Concrete composite electrode and continuous interface all-solid-state cement-based structure supercapacitor and preparation method

Abstract

This invention provides a concrete composite electrode and a continuous-interface all-solid-state cement-based supercapacitor, along with their fabrication method. The method includes preparing a conductive cement-based electrode slurry, preparing an ion-transporting cement-based membrane slurry, placing a current collector within the conductive cement-based electrode slurry to form two concrete composite electrodes, and then placing and in-situ curing a cement-based membrane layer between the two concrete composite electrodes. After curing, a continuous-interface all-solid-state cement-based supercapacitor is obtained. This supercapacitor can operate directly after curing without further soaking, enabling the integral construction of the electrode layer, membrane layer, and current collector, reducing interlayer impedance, and improving the overall integrity and structural continuity of the device.

Description

Technical Field

[0001] This invention relates to the field of supercapacitors, and more specifically, to a concrete composite electrode and a continuous interface all-solid-state cement-based supercapacitor and its preparation method. Background Technology

[0002] With the development of integrated energy infrastructure and functionalized building materials, structural supercapacitors that combine load-bearing capacity and energy storage function have gradually become an important research direction in the interdisciplinary field of civil engineering and energy storage materials. Cement-based materials are widely available, low in cost, highly malleable, and can be molded on a large scale through casting processes, thus they are considered an important candidate system for constructing structural energy storage devices.

[0003] Existing cement-based supercapacitors typically utilize electrodes made by introducing conductive carbon materials into a cement matrix, combined with a diaphragm and electrolyte to achieve energy storage, as illustrated in invention patent applications CN117809988A and CN120309287A. However, existing technologies still suffer from the following main problems: First, many devices still employ a layered assembly method involving electrode prefabrication, electrolyte immersion, diaphragm clamping, and post-packaging. The functional layers of the device rely on post-contact to form the working interface, resulting in significant interfacial discontinuities between the electrode layer, diaphragm layer, and electrolyte layer, which can easily lead to high interlayer contact resistance or interface impedance. Second, liquid electrolyte immersion systems usually require subsequent saturation treatment, and their interface state is greatly affected by the degree of wetting, electrolyte retention capacity, and long-term service environment, making it difficult to form a stable, all-solid-state integrated device. Third, the traditional layered assembly route lacks compatibility with the template casting, continuous curing, and integrated structural molding processes commonly used in civil engineering, making it difficult to directly extend to integral building components with load-bearing functions.

[0004] Furthermore, existing technologies for preparing conductive electrodes and separators using cementitious materials lack clear and systematic solutions regarding how to form a continuous and stable ion transport interface between the electrode layer and the separator layer, how to avoid the layered structural defects that still exist even with material replacement, and how to adapt the device construction method to civil engineering casting processes. Summary of the Invention

[0005] The purpose of this invention is to provide a concrete composite electrode and a continuous interface all-solid cement-based supercapacitor and its preparation method, so as to solve the problems of high interlayer interface impedance, insufficient structural continuity, poor long-term stability and difficulty in adapting to civil engineering casting processes caused by existing cement-based supercapacitors that rely on layered assembly and post-immersion in liquid electrolyte.

[0006] Another objective of this invention is to provide an all-solid-state energy storage supercapacitor with a continuous interface formed by in-situ co-curing of the electrode layer and the separator layer. In this supercapacitor, the electrode layer undertakes electron transport and energy storage functions, while the separator layer undertakes ion transport and electron isolation functions, and simultaneously acts as an interlayer connecting layer to fix the two electrode layers together. The supercapacitor does not require initial immersion to establish a working interface, and exhibits better interface stability and overall continuity during storage, weathering, or long-term service, which helps to reduce the performance degradation rate and improve the adaptability to engineering applications, thereby achieving the integration of load-bearing and energy storage functions.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a concrete composite electrode, comprising the following steps: mixing cementitious materials, mixing and activating liquid, conductive filler and reinforcing conductive fiber material in a mass ratio of 1:(0.8-1):(0.01-0.30):(0.001-0.10) to prepare a conductive cement-based electrode slurry; pouring the conductive cement-based electrode slurry into two electrode molds respectively, inserting current collectors into each mold, and obtaining two concrete composite electrodes after molding; wherein the cementitious material is a cement-based cementitious material or a geopolymer cementitious material, and the mixing and activating liquid includes one or a combination of at least two of potassium hydroxide solution, sodium hydroxide solution, potassium silicate and sodium silicate.

[0008] Based on the above, the cement-based cementitious material includes one or a combination of at least two of silicate cement, slag cement, high belite cement, and magnesium slag silicate cement, and the geopolymer cementitious material includes fly ash or slag powder or a mixture of fly ash and slag powder in a mass ratio of (3-4):2.

[0009] The present invention also provides a concrete composite electrode prepared by the above preparation method.

[0010] The present invention also provides an application of the concrete composite electrode in the preparation of a continuous interface all-solid-state cement-based supercapacitor.

[0011] This invention also provides a method for preparing a continuous interface all-solid-state cement-based supercapacitor using the aforementioned concrete composite electrode, comprising the following steps: Step 1: Prepare the concrete composite electrode; Step 2: Prepare an ion-transporting cementitious membrane slurry by mixing the cementitious material, mixing and activating liquid and diaphragm fiber material in a mass ratio of 1:(0.8~1):(0.001~0.10). Step 3: The ion-transporting cement-based diaphragm slurry is placed and solidified in situ between the two concrete composite electrodes to form a cement-based diaphragm layer. After curing, a continuous interface all-solid cement-based supercapacitor is obtained.

[0012] The present invention also provides a continuous interface all-solid-state cement-based supercapacitor, comprising two opposing conductive cement-based electrode layers, a cement-based separator layer located between the two conductive cement-based electrode layers, and a current collector disposed inside the conductive cement-based electrode layers; The cement-based membrane layer and the conductive cement-based electrode layers on both sides are formed into a continuous interface through in-situ curing, so as to connect the conductive cement-based electrode layers on both sides into an integral load-bearing structure. The conductive cement-based electrode layer is used to form an electron transport network and an energy storage active interface. The cement-based membrane layer is used to form an ion transport channel and block direct electron conduction between the two electrode layers. The current collector is used to collect the charge in the conductive cement-based electrode layer and conduct it outward.

[0013] In this invention, the cement-based membrane layer simultaneously serves as an ion transporter, an electron separator, and an interlayer structural connector in the supercapacitor. A continuous interface is formed between the concrete composite electrode and the cement-based membrane layer through in-situ curing.

[0014] In this invention, preferably, the cementing material is a geopolymer cementing system. The conductive filler is used to construct an electron transport network in the cured electrode layer and to form an energy storage active interface when the electrode comes into contact with the ion-conducting phase. The conductive filler is preferably carbon black or nano-carbon black.

[0015] The reinforcing conductive fiber material is used to improve the spatial distribution and connectivity of the conductive filler in the gelation system, while also considering crack suppression, stress transmission, and the structural stability of the overall electrode layer within the cured body. The reinforcing conductive fiber material can be chopped carbon fibers, carbon fiber shavings, conductive fiber bundles, or other alkali-resistant conductive fibers. Chopped carbon fibers are preferred.

[0016] In this invention, in the conductive cement-based electrode slurry, the mass ratio of the conductive filler to the cementitious material is 0.01–0.30:1, preferably 0.05–0.15:1. The mass ratio of the reinforcing conductive fiber material to the cementitious material is 0.001–0.10:1, preferably 0.01–0.05:1.

[0017] The current collector is used to collect and conduct the charge stored or released in the electrode layer. The current collector can be a mesh current collector, a wire mesh current collector, a rod-shaped current collector, a fabric current collector, or other alkali-resistant conductive framework. Its material can be carbon fiber rods, carbon fiber fabric, metal mesh, alkali-resistant conductive composite materials, etc. Preferably, the current collector is a mesh current collector made of carbon fiber rods.

[0018] The current collector can be inserted after the conductive cement-based electrode slurry is poured into the mold; alternatively, the current collector can be pre-fixed in the mold, and then the conductive cement-based electrode slurry can be poured into the mold. Alternatively, the conductive cement-based electrode slurry can cover part or all of the current collector, so that the current collector is embedded inside the electrode layer.

[0019] In the ion-transporting cement-based diaphragm slurry, the cementitious material can use a homologous cementitious system with the conductive cement-based electrode slurry, or it can use a compatible cementitious system. Preferably, to improve interlayer bonding and overall curing continuity, the diaphragm slurry and the conductive cement-based electrode slurry use a homologous cementitious system.

[0020] The membrane fiber material is used to improve the pore connectivity and ion migration ability of the cement-based membrane layer after curing, while also enhancing the volume stability and crack resistance of the membrane layer. The membrane fiber material can be one or a combination of at least two of paper fibers, cellulose fibers, plant fibers, and recycled paper fibers. Paper fibers are preferred.

[0021] The mass ratio of fiber material to cementitious material in the ion-transporting cementitious membrane slurry is 0.001 to 0.10:1, preferably 0.005 to 0.03:1.

[0022] In the conductive cement-based electrode slurry and the ion-transporting cement-based diaphragm slurry, the mass ratio of the total amount of the mixing and activating liquid to the total amount of the cementitious material is preferably 0.92:1. The thickness of the diaphragm layer is 0.1 mm to 10 mm, preferably 0.5 mm to 5 mm. If the diaphragm layer is too thin, it may not effectively block electronic short circuits; if it is too thick, it may increase the ion transport path and raise the internal resistance of the device.

[0023] After the cement-based membrane layer is installed, the overall structure is cured and maintained to obtain a continuous interface all-solid cement-based supercapacitor. The curing time can be determined according to the type of cementitious material, ambient temperature and humidity, and component size, generally ranging from 3 days to 60 days, preferably from 7 days to 28 days.

[0024] In step three, methods such as laying, coating, grouting, scraping, clamping and compacting, or other methods that enable the ion-transporting cement-based diaphragm slurry to fully contact the two concrete composite electrodes can be used. Preferably, the ion-transporting cement-based diaphragm slurry is applied when at least one side of the two concrete composite electrodes is in a partially cured, wet, activated, or bondable state, so that a continuous interface is formed between the ion-transporting cement-based diaphragm slurry and the two concrete composite electrodes during the curing process.

[0025] In this invention, the "continuous interface" refers to a continuous transition zone formed in situ between the cement-based diaphragm layer and the concrete composite electrode, rather than through mechanical splicing of prefabricated solid layers, independent diaphragm clamping, or impregnation with liquid electrolyte. This transition zone allows ion transport pathways to extend from the diaphragm layer to the electrode surface and even the near-surface pore region, while simultaneously reducing interfacial contact resistance and the risk of interlayer delamination.

[0026] Specifically, the mixing and activating liquid in this invention has at least the following functions: First, it is used to activate the cementitious material and give the slurry the workability of being castable, moldable, and curable. Second, it is used to form and retain the porous liquid phase required for ion transport within the cured electrode layer and diaphragm layer. Third, it is used to construct a continuous ion transport path within the continuous interface region formed by the cement-based diaphragm layer, the concrete composite electrode, and the two, thereby enabling the device to form the ion transport environment required for operation after curing.

[0027] Because both the conductive cement-based electrode slurry and the ion-transporting cement-based diaphragm slurry incorporate a mixing and activating liquid, and because they are in direct contact and in-situ cured while not fully cured, a continuous ion-transporting phase can be formed in the cement-based diaphragm layer, the concrete composite electrode, and the adjacent area of ​​their interface. This ion-transporting phase is already internally present after device curing and does not rely on subsequent external liquid electrolyte immersion to establish a working interface. Therefore, the device obtained by this invention can be directly subjected to electrochemical testing and operation after curing without further immersion.

[0028] Meanwhile, if the amount of mixing and activating liquid added to the conductive cement-based electrode slurry or ion-transporting cement-based diaphragm slurry is too low, the slurry's formability, degree of gelation reaction, and continuity of the ion-transporting phase after curing will be insufficient, easily leading to a decrease in the initial working performance of the device or an increase in interfacial impedance. If the amount added is too high, although the slurry's fluidity increases, it may lead to excessive porosity of the cured body, a decrease in mechanical properties, or a deterioration in long-term stability. Therefore, the amount of mixing and activating liquid added should be controlled within a range that satisfies both the requirements of gelation reaction and forming, and maintains a continuous ion-transporting phase after device curing.

[0029] Compared with the prior art, the present invention has the following advantages: (1) The present invention forms a continuous interface by co-curing the cement-based diaphragm layer and the concrete composite electrode in situ, which is different from the traditional layered assembly route of prefabricated electrodes, independent diaphragms and subsequent soaking / encapsulation. This can reduce the interlayer interface impedance and improve the overall integrity of the device.

[0030] (2) The mixing and activating liquid in this invention is not only used for gelation reaction and slurry forming, but also forms an endogenous ion transport phase in the cement-based diaphragm layer and concrete composite electrode and their continuous interface area after the device is cured, so that the device does not need to be soaked again by external liquid electrolyte to establish the working interface after curing.

[0031] (3) The cement-based diaphragm layer in this invention not only has the functions of ion transport and electronic isolation, but also undertakes the functions of interlayer bonding and structural connection, thereby connecting the two electrode layers into an integral load-bearing structure, so that the diaphragm is transformed from a simple separation to a diaphragm-connection integrated layer.

[0032] (4) This invention constructs an electron transport network in the electrode layer, constructs a continuous ion transport path in the cement-based membrane layer and its interface region, and forms a continuous interface through in-situ curing, thereby achieving synergistic coupling of the electron-conducting phase and the ion-conducting phase, which is beneficial to balance electrochemical performance and structural performance.

[0033] Therefore, the supercapacitor obtained by this invention does not require initial immersion to establish a working interface, and has better interface stability and overall continuity during storage, weathering, or long-term service, which is beneficial for reducing the performance degradation rate and improving the adaptability to engineering applications. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the integrated construction process of a continuous interface all-solid-state cement-based supercapacitor according to the present invention.

[0035] Figure 2 This is a schematic diagram of the overall structure of a continuous interface all-solid-state cement-based supercapacitor provided by the present invention.

[0036] Figure 3 This is a physical image and a cross-sectional view of the continuous interface region of a supercapacitor with a continuous interface all-solid-state cement-based structure according to the present invention.

[0037] In the figure: 1. Concrete composite electrode; 2. Cement-based membrane layer; 3. Current collector; 4. Continuous interface region. Detailed Implementation

[0038] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0040] In this invention, unless otherwise stated, all amounts of raw materials are parts by mass or mass ratios. Unless otherwise specified, the preparation processes, testing methods, etc., used are conventional methods in the art, and the raw materials and equipment used are commercially available.

[0041] In the following embodiments, the chopped carbon fiber has a length of 3 mm, the paper fiber is turmeric paper fiber with a diameter of 10-20 μm, the carbon black has an average particle size of 9 μm and a specific surface area of ​​approximately 1800 m² / g; the current collector is a mesh-shaped current collector made of carbon fiber rods with a diameter of 2-3 mm. Example 1

[0042] This embodiment provides a method for preparing a concrete composite electrode, the steps of which include: Preparation of conductive cement-based electrode slurry: 450 g potassium hydroxide solution, 470 g potassium silicate, 600 g fly ash and 400 g slag powder were mixed evenly to prepare a geopolymer slurry; then 20 g chopped carbon fibers and 50 g carbon black were added and stirred thoroughly to prepare a uniformly mixed conductive cement-based electrode slurry.

[0043] The conductive cement-based electrode slurry was poured into two electrode molds, and a mesh-like carbon fiber current collector was inserted into each mold. After standing and molding, two concrete composite electrodes to be cured were obtained. Example 2

[0044] This embodiment provides an integrated construction method for a continuous interface all-solid-state cement-based supercapacitor, such as... Figure 1 As shown, it includes the following steps: Step 1: Mix 450 g of potassium hydroxide solution, 470 g of potassium silicate, 600 g of fly ash and 400 g of slag powder evenly to prepare a geopolymer slurry; then add 20 g of chopped carbon fibers and 50 g of carbon black, and stir thoroughly to obtain a conductive cement-based electrode slurry; pour the conductive cement-based electrode slurry into two electrode molds respectively, and insert a mesh-like carbon fiber current collector into each of the two electrode molds, and let it stand to form, to obtain two conductive cement-based electrodes to be cured.

[0045] Step 2: Mix 450 g of potassium hydroxide solution, 470 g of potassium silicate, 600 g of fly ash and 400 g of slag powder evenly to prepare a geopolymer slurry; then add 20 g of dry paper fiber and stir thoroughly to obtain an ion transport type cement-based membrane slurry. Step 3: After demolding the two conductive cement-based electrodes to be cured, place them opposite each other and coat the ion-transporting cement-based membrane slurry between their opposite surfaces. This allows the ion-transporting cement-based membrane slurry to directly contact both conductive cement-based electrodes to be cured simultaneously, forming a cement-based membrane layer. This creates a continuous interface region between the cement-based membrane layer and the conductive cement-based electrodes on both sides. After fixing the above layered structure as a whole, cure it and then cure it for 28 days to obtain a continuous interface all-solid-state cement-based supercapacitor.

[0046] This embodiment also provides a continuous interface all-solid-state cement-based supercapacitor prepared by this method, specifically, as follows: Figure 2 As shown, it comprises a conductive cement-based electrode layer 1, a cement-based membrane layer 2, and a current collector 3. The cement-based membrane layer 22, after curing, simultaneously performs ion transport, electron isolation, and interlayer structural bonding functions. A structure is formed between the conductive cement-based electrode layer 1 and the cement-based membrane layer 2 as shown. Figure 3 The continuous interface region 4 is shown. Example 3

[0047] This embodiment provides an integrated construction method for a continuous interface all-solid-state cement-based supercapacitor, which is basically the same as that in Embodiment 2, except that in this embodiment, the amount of carbon black added to the conductive cement-based electrode slurry is 100 g, while the other conditions remain unchanged. Example 4

[0048] This embodiment provides an integrated construction method for a continuous interface all-solid-state cement-based supercapacitor, which is basically the same as that in Embodiment 2, except that: in this embodiment, the amount of carbon black added to the conductive cement-based electrode slurry is 150g, and the other conditions remain unchanged. Example 5

[0049] This embodiment provides an integrated construction method for a continuous interface all-solid-state cement-based supercapacitor, which is basically the same as that in Embodiment 2, except that in this embodiment, 110 g of graphite is used as the conductive filler in the conductive cement-based electrode slurry, while the other conditions remain unchanged. Example 6

[0050] This embodiment provides an integrated construction method for a continuous interface all-solid-state cement-based supercapacitor, which is basically the same as that in Embodiment 2, except that in this embodiment, 120 g of graphene is used as a conductive filler in the conductive cement-based electrode slurry, while the other conditions remain unchanged. Example 7

[0051] This embodiment provides an integrated construction method for a continuous interface all-solid-state cement-based supercapacitor, which is basically the same as that in Embodiment 2, except that in this embodiment, 25g of carbon fiber shreds are used as the reinforcing conductive fiber material in the conductive cement-based electrode slurry, while the other conditions remain unchanged.

[0052] To verify that the integrated construction method provided by the inventor is an indivisible whole, this invention provides the following comparative examples by changing the amount or steps of the added components, based on Example 2. The specific comparative examples are shown in Table 1.

[0053] Table 1. Differences between the comparative example and Example 2 Comparative Example 2 200 g of conductive cement-based electrode slurry carbon black Comparative Example 3 Conductive cement-based electrode slurry omits short-cut carbon fibers Comparative Example 4 100g of short-cut carbon fiber in conductive cement-based electrode slurry Comparative Example 5 200 g of conductive cement-based electrode slurry mixing and activation solution Comparative Example 6 1500 g of conductive cement-based electrode slurry mixing and activation solution Comparative Example 7 200 g of ion-transporting cement-based diaphragm slurry mixing and activating liquid Comparative Example 8 Paper fibers are omitted in ion-transport type cement-based diaphragm slurries. Comparative Example 9 100g of paper fiber in ion transport type cement-based diaphragm slurry Comparative Example 10 The pouring and curing sequence was changed; the conductive cement-based electrode layer and the cement-based diaphragm layer were fully cured and maintained separately before assembly. Comparative Example 11 After the conductive cement-based electrode layer and cement-based membrane layer are prepared and fully cured, the working interface is established by immersion in liquid electrolyte before device assembly.

[0054] 1) Initial electrochemical performance test: The capacitors prepared in Examples 2 to 4 and Comparative Examples 1 to 11 were subjected to constant current charge-discharge test, cyclic voltammetry test and AC impedance test. The test instrument was a Princeton VersaSTAT 3F electrochemical workstation.

[0055] The capacitors obtained in Examples 2-4 and Comparative Examples 1-10 were subjected to electrochemical testing directly after curing without immersion in an external liquid electrolyte. The capacitor obtained in Comparative Example 11, however, was immersed in a liquid electrolyte for 24 hours before electrochemical testing. Specific test results are shown in Table 2.

[0056] Table 2 Initial Electrochemical Performance Test Results Example 2 <![CDATA[2.47×10 6 ]]> 0.82 Example 3 <![CDATA[3.95×10 5 ]]> 1.56 Example 4 <![CDATA[5.64×10 6 ]]> 0.74 Comparative Example 1 <![CDATA[3.21×10 -5 ]]> 9.80 Comparative Example 2 <![CDATA[6.98×10 6 ]]> 1.95 Comparative Example 3 <![CDATA[1.12×10 3 ]]> 6.28 Comparative Example 4 <![CDATA[4.86×10 6 ]]> 1.12 Comparative Example 5 <![CDATA[8.50×10 5 ]]> 2.34 Comparative Example 6 <![CDATA[1.93×10 6 ]]> 1.67 Comparative Example 7 <![CDATA[9.70×10 6 ]]> 2.08 Comparative Example 8 <![CDATA[4.10×10 3 ]]> 6.46 Comparative Example 9 <![CDATA[5.28×10 6 ]]> 1.92 Comparative Example 10 <![CDATA[1.35×10 -5 ]]> 11.71 Comparative Example 11 <![CDATA[2.06×10 6 ]]> 1.05 2) Compressive strength test: The compressive strength of the corresponding devices in Examples 2-4 and Comparative Examples 1-11 was tested using a computer-controlled electro-hydraulic servo pressure testing machine HCT206A. The specific test results are shown in Table 3.

[0057] Table 3 Compressive Strength Test Results Example 2 44.13 Example 3 37.21 Example 4 30.28 Comparative Example 1 46.97 Comparative Example 2 16.52 Comparative Example 3 43.84 Comparative Example 4 24.65 Comparative Example 5 39.72 Comparative Example 6 38.46 Comparative Example 7 35.18 Comparative Example 8 44.40 Comparative Example 9 36.91 Comparative Example 10 / Comparative Example 11 / 3) Direct operational capability test: Electrochemical tests were performed directly on Examples 2-4 and Comparative Examples 1-10 after curing to record whether the devices could form a measurable capacitance response normally without immersion in an external liquid electrolyte. Comparative Example 11 was used as a post-immersion assembled device for comparison. Specific test results are shown in Table 4.

[0058] Table 4. Results of Direct Work Capability Test Example 2 yes no Example 3 yes no Example 4 yes no Comparative Example 1 Yes, but the response is extremely weak. no Comparative Example 2 yes no Comparative Example 3 Yes, but the response is extremely weak. no Comparative Example 4 yes no Comparative Example 5 yes no Comparative Example 6 yes no Comparative Example 7 yes no Comparative Example 8 Yes, but the interface impedance is high. no Comparative Example 9 yes no Comparative Example 10 no yes Comparative Example 11 no yes 4) Performance retention test after storage / weathering: Examples 2-4 and Comparative Examples 10 and 11 were stored in a room temperature air environment for 7 days, 28 days, and 56 days, respectively. The specific capacitance retention rate, internal resistance change rate, and mass change rate were tested to evaluate the long-term stability and weather resistance of the devices. The specific test results are shown in Table 5.

[0059] Table 5. Results of Performance Retention Rate Tests After Storage / Weathering Example 2 7 d 96.2 4.8 0.9 Example 2 28 d 92.5 9.7 1.8 Example 2 56 d 88.9 15.4 2.9 Example 3 7 d 93.8 6.2 1.1 Example 3 28 d 89.4 12.8 2.3 Example 3 56 d 84.7 18.9 3.5 Example 4 7 d 95.4 5.1 1.0 Example 4 28 d 91.1 10.6 2.0 Example 4 56 d 86.8 16.8 3.2 Comparative Example 10 7 d 99.7 2.4 1.4 Comparative Example 10 28 d 95.5 3.3 2.2 Comparative Example 10 56 d 92.4 3.8 3.6 Comparative Example 11 7 d 0 / 11.7 Comparative Example 11 28 d 0 / 12.1 Comparative Example 11 56 d 0 / 12.3 5) Recovery Test After Attenuation: Recovery tests were performed on devices whose performance had degraded after storage or weathering treatment. Record whether Examples 2-4 and Comparative Example 11 required re-immersion to restore their test state after degradation, and the degree of performance recovery after re-immersion. Specific test results are shown in Table 6.

[0060] Table 6 Results of the Recovery Test After Attenuation Example 2 No or surface maintenance only 93.6 Example 3 No or surface maintenance only 90.8 Example 4 No or surface maintenance only 92.4 Comparative Example 11 yes 81.5

[0061] As shown in Tables 2-6, when conductive filler is missing or excessive, it is difficult to achieve both electrochemical and mechanical properties of the device. When the reinforcing conductive fiber material is missing, excessive, or the amount of mixing / excitation solution added deviates from the appropriate range, the overall integrity, interface stability, and direct working capability of the device are all adversely affected.

[0062] Meanwhile, Examples 2-4 can be directly tested for electrochemical properties after curing, while the comparative examples of the immersion assembly type require immersion in an external liquid electrolyte to establish a working interface. This shows that the present invention achieves an all-solid-state integrated device that can work without immersion by in-situ co-curing of the electrode layer and the membrane layer and constructing an endogenous ion transport phase.

[0063] Furthermore, performance retention tests after storage / weathering show that the devices of the present invention exhibit a low performance degradation rate and good interface stability under long-term storage or weathering conditions, thus demonstrating the unique advantages brought by the one-piece molding and no-immersion solution.

[0064] Under normal operating conditions, the device obtained by this invention does not rely on periodic re-immersion. The device can be directly put into electrochemical operation after curing, with its working interface provided by a continuous ion transport phase formed in situ within the device.

[0065] If the capacitance performance of a device degrades under prolonged water loss, low humidity, or other extreme environmental conditions, further degradation can be mitigated through external surface sealing, environmental humidity control, electrolyte replenishment, or other conventional maintenance methods. For situations requiring evaluation of maintenance effectiveness, the specific capacitance, internal resistance, and recovery rate of the device before and after maintenance can be recorded.

[0066] When the performance degradation of a device exceeds a preset threshold, maintenance, replacement, or disposal can be selected based on specific application requirements. The core advantage of this invention is that after initial device maintenance, there is no need to establish a working interface through external liquid electrolyte immersion.

[0067] In other embodiments of the present invention, the fiber material in the diaphragm layer can be replaced with other cellulose-based fibers or plant fibers; the current collector 3 can be replaced with a metal mesh current collector, a carbon fiber fabric current collector, or other alkali-resistant conductive skeleton; the cementing system can also be a common cement-based system, a high-belite cement system, a slag-based polymer system, or other compatible cementing systems.

[0068] In other embodiments of the present invention, the electrode layer 1 may first reach a preliminary or partially solidified state before the diaphragm slurry is applied; alternatively, the diaphragm slurry may be applied directly when the electrode layer 1 is not fully solidified.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for preparing a concrete composite electrode, comprising the following steps: Conductive cement-based electrode slurry is prepared by mixing cementitious materials, mixing and activating liquid, conductive filler and reinforcing conductive fiber materials in a mass ratio of 1:(0.8~1):(0.01~0.30):(0.001~0.10). The conductive cement-based electrode slurry is poured into two electrode molds and current collectors are inserted into them respectively. After molding, two concrete composite electrodes are obtained. The cementitious material is cement-based cementitious material or geopolymer cementitious material. The mixing and activating liquid includes one or a combination of at least two of potassium hydroxide solution, sodium hydroxide solution, potassium silicate and sodium silicate.

2. The method for preparing the concrete composite electrode according to claim 1, characterized in that: The cement-based cementitious material includes one or a combination of at least two of silicate cement, slag cement, high belite cement, and magnesium slag silicate cement. The geopolymer cementitious material includes fly ash or slag powder or a mixture of fly ash and slag powder in a mass ratio of (3-4):

2.

3. The method for preparing the concrete composite electrode according to claim 2, characterized in that: The conductive filler is one or a combination of at least two of carbon black, nano carbon black, graphite, graphene, carbon nanotubes, or conductive carbon materials, and the reinforcing conductive fiber material is one or a combination of at least two of chopped carbon fibers, carbon fiber shavings, or conductive fiber bundles.

4. The method for preparing the concrete composite electrode according to claim 1, 2, or 3, characterized in that: The current collector is a mesh current collector made of carbon fiber rod, a carbon fiber fabric current collector, a metal mesh current collector, or an alkali-resistant conductive skeleton.

5. A concrete composite electrode prepared by the preparation method of claim 4.

6. The application of the concrete composite electrode according to claim 5 in the preparation of a continuous interface all-solid-state cement-based supercapacitor.

7. A method for preparing a continuous interface all-solid-state cement-based supercapacitor using the concrete composite electrode of claim 5, comprising the following steps: Step 1: Prepare the concrete composite electrode as described in claim 5; Step 2: Prepare an ion-transporting cementitious membrane slurry by mixing the cementitious material, mixing and activating liquid and diaphragm fiber material in a mass ratio of 1:(0.8~1):(0.001~0.10). Step 3: The ion-transporting cement-based diaphragm slurry is placed and solidified in situ between the two concrete composite electrodes to form a cement-based diaphragm layer. After curing, a continuous interface all-solid cement-based supercapacitor is obtained.

8. The method for preparing a continuous interface all-solid-state cement-based supercapacitor according to claim 7, characterized in that: In step two, the cementitious material is either a cement-based cementitious material or a geopolymer cementitious material; the mixing and activating liquid includes one or a combination of at least two of potassium hydroxide solution, sodium hydroxide solution, potassium silicate, and sodium silicate; and the diaphragm fiber material is one or a combination of at least two of paper fiber, cellulose fiber, plant fiber, or recycled paper fiber.

9. A continuous interface all-solid-state cement-based supercapacitor, characterized in that: It includes two opposing conductive cement-based electrode layers, a cement-based membrane layer located between the two conductive cement-based electrode layers, and a current collector disposed inside the conductive cement-based electrode layers; The cement-based membrane layer and the conductive cement-based electrode layers on both sides are formed into a continuous interface through in-situ curing, so as to connect the conductive cement-based electrode layers on both sides into an integral load-bearing structure. The conductive cement-based electrode layer is used to form an electron transport network and an energy storage active interface. The cement-based membrane layer is used to form an ion transport channel and block direct electron conduction between the two electrode layers. The current collector is used to collect the charge in the conductive cement-based electrode layer and conduct it outward.

10. The continuous interface all-solid-state cement-based supercapacitor according to claim 9, characterized in that: The thickness of the cement-based diaphragm layer is 0.1 mm to 10 mm.

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