode. The membrane electrode is composed of a reaction zone and a humidification zone. The corresponding reaction zone and humidification zone are also included in the plate and the cathode flow field plate. After the cathode reaction air enters the fuel cell unit, it first passes through the humidification area of the cathode flow field plate, then enters the reaction area to participate in the electrochemical reaction, and then enters the humidification area of the anode flow field plate through the gas channel set on the membrane electrode. The water can pass through the proton exchange membrane in the membrane electrode humidification area to humidify the intake air. The invention directly uses air tail gas to humidify the intake air, the humidification zone and the reaction zone are on the same membrane electrode, the structure is simple, the water management of the fuel cell can be greatly simplified, and the power density of the system can be improved. The fuel cell can be applied to various fields such as an uninterruptible power supply system, an electric vehicle engine system, and the like.

Description

A fuel cell with single cell humidification zone

technical field

The invention belongs to the field of fuel cells, in particular to the proton exchange membrane fuel cell technology using no external humidification.

Background technique

A fuel cell is a continuous power generation device that converts chemical energy in externally supplied fuel and oxidant into electrical energy. Because of its high power density and energy density, clean and efficient, and wide power range, fuel cells have broad application prospects in various fields such as micro power sources, mobile power sources, vehicle engines, and stationary power stations, so they have received extensive attention from countries all over the world. The United States, Japan, Canada, and European countries are actively developing fuel cell technology. At present, almost all major automakers in the world are developing fuel cell electric vehicles.

The current fuel cell technology is mainly divided into several types according to different electrolytes, such as alkaline fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, proton exchange membrane fuel cells and solid oxide fuel cells. At present, the most mature and most widely used is the proton exchange membrane fuel cell (Proton Exchange Membrane FuelCell, PEMFC).

In proton exchange membrane fuel cells, the electrolyte is a proton exchange membrane with proton transfer performance, and the perfluorosulfonic acid membrane is widely used at present. The transfer of protons in the electrolyte membrane depends on water molecules as the conductive carrier. Therefore, the water content in the proton exchange membrane has a great influence on the performance of the fuel cell. When the water in the membrane is saturated, it has the best proton conductivity. Fuel cells can also play the best power generation performance. Therefore, humidifying or moisturizing the proton exchange membrane is an inevitable choice in the proton exchange membrane fuel cell.

At present, the traditional PEMFC humidification technology is an active humidification method, that is, water is provided from the outside. Humidification methods include bubbling humidification, membrane humidification, dew point humidification, direct water injection, etc. According to the closeness of integration with the battery stack, it can be divided into two types: external humidification and internal humidification: external humidification is the humidification subsystem Separate from the battery, humidify before the reactive gas enters the battery; internal humidification integrates the humidification subsystem with the battery, and humidifies after the reactive gas enters the battery.

系列离子交换膜，也有利用超滤膜(UF)和反渗透膜(RO)作为增湿膜的研究报道(Journal of Power Sources，1998，74：146-150)。对于膜增湿器，实用采用外部水循环提供增湿水，同时电堆冷却需要冷却水，由于水质要求不同，两种水又不能合二为一，系统中需要构建两套水循环系统，造成系统复杂，辅机功耗高。Canada's Ballard Energy Systems Corporation proposed a scheme to build a humidifier in the stack, using the cooling water of the stack to humidify the reaction gas (WO 01/67533). Such a battery system usually uses a membrane to achieve internal humidification, and the membrane material of the humidifier is currently produced by DuPont.

A series of ion exchange membranes, there are also research reports on the use of ultrafiltration membranes (UF) and reverse osmosis membranes (RO) as humidification membranes (Journal of Power Sources, 1998, 74: 146-150). For membrane humidifiers, it is practical to use external water circulation to provide humidification water. At the same time, cooling water is required for stack cooling. Due to different water quality requirements, the two kinds of water cannot be combined into one. Two sets of water circulation systems need to be built in the system, resulting in complex systems. , Auxiliary power consumption is high.

Direct water injection humidification allows the user to customize the amount of humidification in the reactive gas, which can be injected with liquid water or injected with water vapor. The former relies on the booster pump to pressurize the sprayed water flow, so that the water flow passes through the high-pressure nozzle to inject water into the reaction gas. DynEco of the United States has developed a 112B4 wet hydrogen circulator with a rated power of 30W, which can well cooperate with the direct water injection humidification technology (US6268074), and the booster pump (12Vdc, 48W) can increase the water pressure to 60~145Psi . US Patent US5958613 discloses a technology for directly injecting liquid water into the anode of PEMFC, which can not only provide water for battery power generation, but also use the latent heat of evaporation of liquid water to cool the stack. The humidifier disclosed in U.S. Patent US5432020 uses a high-speed reaction air flow mixed with water mist to achieve the purpose of humidification. Liquid water is good for cooling. Direct humidification with liquid water can simplify the humidification system, but the amount of liquid water entering the battery needs to be carefully controlled.

Humidification of the fuel cell stack by using an external water source requires the construction of a water system, which requires at least water tanks, water circulation pipelines, pumps, valves and other related components. At the same time, it is necessary to monitor the water level and replenish water when the water level in the water tank is insufficient. However, since the hydrogen and oxygen react to produce water when the fuel cell is in operation, the water produced can be recycled to the water tank after the steam-water separation. From this point of view, additional water humidification brings system complexity. For fuel cells, the role of water is to maintain the wettability of the membrane to maintain good ion conductivity. In fact, the water produced by the reaction is sufficient. Therefore, it is very important to recover the water vapor in the exhaust gas of the fuel cell to humidify the intake air, especially the cathode exhaust gas of the fuel cell. Recovering the water vapor in the exhaust gas is used to humidify the intake air, which is beneficial to simplify the system, reduce the power consumption of auxiliary machines inside the system, and increase the power density.

U.S. Emprise Corporation has developed an external humidifier (US6013385) that uses the reaction tail gas of the stack to humidify the reaction gas. Its core is a disc-shaped ceramic porous material with a chemical composition of cordierite (2MgO-2Al2O3- 5SiO2), the material has low gas transmission resistance, high mechanical strength and strong water absorption. The humidifier is divided into two chambers. The exhaust gas discharged from the stack contains a certain amount of waste heat and a large amount of water. When it flows through the cordierite material, it releases heat and is dehydrated, so that when the motor drives the cordierite disc to rotate , the dry reaction gas on the other side is humidified. The water recovery rate can reach 85-90%, and its life test has exceeded 10,000 hours. U.S. Patent No. 6,471,195 discloses a hollow fiber humidifier, which adopts a hollow fiber tube with a diameter of 2 mm and a length of 250 mm as the moisture exchange material. When the exhaust gas discharged from the fuel cell cathode flows through these hollow fiber membrane materials, a large amount of moisture in the exhaust gas is condensed and transferred to the external fresh air through the capillary tube wall to achieve the purpose of humidification.

The above two humidification methods use the cathode tail gas to humidify the air intake. The Nafion tube humidifier is used to recover the water vapor in the cathode tail gas for air humidification. The effect of this humidifier has been commercialized. In the fuel cell system, the use of an external humidifier can achieve a good humidification effect, no matter whether it is a humidification method with an external water source or a water vapor recovery method without an external water source. However, after the reaction gas is humidified by an external humidifier, it needs to be transported to the fuel cell through an insulated pipeline to avoid condensation of water vapor. At the same time, the humidified reaction gas enters the gas distribution pipeline of the stack, and then enters the gas distribution flow field of the single cell through the gas channel on the single cell. Since the water vapor will partially condense in the gas distribution pipe when the humidified reaction gas enters the cell flow field from the gas distribution pipe, it is difficult to maintain the same humidity level of the gas entering each cell arrived. Due to the uneven gas distribution, it is easy to cause the difference in the performance of the single battery, and this difference will be amplified after the stack works for a long time. It has been proved by experiments that the probability and range of performance attenuation of the single cells at both ends of the fuel cell are greater than that of the single cells at the middle. Therefore, how to maintain the uniformity of gas and water distribution in each single cell is a key problem to be solved for the long-term stable operation of fuel cells.

In the fuel cell stack, because it is connected in series, the current flowing through each single cell is the same, and the amount of water produced is the same. That is to say, if the amount of reactant gas entering each unit cell is approximately the same through flow field optimization, the humidity of the gas flowing out of the unit cells is also approximately the same. If the exhaust gas flowing out of each single cell is used to humidify the intake air flowing into the single cell, it can ensure that each single cell is at a similar humidity level, so that the fuel cell maintains a better consistency. sex.

Contents of the invention

The purpose of the present invention is to provide a fuel cell with a humidification zone, each fuel cell has a humidification zone and a reaction zone, the reaction gas entering the fuel cell monomer is first humidified through the humidification zone, and then Then enter the reaction zone to participate in the electrochemical reaction, and the high-humidity tail gas after passing through the reaction zone flows through the humidification zone to humidify the intake air. Through this humidification method, the reaction gas entering each single fuel cell can maintain a consistent humidity, which is conducive to the long-term stable operation of the fuel cell. At the same time, the use of this internal humidification method simplifies the water management of the fuel cell system , can make the battery structure more compact and improve the energy density of the system.

Technical scheme of the present invention is as follows:

A fuel cell with a single cell humidification zone, which is formed by stacking at least two fuel cell cells, each fuel cell cell sequentially contains an anode flow field plate 100, a membrane electrode 200 and a cathode flow field plate 300, It is characterized in that: each fuel cell membrane electrode 200 includes a humidification area 202 and a reaction area 203, each fuel cell anode flow field plate 100 includes an anode humidification flow field 102 and an anode gas reaction flow field 103, each A single fuel cell cathode flow field plate 300 includes a cathode humidification flow field 302 and a cathode gas reaction flow field 303; the positions of the anode humidification flow field 102, the membrane electrode humidification area 202, and the cathode humidification flow field 302 correspond to each other; After the reaction gas 309 enters the fuel cell unit, it flows through the cathode humidification flow field 302 to be humidified and then enters the cathode gas reaction flow field 303, and then passes through the membrane electrode, flows through the anode humidification flow field 102, and then flows out of the battery; In the flow field 102 , the water vapor in the cathode reaction tail gas 310 passes through the humidification area 202 of the membrane electrode and is transferred to the cathode humidification flow field 302 to humidify at least one of the cathode reaction gas 309 and the anode reaction gas 109 .

The reaction zone 203 of the fuel cell membrane electrode 200 of the present invention includes an anode diffusion layer 211, an anode catalyst layer 212, a proton exchange membrane 213, a cathode catalyst layer 214, and a cathode diffusion layer 215; the fuel cell membrane electrode 200 The humidification zone 202 includes an anode support layer 216, a proton exchange membrane 213, and a cathode support layer 217; gas through-holes 204 are arranged on the fuel cell membrane electrode 200 to communicate with the cathode gas reaction flow on the cathode flow field plate 300 Field 303 and the anode humidification flow field 102 on the anode flow field plate 100 .

The technical feature of the present invention is also that: an anode seal 106 is arranged between the anode flow field plate 100 and the membrane electrode 200 to isolate the anode reaction gas 109 from the cathode reaction tail gas 310 while maintaining the anode reaction gas 109 and the cathode reaction gas. The airtightness of the reaction gas 309 to the outside world. A cathode seal 306 is provided between the cathode flow field plate 300 and the membrane electrode 200 to keep the anode reaction gas 109 and the cathode reaction gas 309 airtight to the outside world, and to make the cathode gas flow according to the designed flow mode.

The anode humidification flow field 102 and the anode gas reaction flow field 103 are arranged on the side of the anode flow field plate 100 facing the membrane electrode 200, and the fuel cell cooling flow is provided on the side of the anode flow field plate facing away from the membrane electrode. Field 401. The cathode humidification flow field 302 and the cathode gas reaction flow field 303 are arranged on the side of the cathode flow field plate 300 facing the membrane electrode 200, and the fuel cell cooling flow field 401 is arranged on the side of the cathode flow field plate facing away from the membrane electrode .

The anode reaction gas 109 of the present invention is hydrogen or a mixed gas containing hydrogen, and the cathode reaction gas 309 is oxygen, oxygen-enriched gas or air.

Compared with the prior art, the present invention has the following advantages and outstanding effects: ①The same fuel cell membrane electrode contains a reaction zone and a humidification zone, and directly utilizes the high-humidity reaction tail gas flowing through the reaction zone in the humidification zone. Humidifying the intake air can keep the humidity of the reaction gas of each single fuel cell in the stack consistent, which is beneficial to improve the stability of the fuel cell. ②The fuel cell humidification area is integrated into the membrane electrode, which avoids the use of an external humidifier, reduces the complexity of the fuel cell system, reduces the power consumption of water management auxiliary equipment, and improves the power density and energy density of the fuel cell. ③The humidification area and the reaction area are integrated in one membrane electrode, and the corresponding gas flow channels are only designed on the anode flow field plate and the cathode flow field plate. The stacking method is exactly the same as that of the traditional fuel cell, which is convenient and simple.

Description of drawings

Fig. 1 is a three-dimensional exploded view of the structure of a fuel cell with a single-cell humidification zone according to the present invention.

Fig. 2 is a schematic side view of an embodiment of the present invention.

Fig. 3 is a simplified schematic side view of another embodiment of the present invention.

Reference signs:

100-anode flow field plate; 101-cathode gas inlet distribution pipe on the anode flow field plate;

102-anode humidification flow field; 103-anode reaction flow field;

104 - the cathode gas inlet entering the anode flow field plate from the cathode flow field plate;

105-cathode gas exhaust distribution pipe on the anode flow field plate;

106-anode seal; 107-anode gas inlet distribution pipe on the anode flow field plate;

108 - anode gas exhaust distribution pipe on the anode flow field plate;

109-anode reaction gas; 110-anode reaction tail gas;

200-membrane electrode; 201-cathode gas inlet hole on the membrane electrode;

202-humidification area; 203-reaction area;

204-gas through hole on the membrane electrode; 205-cathode gas exhaust hole on the membrane electrode;

207-the anode gas inlet hole on the membrane electrode; 208-the anode gas exhaust hole on the membrane electrode;

211-membrane electrode anode diffusion layer; 212-membrane electrode anode catalyst layer;

213-proton exchange membrane; 214-membrane electrode cathode catalyst layer;

215-Membrane electrode cathode diffusion layer; 216-Membrane electrode humidification zone anode support layer;

217-cathode supporting layer in membrane electrode humidification area; 300-cathode flow field plate;

301 - the cathode gas inlet distribution pipe on the cathode flow field plate;

302-cathode humidification flow field; 303-cathode reaction flow field;

304 - Cathode gas outlet flowing from the cathode flow field plate to the anode flow field plate;

305 - Cathode gas exhaust distribution pipe on the cathode flow field plate;

306-cathode seal; 307-anode gas inlet distribution pipe on the cathode flow field plate;

308 - anode gas exhaust distribution pipe on the cathode flow field plate;

309-cathode reaction gas; 310-cathode reaction tail gas; 401-fuel cell cooling flow field.

Detailed ways

The structure and specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

Embodiment one:

One embodiment of the invention is shown in FIGS. 1 and 2 . The fuel cell with single cell humidification zone of the present invention is formed by stacking two or more fuel cell cells. Fig. 1 shows a schematic diagram of a three-dimensional exploded structure of a fuel cell cell of the invention, and Fig. 2 is a fuel cell cell Side view of a battery cell. As can be seen from FIG. 1, the fuel cell unit contains an anode flow field plate 100, a membrane electrode 200 and a cathode flow field plate 300 in sequence, wherein the fuel cell unit membrane electrode 200 includes a humidification zone 202 and a reaction zone 203, The anode flow field plate 100 includes an anode humidification flow field 102 and an anode gas reaction flow field 103 , and the cathode flow field plate 300 includes a cathode humidification flow field 302 and a cathode gas reaction flow field 303 . The positions of the anode gas reaction flow field 103, the reaction zone 203 of the membrane electrode, and the cathode gas reaction flow field 303 correspond to each other, constituting the electrochemical reaction part of the fuel cell unit. In this area, an electrochemical reaction occurs, and the anode reaction gas 109 and The chemical energy in the cathode reactant gas 309 is converted into electrical energy. The positions of the anode humidification flow field 102, the membrane electrode humidification area 202 and the cathode humidification flow field 302 correspond to each other, and constitute the humidification part of the fuel cell. Water vapor passes through the membrane electrode from the anode humidification flow field 202. The humidification zone 202 enters the cathode humidification flow field 302 to humidify the cathode reaction gas 309 . In this embodiment, the humidification part of the fuel cell is located at the lower part of the battery, and the reaction part is located at the upper part. The positions of the humidifying part and the reaction part of the fuel cell in the fuel cell are not necessarily fixed. The humidifying part can be on the upper or lower part, left or right of the fuel cell, but it must be kept in the shade. , the anode reaction flow field and the membrane electrode reaction zone correspond to each other, and the cathode and anode humidification flow fields correspond to the membrane electrode humidification zone. In this embodiment, the arrangement of the humidifying part at the lower part of the reaction part is adopted. This arrangement has an advantage that after the supersaturated water generated in the reaction part condenses into a liquid state, it will flow down to the humidifying part under the action of gravity, which is beneficial to Keeping the water source of the humidification part is also beneficial to the drainage of the fuel cell.

In this embodiment, only the cathode reaction gas 309 is humidified, and the anode reaction gas 109 is not humidified. 1 and 2, the specific flow of gas in the fuel cell is as follows: the cathode reaction gas 309 enters the fuel cell distribution pipe from the cathode gas inlet of the stack, and enters the fuel cell distribution pipe from the cathode gas inlet distribution pipe on the cathode flow field plate. 301 enters the single fuel cell flow field, and first flows through the humidification flow field 302 on the cathode flow field plate, where water vapor permeates through the anode support layer 216, the proton exchange membrane 213 and the cathode in the membrane electrode humidification area. The support layer 217 transfers from the anode humidification flow field 102 to the cathode humidification flow field 302 to increase the humidity of the cathode gas entering the fuel cell. The humidified cathode reaction gas then flows into the cathode reaction flow field 303 on the cathode flow field plate. In the reaction zone, due to the electrochemical reaction of the fuel cell, water is generated at the cathode, and the humidity of the cathode gas increases with the flow of the cathode gas in the flow channel. The cathode gas passing through the reaction zone finally flows through the cathode flow field plate to the cathode gas outlet 304 of the anode flow field plate, flows out of the cathode flow field plate, passes through the gas through hole 204 on the membrane electrode, and passes through the cathode gas inlet on the anode flow field plate. 104 and enters the humidified flow field of the anode flow field plate. In the anode humidification flow field, the water vapor in the cathode gas tail gas can pass through the membrane electrode humidification area and enter the cathode humidification flow field 302 to humidify the cathode gas intake. At the same time, the heat in the cathode gas tail gas and the cathode gas The latent heat released by the tail gas water vapor during the condensation process is also transferred to the cathode gas intake through the membrane electrode humidification zone, which plays the role of heat exchange, so that the cathode gas can be preheated before entering the reaction zone. Since the humidification zone is set at the lower part of the fuel cell, if the cathode gas is supersaturated during the reaction process, the condensed liquid water can also be brought to the humidification zone by the cathode gas through the gas flow channel to maintain the humidity of the proton exchange membrane in the membrane electrode humidification zone. high humidity. After sufficient water and heat exchange occurs in the anode humidification flow field, the cathode gas tail gas enters the cathode gas exhaust distribution pipe 105 on the anode flow field plate, and finally exits the stack through the cathode gas outlet of the stack. Excess liquid water in the stack also flows out of the cell through the cathode gas exhaust distribution pipe. After the anode gas enters the anode gas inlet distribution pipe of the stack from the anode gas inlet of the stack, it enters the single fuel cell from the anode gas inlet distribution pipe 107 on the anode plate, and flows through the anode reaction flow field 103 from the anode gas inlet distribution pipe on the anode plate. The anode gas exhaust distribution pipe flows out of the single fuel cell, and then flows out of the fuel cell stack from the anode gas exhaust outlet of the stack.

As can be seen from FIG. 2 , in this embodiment, an anode seal 106 is provided between the anode flow field plate 100 and the membrane electrode 200 to isolate the anode reaction gas 109 from the cathode reaction tail gas 310 while maintaining the anode reaction gas 109 and the airtightness of the cathode reaction gas 309 to the outside world. A cathode seal 306 is provided between the cathode flow field plate 300 and the membrane electrode 200 to keep the anode reaction gas 109 and the cathode reaction gas 309 airtight to the outside world, and enable the cathode gas to flow in the above-mentioned flow mode. For the sealing of the fuel cell, only one of the anode seal 106 and the cathode seal 306 can be used. As long as the design is proper, it can also realize the isolation between the anode gas and the cathode gas, the isolation of the reaction gas and the outside world, and ensure Anode gas and cathode gas flow according to the designed flow pattern.

It can be seen from FIG. 2 that the anode flow field plate 100 is arranged with an anode humidification flow field 102 and an anode gas reaction flow field 103 on the side facing the membrane electrode 200, and a fuel cell cooling flow field is arranged on the side facing away from the membrane electrode 200. 401, while the side of the cathode flow field plate 300 facing the membrane electrode 200 is arranged with a cathode humidification flow field 302 and a cathode gas reaction flow field 303, and the side facing away from the membrane electrode 200 is a light plate. A coolant (which may be air, water or other coolants) flows through the fuel cell cooling flow field 401 to control the temperature of the fuel cell. In this design, the anode flow field plate 100 is a bipolar plate, which not only functions as an anode gas flow field plate, but also as a cooling plate. For the cooling of the fuel cell, there are many design methods, either a cooling flow field 401 can be provided on the side of the anode flow field plate 100 facing away from the membrane electrode 200, or a cooling flow field 401 can be provided on the side of the cathode flow field plate 300 facing away from the membrane electrode 200 The cooling flow field 401 is set, and the cooling flow field 401 can also be set on the anode flow field plate 100 and the cathode flow field plate 300, or even no cooling flow field can be designed on the anode flow field plate 100 and the cathode flow field plate 300 401, and add another cooling plate between the two fuel cell monomers, and design a cooling flow field on the cooling plate.

The most commonly used anode reaction gas 109 in fuel cells is hydrogen, or a mixed gas containing hydrogen, such as reformed natural gas, etc., and the most commonly used cathode reaction gas is air, which can also be oxygen or oxygen-enriched gas.

In this embodiment, only the tail gas of the cathode gas is used to humidify the intake air of the cathode gas, and the intake air of the anode gas is not humidified. For hydrogen-air fuel cells, since the air flow rate is 2 to 5 times greater than the hydrogen flow rate, if the cathode is fed with dry air, it is extremely easy to take out all the moisture inside the fuel cell in gaseous form, making the membrane electrode reaction area closed. Blow dry, battery performance and life will be reduced. This situation is very important for fuel cells operating at atmospheric pressure, so humidification of the cathode air feed is necessary. The anode hydrogen flow rate is small, and the anode closed operation can also be adopted. With the intermittent exhaust method, the performance of the fuel cell will not be greatly reduced, so it is possible to only humidify the cathode air intake, and not increase the anode hydrogen intake. wet.

Embodiment two:

Fig. 3 shows a simplified schematic diagram of another embodiment, that is, the simultaneous humidification of anode gas and cathode gas inlet by using air tail gas. In this embodiment, the flow mode of the cathode gas is the same as that in the first embodiment, the difference is that when the anode gas enters the single fuel cell, it first flows through the humidification flow field 302 on the cathode flow field plate 300 . At this time, the humidification flow field on the cathode flow field plate is divided into two parts, one part is the anode gas humidification flow field, and the other part is the cathode gas humidification flow field. The chambers are separated from each other by a seal 306 to prevent the anode gas and cathode gas from mixing with each other. The corresponding membrane electrode humidification area is also divided into two parts: the anode gas humidification area and the cathode gas humidification area. After the anode gas enters the anode gas humidification zone on the cathode flow field plate, after absorbing the moisture and heat transferred from the anode humidification flow field 102 through the anode gas humidification zone on the membrane electrode 200, the humidity is increased, and then Then flow from the anode gas humidification flow field on the cathode flow field plate 300 to the anode reaction flow field 103 on the anode flow field plate 100 through the gas through hole 204 on the membrane electrode, and participate in the electrochemical reaction in the membrane electrode reaction zone 203, Finally, it flows into the anode gas exhaust distribution pipe and then flows out of the battery. In this embodiment, both the anode reaction gas 109 and the cathode reaction gas 309 are humidified and preheated by the tail gas of the cathode gas 310, which is more beneficial to the reaction of the fuel cell. However, since both the anode reaction gas 109 and the cathode reaction gas 309 need to be humidified, the two gases must be separated on the anode flow field plate 100 and the cathode flow field plate 300, and seals need to be added, which increases the complexity of the structure. Membrane electrode fabrication is more troublesome. At the same time, since the anode gas and the cathode gas share the same humidification area, in order to ensure sufficient humidification, the area of the humidification area needs to be increased accordingly.

The actual working principle of the patent of the present invention is as follows: during the working process of the proton exchange membrane fuel cell, water will be generated at the cathode, and as the cathode gas flows from the inlet to the outlet in the cathode flow field, the humidity of the gas will increase, and the May reach supersaturation. However, for the anode and cathode reaction gases entering the fuel cell, a certain degree of humidification is required to better exert the performance of the fuel cell. The proton exchange membrane in the fuel cell membrane electrode itself is hydrophilic, and water can be transferred in the proton exchange membrane under the concentration gradient. Therefore, it is possible to use the high-humidity cathode tail gas to humidify the dry gas of the anode and cathode reaction gases. . In the present invention, the membrane electrode of the fuel cell unit includes a reaction zone and a humidification zone, where the reaction of the fuel cell takes place, and the humidification zone only takes place the transfer of water vapor in the proton exchange membrane. The corresponding anode flow field plate includes an anode reaction flow field and an anode humidification flow field, and the cathode flow field plate also includes a cathode reaction flow field and a cathode humidification flow field. When the dry gas of the cathode reaction gas enters the fuel cell unit, it first flows through the cathode humidification flow field, and the humidity is increased, and then enters the cathode reaction flow field, where an electrochemical reaction occurs, and the humidity gradually increases, and finally enters the anode humidification flow field. The water vapor in it is transmitted to the cathode humidification flow field through the proton exchange membrane to humidify the cathode reaction gas. Similarly, the anode reaction gas can also first enter the cathode humidification flow field on the cathode flow field plate, enter the anode reaction flow field after obtaining humidification, and flow out of the fuel cell monomer after an electrochemical reaction occurs. The anode reaction gas can also directly enter the anode reaction flow field and then flow out of the fuel cell unit without humidification. In the present invention, the humidification and reaction of the fuel cell are integrated, which is beneficial to simplify the humidification, reduce the complexity of the system, and increase the energy density of the fuel cell system.

Claims (7)

1. fuel cell with humidification zone of single cell, it is formed by stacking by at least two fuel cells, each fuel cell contains anode flow field board (100) successively, membrane electrode (200) and cathode flow field plate (300), it is characterized in that: each fuel cell membrane electrode (200) comprises humidification zone (202) and reaction zone (203), each fuel cell anode flow field board (100) comprises anode humidification flow field (102) and anodic gas reactive flowfield (103), and each fuel cell cathode flow field plate (300) comprises negative electrode humidification flow field (302) and cathode gas reactive flowfield (303); Anode humidification flow field (102), membrane electrode humidification zone (202), position, negative electrode humidification flow field (302) are corresponding mutually; After cathode reaction gas (309) enters fuel cell, enter cathode gas reactive flowfield (303) behind negative electrode humidification flow field (302) humidification of flowing through, pass flow through anode humidification flow field (102) back of membrane electrode again and flow out battery; In anode humidification flow field (102), the humidification zone (202) that steam in the cathode reaction tail gas (310) sees through membrane electrode is delivered in the negative electrode humidification flow field (302), is at least a humidification that carries out in cathode reaction gas (309) and the anode reaction gas (109).

2. according to the described a kind of fuel cell with humidification zone of single cell of claim 1, it is characterized in that: the reaction zone (203) of described fuel cell membrane electrode (200) comprises anode diffusion layer (211), anode catalyst layer (212), proton exchange membrane (213), cathode catalysis layer (214) and cathode diffusion layer (215); The humidification zone (202) of described fuel cell membrane electrode (200) comprises anode support (216), proton exchange membrane (213) and cathode support layer (217); Be furnished with gas via-hole (204) on the described fuel cell membrane electrode (200), cathode gas reactive flowfield (303) on the gas via-hole connection cathode flow field plate (300) and the anode humidification flow field (102) on the anode flow field board (100).

3. according to the described a kind of fuel cell of claim 1 with humidification zone of single cell, it is characterized in that: be provided with anode seal (106) between described anode flow field board (100) and the membrane electrode (200), anode reaction gas (109) and cathode reaction tail gas (310) are kept apart, simultaneously holding anode reacting gas (109) and cathode reaction gas (309) air-tightness to external world.

4. according to the described a kind of fuel cell of claim 1 with humidification zone of single cell, it is characterized in that: be provided with negative electrode seal (306) between described cathode flow field plate (300) and the membrane electrode (200), holding anode reacting gas (109) and cathode reaction gas (309) air-tightness to external world, and cathode gas is flowed according to the type of flow of design.

5. according to the described a kind of fuel cell of claim 1 with humidification zone of single cell, it is characterized in that: described anode humidification flow field (102) and anodic gas reactive flowfield (103) are arranged on the side of anode flow field board (100) towards membrane electrode (200), are provided with fuel cell coolant flow field (401) on the side of membrane electrode dorsad at anode flow field board.

6. according to the described a kind of fuel cell of claim 1 with humidification zone of single cell, it is characterized in that: described negative electrode humidification flow field (302) and cathode gas reactive flowfield (303) are arranged on the side of cathode flow field plate (300) towards membrane electrode (200), cathode flow field plate dorsad membrane electrode one side be provided with fuel cell coolant flow field (401).

7. according to the described a kind of fuel cell of claim 1 with humidification zone of single cell, it is characterized in that: described anode reaction gas (109) is the mist of hydrogen or hydrogen, and described cathode reaction gas (309) is oxygen, oxygen rich gas or air.

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