Conductive hydrogel pole piece, preparation method thereof and conductive hydrogel battery

Abstract

The invention belongs to the technical field of new energy, and particularly relates to a conductive hydrogel pole piece, a preparation method thereof and a conductive hydrogel battery. The preparation method of the conductive hydrogel pole piece comprises the following steps: 1) uniformly mixing bovine serum albumin and polypyrrole dispersion liquid, stirring at normal temperature, and uniformly dispersing; (2) uniformly dispersing an iron metal organic framework material into the solution obtained in the step (1); 3) dispersing a cross-linking agent and the like into the solution, and fully stirring and dissolving; and 4) taking out the solution, pouring the solution into a mold, and heating in a water bath to prepare a bovine serum albumin, polypyrrole hydrogel and iron metal organic framework composite material, thereby obtaining the conductive hydrogel pole piece. The protein is used as the main body structure of the hydrogel electrode, the conductive material and the catalytic material are added to form the cathode and the anode of the battery, the biomimetic fluid can be used for supplying energy, and the problems that an external power supply is needed for charging and the biocompatibility of the material is poor can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of new energy, and in particular relates to a conductive hydrogel electrode, a preparation method thereof, and a conductive hydrogel battery. Background Art

[0002] At present, the batteries commonly used in our daily lives include dry batteries, lead-acid batteries, lithium batteries, etc., which are made of hard materials and are relatively large in size. They are not suitable for small wearable devices, and these batteries need to be charged or replaced regularly and cannot be used for a long time. At present, research has found that self-powered battery technologies such as piezoelectric and friction electrification technologies can make batteries miniaturized, but the electricity generated by these technologies has disadvantages such as instability and unsustainability. Compared with the above methods, enzyme biofuel cells can use biological enzymes as efficient electrocatalysts to convert glucose, ascorbic acid, lactic acid, electrolytes and other substances in the body into stable and continuous current. This type of battery can be miniaturized, improve portability during use, and have low production costs. It also has the advantages of being green and biocompatible.

[0003] Biological skin is made of soft, water-rich tissue. When batteries are constructed with hard, dry electronic components, the resistance between the biological tissue and the electrode will increase greatly, affecting the electrochemical performance. Hydrogel, as a lightweight patch suitable for biological skin, does not hinder the movement of the organism, so it is more suitable for use in wearable miniaturized devices in real life than traditional batteries. Summary of the invention

[0004] In order to solve the deficiencies of the prior art, the present invention provides a conductive hydrogel electrode, a preparation method thereof and a conductive hydrogel battery. The present invention uses protein as the main structure of the hydrogel electrode, adds conductive materials and catalytic materials to form the positive and negative poles of the battery, and can use biological fluids to provide energy, thereby solving the problems of needing an external power supply for charging and poor biocompatibility of materials.

[0005] The technical solution provided by the present invention is as follows:

[0006] A method for preparing a conductive hydrogel electrode comprises the following steps:

[0007] 1) uniformly mixing bovine serum albumin and polypyrrole dispersion, stirring at room temperature, and uniformly dispersing;

[0008] 2) evenly dispersing the iron metal organic framework material into the solution obtained in step 1);

[0009] 3) dispersing 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide into the above solution, and stirring thoroughly to dissolve;

[0010] 4) The solution is taken out and poured into a mold, and after heating in a water bath, a composite material of bovine serum albumin, polypyrrole hydrogel and iron metal organic framework is prepared to obtain a conductive hydrogel electrode.

[0011] In the above technical solution, bovine serum albumin is used as the main material of the hydrogel, polypyrrole is used as the conductive material, and the iron metal organic framework material is used as the catalytic conductive material. The obtained material can be used as a positive electrode or a sensor material. Under the action of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide, bovine serum albumin forms a main framework structure of the hydrogel through self-polymerization and cross-linking. It is further physically cross-linked and cured in a water bath.

[0012] Specifically, in the solution obtained in step 1), the content of bovine serum albumin is 30-60 wt %; the content of polypyrrole is 3.68×10 -2 ~7.35×10 -2 wt%.

[0013] Specifically, in the solution obtained in step 2), the content of the iron metal organic framework material is 0.5-1 wt%.

[0014] Specifically, in the solution obtained in step 3), the content of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1.10-1.84 wt %; and the content of N-hydroxysuccinimide is 1.02-1.93 wt %.

[0015] Specifically, in the solution obtained in step 4), the water bath heating temperature is 45 to 55° C., and the water bath heating time is 25 to 35 minutes.

[0016] Furthermore, in step 2), glucose oxidase is also added, and the content of glucose oxidase in the obtained solution is 0.5-1.5 wt %, preferably 10-20 mM.

[0017] Based on the above technical solution, by further adding glucose oxidase, glucose can be oxidized to release hydrogen peroxide, which is further catalyzed by the iron metal organic framework material to obtain hydroxyl radicals, which can be used as a battery negative electrode to carry out battery reactions.

[0018] The present invention also provides a conductive hydrogel electrode sheet prepared by the above preparation method.

[0019] The present invention also provides a conductive hydrogel battery, comprising:

[0020] Sealed housing;

[0021] The conductive hydrogel positive electrode sheet provided by the above technical solution is fixed on one side of the sealed shell;

[0022] The conductive hydrogel negative electrode sheet provided by the above technical solution is fixed on the other side of the sealed shell;

[0023] and a biological fluid-like electrolyte filled in the sealed shell.

[0024] Based on the above technical scheme, the conductive hydrogel battery, as an enzyme biofuel cell, can imitate biological fluids or biological fluids to provide energy for electrolytes.

[0025] Specifically, the bio-fluid-like electrolyte is an aqueous solution, which contains at least glucose. The content of glucose can be any concentration below the saturation concentration. The bio-fluid-like electrolyte contains dissolved oxygen.

[0026] The present invention also provides an application of a conductive hydrogel electrode for preparing a wearable sensor or an implantable sensor. The preparation method of the electrode adopts the above method without adding an iron metal organic framework material or glucose oxidase.

[0027] Based on the above technical solution, due to its good biocompatibility, it can be used as an implantable sensor or a wearable sensor, can output stable signals for a long time, has high conductivity, can be used as a human motion signal sensor, has good mechanical properties, and has good comfort, can be miniaturized, and has a simple structure.

[0028] Because it can adapt to human skin, can be implanted in the body, and has stable output electrochemical properties, it can be used as a sensor for signal sensing such as electrocardiogram, electromyography, motion and sound output. Furthermore, this hydrogel battery can be used to monitor body fluid concentration.

[0029] The beneficial effects of the present invention are:

[0030] 1. The present invention uses bovine serum albumin as the main frame material of the hydrogel, so that this protein hydrogel electrode has better biocompatibility than other hydrogel electrodes;

[0031] 2. The present invention uses polypyrrole materials and metal organic framework materials as conductive materials, providing the hydrogel battery with dual conductivity of electronic conductivity and ionic conductivity, and has better sensing performance than other hydrogels made of single conductive materials;

[0032] 3. The hydrogel battery of the present invention has good mechanical properties and adhesion properties, and is more comfortable than commercial rubber, plastic, metal-based electrodes;

[0033] 4. The hydrogel battery of the present invention does not require external power supply for charging and can be directly powered by electrolyte;

[0034] 5. The hydrogel electrode of the present invention can be used as an electrode to monitor multiple physiological indicators, such as electrocardiogram, electromyographic action and sound output signals, and can further monitor body fluid concentration when used as an implanted battery;

[0035] 6. The hydrogel battery of the present invention has multiple functions and can be further functionalized while performing monitoring and sensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a physical picture of the hydrogel electrode.

[0037] Figure 2 This is a cell growth diagram of the hydrogel electrode and cells co-incubated in the embodiment.

[0038] Figure 3 This is a motion signal sensing diagram of the hydrogel electrode attached to the human body in the embodiment.

[0039] Figure 4 Graph showing the output voltage of the hydrogel battery in the embodiment.

[0040] Figure 5 Schematic diagram of the structure of the conductive hydrogel battery in the embodiment.

[0041] Figure 6 Schematic diagram of the conductive hydrogel battery in the embodiment.

[0042] Attached Figure 5 The structures represented by the labels are listed below:

[0043] 1. Sealed shell, 2. Positive electrode, 3. Negative electrode. DETAILED DESCRIPTION

[0044] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0045] Unless otherwise specified, the test methods used in the embodiments of the present invention are all conventional methods; the materials, reagents, etc. used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0046] Preparation of iron metal organic framework material: add 2-methylimidazole with a mass fraction of 8.5wt% after configuration into ultrapure water, and after fully dissolving under magnetic stirring at 1000r / min, add zinc nitrate with a mass fraction of 1.4wt% after configuration and ferrous sulfate with a mass fraction of 0.08wt% after configuration into the above solution, then heat in a water bath at 15°C and magnetically stir at 1000r / min for 20 minutes, collect the generated solid material, wash with ultrapure water, and centrifuge at 12000rpm at 4°C in a low-temperature high-speed centrifuge, repeat the washing and centrifugation 5 times, collect the precipitate, put it into a -80°C refrigerator and freeze it for 24h, and then use a freeze dryer to vacuum dry it at -60°C for 24h to obtain the iron metal organic framework material.

[0047] The synthesis method of the metal organic framework material loaded with glucose oxidase is similar to that of the iron metal organic framework material, except that glucose oxidase with a mass fraction of 1 wt % after configuration is added during the synthesis process.

[0048] In one embodiment, when preparing a bovine serum albumin / polypyrrole hydrogel electrode, a bovine serum albumin having a mass fraction of 30 to 60 wt% after configuration and a bovine serum albumin having a mass fraction of 3.68×10 -2 ~7.35×10 -2 wt% polypyrrole dispersion is evenly mixed, stirred at room temperature for 1 hour, and evenly dispersed; then the iron metal organic framework material with a mass fraction of 0.5-1wt% after configuration is evenly dispersed in the above solution, and fully and evenly dispersed for 1 hour; further, 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride with a mass fraction of 1.10-1.84wt% after configuration and N-hydroxysuccinimide with a mass fraction of 1.02-1.93wt% after configuration are dispersed in the above solution, fully stirred for 10 minutes, and dissolved; the solution is taken out and poured into a mold, and heated in a water bath at 50°C for 30 minutes to complete the preparation of the cathode electrode, which is used as the positive electrode of the battery.

[0049] The iron metal organic framework material is replaced with a metal organic framework material loaded with glucose oxidase, and the anode electrode is prepared according to the same steps as above and used as the negative electrode of the battery.

[0050] Embodiment 1

[0051] Step 1: prepare bovine serum albumin gel, disperse bovine serum albumin with a mass fraction of 30 wt% in ultrapure water, stir at room temperature for 1 hour, and disperse evenly;

[0052] Step 2: Disperse 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride having a mass fraction of 1.10 wt% and N-hydroxysuccinimide having a mass fraction of 1.02 wt% into the above solution, stir thoroughly for 10 min, and dissolve;

[0053] Step 3: Take out the solution and pour it into the mold. Heat it in a 50°C water bath for 30 minutes to complete the preparation of the bovine serum albumin gel.

[0054] Test its biocompatibility.

[0055] Embodiment 2

[0056] Step 1: Prepare bovine serum albumin / polypyrrole hydrogel electrode, and mix bovine serum albumin with a mass fraction of 30 wt% and a -2 wt% polypyrrole dispersion was uniformly mixed and stirred for 1 h at room temperature until it was evenly dispersed;

[0057] Step 2: Disperse 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride having a mass fraction of 1.10 wt% and N-hydroxysuccinimide having a mass fraction of 1.02 wt% into the above solution, stir thoroughly for 10 min, and dissolve;

[0058] Step 3: Take out the solution and pour it into the mold. Heat it in a 50°C water bath for 30 minutes to complete the preparation of the bovine serum albumin / polypyrrole hydrogel electrode.

[0059] Test its human motion sensing performance and biocompatibility.

[0060] Embodiment 3

[0061] Step 1: Prepare bovine serum albumin / polypyrrole hydrogel / iron metal organic framework material electrode, and mix bovine serum albumin with a mass fraction of 30 wt% and a -2 wt% polypyrrole dispersion was uniformly mixed and stirred for 1 h at room temperature until it was evenly dispersed;

[0062] Step 2: Evenly disperse the iron metal organic framework material with a mass fraction of 0.50wt% after configuration into the above solution, and fully and evenly disperse it for 1h;

[0063] Step 3: Disperse 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride having a mass fraction of 1.10 wt% and N-hydroxysuccinimide having a mass fraction of 1.02 wt% into the above solution, stir thoroughly for 10 min, and dissolve;

[0064] Step 4: Take out the solution and pour it into the mold. After heating in a 50°C water bath for 30 minutes, the preparation of the bovine serum albumin / polypyrrole hydrogel / iron metal organic framework material cathode electrode is completed.

[0065] Test the electrochemical performance and biocompatibility.

[0066] Embodiment 4

[0067] The difference from Example 3 is that the iron metal organic framework material loaded with glucose oxidase is added in step 2. The hydrogel electrode prepared in this example is a bovine serum albumin / polypyrrole hydrogel / glucose oxidase iron metal organic framework material anode.

[0068] Test the electrochemical performance and biocompatibility.

[0069] Test results:

[0070] 1. Test the biocompatibility of the hydrogel electrodes, such as Figure 1 The actual picture of the hydrogel electrode is shown in Figure 1. Weigh 1g of the hydrogels of Examples 1, 2, 3, and 4 respectively, and soak them in 3mL of DMEM medium for 24h. Take out the leaching liquid of different hydrogels respectively, and add 10% fetal bovine serum to each of them. Next, press 2×10 4 NIH 3T3 cells were inoculated into 12-well plates at a density of 1.5 cells / well. After the NIH 3T3 cells adhered to the wall, the culture medium extracts of different groups of hydrogel electrodes were added and cultured in a 37°C incubator for 24 hours and 48 hours. After completion, the CCK-8 kit was used to detect the toxic effects of each group of hydrogels on cells. The results are shown in Figure 2 The figure shows the cell growth diagram of the hydrogel electrode and cells co-incubated in the embodiment. The NIH 3T3 cells cultured in each group of hydrogel culture medium extract grew normally as the NIH 3T3 cell blank control group without hydrogel extract, which proves that the hydrogels prepared in the above embodiments have excellent biocompatibility and will not affect the normal growth of cells.

[0071] 2. Test the human motion signal sensing performance. The bovine serum albumin / polypyrrole hydrogel electrode prepared in Example 2 was attached to the finger joints, and the hydrogel electrode was connected to the Keithley 2450 through a wire. The resistance detection mode was adjusted. The finger was bent to 30°, 60°, 90°, and 0° respectively. The resistance change of the hydrogel electrode was detected, and the resistance change rate of the hydrogel was further calculated to observe the sensing ability of the hydrogel electrode. Figure 3 The figure shows the motion signal sensing diagram of the hydrogel electrode attached to the human body in the embodiment. This hydrogel electrode shows excellent motion signal sensing ability, fast and sensitive response, and excellent stability of continuous sensing signals, proving that this hydrogel electrode can be used as a wearable sensing device.

[0072] 3. Test the electrochemical signal. The cathode electrode of bovine serum albumin / polypyrrole hydrogel / iron metal organic framework material of Example 3 and the anode electrode of bovine serum albumin / polypyrrole hydrogel / glucose oxidase iron metal organic framework material of Example 4 were placed in a 15 mM glucose solution after connecting the positive and negative hydrogel electrodes with wires. They were connected to Shanghai Chenhua CHI660E electrochemical workstation respectively to test their open circuit voltages. Figure 4 The output voltage of the hydrogel battery in the embodiment is shown in FIG. A long-term stable output voltage can be observed, proving that the conductive hydrogel battery is an enzyme biofuel cell that does not require external power supply and can be directly powered by glucose, one of the biological fluids.

[0073] Embodiment 5

[0074] like Figure 5 As shown, the conductive hydrogel battery comprises: a sealed shell 1; a positive electrode sheet 2 fixed on one side of the sealed shell 1; and a negative electrode sheet 3 fixed on the other side of the sealed shell 1. The sealed shell is filled with a biological fluid electrolyte. The sealed shell can be provided with a liquid injection port. The positive electrode sheet and the negative electrode sheet can be selected from the electrode sheets of the fourth embodiment. Figure 6 The figure shows the schematic diagram of a conductive hydrogel battery. Current is generated during the anode and cathode reactions. The anode serves as the negative electrode of the battery and the cathode serves as the positive electrode of the battery.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a conductive hydrogel electrode, characterized in that: The following steps are involved: 1) uniformly mixing bovine serum albumin and polypyrrole dispersion, stirring at room temperature, and uniformly dispersing; 2) evenly dispersing the iron metal organic framework material into the solution obtained in step 1); 3) dispersing 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide into the above solution, and stirring thoroughly to dissolve; 4) The solution is taken out and poured into a mold, and after heating in a water bath, a composite material of bovine serum albumin, polypyrrole hydrogel and iron metal organic framework is prepared to obtain a conductive hydrogel electrode.

2. The method for preparing a conductive hydrogel electrode according to claim 1, characterized in that: In the solution obtained in step 1), the content of bovine serum albumin is 30-60 wt %; the content of polypyrrole is 3.68×10 -2 ~7.35×10 -2 wt%.

3. The method for preparing a conductive hydrogel electrode according to claim 1, characterized in that: In the solution obtained in step 2), the content of the iron metal organic framework material is 0.5-1 wt%.

4. The method for preparing a conductive hydrogel electrode according to claim 1, characterized in that: In the solution obtained in step 3), the content of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1.10-1.84 wt %; the content of N-hydroxysuccinimide is 1.02-1.93 wt %.

5. The method for preparing a conductive hydrogel electrode according to claim 1, characterized in that: In step 4), the solution obtained is heated in a water bath at a temperature of 45 to 55° C. and a heating time of 25 to 35 min.

6. The method for preparing a conductive hydrogel electrode according to any one of claims 1 to 5, characterized in that: In step 2), glucose oxidase is also added, and the content of glucose oxidase in the obtained solution is 0.5-1.5wt%.

7. A conductive hydrogel electrode prepared according to the preparation method according to any one of claims 1 to 6.

8. A conductive hydrogel battery, characterized in that: include: Sealed housing; A conductive hydrogel electrode according to any one of claims 1 to 5 fixed to one side of the sealed shell as a positive electrode; The conductive hydrogel electrode sheet according to claim 6 fixed on the other side of the sealed shell serves as a negative electrode sheet; and a biological fluid-mimicking electrolyte filled in the sealed shell.

9. The conductive hydrogel battery according to claim 8, characterized in that: The bio-fluid-mimicking electrolyte is an aqueous solution, which contains at least glucose.

10. A conductive hydrogel electrode according to claim 7, characterized in that: Used to prepare wearable sensors or implantable sensors.

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