Electrode assembly for submarine microbial fuel cell, preparation method and device

Abstract

The invention provides an electrode assembly for a submarine microbial fuel cell, a preparation method and a device, belongs to the technical field of fuel cells, and solves the technical problem of low synergistic energy supply efficiency of a cathode and an anode of a fuel cell. The co-treatment anode is treated by urea and sodium persulfate; the ternary composite cathode is electrically connected with the co-processing anode through a wire; the co-processing anode releases electrons in seabed sludge through an oxidation reaction of microorganisms on organic matters, and the electrons are transmitted to the ternary composite cathode through a wire; a seabed sludge and seawater interface is used as a natural proton exchange membrane to realize a proton and electron transfer path between the anode and the cathode; the electrode assembly generates a potential difference through electron transfer and redox reaction and outputs energy. The method is suitable for preparing the electrode of the submarine microbial fuel cell.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fuel cells, and particularly relates to the technical field of electrode preparation of fuel cells, and is used for electrode preparation of a seabed microorganism fuel cell. BACKGROUND

[0002] Underwater sensors are the core equipment of the construction of the ocean observation network, are indispensable in the collection of deep-sea hydrological information and long-term ecological monitoring, and are the key support for promoting the development of marine scientific research and marine industry. Although such microelectronic devices have low power consumption of up to milliwatts, traditional solid-state power sources such as lithium batteries and lead-acid batteries have problems such as easy leakage of electrolyte, corrosion of active substances by seawater, and reduction of energy density with temperature, resulting in insufficient endurance and difficulty in meeting the needs of long-term stable operation of the equipment underwater. At the same time, due to the constraints of the complex underwater environment, the cost of equipment salvage and power replacement is high, and the technical difficulty is great. The benthic microbial fuel cell can use seabed silt organic matter to realize long-term power supply, but the traditional carbon felt cathode is easily contaminated by impurities, which reduces the potential and open-circuit voltage of the cathode, prolongs the start-up time, and the electron transfer rate of the anode is relatively slow, which significantly affects the performance of the entire system.

[0003] In the benthic microbial fuel cell, the cathode plays a role in collecting electrons and providing oxidizing agents. Traditional carbon-based cathode preparation and modification mostly focus on using physical and chemical methods to modify the physicochemical properties of the cathode, improve the cathode potential and improve the electrode efficiency, but lack effective improvement schemes for the start-up time of the cathode. In addition, the pores formed on the surface of the modified cathode are easily attached by impurities during long-term use and are difficult to remove; the existing anode modification methods are very rich, but most of them have the disadvantages of high cost and complex implementation. SUMMARY

[0004] The purpose of the present application is to solve the technical problem of low synergistic power supply efficiency of the cathode and anode of a fuel cell.

[0005] The present application is realized by the following technical scheme, and the present application proposes an electrode assembly for a seabed microbial fuel cell, characterized in that the electrode assembly comprises: a ternary composite cathode formed by pressing and calcining; a synergistically treated anode treated by urea and sodium persulfate; The ternary composite cathode and the synergistically treated anode are electrically connected by wires; The synergistically treated anode is buried in seabed silt, the ternary composite cathode is placed on the seabed silt and immersed in seawater, and the interface between the seabed silt and the seawater constitutes a natural proton exchange membrane.

[0006] Further, the ternary composite cathode is in a cylindrical structure, with a size of 30mm in diameter and 35mm in height, and has a three-dimensional void network formed by urea decomposition inside.

[0007] Further, the ternary composite cathode is prepared by a tablet press, calcination and cooling; wherein, The pressing pressure is 19-21MPa, and the pressing time is 23-24 hours; The calcination temperature is 440-450℃, and the calcination time is 28-30 minutes.

[0008] Further, the components of the ternary composite cathode include carbon powder, copper powder and urea, with a mass ratio of 5:5:1; wherein, the mesh number of the carbon powder and the copper powder is 1000 mesh.

[0009] Further, the material of the synergistically treated anode is carbon felt, with a size of 30mm*30mm*3mm and a surface porosity ratio of 88%.

[0010] Further, in the urea and sodium persulfate treatment, the concentration of sodium persulfate is 20-100g / L, and the concentration of urea is 80-280g / L.

[0011] Further, in the synergistically treated anode, the heat preservation and heating time is 30-40 minutes, the heat preservation and heating temperature is 50-70℃, and the temperature rising temperature is 440-460℃.

[0012] Further, the electrode assembly realizes energy transmission through the following electrochemical signal transmission process: The synergistically treated anode releases electrons through microbial oxidation of organic matter in the seabed sludge; The released electrons are transmitted to the ternary composite cathode through a wire; The ternary composite cathode receives the electrons and undergoes an electrochemical reaction with dissolved oxygen in seawater; The interface between the seabed sludge and seawater serves as a natural proton exchange membrane, realizing the proton and electron transmission path between the anode and the cathode; The electrode assembly generates a potential difference through electron transmission and redox reaction and outputs energy.

[0013] The application also provides a preparation method of an electrode assembly, which is used for preparing the electrode assembly according to any one of the application, and the preparation method comprises: The preparation method of the ternary composite cathode: urea particles are ground into urea powder, and the urea powder is mixed with carbon powder and copper powder to prepare a composite powder; the composite powder is placed in a mold to be pressed into a crude cathode; the crude cathode is calcined and cooled to obtain a ternary composite cathode; Preparation method of the synergistically treated anode: cutting carbon felt into pieces as electrode pieces; placing the electrode pieces in a mixed solution of urea and sodium persulfate, heating and stirring; ultrasonic cleaning, drying and calcining the treated electrode pieces, and obtaining the synergistically treated anode after cooling.

[0014] The application also provides an energy supply device for a seabed microorganism detection device, which comprises the electrode assembly according to any one of the application, and supplies electric energy for the detection device through an open circuit voltage.

[0015] The application has the following beneficial effects: The electrode assembly provided by the application focuses on designing a battery cathode with high power generation efficiency, fast start-up, strong anti-pollution ability and long service life, and an anode with high open circuit voltage, based on the problems in the prior art.

[0016] The cathode prepared by the application has fast start-up time, is not easily polluted by impurities and has long service life, and is combined with the anode with high open circuit voltage to form an efficient energy supply unit.

[0017] The three-dimensional pore structure of the cathode can accelerate start-up; the three-dimensional pore structure is constructed on the surface and inside of the cathode to provide sufficient reaction active sites for dissolved oxygen in seawater, thereby accelerating the electrochemical reaction process and effectively solving the problem of prolonged start-up time of the traditional cathode.

[0018] The CuO catalysis and carbon skeleton of the cathode can guarantee the service life; the CuO generated by calcination acts as an efficient solid catalyst and cooperates with the carbon powder as the electrode skeleton.

[0019] The stable structure of the cathode can resist pollution; the stable cathode structure formed by pressing and calcination is not easily attached by impurities on the surface and inside of the pores in long-term use, and has the characteristic of not being easily polluted by impurities.

[0020] The functionalized surface of the anode can improve electron transfer; the number of oxygen-containing functional groups and nitrogen-containing functional groups on the surface of the anode is increased through treatment.

[0021] The ternary composite cathode realizes fast starting time, is not easy to be polluted by impurities, and has long service life; urea is innovatively used as a pore forming agent, urea decomposition in the calcination link constructs a three-dimensional pore structure on the surface and inside of the cathode, provides sufficient reactive sites for dissolved oxygen in seawater, and thus accelerates the electrochemical reaction process. It needs to be particularly pointed out that the urea addition amount is strictly controlled to balance the relationship between pore forming efficiency and structural stability. The calcination process promotes the oxidation of copper powder on the electrode surface to generate CuO, which further improves the electrochemical reaction efficiency of the cathode as a high-efficiency solid catalyst; at the same time, the metal oxide has stronger seawater corrosion resistance than the metal element, which can effectively prolong the service life of the electrode. The carbon powder not only guarantees the stability of the electron transmission path, but also can inhibit the electrochemical corrosion of the metal inside.

[0022] The synergistically treated anode uses the carbon felt anode including urea and sodium persulfate innovatively and is synergistically treated. The synergistic treatment of sodium persulfate and urea increases the number of oxygen-containing functional groups and nitrogen-containing functional groups on the surface of the anode, and existing researches show that these functional groups can improve the surface activity of the electrode and improve the biocompatibility, which is beneficial to the adhesion and growth of microorganisms, thereby increasing the efficiency of electron transfer and increasing the open circuit voltage. The synergistically treated anode has high open circuit voltage, simple preparation steps, low cost, and provides a high-efficiency and reliable cathode solution for the engineering application of the seabed microbial battery. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0024] Figure 1 is a schematic diagram of the synergistically treated anode after 36 groups of different concentrations of sodium persulfate and urea are synergistically treated.

[0025] Figure 2 is a schematic diagram of the experimental platform for testing the performance of the anode and the cathode.

[0026] Figure 3 is a schematic diagram of the influence of sodium persulfate and urea at different concentrations on the open circuit voltage of the synergistically treated anode.

[0027] Figure 4 is a schematic diagram of the influence of ammonium ions and sodium ions on the open circuit voltage of the synergistically treated anode.

[0028] Figure 5 is a schematic diagram of the influence of the sequence of heat treatment and acid treatment on the open circuit voltage of the synergistically treated anode.

[0029] Figure 6 is a schematic diagram reflecting the influence of heat treatment on the open circuit voltage of the synergistically treated anode.

[0030] Figure 7 is a cathode-anode potential diagram measured by a mercury-mercury electrode.

[0031] Figure 8 is a schematic diagram of a comparison between the three-way composite cathode of the embodiment ten of the present application and other three traditional cathodes.

[0032] Figure 9 is a schematic diagram of the open circuit voltage of devices of different types of cathodes. EMBODIMENT

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0034] Embodiment one, the electrode assembly for the seabed microbial fuel cell comprises: a three-way composite cathode formed by pressing and calcination; a synergistically treated anode treated by urea and sodium persulfate; the three-way composite cathode and the synergistically treated anode are electrically connected by wires; the synergistically treated anode is buried in seabed silt, the three-way composite cathode is placed on the seabed silt and immersed in seawater, and the interface between the seabed silt and the seawater constitutes a natural proton exchange membrane.

[0035] Further, the three-way composite cathode is in a cylindrical structure with a size of 30 mm in diameter and 35 mm in height, and has a three-dimensional void network formed by urea decomposition inside.

[0036] Further, the three-way composite cathode is made by pressing, calcination and cooling by a tablet press; wherein, the pressing pressure is 19-21 MPa, and the pressing time is 23-24 hours; the calcination temperature is 440-450℃, and the calcination time is 28-30 minutes.

[0037] Further, the composition of the three-way composite cathode comprises carbon powder, copper powder and urea with a mass ratio of 5:5:1; wherein, the mesh number of the carbon powder and the copper powder is 1000 mesh.

[0038] Further, the material of the synergistically treated anode is carbon felt with a size of 30mm*30mm*3mm and a surface porosity ratio of 88%.

[0039] Further, in the treatment of urea and sodium persulfate, the concentration of sodium persulfate ranges from 20 to 100 g / L, and the concentration of urea ranges from 80 to 280 g / L.

[0040] Further, in the synergistically treated anode, the heat preservation and heating time is 30-40 minutes, the heat preservation and heating temperature is 50-70℃, and the temperature rising temperature is 440-460℃.

[0041] Further, the electrode assembly realizes energy transmission through the following electrochemical signal transmission process: The synergistically treated anode releases electrons through the oxidation reaction of organic matter by microorganisms in the seabed sludge; The released electrons are transmitted to the ternary composite cathode through the wire; The ternary composite cathode receives electrons and undergoes an electrochemical reaction with dissolved oxygen in seawater; The interface between the seabed sludge and seawater serves as a natural proton exchange membrane, realizing the proton and electron transmission path between the anode and the cathode; The electrode assembly generates a potential difference through electron transmission and redox reaction and outputs energy.

[0042] In the embodiment, the ternary composite cathode has the characteristics of fast working start-up time, high working potential, and difficulty in adhering impurities, and the synergistically treated anode has the characteristics of high open-circuit voltage and low cost.

[0043] Specifically, the preparation method of the electrode assembly includes: The preparation method of the ternary composite cathode includes: grinding urea particles into urea powder, mixing the urea powder with carbon powder and copper powder to form a composite powder, pressing the composite powder in a mold to form a crude cathode, calcining and cooling the crude cathode to obtain a ternary composite cathode. The preparation method of the synergistically treated anode includes: cutting carbon felt into pieces as electrode pieces, placing the electrode pieces in a mixed solution of urea and sodium persulfate, heating and stirring, ultrasonic cleaning, drying and calcining the treated electrode pieces, and cooling to obtain a synergistically treated anode.

[0044] In the embodiment, The cathode is prepared by the following steps: first, grinding urea particles in a quartz mortar; second, mixing carbon powder, copper powder and urea powder in a beaker according to a certain proportion, and stirring uniformly with a glass plate to prepare a mixed powder; third, placing the mixed powder in a tablet press mold, and pressing and keeping pressure to prepare a crude cathode; and fourth, calcining the prepared crude cathode to obtain the cathode after cooling. The material is formed by compounding and calcining copper powder, carbon powder and urea powder, has rich three-dimensional pore structure on the surface and inside, excellent structural strength and high potential, and realizes fast start-up time, is not easily polluted by impurities and has long service life as a seabed microbial fuel cell cathode.

[0045] Specifically, Step 1: grinding urea particles dried to no crystallization water in a quartz mortar for 2-4 min; Step 2: mixing carbon powder, copper powder and urea powder in a beaker according to a mass ratio, and stirring with a glass plate until the powder is uniformly colored to prepare a composite powder; Step 3: placing the composite powder in a tablet press mold, and pressing and keeping pressure to prepare a crude cathode; Step 4: calcining the crude cathode to obtain a ternary composite cathode after cooling.

[0046] In step 2, the mesh number of copper powder and carbon powder is preferably 1000 mesh, and the mixed mass ratio of carbon powder, copper powder and urea powder is 5:5:1, and the stirring is continued until the whole powder is black. In step 4, the calcination temperature is 450 DEG C, the calcination time is 30 min, and the calcined product should be cooled at room temperature.

[0047] The seabed microbial fuel cell cathode preparation method has the following remarkable features: (1) mixing copper powder, carbon powder and urea powder in a specific mass ratio of 5:5:1, pressing by a tablet press and then calcining at 450 DEG C to obtain the cathode after cooling.

[0048] (2) obtaining three-dimensional pore structure on the surface and inside of the cathode by calcining and decomposing urea molecules in the crude cathode. This method not only effectively reduces the number of impurities attached to the surface of the cathode, but also improves the cathode potential and increases the reaction rate on the surface of the cathode, realizes fast start-up time, is not easily polluted by impurities and has long service life as a seabed microbial fuel cell cathode, and has certain application prospect in the field of seabed microbial fuel cells.

[0049] The anode is prepared by the following steps: first, cutting the carbon felt into square electrode pieces; second, placing the electrode pieces in a mixed solution of urea and sodium persulfate with a proper concentration, and heating in a water bath; third, cleaning the electrode pieces in an ultrasonic cleaner; and fourth, drying and calcining the electrode pieces to obtain the anode.

[0050] Specifically, Step 1: cutting the carbon felt with a surface porosity ratio of 90±3% into electrode pieces with a size of 30mm×30mm×3mm; Step 2: placing the electrode pieces in a mixed solution of urea and sodium persulfate with a proper concentration, and heating in a water bath; Step 3: cleaning the soaked electrode pieces in an ultrasonic cleaner for 15-20min, and then drying at a temperature of 90℃ for 30-60min.

[0051] Step 4: calcining the dried electrode pieces, and cooling to obtain the synergistically treated anode.

[0052] In step 2, the concentration of urea is preferably 70g / 250mL, the concentration of sodium persulfate is preferably 5g / 250mL, the water bath heating temperature is preferably 60℃, stirring is maintained during heating, and the heating time is preferably 30min.

[0053] In step 4, the calcination temperature is 450℃, the calcination time is 30min, and the calcined electrode pieces are cooled at room temperature.

[0054] The anode treatment method of the seabed microbial fuel cell of the present application has the following remarkable features: (1) The anode is treated with a mixed solution of urea 70g / 250mL and sodium persulfate 5g / 250mL, dried, calcined, and naturally cooled at room temperature.

[0055] (2) Sodium persulfate can be activated in water to obtain sulfate radical (·SO - 4), which can further produce strong oxidizing hydroxyl radical (·OH) under alkaline conditions. Both of them can react with the surface of carbon felt to obtain oxygen-containing functional groups, and urea can modify the surface of carbon felt to obtain nitrogen-containing functional groups including pyridine and pyrrole. The synergistic soaking treatment of the anode with sodium persulfate and urea can increase the number of oxygen-containing functional groups and nitrogen-containing functional groups on the surface of the anode. Studies have shown that these two kinds of functional groups can improve the surface activity of the electrode, facilitate the adhesion and growth of microorganisms, increase the electron transfer rate, improve the open circuit voltage, and shorten the start-up time.

[0056] Specific embodiment three, the preparation method of the electrode assembly based on the specific embodiment two, through the experiment, the preparation of anode assembly and cathode assembly.

[0057] (1) Anode assembly preparation Anode assembly 1: First step: cut the carbon felt with a surface porosity ratio of 88% into 30mm x 30mm x 3mm square electrode pieces.

[0058] Second step: sodium persulfate is grouped in the range of 5-25g / 250mL with a step of 5g / 250mL, and urea is set in 6 groups in the range of 20-70g / 250mL with a step of 10g / 250mL, and the two groups are orthogonal to form 36 groups of sodium persulfate and urea mixed solutions with different concentration ratios.

[0059] Third step: Put the electrode pieces into the above 36 groups of sodium persulfate and urea mixed solutions with different concentration ratios respectively, use a constant temperature electromagnetic stirrer to heat at 60°C for 30 minutes, then use an ultrasonic cleaning machine to clean for 15 minutes, and put them into a drying machine to dry.

[0060] Fourth step: Put the electrode pieces into a muffle furnace, heat to 450°C at a heating rate of 10°C / min and keep for 30 min, then take out and cool to room temperature. Label the 36 groups of electrode pieces as anode assembly 1 as shown in Figure 1 .

[0061] Anode assembly 2: First step: cut the carbon felt with a surface porosity ratio of 88% into 30mm x 30mm x 3mm square electrode pieces.

[0062] Second step: Put the electrode pieces into 25g / 250mL, 50g / 250mL, and 70g / 250mL concentration sodium persulfate solutions respectively, use a constant temperature electromagnetic stirrer to heat at 60°C for 30 minutes, then use an ultrasonic cleaning machine to clean for 15 minutes, and put them into a drying machine to dry.

[0063] Third step: transfer to a muffle furnace, adjust the muffle furnace controller to set the calcination temperature to 450°C, close the furnace door and start calcination, the muffle furnace rises from 20°C to 450°C in 45 minutes, keeps for 30 minutes, closes the muffle furnace, opens the furnace after cooling in the furnace for 1 hour, and cools to room temperature to obtain a synergistically treated anode, labeled as anode assembly 2.

[0064] Anode assembly 3: The difference between this anode assembly and anode assembly 2 is that the anode pieces are treated with 25g / 250mL, 50g / 250mL, and 70g / 250mL concentration ammonium persulfate respectively.

[0065] Anode assembly 4: The difference between this anode assembly and anode assembly 2 is that the third step is used to treat the electrode sheet first, and then the second step is used to treat the electrode sheet.

[0066] Anode assembly 5: The difference between this anode assembly and anode assembly 3 is that the third step is used to treat the electrode sheet first, and then the second step is used to treat the electrode sheet.

[0067] Anode assembly 6: Only the first step is used to treat the anode sheet.

[0068] Anode assembly 7: Only the first step and the third step are used to treat the anode sheet.

[0069] The experimental platform is built as shown in Figure 2 The anode assembly 1 is buried in the silt, and the cathode calcined carbon brush (the same treatment as the third step of the anode assembly 1) is connected to the anode with a crocodile clip and placed on the surface of the silt. Sea water is added to immerse the entire cathode. The open circuit voltage of the anode and cathode is measured with a voltmeter. After the voltage is stable, the measured open circuit voltage can reflect the influence of different concentrations of sodium persulfate and urea on the open circuit voltage of the anode as shown in Figure 3 The results show that the sodium persulfate treatment has a double-peak effect on the open circuit voltage, and the peak concentrations are 5 g / 250 mL and 25 g / 250 mL, respectively.

[0070] The anode assemblies 2 and 3 are connected to the experimental platform, respectively. The open circuit voltage of the anode and cathode is measured with a voltmeter. After the voltage is stable, the measured open circuit voltage can reflect the influence of ammonium ions and sodium ions on the open circuit voltage of the anode as shown in Figure 4 The results show that the anode treated with sodium ions at the same concentration exhibits a higher open circuit voltage, and the improvement amplitude is 9.92% at a concentration of 25 g / 250 mL.

[0071] The anode assemblies 2, 3, 4, and 5 are connected to the experimental platform, respectively. The open circuit voltage of the anode and cathode is measured with a voltmeter. After the voltage is stable, the measured open circuit voltage can reflect the influence of the sequence of heat treatment and acid treatment on the open circuit voltage of the anode as shown in Figure 5 The results show that the sequence of acid treatment and heat treatment has no significant effect on the open circuit voltage of the electrode. As shown in Figure 6 Based on the process simplification, the "acid treatment first and then heat treatment" is adopted.

[0072] The anode assemblies 6 and 7 are connected to the experimental platform, respectively. The open circuit voltage of the anode and cathode is measured with a voltmeter. After the voltage is stable, the measured open circuit voltage can reflect the influence of heat treatment on the open circuit voltage of the anode as shown in Figure 7 The results show that the carbon felt electrode treated by heat can improve the open circuit voltage of the battery, and the improvement amplitude is about 7.1%.

[0073] The above experiments prove that the anode treated by sodium persulfate and urea in cooperation and calcined can produce a higher open circuit voltage.

[0074] (II) Preparation of cathode assembly Cathode assembly 1: First step, put urea particles in a quartz mortar and grind for 3 minutes; Second step, put 50g of 1000 mesh carbon powder, 50g of 1000 mesh copper powder, and 10g of urea powder into a beaker and stir with a glass rod until the powder is completely black, to make a composite powder; Third step, put the composite powder into a cylindrical mold with a diameter of 30mm and a height of 35mm, fill the mold volume, and flatten the surface with a glass rod. Put the filled mold into the powder tablet press and pull the lever back and forth to apply pressure to 20MPa. Keep the pressure for 24 hours to make a crude cathode.

[0075] Fourth step, place the pressed crude cathode in the center of a quartz crucible and put it in a muffle furnace. Adjust the muffle furnace controller to set the calcination temperature to 450℃. Close the furnace door and start calcination. After 45 minutes, the muffle furnace rises from 20℃ to 450℃ and maintains the temperature for 30 minutes. Turn off the muffle furnace and cool it in the furnace for 1 hour. After cooling to room temperature, a ternary mixed cathode is obtained, marked as cathode assembly 1.

[0076] Cathode assembly 2: The difference between this cathode assembly and cathode assembly 1 is that the mass ratio of copper powder, carbon powder, and urea powder is 1:2:1.

[0077] Cathode assembly 3: The difference between this cathode assembly and cathode assembly 1 is that the mass ratio of copper powder, carbon powder, and urea powder is 5:5:2.

[0078] Studies have shown that 1000 mesh copper powder and carbon powder are significantly better than 300 mesh copper powder and carbon powder in terms of structural density, mechanical strength and surface gloss. After calcination, the structure remains intact, so 1000 mesh copper powder and carbon powder are preferred in this experiment.

[0079] In the experiment, the pressing pressure is maintained at 20MPa and the pressing time is 24 hours. Low pressure leads to unshaped cathode, and high pressure causes the cathode to be easily broken.

[0080] Cathode assembly 1, cathode assembly 2, and cathode assembly 3 are connected with copper wire and epoxy resin, and are placed in the experimental tank together. The anode is buried in the sludge, and the cathode is placed on the surface of the sludge. Add seawater with 10g / 250mL sodium persulfate and 20g / 250mL urea to treat the calcined anode to form a microbial fuel cell. Measure the potential with a calomel electrode every day as shown in Figure 7 The results show that cathode assembly 1 has the best effect.

[0081] Cathode assembly 1, carbon fiber brush, 300 mesh stainless steel mesh, and carbon felt areFigure 8 As shown, the same anode was selected and put into the experimental jar, and the open circuit voltage was recorded after stabilization, as shown in FIG. 4. Figure 9 As shown, the same anode was selected and put into the experimental jar, and the open circuit voltage was recorded after stabilization, as shown in FIG. 4.

[0082] In a fourth embodiment, the energy supply device of the seabed microorganism detection device comprises the electrode assembly of any one of the embodiments of the present application, and the electrode assembly supplies electric energy to the detection device through the output open circuit voltage.

[0083] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. An electrode assembly for a seafloor microbial fuel cell, characterized by, The electrode assembly comprises: a ternary composite cathode formed by pressing and calcination; a synergistically treated anode treated by urea and sodium persulfate; the ternary composite cathode and the synergistically treated anode are electrically connected by wires; the synergistically treated anode is buried in seabed silt, the ternary composite cathode is placed on the seabed silt and immersed in seawater, and the interface between the seabed silt and the seawater constitutes a natural proton exchange membrane.

2. The electrode assembly of claim 1, wherein, The ternary composite cathode has a cylindrical structure with a size of 30 mm in diameter and 35 mm in height, and has a three-dimensional void network formed by urea decomposition inside.

3. The electrode assembly of claim 1, wherein, The ternary composite cathode is prepared by pressing, calcination and cooling by a tablet press; wherein, the pressing pressure is 19-21 MPa, and the pressing time is 23-24 hours; the calcination temperature is 440-450℃, and the calcination time is 28-30 minutes.

4. The electrode assembly of claim 1, wherein, The composition of the ternary composite cathode includes carbon powder, copper powder and urea, with a mass ratio of 5:5:1; wherein, the mesh number of the carbon powder and the copper powder is 1000 mesh.

5. The electrode assembly of claim 1, wherein, The material of the synergistically treated anode is carbon felt with a size of 30 mm x 30 mm x 3 mm and a surface porosity ratio of 88%.

6. The electrode assembly of claim 1, wherein, In the urea and sodium persulfate treatment, the concentration of sodium persulfate ranges from 20 to 100 g / L, and the concentration of urea ranges from 80 to 280 g / L.

7. The electrode assembly of claim 1, wherein, In the synergistically treated anode, the heat preservation heating time is 30-40 minutes, the heat preservation heating temperature is 50-70℃, and the temperature rising temperature is 440-460℃.

8. The electrode assembly of claim 1, wherein, The electrode assembly realizes energy transmission through the following electrochemical signal transmission process: The synergistically treated anode releases electrons through microbial oxidation of organic matter in seabed silt; The released electrons are transmitted to the ternary composite cathode through wires; The ternary composite cathode receives electrons and undergoes electrochemical reaction with dissolved oxygen in seawater; The interface between seabed silt and seawater serves as a natural proton exchange membrane, realizing proton and electron transmission path between anode and cathode; The electrode assembly generates potential difference through electron transmission and redox reaction and outputs energy.

9. A method of making an electrode assembly, characterized by, The preparation method is used to prepare the electrode assembly of any one of claims 1-8, and the preparation method comprises: A preparation method of the ternary composite cathode: grinding urea particles into urea powder, mixing with carbon powder and copper powder to form a composite powder, pressing the composite powder into a mold to form a crude cathode, calcining and cooling the crude cathode to obtain a ternary composite cathode; A preparation method of the synergistically treated anode: cutting carbon felt into electrode sheets; placing the electrode sheets in a mixed solution of urea and sodium persulfate, heating and stirring; ultrasonic cleaning, drying and calcining the treated electrode sheets, and cooling to obtain a synergistically treated anode.

10. An energy supply device for a seabed microorganism detection apparatus, characterized by comprising: The energy supply device comprises the electrode assembly of any one of claims 1-8, and the electrode assembly supplies electrical energy to the detection equipment by outputting an open circuit voltage.

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