阅读说明：本技术 一种便携式凝胶型自呼吸微型无膜燃料电池 (Portable gel type self-breathing micro membraneless fuel cell ) 是由 朱恂 周远 叶丁丁 廖强 陈蓉 李俊 付乾 张亮 于 2019-11-08 设计创作，主要内容包括：本发明公开了一种便携式凝胶型自呼吸微型无膜燃料电池，包括相对设置的自呼吸阴极电极和自呼吸阳极电极；其特征在于：在自呼吸阴极电极与自呼吸阳极电极之间设置有阴极水凝胶和阳极水凝胶；阴极水凝胶设置在自呼吸阴极电极一侧，阳极水凝胶设置在自呼吸阳极电极一侧，所述阳极水凝胶与自呼吸阳极电极的催化层接触构成阳极反应界面，所述阴极水凝胶与自呼吸阴极电极的催化层接触构成阴极反应界面；所述阳极水凝胶由水凝胶浸没在一定浓度的燃料与电解液的混合溶液中直至水凝胶达到饱和而获得；所述阴极水凝胶由水凝胶浸没在一定浓度的电解液溶液中直至水凝胶达到饱和而获得；本发明可广泛应用在能源、化工、环保等领域。(The invention discloses a portable gel-type self-breathing micro membraneless fuel cell, which comprises a self-breathing cathode electrode and a self-breathing anode electrode which are oppositely arranged; the method is characterized in that: cathode hydrogel and anode hydrogel are arranged between the self-respiration cathode electrode and the self-respiration anode electrode; the cathode hydrogel is arranged on one side of the self-breathing cathode electrode, the anode hydrogel is arranged on one side of the self-breathing anode electrode, the anode hydrogel is contacted with a catalyst layer of the self-breathing anode electrode to form an anode reaction interface, and the cathode hydrogel is contacted with the catalyst layer of the self-breathing cathode electrode to form a cathode reaction interface; the anode hydrogel is obtained by immersing hydrogel in a mixed solution of fuel and electrolyte with a certain concentration until the hydrogel is saturated; the cathode hydrogel is obtained by immersing hydrogel in electrolyte solution with certain concentration until the hydrogel is saturated; the invention can be widely applied to the fields of energy, chemical industry, environmental protection and the like.)

1. A portable gel type self-breathing micro membraneless fuel cell comprises a self-breathing cathode electrode (3) and a self-breathing anode electrode (10) which are oppositely arranged; the self-breathing cathode electrode (3) and the self-breathing anode electrode (10) both comprise catalytic layers;

the method is characterized in that:

a cathode hydrogel (4) and an anode hydrogel (9) are arranged between the self-respiration cathode electrode (3) and the self-respiration anode electrode (10); the cathode hydrogel (4) is arranged on one side of the self-breathing cathode electrode (3), the anode hydrogel (9) is arranged on one side of the self-breathing anode electrode (10), the anode hydrogel (9) is in contact with a catalyst layer of the self-breathing anode electrode (10) to form an anode reaction interface, and the cathode hydrogel (4) is in contact with the catalyst layer of the self-breathing cathode electrode (3) to form a cathode reaction interface;

the anode hydrogel (9) is obtained by immersing hydrogel in a mixed solution of fuel and electrolyte with a certain concentration until the hydrogel is saturated; the cathode hydrogel is obtained by immersing hydrogel in electrolyte solution with certain concentration until the hydrogel is saturated;

and a carbon dioxide selective permeation membrane (11) is arranged on the contact surface of the self-breathing anode electrode (10) and the air.

2. The portable gel-type self-breathing micro membraneless fuel cell according to claim 1, characterized in that: the fuel cell is also provided with a cathode cover plate (1) and an anode plate (13); the cathode cover plate (1) is provided with a cathode air breathing hole (2), the self-breathing cathode electrode (3) is placed in the cathode air breathing hole (2), the anode plate (13) is provided with an anode self-breathing through hole (12), and the self-breathing anode electrode (10) is placed in the anode self-breathing through hole (12) and is in contact with air through a carbon dioxide selective permeation membrane (11).

3. The portable gel-type self-breathing micro membraneless fuel cell according to claim 1 or 2, characterized in that: the hydrogel is chitosan hydrogel or agar hydrogel.

4. The portable gel-type self-breathing micro membraneless fuel cell according to claim 2, characterized in that: the fuel cell is also provided with a hydrogel packaging chamber (5), the hydrogel packaging chamber is a cuboid with a rectangular through hole and is composed of a first end plate (5a) and a fourth end plate (5d), the upper ends of the first end plate (5a) and the fourth end plate (5d) are fixed on the cathode cover plate (1), the lower ends of the first end plate (5a) and the fourth end plate (5d) are fixed on the anode plate (13), and the cathode hydrogel (4) and the anode hydrogel (9) are placed in the hydrogel packaging chamber.

5. The portable gel-type self-breathing micro membraneless fuel cell according to claim 4, characterized in that: a through hole is formed in the first end plate (5a), a fuel liquid storage tank (7) is arranged on the outer side of the first end plate (5a), and the liquid outlet end of the fuel liquid storage tank (7) penetrates through the through hole in the first end plate (5) to be connected with the anode hydrogel (9); and a liquid replenishing valve (6) is arranged on the fuel liquid storage tank (7).

6. The portable gel-type self-breathing micro membraneless fuel cell according to claim 4, characterized in that: the first end plate (5a) is provided with a through hole, the outer side of the first end plate (5a) is provided with a pressure regulator (8), the pressure regulator (8) is provided with a telescopic arm, and the telescopic arm penetrates through the through hole in the first end plate (5a) and applies pressure to the anode hydrogel (9).

7. The portable gel-type self-breathing micro membraneless fuel cell according to claim 1, characterized in that:

the self-breathing cathode electrode (3) consists of hydrophobic porous carbon paper with a leveling layer and a Pt/C catalytic layer;

the self-breathing anode electrode (10) is composed of porous carbon paper or carbon cloth with a leveling layer and hydrophobicity and a Pd/C catalytic layer with hydrophilicity.

Technical Field

The invention relates to the field of fuel cells, in particular to a portable gel-type self-breathing micro membraneless fuel cell.

Background

The fuel cell is a power generation device which directly converts chemical energy in fuel into electric energy through electrochemical reaction, is not limited by Carnot cycle and has high energy conversion efficiency. Proton exchange membrane fuel cells (proton exchange membrane cells) are one of the most promising power sources in various types of fuel cells. In a power supply for portable electronic equipment, a Direct Methanol Fuel Cell (DMFC) using liquid methanol as a fuel and a proton exchange membrane as an electrolyte is popularized and applied because of its advantages of abundant fuel sources (bio-fermentation, photocatalytic reduction of CO2, etc.), convenient transportation and storage (normal temperature and pressure), high energy density (17.5J/ml), etc. However, research has shown that a proton exchange membrane (generally a Nafion membrane manufactured by dupont) used in a direct methanol fuel cell can not only conduct hydrogen ions, but also anode water can permeate the membrane to reach a cathode, so that cathode flooding is aggravated, air transmission is hindered, and cell performance is reduced. A more serious problem is that methanol can permeate the Nafion membrane to reach the cathode and directly react with oxygen, which not only causes fuel waste, but also reduces the performance of the cell due to the mixed potential of the cathode caused by fuel permeation. Therefore, the concentration of methanol used by the direct methanol fuel cell is generally about 2mol/L (low concentration causes low output power density, high concentration causes fuel permeation), and meanwhile, the catalytic oxidation kinetics of methanol is also poor, intermediates such as COADs and the like generated in the oxidation process can poison the catalyst, and the service life and the catalytic activity of the catalyst are reduced. Due to the above disadvantages, a direct formic acid fuel cell using formic acid as a fuel instead of methanol has been a research focus in recent years. Compared with methanol, formic acid is non-toxic and non-flammable, and is safe and convenient to store and transport. In addition, although the energy density of formic acid is low, the open-circuit voltage of the battery is higher (1.43V vs.1.21V), so that higher power density is more favorably output in the actual operation process. Meanwhile, formic acid is used as a strong acid electrolyte, the concentration of hydrogen ions in the solution can be increased, and the high proton conductivity effectively reduces the ohmic internal resistance of the battery. And the formic acid has better catalytic oxidation kinetics, and the electrochemical oxidation product of the formic acid is not easy to poison catalysts such as Pt, Pd and the like. Formic acid also has a low permeability to Nafion membranes and can be run at high fuel concentrations (10 mol/L).

At present, the fuel supply mode of the direct formic acid fuel cell is mainly divided into an active mode and a passive mode, wherein the active mode needs to pump fuel into a channel by a pump, and on the one hand, the pump work needs to be consumed, so that the net output power density of the cell is reduced; on the other hand, the additional equipment such as a pump increases the complexity of the battery system, which is not favorable for the miniaturization of the battery. Passive fuel reservoirs are typically provided outside the cell to deliver fuel by gravity or capillary transport, but the connection between the fuel reservoir and the cell and its seal design add to the cost of the cell. In addition, proton exchange membranes have problems of high cost, complex water management, aging degradation, and the like. Moreover, during the operation of the cell, formic acid is oxidized to generate a large amount of carbon dioxide bubbles, and the carbon dioxide bubbles occupy the effective reaction area on the surface of the anode, block the anode flow channel, hinder fuel transmission and deteriorate the cell performance.

Disclosure of Invention

The invention provides a portable gel type self-breathing micro membraneless fuel cell aiming at the defects in the prior art.

The technical scheme of the invention is as follows: a portable gel type self-breathing micro membraneless fuel cell comprises a self-breathing cathode electrode and a self-breathing anode electrode which are oppositely arranged; the self-breathing cathode electrode and the self-breathing anode electrode both comprise catalytic layers.

The method is characterized in that:

cathode hydrogel and anode hydrogel are arranged between the self-respiration cathode electrode and the self-respiration anode electrode; the cathode hydrogel is arranged on one side of the self-breathing cathode electrode, the anode hydrogel is arranged on one side of the self-breathing anode electrode, the anode hydrogel is in contact with a catalyst layer of the self-breathing anode electrode to form an anode reaction interface, and the cathode hydrogel is in contact with the catalyst layer of the self-breathing cathode electrode to form a cathode reaction interface.

The anode hydrogel is obtained by immersing hydrogel in a mixed solution of fuel and electrolyte with a certain concentration until the hydrogel is saturated; the cathode hydrogel is obtained by immersing the hydrogel in a solution of electrolyte with a certain concentration until the hydrogel is saturated.

And a carbon dioxide selective permeation membrane is arranged on the outer side of the self-breathing anode electrode, namely the contact surface of the self-breathing anode electrode and air.

According to the invention, the fuel and the electrolyte are filled into the hydrogel, the hydrogel with hydrophilicity is adopted as a secondary liquid storage medium of the fuel/the electrolyte, and the hydrogel filled with the electrolyte is used as a solid electrolyte of the battery, so that a proton exchange membrane is removed, the integration level of the battery is further improved, the miniaturization is facilitated, and the cost of the battery is reduced. The anode and the cathode are respectively arranged on two sides of the anode hydrogel and the cathode hydrogel, and the air self-breathing electrode is adopted to enhance the oxygen transmission of the cathode so as to improve the performance of the battery. The fuel in the anode hydrogel reaches the surface of the anode through diffusion to react, the generated carbon dioxide is discharged through the self-breathing anode, the whole cell is solid, and the leakage problem of liquid fuel/electrolyte is avoided due to the good water retention property of the hydrogel.

According to the preferable scheme of the portable gel type self-breathing micro membraneless fuel cell, the fuel cell is also provided with a cathode cover plate and an anode plate; the cathode cover plate is provided with a cathode air breathing hole, the self-breathing cathode electrode is placed in the cathode air breathing hole, the anode plate is provided with an anode self-breathing through hole, and the self-breathing anode electrode is placed in the anode self-breathing through hole and is in contact with air through the carbon dioxide selective permeation membrane.

According to the preferable scheme of the portable gel-type self-breathing micro membraneless fuel cell, the hydrogel adopts chitosan hydrogel or agar hydrogel.

According to the preferable scheme of the portable gel-type self-breathing micro membraneless fuel cell, the fuel cell is further provided with a hydrogel packaging chamber, the hydrogel packaging chamber is a cuboid with rectangular through holes and is composed of a first end plate to a fourth end plate, the upper ends of the first end plate to the fourth end plate are fixed on a cathode cover plate, the lower ends of the first end plate to the fourth end plate are fixed on an anode plate, and cathode hydrogel and anode hydrogel are placed in the hydrogel packaging chamber.

According to the preferable scheme of the portable gel-type self-breathing micro membraneless fuel cell, a through hole is formed in the first end plate, a fuel liquid storage tank is arranged on the outer side of the first end plate, and the liquid outlet end of the fuel liquid storage tank penetrates through the through hole in the first end plate to be connected with anode hydrogel; and a liquid replenishing valve is arranged on the fuel liquid storage tank.

Through setting up the fuel liquid storage pot, guaranteed at the battery operation in-process, the fuel in the fuel liquid storage pot continuously to the diffusion of anode hydrogel layer supply fresh fuel, make the battery can stably continue to output and produce the electricity. The fuel tank is provided with the liquid replenishing valve, the liquid replenishing valve is opened, fuel can be replenished to the fuel liquid storage tank by using the injection pump or other equipment, the anode hydrogel does not need to be replaced by disassembling the battery, and the operation is simple.

According to the preferable scheme of the portable gel-type self-breathing micro membraneless fuel cell, the first end plate is provided with a through hole, the outer side of the first end plate is provided with a pressure regulator, the pressure regulator is provided with a telescopic arm, and the telescopic arm penetrates through the through hole in the first end plate to apply pressure to anode hydrogel.

The pressure regulator is used for increasing the pressure of the anode hydrogel through the pressure regulator to maintain the supply rate of the fuel when the fuel in the anode hydrogel is consumed and the current density of the cell is reduced due to the reduction of the fuel concentration.

According to a preferred embodiment of the portable gel-type self-breathing micro membraneless fuel cell of the present invention, the self-breathing cathode electrode is composed of a hydrophobic porous carbon paper with a leveling layer and a Pt/C catalytic layer;

the self-breathing anode electrode consists of porous carbon paper or carbon cloth with a leveling layer and hydrophobicity and a Pd/C catalytic layer with hydrophilicity.

The portable gel type self-breathing micro membraneless fuel cell has the beneficial effects that:

1) the invention does not need a proton exchange membrane, the hydrogel can be repeatedly used, and the cost for running the battery is effectively reduced.

2) The hydrogel is simultaneously used as a fuel liquid storage tank, an electrolyte liquid storage tank and a solid electrolyte of the cell, and is beneficial to realizing the miniaturization and integration of the cell.

3) The self-breathing anode can directly discharge the generated carbon dioxide, reduces the influence of CO2 bubbles on the performance of the battery, does not need redundant vent holes, and is favorable for further simplifying the structure of the battery.

4) The whole battery is solid, so that the problem of liquid leakage is avoided, and the battery is convenient to carry and assemble.

5) Air is used as an oxidant, other oxidants are not needed, and the operation cost of the battery is effectively reduced. The reaction products of the battery are carbon dioxide and water, and the battery has no pollution to the environment.

6) Through setting up the fuel liquid storage pot, the fuel in the fuel liquid storage pot lasts to the diffusion of anode hydrogel layer and replenishes fresh fuel, need not to dismantle the battery and changes anode hydrogel, easy operation.

7) By arranging the pressure regulator, the pressure is graded according to the consumption condition of the fuel in the anode hydrogel, and the effective stable maintenance and quick recovery of the cell performance can be realized.

The invention can be widely applied to the fields of energy, chemical industry, environmental protection and the like.

Drawings

Fig. 1 is a schematic structural diagram of a portable gel-type self-breathing micro membraneless fuel cell according to embodiment 1 of the present invention.

Fig. 2 is a schematic structural diagram of a portable gel-type self-breathing micro membraneless fuel cell according to embodiment 2.

Fig. 3 is a top view of fig. 2.

Fig. 4 is a left side view of fig. 2.

Fig. 5 is a schematic structural diagram of a portable gel-type self-breathing micro membraneless fuel cell according to embodiment 3.

Fig. 6 is a top view of fig. 5.

Fig. 7 is a left side view of fig. 5.

Fig. 8 is a schematic structural diagram of a portable gel-type self-breathing micro membraneless fuel cell according to embodiment 4.

Fig. 9 is a top view of fig. 8.

Fig. 10 is a left side view of fig. 8.

Detailed Description

Referring to fig. 1, embodiment 1. a portable gel-type self-breathing micro membraneless fuel cell, which is composed of a self-breathing cathode electrode 3, a cathode hydrogel 4, an anode hydrogel 9, a self-breathing anode electrode 10, and a carbon dioxide selective permeation membrane 11; the self-respiration cathode electrode 3 and the self-respiration anode electrode 10 are oppositely arranged; the self-respiration cathode electrode 3 and the self-respiration anode electrode 10 both comprise catalytic layers; the self-breathing cathode electrode 3 consists of hydrophobic porous carbon paper with a leveling layer and a Pt/C catalytic layer; the self-breathing anode electrode 10 consists of a porous carbon paper or graphite plate with a leveling layer and hydrophobicity and a Pd/C catalytic layer with hydrophilicity.

A cathode hydrogel 4 and an anode hydrogel 9 are arranged between the self-respiration cathode electrode 3 and the self-respiration anode electrode 10; the cathode hydrogel 4 is arranged on one side of the self-breathing cathode electrode 3, the anode hydrogel 9 is arranged on one side of the self-breathing anode electrode 10, and the anode hydrogel 9 is in contact with a catalytic layer of the self-breathing anode electrode 10 to form an anode reaction interface. The cathode hydrogel 4 is contacted with a catalytic layer of the self-breathing cathode electrode 3 to form a cathode reaction interface; while hindering fuel permeation to the cathode.

A carbon dioxide selective permeation membrane 11 is arranged on the outer side of the self-respiration anode electrode 10, namely on the contact surface of the self-respiration anode electrode 10 and air. The main function of the carbon dioxide permeable membrane is to allow carbon dioxide to escape and to block oxygen from reaching the anode catalytic layer.

The anode hydrogel 9 is obtained by immersing hydrogel in a mixed solution of fuel and electrolyte with a certain concentration until the hydrogel is saturated; the cathode hydrogel is obtained by immersing hydrogel in electrolyte solution with certain concentration until the hydrogel is saturated; the hydrogel can be chitosan hydrogel or agar hydrogel. The electrolyte can adopt acid electrolyte or alkaline electrolyte; the acid electrolyte can be sulfuric acid solution, etc., the alkaline electrolyte can be potassium hydroxide solution, etc., and the fuel can be formic acid, methanol, ethanol, etc. In specific implementation, the hydrogel can be immersed in a mixed solution of 0.5-1mol/L fuel and 0.5-2mol/L electrolyte until the hydrogel is saturated to obtain the anode hydrogel; the cathode hydrogel can be obtained by immersing the hydrogel in 0.5-2mol/L electrolyte solution until the hydrogel is saturated.

In a specific example, when the self-breathing cathode electrode 3 is prepared, the Pt/C catalyst paste may be uniformly sprayed on the surface of the hydrophobic carbon paper having a leveling layer by a spraying method.

When the self-breathing anode electrode 10 is prepared, firstly, porous carbon paper or carbon cloth is soaked in a PTFE solution with a certain concentration for hydrophobic treatment, so that fuel in hydrogel is prevented from leaking, and carbon dioxide bubbles generated by an anode catalyst layer are promoted to be discharged outwards. And then, ultrasonically mixing carbon powder with a PTFE solution with a certain concentration, and uniformly spraying the mixture on one side of the treated porous carbon paper or carbon cloth to prepare a leveling layer. And finally, uniformly spraying the Pd/C catalyst slurry on the surface of the carbon paper by a spraying method, and carrying out hydrophilic treatment on the catalyst layer.