Implantable integrated supercapacitor and battery and preparation method thereof

Abstract

The present invention discloses an implantable integrated supercapacitor and battery and a preparation method thereof. The phase transformation film-forming property of polyethersulfone is utilized to prepare the integrated supercapacitor by layer-by-layer coating of the positive electrode-diaphragm-negative electrode casting solution and a one-step phase transformation process without the need for any binder or diaphragm. Finally, a current collector is introduced on the positive and negative electrodes by magnetron sputtering. The continuous distribution of polyethersulfone in each functional layer eliminates the interface, and the low-tortuosity finger-like pores generated during the phase separation process provide a fast ion transmission channel for the electrolyte ions. This method is not only simple, efficient, and controllable, but also can customize the shape, capacity, and mechanical strength of the integrated supercapacitor by changing the content, type, and additive amount of the active substance. Due to the excellent biocompatibility of the matrix material, the integrated supercapacitor and battery can be directly implanted into the human body without encapsulation and use body fluids as the electrolyte.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to an implantable integrated supercapacitor and battery and a preparation method thereof. Background Art

[0002] Implantable medical electronic devices, with their powerful diagnostic and therapeutic capabilities, offer a new approach to curing chronic diseases. Real-time monitoring of human physiological characteristics can improve treatment outcomes and reduce healthcare costs. Long-term use of implantable medical electronic devices requires high reliability, long service life, excellent biocompatibility, and miniaturization. However, the large size, poor flexibility, and biocompatibility of conventional energy storage devices limit their practical application. Therefore, the development of a new generation of miniaturized, flexible, implantable batteries or supercapacitors with excellent safety and long-term stability is crucial.

[0003] Currently, research on implantable batteries and supercapacitors primarily focuses on the preparation of high-performance electrodes. Device assembly typically involves sandwiching a gel electrolyte or separator between a pair of electrodes. During implantation, the device requires further encapsulation to ensure good contact between the electrodes and the electrolyte. While encapsulation can ensure basic device structural stability, prevent stress damage caused by tissue deformation after implantation, and isolate harmful electrolytes from the body, it not only significantly increases device size but also requires additional consideration of the safety and stability of the encapsulation materials. Damage to the encapsulation layer can lead to leakage of harmful electrolytes and collapse of the device structure. This traditional sandwich structure severely impacts the safety and stability of energy storage devices after implantation. Peng Huisheng et al. developed open-system batteries or supercapacitors using human body fluids (serum, blood) as electrolytes, which can completely eliminate the risk of harmful electrolyte leakage (Application Publication No.: CN 107221453A). However, the separated electrode and electrolyte layers can experience relative slippage between the layers during long-term implantation due to tissue deformation and body fluid penetration, reducing electrochemical performance. For some implantable batteries or supercapacitors that require the use of gel electrolytes (Mosa IM, et al. Ultrathin Graphene-Protein Supercapacitors for Miniaturized Bioelectronics. Advanced Energy Materials 2017, 7(17): 1700358; Sheng H, et al. Athin, deformable, high-performance supercapacitor implant that can be biodegraded and bioabsorbed within an animal body. Science Advances 2021, 7(2): eabe3097), fatal short circuit problems may even occur due to the degradation of the gel electrolyte. Therefore, the stability of the structure and performance of the device remains a huge challenge. For long-term implanted supercapacitors or batteries, all components (electrodes, electrolytes / diaphragms, and current collectors) must be constructed as a whole to ensure the stability of structural integrity, electrochemical properties, and mechanical properties that match the human body. Continuous and non-interface connections must be formed between the electrodes and the current collectors and the electrolytes / diaphragms. The integrated structure is conducive to the transport of ions and can avoid changes in the device structure during continuous deformation and extrusion of the tissue. Furthermore, batteries or supercapacitors used in open systems must be miniaturized and each component should have excellent biocompatibility.

[0004] So far, there is no method for preparing an integrated supercapacitor or battery for the implantable field. There are many existing methods for constructing integrated devices (application publication numbers: CN 107093520 A, CN 105977546 A), but the preparation method that completely eliminates the electrode-electrolyte / diaphragm interface is mainly an in-situ polymerization method using hydrogel as a substrate (Wang K, et al. Chemically Crosslinked Hydrogel Film Leads to Integrated Flexible Supercapacitors with Superior Performance. Advanced Materials 2015, 27(45): 7451-7457). The supercapacitor prepared by this method is usually thicker, which is not conducive to implantation and the stability of long-term implantation is limited. Therefore, developing a simple and efficient method to prepare ultra-thin, non-interface integrated supercapacitors and batteries suitable for the implantable field is crucial to the development of implantable medical electronic devices. Summary of the Invention

[0005] 1. Technical problems to be solved

[0006] The purpose of the present invention is to solve the problem that the integrated supercapacitors and batteries prepared in the prior art are usually thick, which is not conducive to implantation and cannot completely eliminate the problem that the long-term implantation stability of the interface is limited, and to propose an implantable integrated supercapacitor and battery and a preparation method thereof.

[0007] 2. Technical solution

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] An implantable integrated supercapacitor and battery includes an integrated thin film structure with a current collector, a positive electrode, a separator, a negative electrode and a current collector, and uses the physiological fluid of the implantation site as an electrolyte without the need for packaging.

[0010] Preferably, the current collector is at least one of metals such as Au, Ag, Mg, Zn, Al, Cu, and Mu magnetron sputtered on both sides of the integrated film.

[0011] Preferably, the implantable integrated supercapacitor membrane of the positive electrode, separator and negative electrode is prepared by phase conversion of a casting solution that has been previously applied layer by layer.

[0012] Preferably, the electrolyte is one of physiological saline, phosphate buffer solution, balanced salt solution, simulated body fluid, urine, blood, sweat, and gastric juice.

[0013] Preferably, the casting solution of the positive electrode portion comprises 0.9 g of polymer, 0.09-0.27 g of additive, 1 mL of ethanol (EtOH), 0.2-2.46 g of electroactive material, and 8 mL of N,N-dimethylacetamide (DMAC).

[0014] Preferably, the casting solution of the diaphragm portion includes 0.9 g of polymer and 8 mL of N,N-dimethylacetamide DMAC.

[0015] Preferably, the casting solution of the negative electrode part has the same components as those of the positive electrode except for the type of active material which may be different from that of the positive electrode.

[0016] Preferably, the phase inversion method is one or two of non-solvent induced phase inversion, heat induced phase inversion, and steam induced phase inversion.

[0017] Preferably, the active material is one or two of activated carbon, carbon nanotubes, polypyrrole, polyaniline, alizarin, graphene, manganese dioxide, manganese pentaoxide, molybdenum oxide, NMO, NTP, NMHCF, KMHCC and the like.

[0018] Preferably, the additive is one or more of amphiphilic block copolymers such as ammoniated polyethersulfone, sulfonated polyethersulfone, sulfonated polysulfone, polyethylene glycol, polyvinyl pyrrolidone, F127, P123, etc.

[0019] Preferably, the polymer is one or more polymers selected from the group consisting of polyethersulfone, polysulfone, polyvinylidene fluoride, cellulose acetate, polyacrylonitrile, polyvinyl alcohol, polylactic acid, polybenzimidazole, poly(phthalazine)ethersulfoneketone, poly(phthalazine)polyarylethersulfone, and poly(phthalazine)polyarylether.

[0020] The present invention also proposes a method for preparing an implantable integrated supercapacitor and battery, comprising the following steps:

[0021] Step 1: prepare the positive electrode casting solution a, the separator casting solution b and the negative electrode casting solution c respectively;

[0022] Step 2: coating the glass substrate with casting solution a, casting solution b and casting solution c in sequence;

[0023] Step 3: Phase-converting the coated three-layer casting solution to obtain an integrated supercapacitor or battery integrating a positive electrode, a separator, and a negative electrode;

[0024] Step 4: Magnetron sputtering Au current collectors on the positive and negative electrodes of the dried supercapacitor respectively to obtain the final implantable integrated supercapacitor or battery.

[0025] Preferably, the overall thickness of the prepared implantable integrated supercapacitor or battery can be controlled between 46-300 μm.

[0026] Preferably, the thickness of the Au current collector is 100 nm.

[0027] 3. Beneficial effects

[0028] Compared with the prior art, the advantages of the present invention are:

[0029] (1) In the present invention, for the first time, the characteristics of polyethersulfone phase conversion membrane are used to prepare an integrated energy storage device integrating positive electrode, separator and negative electrode through a one-step method. This method is simple and efficient, and overcomes the problem that the existing integrated preparation method cannot take into account the ultra-thin (1.2×1.2×0.01cm 3 The mass of the device is only 6.3 mg) and the disadvantages of the interface between the electrode and the electrolyte are completely eliminated, which makes it very controllable and universal.

[0030] (2) In the present invention, since polyethersulfone itself has excellent biocompatibility, the device prepared by this method does not need to be modified in terms of biocompatibility and can be used directly in an open human body environment.

[0031] (3) In the present invention, the shape, thickness, specific capacity, tensile strength and Young's modulus of the integrated supercapacitor and battery can be adjusted within a certain range.

[0032] (4) In the present invention, polyethersulfone has very good stability and will not decompose when immersed in physiological fluids for a long time. Moreover, the mechanical properties that match the mechanical properties of human soft tissues remain at a very high level when immersed in physiological fluids for a long time, making it very suitable for implantable bioelectronics.

[0033] (5) The integrated device prepared in the present invention exhibits excellent biocompatibility, mechanical properties similar to those of human soft tissue, and excellent electrochemical performance in an open physiological fluid environment without encapsulation. In particular, it maintains excellent stability under long-term implantation conditions. In particular, the capacity retention rate can still reach 94.03% after 40,000 charge-discharge cycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a laser confocal micrograph of an implantable integrated supercapacitor;

[0035] Figure 2 This is a scanning electron microscope image of an implantable integrated supercapacitor;

[0036] Figure 3 Cyclic voltammetry curves of implantable integrated supercapacitors at different scan rates in cell culture medium;

[0037] Figure 4The constant current charge and discharge curves of the implantable integrated supercapacitor at different current densities in cell culture medium;

[0038] Figure 5 The current density of the implantable integrated supercapacitor in phosphate buffer with a pH of 7.2-7.4 is 0.3 A·cm -3 Long cycle performance;

[0039] Figure 6 The Young's modulus and toughness of the implantable integrated supercapacitor after soaking in phosphate buffer solution for different times;

[0040] Figure 7 This is a bar graph of the in vitro cell proliferation rate of the implantable integrated supercapacitor;

[0041] Figure 8 Determination of coagulation time and fibrinogen content (blood PT, TT, APTT and FAB) of the implantable integrated supercapacitor body;

[0042] Figure 9 This is an H&E-stained photograph of a tissue section from the implantation site of an implantable integrated supercapacitor 15 days after it was implanted subcutaneously in the back of a mouse.

[0043] Figure 10 The implantable integrated supercapacitor with different amounts of aminated polyethersulfone was tested at a scan rate of 100mVs -1 Cyclic voltammetry curves when

[0044] Figure 11 The stress-strain curves of implantable integrated supercapacitors with different amounts of aminated polyethersulfone added. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0046] Example 1:

[0047] In the present invention, an implantable integrated supercapacitor and battery includes an integrated thin film structure having a current collector, a positive electrode, a separator, a negative electrode and a current collector, and uses the physiological fluid of the implantation site as an electrolyte without the need for packaging.

[0048] In the present invention, the preparation method of the implantable integrated supercapacitor and battery comprises the following steps:

[0049] Step 1: prepare the positive electrode casting solution a, the separator casting solution b and the negative electrode casting solution c respectively;

[0050] Step 2: coating the glass substrate with casting solution a, casting solution b and casting solution c in sequence;

[0051] Step 3: Phase-converting the coated three-layer casting solution to obtain an integrated supercapacitor or battery integrating a positive electrode, a separator, and a negative electrode;

[0052] Step 4: Magnetron sputtering Au current collectors on the positive and negative electrodes of the dried supercapacitor respectively to obtain the final implantable integrated supercapacitor or battery.

[0053] Example 2:

[0054] Under magnetic stirring at room temperature, 1 mL of anhydrous ethanol, 0.9 g of PES, 0.135 g of PES-NH2, and 2.46 g of AC-COOH were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution a. Simultaneously, 0.5 mL of anhydrous ethanol and 0.9 g of PES were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution b. Casting solution c was prepared using the same method as casting solution a. A preformed supercapacitor film was then prepared by sequentially casting casting solutions a, b, and c onto a glass substrate using a spin coater. The glass substrate coated with the casting solutions was then placed in deionized water for phase inversion to form an integrated supercapacitor. After completion, the film was immersed in deionized water for 24 hours to remove residual solvent and dried at 60°C for 12 hours. Finally, a 100 nm thick layer of gold was deposited on both sides of the supercapacitor as a current collector by magnetron sputtering.

[0055] Example 3:

[0056] Under magnetic stirring at room temperature, 1 mL of anhydrous ethanol, 0.9 g of PES, 0.135 g of PES-NH2, and 1.23 g of AC-COOH were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution a. Simultaneously, 0.5 mL of anhydrous ethanol and 0.9 g of PES were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution b. Casting solution c was prepared using the same method as casting solution a. A preformed supercapacitor film was then prepared by sequentially casting casting solutions a, b, and c onto a glass substrate using a spin coater. The glass substrate coated with the casting solutions was then placed in deionized water for phase inversion to form an integrated supercapacitor. After completion, the supercapacitor was immersed in deionized water for 24 hours to remove residual solvent and dried at 60°C for 12 hours. Finally, a 100 nm thick layer of gold was deposited on both sides of the supercapacitor by magnetron sputtering as the current collector.

[0057] Example 4:

[0058] Under magnetic stirring at room temperature, 1 mL of anhydrous ethanol, 0.9 g of PES, 0.09 g of PES-NH2, and 1.23 g of AC-COOH were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution a. Simultaneously, 0.5 mL of anhydrous ethanol and 0.9 g of PES were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution b. Casting solution c was prepared using the same method as casting solution a. A preformed supercapacitor film was then prepared by sequentially casting casting solutions a, b, and c onto a glass substrate using a spin coater. The glass substrate coated with the casting solutions was then placed in deionized water for phase inversion to form an integrated supercapacitor. After completion, the film was immersed in deionized water for 24 hours to remove residual solvent and dried at 60°C for 12 hours. Finally, a 100 nm thick layer of gold was deposited on both sides of the supercapacitor as a current collector by magnetron sputtering.

[0059] Example 5:

[0060] Under magnetic stirring at room temperature, 1 mL of anhydrous ethanol, 0.9 g of PES, 0.18 g of PES-NH2, and 1.23 g of AC-COOH were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution a. Simultaneously, 0.5 mL of anhydrous ethanol and 0.9 g of PES were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution b. Casting solution c was prepared using the same method as casting solution a. A preformed supercapacitor film was then prepared by sequentially casting casting solutions a, b, and c onto a glass substrate using a spin coater. The glass substrate coated with the casting solutions was then placed in deionized water for phase inversion to form an integrated supercapacitor. After completion, the supercapacitor was immersed in deionized water for 24 hours to remove residual solvent and dried at 60°C for 12 hours. Finally, a 100 nm thick layer of gold was deposited on both sides of the supercapacitor by magnetron sputtering as the current collector.

[0061] Example 6:

[0062] Under magnetic stirring at room temperature, 1 mL of anhydrous ethanol, 0.9 g of PES, 0.27 g of PES-NH2, and 1.23 g of AC-COOH were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution a. Simultaneously, 0.5 mL of anhydrous ethanol and 0.9 g of PES were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution b. Casting solution c was prepared using the same method as casting solution a. A preformed supercapacitor film was then prepared by sequentially casting casting solutions a, b, and c onto a glass substrate using a spin coater. The glass substrate coated with the casting solutions was then placed in deionized water for phase inversion to form an integrated supercapacitor. After completion, the film was immersed in deionized water for 24 hours to remove residual solvent and dried at 60°C for 12 hours. Finally, a 100 nm thick layer of gold was deposited on both sides of the supercapacitor as a current collector by magnetron sputtering.

[0063] Example 7:

[0064] Under magnetic stirring at room temperature, 1 mL of anhydrous ethanol, 0.9 g of PES, 0.135 g of PES-NH2, and 0.3 g of CNT were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution a. Simultaneously, 0.5 mL of anhydrous ethanol and 0.9 g of PES were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution b. Casting solution c was prepared using the same method as casting solution a. A preformed supercapacitor film was then prepared by sequentially casting casting solutions a, b, and c onto a glass substrate using a spin coater. The glass substrate coated with the casting solutions was then placed in deionized water for phase inversion to form an integrated supercapacitor. After completion, the supercapacitor was immersed in deionized water for 24 hours to remove residual solvent and dried at 60°C for 12 hours. Finally, a 100 nm thick layer of gold was deposited on both sides of the supercapacitor by magnetron sputtering as the current collector.

[0065] Example 8:

[0066] Under magnetic stirring at room temperature, 1 mL of anhydrous ethanol, 0.9 g of PES, 0.135 g of PES-NH2, and 0.87 g of PPy were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution a. Simultaneously, 0.5 mL of anhydrous ethanol and 0.9 g of PES were added to 8 mL of DMAC and stirred at room temperature for 24 hours to form casting solution b. Casting solution c was prepared using the same method as casting solution a. A preformed supercapacitor film was then prepared by sequentially casting casting solutions a, b, and c onto a glass substrate using a spin coater. The glass substrate coated with the casting solutions was then placed in deionized water for phase inversion to form an integrated supercapacitor. After completion, the supercapacitor was immersed in deionized water for 24 hours to remove residual solvent and dried at 60°C for 12 hours. Finally, a 100 nm thick layer of gold was deposited on both sides of the supercapacitor by magnetron sputtering as the current collector.

[0067] Example 9:

[0068] Under magnetic stirring at room temperature, 0.5 mL of anhydrous ethanol, 0.75 g of PES, 0.113 g of PES-NH2, and 0.272 g of PPy were added to 5 mL of DMAC and stirred at room temperature for 24 hours to form casting solution a. Casting solution b was then added to 5 mL of DMAC and stirred at room temperature for 24 hours to form casting solution c. Casting solution a, b, and c were then layered onto a glass substrate using a spin coater to prepare a preformed aqueous sodium-ion battery. The glass substrate coated with the casting solutions was then placed in deionized water for phase inversion to produce an integrated aqueous sodium-ion battery. After completion, the solution was immersed in deionized water for 24 hours to remove residual solvent and then dried at 60°C for 12 hours. Finally, 100 nm thick gold was deposited on both sides of the supercapacitor as the current collector by magnetron sputtering.

[0069] Example 10:

[0070] The structural characterization and electrochemical performance testing of the implantable integrated supercapacitor prepared in Example 1 of the present invention include the following steps:

[0071] S1. The structure and micromorphology of the implantable integrated supercapacitor were characterized by laser confocal microscopy and scanning electron microscopy.

[0072] The structure of the implantable integrated supercapacitor prepared in Example 1 of the present application can be characterized by Figure 1-2As shown, the supercapacitor prepared by the method of the present invention exhibits a structure integrating the positive electrode, negative electrode, and separator, and no interface is found in the cross-sectional scanning electron microscope, indicating that this method can completely eliminate the electrode-electrolyte interface.

[0073] S2. The electrochemical properties of the implantable integrated supercapacitor prepared in Example 1 were tested by cyclic voltammetry, constant current charge and discharge, and electrochemical impedance spectroscopy using an electrochemical workstation.

[0074] In step 2, the cyclic voltammetry test conditions are: in the potential range of 0-0.8 V, 10-100 mV s -1 The electrochemical performance of the implantable integrated supercapacitor prepared in Example 1 was tested at different scan rates.

[0075] In step 2, the constant current charge and discharge test conditions are: in the potential range of 0-0.8V, 0.02-1A cm -3 The electrochemical performance of the implantable integrated supercapacitor prepared in Example 1 was tested at a current density of .

[0076] In step 2, the electrochemical impedance spectroscopy test conditions are: -2 -10 5 Hz frequency range, the electrochemical performance of the implantable integrated supercapacitor prepared in Example 1 was tested.

[0077] The electrochemical performance test results of the implantable integrated supercapacitor prepared in Example 1 of the present application can be obtained by Figure 3-4 As shown in Figure 2, the implantable integrated supercapacitor has good charge and discharge behavior at a current density of 0.1 A cm -3 When 11.74F cm -3 High volumetric capacity.

[0078] S3. The cycling performance of the implantable integrated supercapacitor prepared in Example 1 was tested using the LAND battery testing system.

[0079] In step 3, the cycle test conditions are: at a current density of 0.3 A cm -3 The long cycle performance of the implantable integrated supercapacitor prepared in Example 1 was tested.

[0080] The results of the cycle performance test of the implantable integrated supercapacitor prepared in Example 1 of the present application can be obtained from Figure 5 As shown, the capacity retention rate of the implantable integrated supercapacitor can reach 94.03% after 40,000 cycles, indicating that the electrochemical performance of the implantable integrated supercapacitor maintains good long-term stability during long-term operation.

[0081] S4. The mechanical properties of the implantable integrated supercapacitor prepared in Example 1 were tested using an electronic universal testing machine.

[0082] The results of the cycle performance test of the implantable integrated supercapacitor prepared in Example 1 of the present application can be obtained from Figure 6 As shown in the figure, the Young's modulus of the implantable integrated supercapacitor decreased and the toughness increased after being continuously immersed in a phosphate buffer solution similar to physiological fluid for 1,440 hours. The decrease in Young's modulus increased the matching of the mechanical properties of the supercapacitor and human soft tissue.

[0083] S5. The cytotoxicity test of the implantable integrated supercapacitor prepared in Example 1 of the present application mainly includes the following steps:

[0084] 1) Cell culture

[0085] DMEM complete medium containing NAH3T3 cells (5,000 cells / well) was cultured in a 96-well plate at 37°C in a 5% CO2 incubator for 24 hours. Then, 10 μL of the sterile extract of the implantable integrated supercapacitor prepared in Example 1 at different concentrations was added to each well of the above 96-well plate, and the 96-well plate was cultured at 37°C in a 5% CO2 incubator for 24, 48 and 72 hours. At the same time, a blank control group and a negative group were set up. The blank control group was not inoculated with NAH3T3 cells, and the negative control group was replaced with DMEM complete medium (10 μL) instead of the sterile extract of the implantable integrated supercapacitor prepared in Example 1 (three parallel control groups were set up for each group).

[0086] 2) The cytotoxicity test of the implantable integrated supercapacitor prepared in Example 1 was performed using the CCK-8 method.

[0087] After the cell culture in step 1) is completed, 10 μL of CCK-8 reagent is added to each well, followed by an additional 2 h of incubation in a 37°C CO2 incubator. The absorbance (OD) of the 96-well plate is then measured at 450 nm using a microplate reader, and the relative cell proliferation rate is calculated according to the following formula.

[0088] Cell proliferation rate (%) = (optical density of experimental group - optical density of blank group) / (optical density of negative group - optical density of blank group) × 100

[0089] The results of the cytotoxicity test on the implantable integrated supercapacitor prepared in Example 1 of the present application are as follows: Figure 7 As shown, the relative cell proliferation rates were all higher than 88.6%, indicating that the implantable integrated supercapacitor prepared in Example 1 had no toxicity to NAH3T3 cells.

[0090] S6. Perform a surface anticoagulation test on the implantable integrated supercapacitor prepared in Example 1 of the present application.

[0091] Fresh rat blood was mixed with sodium citrate and centrifuged at 4000 rpm for 15 minutes to obtain platelet-poor plasma (PPP). 2 The implantable integrated supercapacitor membrane was soaked in 3 mL of PBS for 24 hours and then incubated with 1 mL of PPP at 37°C for 30 minutes. The membrane was removed and 50 μL of PPP was used to measure in vitro coagulation times, including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), and fibrinogen (FAB). Measurements were performed on a CA-5100 automated blood coagulation analyzer.

[0092] The results of the cytotoxicity test on the implantable integrated supercapacitor prepared in Example 1 of the present application are as follows: Figure 8 As shown in the figure, the APTT and TT of the integrated implantable supercapacitor are longer than those of the control sample, the TT is increased by about 4 times compared with the control sample, and the FAB content is reduced, indicating that the integrated implantable supercapacitor has good anti-coagulation ability and will not produce thrombus on its surface after implantation in the body.

[0093] S7. Perform pathological analysis and testing on the implantable integrated supercapacitor prepared in Example 1 of the present application.

[0094] Male Sprague-Dawley rats (white, 200-220 g, 40 days old) were purchased from the Animal Center of Lanzhou University School of Medicine and housed in an environment with a temperature of 22 ± 1°C under standard 12-h light / dark conditions with ad libitum access to food and water. The animals were used only once and were well cared for and treated humanely. We followed the protocol approved by the Ethics Committee of Lanzhou University (authorization number: D2022-314). Our investigation complied with the animal policy of Lanzhou University and the accreditation standards of the Association for the Accreditation of Laboratory Animal Care. All efforts were made to minimize animal suffering and reduce the number of animals used. Rats were fed under experimental conditions for 1 week before surgery. Rats were anesthetized with halothane gas (4% pure medical grade oxygen) and then intraperitoneally injected with 1% sodium pentobarbital (40 mg / kg -1 ) for induction and maintenance of anesthesia. The supercapacitor was disinfected by soaking in 75% alcohol for 24 hours and implanted subcutaneously on the back of SD rats. The rats were euthanized 2 weeks after implantation. The biocompatibility of the supercapacitor was examined. The dorsal tissue attached to the supercapacitor 2 weeks after implantation was stained with hematoxylin and eosin (H&E, for histology) and imaged using a slide scanner to assess the microscopic tissue inflammatory response.

[0095] The results of the cytotoxicity test on the implantable integrated supercapacitor prepared in Example 1 of the present application are as follows: Figure 9As shown, no obvious inflammatory reaction was observed at the implantation site, indicating that the integrated supercapacitor is suitable for implantable fields and will not cause harm to the human body.

[0096] In the present invention, for the first time, the characteristics of polyethersulfone phase conversion membrane are used to prepare an integrated energy storage device integrating positive electrode, separator and negative electrode through a one-step method. This method is simple and efficient, and overcomes the problem that the existing integrated preparation method cannot take into account the ultra-thin (1.2×1.2×0.01cm -3 The mass of the device is only 6.3 mg) and the disadvantages of the interface between the electrode and the electrolyte are completely eliminated, which makes it very controllable and universal.

[0097] The integrated device fabricated in this invention exhibits excellent biocompatibility, mechanical properties similar to those of human soft tissue, and superior electrochemical performance in an open physiological fluid environment without encapsulation. In particular, it maintains excellent stability under long-term implantation conditions. Notably, it maintains a capacity retention rate of 94.03% after 40,000 charge-discharge cycles.

[0098] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. An implantable integrated device supercapacitor, characterized in that: The invention comprises an integrated thin film structure with a current collector, a positive electrode, a separator, a negative electrode and a current collector, and an electrolyte that uses a physiological fluid at the implantation site without packaging. The current collector is Au metal magnetron sputtered on both sides of the integrated film. The implantable integrated supercapacitor film of the positive electrode, separator and negative electrode is prepared by phase conversion of casting liquids previously applied in a solution state, namely, a positive electrode casting liquid, a separator liquid and a negative electrode casting liquid. The electrolyte is one of physiological saline, phosphate buffer solution, balanced salt solution, simulated body fluid, urine, blood, sweat and gastric juice. The casting liquid composition of the positive electrode portion includes 0.9g of polymer polyethersulfone, 0.09-0.27g of additive aminated polyethersulfone, 1mL of ethanol EtOH, 0.2-2.46g of electroactive material and N, 8 mL of N-dimethylacetamide (DMAC), the electroactive material is one or two of activated carbon, carbon nanotubes, and polypyrrole, and the casting solution of the diaphragm portion includes 0.9 g of polymer polyethersulfone and 8 mL of N, N-dimethylacetamide (DMAC).

2. The implantable integrated supercapacitor according to claim 1, characterized in that: The casting liquid composition of the negative electrode part is consistent with that of the positive electrode except that the type of active material may be different.

3. The implantable integrated supercapacitor according to claim 1, characterized in that: The phase inversion method is one or two of non-solvent induced phase inversion, heat induced phase inversion, and steam induced phase inversion.

4. The method for preparing an implantable integrated supercapacitor according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: prepare the positive electrode casting solution a, the separator casting solution b and the negative electrode casting solution c respectively; Step 2: coating the glass substrate with the casting liquid a, the casting liquid b and the casting liquid c in sequence; Step 3: Phase-converting the coated three-layer casting solution to obtain an integrated device supercapacitor integrating a positive electrode, a separator and a negative electrode; Step 4: Magnetron sputtering Au current collectors on the positive and negative electrodes of the dried supercapacitor respectively to obtain the final implantable integrated device supercapacitor.

5. The method for preparing an implantable integrated device supercapacitor according to claim 4, characterized in that: The overall thickness of the prepared implantable integrated device supercapacitor can be controlled between 46 and 300 μm.

6. The method for preparing an implantable integrated device supercapacitor according to claim 4, characterized in that: The thickness of the Au current collector is 100 nm.

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