Highly ionically conductive, uniformly distributed, porous solid waste-fiber composite electrolyte and preparation and use thereof

Abstract

This invention belongs to the field of solid waste resource utilization and energy storage technology, specifically relating to a highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte and its preparation and application. Currently, cement-based electrolytes exhibit low ionic conductivity, small pore size, and poor connectivity. This invention involves bridging two copper meshes with fibers to form a chain-like aggregate structure, creating a three-dimensional framework. A mixed slurry of steel slag, mineral powder, and polymer microspheres is then filled into this framework. The polymer microspheres are then removed to create uniformly distributed pores, yielding the solid waste-fiber composite electrolyte. This invention utilizes industrial solid waste to prepare the electrolyte matrix, introduces fibers to form short-distance interconnected ion channels, and incorporates soluble polymer microspheres to create a controllable and uniformly distributed pore structure within the solid waste-fiber composite electrolyte, thereby improving the electrolyte's ionic conductivity. The prepared composite electrolyte can be used to assemble supercapacitors, achieving performance optimization.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization and energy storage technology, and specifically relates to a highly conductive ion-uniformly distributed porous solid waste-fiber composite electrolyte and its preparation and application. Background Technology

[0002] The construction industry is undergoing a comprehensive transformation from traditional high-energy-consumption and high-emission models to green and low-carbon development. Therefore, the construction industry urgently needs new energy storage technologies to achieve efficient energy utilization and reduce carbon emissions. In recent years, the development of structural supercapacitors, which combine building materials with energy storage technologies and possess both mechanical and electrochemical properties, has gradually become a research hotspot in the construction field. These structural supercapacitors can serve as building components, achieving an integrated "load-bearing + energy storage" system. In structural supercapacitors, the electrolyte, as the medium for ion conduction, directly affects the capacitor's ionic conductivity, charge / discharge efficiency, and service life.

[0003] Current research on electrolytes for supercapacitors mainly focuses on using cement materials to prepare electrolytes. These electrolytes possess good mechanical properties, but cement production is energy-intensive and generates significant emissions. Furthermore, cement-based electrolytes have low ionic conductivity, small pore size, and poor connectivity. Therefore, there is an urgent need for low-carbon materials to prepare electrolytes with high ionic conductivity. Currently, my country urgently needs effective recycling measures for its industrial solid waste stockpiles. Some industrial solid wastes have similar compositions to cement, presenting a potential advantage in electrolyte preparation. However, some industrial solid wastes have a single composition and can replace cement in electrolyte preparation through co-utilization. Further optimization of their structure and composition is still needed to improve ionic conductivity.

[0004] Currently, the optimization of electrolyte structure and performance mainly focuses on two aspects: (1) Hydrogel construction of ion channels. By introducing hydrogel to construct ion channels, the resistance to ion migration can be effectively reduced, thereby significantly improving the electrochemical performance of the electrolyte. However, when too much hydrogel is added, it is easy to form an uneven gel volume distribution inside the electrolyte, resulting in the blockage of some pore channels. In addition, it is difficult to achieve an effective uniform distribution of the constructed channels, which in turn limits the effective transport of ions in the electrolyte and ultimately affects the ionic conductivity. (2) Adding redox additives to form pores with uniform pore size. Adding redox additives to the electrolyte can form a uniform pore structure, increase porosity, and thus provide more channels for ion transport, thereby improving the ionic conductivity. However, since the distribution of reactants and the reaction rate during the redox reaction are difficult to control precisely, and the formation of pores is a dynamic process, which is affected by a combination of factors such as hydration reaction, additive concentration, and reaction temperature, it is still difficult to form a pore structure with uniform pore size in the electrolyte through redox reaction. Summary of the Invention

[0005] To address the aforementioned problems, the primary objective of this invention is to provide a highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte. Secondly, the objective of this invention is to provide a method for preparing this solid waste-fiber composite electrolyte. Thirdly, the objective of this invention is to provide the application of this solid waste-fiber composite electrolyte material in structural supercapacitors.

[0006] The high-conductivity, ion-uniformly distributed porous solid waste-fiber composite electrolyte of the present invention is composed of an electrolyte body, fibers, and copper mesh. Several fibers are entangled at both ends on two opposing copper meshes, so that the fibers and copper meshes are bridged to form a three-dimensional frame. The electrolyte body is filled in the three-dimensional frame formed by the fibers and copper mesh.

[0007] The electrolyte matrix is ​​mainly composed of steel slag, mineral powder and pores; each fiber has several entangled aggregates called "knots", and each fiber is a chain-like aggregate.

[0008] The mass ratio of steel slag to mineral powder in the electrolyte matrix is ​​(20~40):(60~80); the pores are formed by dissolving and removing polymer microspheres contained in the electrolyte matrix, and the pore size is 20nm~50µm; the polymer microspheres include polystyrene microspheres, polymethyl methacrylate microspheres or polyethylene microspheres.

[0009] The diameter of the fiber is 1 mm to 10 mm, preferably 1 mm to 5 mm; the fiber has hydrophilic functional groups, including carboxyl or hydroxyl groups; it is preferably cotton fiber; each fiber preferably has 4 to 6 entangled aggregates "knots"; one fiber is entangled every 1 to 3 meshes; the copper mesh is 10 to 100 meshes, preferably 10 to 50 meshes.

[0010] The preparation method of the highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte of the present invention includes the following steps:

[0011] (1) Fiber pretreatment: Take several fibers, remove impurities from the fiber surface, and cross-link each fiber into several aggregates "knots". Each fiber is a chain aggregate;

[0012] (2) Fiber bridging copper mesh: The fiber entanglement bridging copper mesh processed in step (1) forms a three-dimensional frame. The three-dimensional frame is inserted into the mold in parallel and vertical directions to construct the ion transport channel.

[0013] (3) Slurry preparation and molding: Steel slag, mineral powder, activator and polymer microspheres are mixed and stirred evenly, and water is added to mix to obtain the slurry for preparing the electrolyte matrix; the mixed slurry is poured into a mold with a three-dimensional frame, cured and hardened to obtain the composite electrolyte matrix;

[0014] (4) Demolding and post-treatment: After the composite electrolyte matrix is ​​demolded, it is immersed in an organic solvent to dissolve and remove the polymer microspheres, forming a pore structure with uniform pore size inside the composite electrolyte matrix, thus obtaining the solid waste-fiber composite electrolyte.

[0015] In step (1), the method for removing impurities from the fiber surface is as follows: the fiber is soaked in an alkaline potassium hydroxide solution with a pH of 10-14 for 1-2 hours, then dried at a temperature of 60-80°C for 1-2 hours to remove hydrophobic impurities such as wax and pectin from the fiber surface, making the fiber surface more hydrophilic.

[0016] In step (2), the bridging method is as follows: two copper meshes stand opposite each other, one end of the fiber is wrapped around one copper mesh, and the other end is horizontally wrapped around the other copper mesh; the higher the mesh count of the copper mesh, the smaller the mesh size, so as to facilitate fiber entanglement and increase the number of entangled fibers, the ion transport channels in the electrolyte can be improved.

[0017] In step (3), the mass ratio of steel slag to mineral powder is (20~40):(60~80), the mass of polymer microspheres is 10%~20% of the total mass of steel slag, mineral powder and polymer microspheres, and the mass of activator is 4%~6% of the total mass of steel slag, mineral powder and polymer microspheres; the activator includes at least one of alkaline activator and sulfate activator.

[0018] In step (3), the mixing method is mechanical stirring, stirring at 800 rpm to 1200 rpm for 5 min to 10 min in a mixer to ensure that the powder is fully and evenly mixed; the water-cement ratio of the slurry is 0.3 to 0.6, preferably 0.5 to 0.6; the curing is to stand for 24 h to 48 h at 40 ℃ to 60 ℃ and humidity > 95%.

[0019] In step (4), the composite electrolyte matrix is ​​first soaked in a saturated sodium sulfate or potassium sulfate solution for 7 to 56 days and then soaked in an organic solvent to dissolve and remove the polymer microspheres. The polymer microspheres dissolve slowly at low temperatures, while high temperatures can accelerate the dissolution process. The polymer microspheres include at least one of polystyrene microspheres, polymethyl methacrylate microspheres, and polyethylene microspheres, with a particle size of 20 nm to 50 µm.

[0020] When the polymer microspheres are polystyrene microspheres, the soaking temperature is 60℃~80℃, the soaking time is 24h~48h, and the organic solvent is at least one of limonene, benzene, toluene, and xylene; when the polymer microspheres are polymethyl methacrylate microspheres, the soaking temperature is 40℃~60℃, the soaking time is 6h~12h, and the organic solvent is at least one of acetone, chloroform, dichloromethane, and ethyl acetate; when the polymer microspheres are polyethylene microspheres, the soaking temperature is 60℃~100℃, the soaking time is 1h~6h, and the organic solvent is at least one of benzene, toluene, and xylene.

[0021] The solid waste-fiber composite electrolyte described in this invention can be used to assemble structural supercapacitors, and the specific method is as follows:

[0022] Method 1, in step (3), the mixed slurry is poured into the mold into which the fiber bridging copper mesh has been inserted. A copper mesh electrode loaded with graphene is inserted parallel and vertically on the outside of the two bridging copper meshes. The other steps are the same as the preparation method of the solid waste-fiber composite electrolyte. Finally, a supercapacitor with a solid waste-fiber composite electrolyte is obtained.

[0023] Method 2 involves assembling a graphene-loaded copper mesh electrode parallel and vertically on the outer sides of the two bridging copper meshes of the final solid waste-fiber composite electrolyte to obtain a structural supercapacitor assembled with the solid waste-fiber composite electrolyte.

[0024] Compared with the prior art, the present invention has achieved the following significant results: (1) The proposed fixed-distance cross-linked entangled fibers, which construct ion transport channels, exhibit significant structural and functional advantages. The precise design of ion transport channels can be achieved by controlling the fiber arrangement and entanglement density. The aggregates formed by fiber entanglement can significantly increase the contact area between the fibers and pores in the electrolyte. This structure provides more transport paths for ions, facilitating the rapid migration of ions to the fiber surface, thereby effectively improving ionic conductivity. The aggregates can also improve the wettability of the electrolyte, promote the uniform distribution of the electrolyte in the matrix, and further optimize the ion transport efficiency. (2) The abundant hydrophilic functional groups such as hydroxyl / carboxyl groups on the fiber surface can effectively adsorb the electrolyte, ensure the wettability inside the electrolyte, and improve ionic conductivity. (3) Adding polymer microspheres to the electrolyte can form a pore structure with uniform pore size distribution. Polymer microspheres are homopolymer microspheres formed by the polymerization of a single monomer. They have high chemical stability, are water-resistant, and acid and alkali-resistant. During the solidification process of the slurry, the presence of microspheres will occupy a certain space. Subsequently, the microspheres are removed by heating in an organic solvent, leaving uniform and controllable pores in the matrix. By adjusting the diameter of the microspheres, the pore size can be precisely controlled to meet specific application requirements. In addition, the activator is used as an external admixture. The incorporation of the activator can accelerate the hydration reaction and improve the strength of the electrolyte. (4) The chain aggregates formed by fiber entanglement and the pore structure formed by polymer microspheres simultaneously achieve a dual enhancement effect, synergistically promoting the improvement of ion mobility. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the process for preparing a highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte according to the present invention. Detailed Implementation

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. It should be noted that the embodiments described in this invention are only for further explanation and illustration, and not for limiting their application scope. Based on this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention.

[0027] To better demonstrate performance, the mold used in this embodiment is a cubic mold with an opening at the top, measuring 20mm × 20mm × 20mm. The copper mesh used for bridging is 10 mesh and measures 20mm × 30mm. The prepared solid waste electrolyte was subjected to impedance spectroscopy (EIS) testing using an electrochemical workstation at a frequency of 0.01Hz to 1,000,000Hz. The assembled structural supercapacitor underwent constant current charge-discharge (GCD) testing at a current density of 0.5mA / cm². 2 .

[0028] Example 1

[0029] The mass ratio of steel slag, mineral powder, activator, and polystyrene microspheres in the electrolyte matrix is ​​6:12:0.8:2, and the pore size is 20 nm. The polystyrene microspheres in the electrolyte matrix are dissolved and formed. Cotton fibers with a diameter of 1 mm are used, and each fiber has 4 aggregates "knots". One fiber is entangled every other grid.

[0030] The preparation methods of solid waste-fiber composite electrolyte and structural supercapacitor are as follows:

[0031] Step 1: Fiber Pretreatment. Cotton fibers with a diameter of 1 mm were soaked in a potassium hydroxide solution with a pH of 12 for 1.5 hours to remove surface impurities, and then dried at 60°C for 2 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with 4 aggregate "knots" prepared from each fiber.

[0032] Step 2: Fiber Bridging of Copper Mesh. The chain-like aggregates are entangled and bridged onto two opposing copper meshes, with one strand entangled every other mesh, evenly distributed across the mesh. After entanglement, the fibers and copper mesh bridge to form a three-dimensional frame, which is then inserted into a mold for later use.

[0033] Step 3: Slurry Preparation and Molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (20nm) in a mass ratio of 6:12:0.8:2 were mixed and manually stirred for 2 minutes to ensure uniform dispersion. Then, water was added and stirred in a mixer at 1200 rpm for 5 minutes to obtain a slurry with a water-cement ratio of 0.3. The slurry was poured into a mold with fiber-bridged copper mesh inserted and cured at 60℃ and >95% humidity for 24 hours to obtain the solid waste-fiber composite electrolyte matrix.

[0034] Simultaneously assemble the structural supercapacitor: pour the slurry into another mold with the same fiber bridging copper mesh, and insert a 200-mesh copper mesh electrode loaded with graphene parallel and vertically on the outside of the two bridging copper meshes. Curing and hardening under the same conditions, the structural supercapacitor is assembled.

[0035] Step 4: Demolding and Post-processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled supercapacitor, they were separately immersed in a saturated potassium sulfate solution for 28 days and then removed. Next, they were placed in a limonene solution at 60°C to dissolve the polystyrene microspheres in the electrolyte matrix. After immersion for 48 hours, they were removed, yielding the solid waste-fiber composite electrolyte and the assembled supercapacitor. The preparation process is as follows: Figure 1 As shown.

[0036] The prepared solid waste-fiber composite electrolyte has an ionic conductivity of 11.02 mS / cm, and the assembled structural supercapacitor has a surface capacitance of 9.71 mF / cm. 2 .

[0037] Example 2

[0038] The mass ratio of steel slag, mineral powder, activator, and polystyrene microspheres in the electrolyte matrix is ​​4:14:1.2:2, and the pore size is 20 nm. The polystyrene microspheres in the electrolyte matrix are dissolved and formed. Cotton fibers with a diameter of 1 mm are used, and each fiber has 5 aggregates "knots". One fiber is entangled every other grid.

[0039] The preparation methods of solid waste-fiber composite electrolyte and structural supercapacitor are as follows:

[0040] Step 1: Fiber Pretreatment. Cotton fibers with a diameter of 1 mm were soaked in a potassium hydroxide solution with a pH of 10 for 2 hours to remove surface impurities, and then dried at 80℃ for 1 hour. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with 5 aggregate "knots" prepared from each fiber.

[0041] Step 2: Fiber Bridging of Copper Mesh. The chain-like aggregates are entangled and bridged onto two opposing copper meshes, with one strand entangled every other mesh, evenly distributed across the mesh. After entanglement, the fibers and copper mesh bridge to form a three-dimensional frame, which is then inserted into a mold for later use.

[0042] Step 3: Slurry Preparation and Molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (20nm) in a mass ratio of 4:14:1.2:2 were mixed and manually stirred for 2 minutes to ensure uniform dispersion. Then, water was added and stirred in a mixer at 800 rpm for 10 minutes to obtain a slurry with a water-cement ratio of 0.35. The slurry was poured into a mold with fiber-bridged copper mesh inserted and cured at 40℃ and >95% humidity for 48 hours to obtain the solid waste-fiber composite electrolyte matrix.

[0043] Simultaneously assemble the structural supercapacitor: pour the slurry into another mold with the same fiber bridging copper mesh, and insert a 200-mesh copper mesh electrode loaded with graphene parallel and vertically on the outside of the two bridging copper meshes. Curing and hardening under the same conditions, the structural supercapacitor is assembled.

[0044] Step 4: Demolding and Post-processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled supercapacitor, they were separately immersed in a saturated potassium sulfate solution for 7 days and then removed. Next, they were placed in a limonene solution at 80°C to dissolve the polystyrene microspheres in the electrolyte matrix. After soaking for 24 hours, they were removed to obtain the solid waste-fiber composite electrolyte and the assembled supercapacitor.

[0045] The prepared solid waste-fiber composite electrolyte has an ionic conductivity of 14.77 mS / cm, and the assembled structural supercapacitor has a surface capacitance of 14.16 mF / cm. 2 .

[0046] Example 3

[0047] The mass ratio of steel slag, mineral powder, activator, and polystyrene microspheres in the electrolyte matrix is ​​5:13:1:2, and the pore size is 50 nm. The polystyrene microspheres in the electrolyte matrix are dissolved and formed. Cotton fibers are used, with a diameter of 1 mm and 6 aggregate "knots" per fiber. One fiber is entangled every other grid.

[0048] The preparation methods of solid waste-fiber composite electrolyte and structural supercapacitor are as follows:

[0049] Step 1: Fiber Pretreatment. Cotton fibers with a diameter of 1 mm were soaked in a potassium hydroxide solution at pH 14 for 1 hour to remove surface impurities, then removed and dried at 70℃ for 1.5 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with 6 aggregate "knots" prepared from each fiber.

[0050] Step 2: Fiber Bridging of Copper Mesh. The chain-like aggregates are entangled and bridged onto two opposing copper meshes, with one strand entangled every other mesh, evenly distributed across the mesh. After entanglement, the fibers and copper mesh bridge to form a three-dimensional frame, which is then inserted into a mold for later use.

[0051] Step 3: Slurry Preparation and Molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (100nm) in a mass ratio of 5:13:1:2 are mixed and manually stirred for 2 minutes to ensure uniform dispersion. Then, water is added and stirred in a mixer at 1000 rpm for 6 minutes to obtain a slurry with a water-cement ratio of 0.4. The slurry is poured into a mold with fiber-bridged copper mesh inserted and cured at 50℃ and >95% humidity for 36 hours to obtain the solid waste-fiber composite electrolyte matrix.

[0052] Simultaneously assemble the structural supercapacitor: pour the slurry into another mold with the same fiber bridging copper mesh, and insert a 200-mesh copper mesh electrode loaded with graphene parallel and vertically on the outside of the two bridging copper meshes. Curing and hardening under the same conditions, the structural supercapacitor is assembled.

[0053] Step 4: Demolding and Post-processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled structural supercapacitor, they were separately immersed in a saturated potassium sulfate solution for 14 days and then removed. Next, they were placed in a limonene solution at 70°C to dissolve the polystyrene microspheres in the electrolyte matrix. After soaking for 36 hours, they were removed to obtain the solid waste-fiber composite electrolyte and the assembled structural supercapacitor.

[0054] The prepared solid waste-fiber composite electrolyte has an ionic conductivity of 13.44 mS / cm, and the assembled structural supercapacitor has a surface capacitance of 12.96 mF / cm. 2 .

[0055] Example 4

[0056] The mass ratio of steel slag, mineral powder, activator, and polystyrene microspheres in the electrolyte matrix is ​​7:11:0.8:2, and the pore size is 50 nm. The polystyrene microspheres in the electrolyte matrix are dissolved and formed. Cotton fibers are used, with a diameter of 3 mm and 5 aggregate "knots" per fiber. One fiber is entangled every 3 grids.

[0057] The preparation methods of solid waste-fiber composite electrolyte and structural supercapacitor are as follows:

[0058] Step 1: Fiber Pretreatment. Cotton fibers with a diameter of 3 mm were soaked in a potassium hydroxide solution with a pH of 10 for 2 hours to remove surface impurities, and then dried at 70℃ for 2 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with 5 aggregate "knots" prepared from each fiber.

[0059] Step 2: Fiber Bridging of Copper Mesh. The chain-like aggregates are entangled and bridged onto two opposing copper meshes, with one strand entangled every three meshes, evenly distributed across the mesh. After entanglement, the fibers and copper mesh bridge to form a three-dimensional frame, which is then inserted into the mold for later use.

[0060] Step 3: Slurry Preparation and Molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (50nm) in a mass ratio of 7:11:0.8:2 were mixed and manually stirred for 2 minutes to ensure uniform dispersion. Then, water was added and stirred in a mixer at 1000 rpm for 6 minutes to obtain a slurry with a water-cement ratio of 0.45. The slurry was poured into a mold with fiber-bridged copper mesh inserted and cured at 55℃ and >95% humidity for 24 hours to obtain the solid waste-fiber composite electrolyte matrix.

[0061] Simultaneously assemble the structural supercapacitor: pour the slurry into another mold with the same fiber bridging copper mesh, and insert a 200-mesh copper mesh electrode loaded with graphene parallel and vertically on the outside of the two bridging copper meshes. Curing and hardening under the same conditions, the structural supercapacitor is assembled.

[0062] Step 4: Demolding and Post-processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled supercapacitor, they were separately immersed in a saturated potassium sulfate solution for 14 days and then removed. Next, they were placed in a limonene solution at 75°C to dissolve the polystyrene microspheres in the electrolyte matrix. After immersion for 28 hours, they were removed to obtain the solid waste-fiber composite electrolyte and the assembled supercapacitor.

[0063] The prepared solid waste-fiber composite electrolyte has an ionic conductivity of 18.15 mS / cm, and the assembled structural supercapacitor has a surface capacitance of 20.92 mF / cm. 2 .

[0064] Example 5

[0065] The mass ratio of steel slag, mineral powder, activator, and polystyrene microspheres in the electrolyte matrix is ​​5:13:1:2, and the pore size is 100 nm. The polystyrene microspheres in the electrolyte matrix are dissolved to form the pores. Cotton fibers with a diameter of 5 mm are used, and each fiber has 6 aggregates "knots". One fiber is entangled every two grids.

[0066] The preparation methods of solid waste-fiber composite electrolyte and structural supercapacitor are as follows:

[0067] Step 1: Fiber Pretreatment. Cotton fibers with a diameter of 5 mm were soaked in a potassium hydroxide solution with a pH of 12 for 2 hours to remove surface impurities, and then dried at 60℃ for 2 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with 6 aggregate "knots" prepared from each fiber.

[0068] Step 2: Fiber Bridging of Copper Mesh. The chain-like aggregates are entangled and bridged onto two opposing copper meshes, with one strand entangled every two meshes, evenly distributed across the mesh. After entanglement, the fibers and copper mesh bridge to form a three-dimensional frame, which is then inserted into the mold for later use.

[0069] Step 3: Slurry Preparation and Molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (100nm) in a mass ratio of 5:13:1:2 were mixed and manually stirred for 2 minutes to ensure uniform dispersion. Then, water was added and stirred in a mixer at 900 rpm for 9 minutes to obtain a slurry with a water-cement ratio of 0.5. The slurry was poured into a mold with fiber-bridged copper mesh inserted and cured at 50℃ and >95% humidity for 36 hours to obtain the solid waste-fiber composite electrolyte matrix.

[0070] Simultaneously assemble the structural supercapacitor: pour the slurry into another mold with the same fiber bridging copper mesh, and insert a 200-mesh copper mesh electrode loaded with graphene parallel and vertically on the outside of the two bridging copper meshes. Curing and hardening under the same conditions, the structural supercapacitor is assembled.

[0071] Step 4: Demolding and Post-processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled supercapacitor, they were separately immersed in a saturated potassium sulfate solution for 28 days and then removed. Next, they were placed in a limonene solution at 60°C to dissolve the polystyrene microspheres in the electrolyte matrix. After immersion for 48 hours, they were removed to obtain the solid waste-fiber composite electrolyte and the assembled supercapacitor.

[0072] The prepared solid waste-fiber composite electrolyte has an ionic conductivity of 16.52 mS / cm, and the assembled structural supercapacitor has a surface capacitance of 16.22 mF / cm. 2 .

[0073] Example 6

[0074] The mass ratio of steel slag, mineral powder, activator, and polystyrene microspheres in the electrolyte matrix is ​​6:11:0.8:3, and the pore size is 100 nm. The polystyrene microspheres in the electrolyte matrix are dissolved to form the pores. Cotton fibers with a diameter of 3 mm are used, and each fiber has 5 aggregates "knots". One fiber is entangled every two grids.

[0075] The preparation methods of solid waste-fiber composite electrolyte and structural supercapacitor are as follows:

[0076] Step 1: Fiber Pretreatment. Cotton fibers with a diameter of 3 mm were soaked in a potassium hydroxide solution with a pH of 11 for 1.8 hours to remove surface impurities, and then dried at 65°C for 1.5 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with 5 aggregate "knots" prepared from each fiber.

[0077] Step 2: Fiber Bridging of Copper Mesh. The chain-like aggregates are entangled and bridged onto two opposing copper meshes, with one strand entangled every two meshes, evenly distributed across the mesh. After entanglement, the fibers and copper mesh bridge to form a three-dimensional frame, which is then inserted into the mold for later use.

[0078] Step 3: Slurry Preparation and Molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (100nm) in a mass ratio of 6:11:0.8:3 were mixed and manually stirred for 2 minutes to ensure uniform dispersion. Then, water was added and stirred in a mixer at 1000 rpm for 8 minutes to obtain a slurry with a water-cement ratio of 0.55. The slurry was poured into a mold with fiber-bridged copper mesh inserted and cured at 55℃ and >95% humidity for 48 hours to obtain the solid waste-fiber composite electrolyte matrix.

[0079] Simultaneously assemble the structural supercapacitor: pour the slurry into another mold with the same fiber bridging copper mesh, and insert a 200-mesh copper mesh electrode loaded with graphene parallel and vertically on the outside of the two bridging copper meshes. Curing and hardening under the same conditions, the structural supercapacitor is assembled.

[0080] Step 4: Demolding and Post-processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled supercapacitor, they were separately immersed in a saturated potassium sulfate solution for 56 days and then removed. Next, they were placed in a limonene solution at 65°C to dissolve the polystyrene microspheres in the electrolyte matrix. After immersion for 36 hours, they were removed to obtain the solid waste-fiber composite electrolyte and the assembled supercapacitor.

[0081] The prepared solid waste-fiber composite electrolyte has an ionic conductivity of 22.40 mS / cm, and the assembled structural supercapacitor has a surface capacitance of 29.97 mF / cm. 2 .

[0082] Example 7

[0083] The mass ratio of steel slag, mineral powder, activator, and polystyrene microspheres in the electrolyte matrix is ​​6:10:0.8:4, and the pore size is 50μm. The polystyrene microspheres in the electrolyte matrix are dissolved and formed. Cotton fibers with a diameter of 3mm are used, and each fiber has 5 aggregates "knots". One fiber is entangled every other grid.

[0084] The preparation methods of solid waste-fiber composite electrolyte and structural supercapacitor are as follows:

[0085] Step 1: Fiber Pretreatment. Cotton fibers with a diameter of 3 mm were soaked in a potassium hydroxide solution with a pH of 13 for 1.5 hours to remove surface impurities, and then dried at 60°C for 2 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with 5 aggregate "knots" prepared from each fiber.

[0086] Step 2: Fiber Bridging of Copper Mesh. The chain-like aggregates are entangled and bridged onto two opposing copper meshes, with one strand entangled every other mesh, evenly distributed across the mesh. After entanglement, the fibers and copper mesh bridge to form a three-dimensional frame, which is then inserted into a mold for later use.

[0087] Step 3: Slurry Preparation and Molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (50 μm) in a mass ratio of 6:10:0.8:4 were mixed and manually stirred for 2 minutes to ensure uniform dispersion. Then, water was added and stirred in a mixer at 1200 rpm for 6 minutes to obtain a slurry with a water-cement ratio of 0.6. The slurry was poured into a mold with fiber-bridged copper mesh inserted and cured at 60℃ and >95% humidity for 48 hours to obtain the solid waste-fiber composite electrolyte matrix.

[0088] Simultaneously assemble the structural supercapacitor: pour the slurry into another mold with the same fiber bridging copper mesh, and insert a 200-mesh copper mesh electrode loaded with graphene parallel and vertically on the outside of the two bridging copper meshes. Curing and hardening under the same conditions, the structural supercapacitor is assembled.

[0089] Step 4: Demolding and Post-processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled structural supercapacitor, they were separately immersed in a saturated potassium sulfate solution for 56 days and then removed. Next, they were placed in a limonene solution at 70°C to dissolve the polystyrene microspheres in the electrolyte matrix. After immersion for 36 hours, they were removed to obtain the solid waste-fiber composite electrolyte and the assembled structural supercapacitor.

[0090] The prepared solid waste-fiber composite electrolyte has an ionic conductivity of 18.28 mS / cm, and the assembled structural supercapacitor has a surface capacitance of 24.38 mF / cm. 2 .

[0091] Comparative Example 1

[0092] This comparative example lacks a three-dimensional framework composed of fibers and copper mesh bridging, and the electrolyte matrix does not contain pores formed by the dissolution of polystyrene microspheres. The mass ratio of steel slag, mineral powder, and activator in the electrolyte matrix material is 6:14:0.8.

[0093] The preparation methods of solid waste composite electrolytes and structural supercapacitors are as follows:

[0094] Step 1: Fiber-free pretreatment step.

[0095] Step 2: Fiberless bridging copper mesh process.

[0096] Step 3: Slurry Preparation and Molding. Steel slag, mineral powder, and potassium sulfate are mixed in a mass ratio of 6:14:0.8 and manually stirred for 2 minutes to ensure uniform dispersion. Then, water is added and stirred in a mixer at 1000 rpm for 5 minutes to obtain a slurry with a water-cement ratio of 0.6. The slurry is poured into a mold and cured for 24 hours at 60℃ and humidity >95% to obtain the solid waste electrolyte matrix.

[0097] Simultaneously assemble the structural supercapacitor: pour the slurry into another mold of the same model, insert a 200-mesh copper mesh electrode loaded with graphene into each end of the mold in parallel and vertical directions, cure and shape it under the same conditions, and assemble it into a structural supercapacitor.

[0098] Step 4: Demolding and Post-processing. After demolding the solid waste electrolyte matrix and the assembled structural supercapacitor, they are respectively immersed in a saturated potassium sulfate solution for 28 days for further curing, finally obtaining the solid waste electrolyte and the structural supercapacitor.

[0099] The ionic conductivity of the solid waste electrolyte was measured to be 4.15 mS / cm, and the surface capacitance of the assembled supercapacitor was 3.00 mF / cm. 2 .

[0100] Comparative Example 2

[0101] The electrolyte matrix in this comparative example did not contain pores formed after the polystyrene microspheres dissolved.

[0102] The mass ratio of steel slag, mineral powder, and activator in the materials used to prepare the electrolyte matrix is ​​6:14:0.8; cotton fibers with a diameter of 1 mm are used, and each fiber has 4 aggregates "knots"; one fiber is entangled every other grid.

[0103] The preparation methods of solid waste-fiber composite electrolyte and structural supercapacitor are as follows:

[0104] Step 1: Fiber Pretreatment. Cotton fibers with a diameter of 1 mm were soaked in a potassium hydroxide solution with a pH of 12 for 2 hours to remove surface impurities, and then dried at 60℃ for 2 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with 4 aggregate "knots" prepared from each fiber.

[0105] Step 2: Fiber Bridging of Copper Mesh. The chain-like aggregates are entangled and bridged onto two opposing copper meshes, with one strand entangled every other mesh, evenly distributed across the mesh. After entanglement, the fibers and copper mesh bridge to form a three-dimensional frame, which is then inserted into a mold for later use.

[0106] Step 3: Slurry Preparation and Molding. Steel slag, mineral powder, and potassium sulfate are mixed in a mass ratio of 6:14:0.8 and manually stirred for 2 minutes to ensure uniform dispersion. Water is then added and stirred in a mixer at 1000 rpm for 5 minutes to obtain a slurry with a water-cement ratio of 0.6. The slurry is poured into a mold with fiber-bridged copper mesh inserted and cured at 60℃ and >95% humidity for 24 hours to obtain the solid waste-fiber composite electrolyte matrix.

[0107] Simultaneously assemble the structural supercapacitor: pour the slurry into another mold with the same fiber bridging copper mesh, and insert a 200-mesh copper mesh electrode loaded with graphene parallel and vertically on the outside of the two bridging copper meshes. Curing and hardening under the same conditions, the structural supercapacitor is assembled.

[0108] Step 4: Demolding and Post-processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled structural supercapacitor, they are respectively immersed in a saturated potassium sulfate solution for 28 days of curing to obtain the solid waste composite electrolyte and the assembled structural supercapacitor.

[0109] The prepared solid waste composite electrolyte has an ionic conductivity of 7.67 mS / cm, and the assembled structural supercapacitor has a surface capacitance of 5.59 mF / cm. 2 .

[0110] Comparative Example 3

[0111] This comparative example lacks a three-dimensional framework composed of fibers and copper mesh. The mass ratio of steel slag, mineral powder, activator, and polystyrene microspheres in the materials used to prepare the electrolyte matrix is ​​6:12:0.8:2.

[0112] The preparation methods of solid waste composite electrolytes and structural supercapacitors are as follows:

[0113] Step 1: Fiber-free pretreatment step.

[0114] Step 2: Fiberless bridging copper mesh process.

[0115] Step 3: Slurry Preparation and Molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (50µm) in a mass ratio of 6:12:0.8:2 were mixed and manually stirred for 2 minutes to ensure uniform dispersion. Then, water was added and stirred in a mixer at 1000 rpm for 5 minutes to obtain a slurry with a water-cement ratio of 0.6. The slurry was poured into a mold and cured at 60℃ and >95% humidity for 24 hours to obtain the solid waste electrolyte matrix.

[0116] Simultaneously assemble the structural supercapacitor: pour the slurry into a mold of the same type, and insert a 200-mesh copper mesh electrode loaded with graphene parallel and vertically on the outside of the two bridging copper meshes. Curing and hardening under the same conditions will form a structural supercapacitor.

[0117] Step 4: Demolding and Post-processing. After demolding the solid waste electrolyte matrix and the assembled supercapacitor, they are separately immersed in a saturated potassium sulfate solution for 28 days and then removed. They are then placed in a limonene solution at 60°C to dissolve the polystyrene microspheres in the electrolyte matrix. After immersion for 24 hours, they are removed to obtain the solid waste electrolyte and the assembled supercapacitor.

[0118] The prepared solid waste electrolyte has an ionic conductivity of 6.91 mS / cm, and the assembled structural supercapacitor has a surface capacitance of 4.35 mF / cm. 2 .

[0119] The test values ​​of the electrolytes and structural supercapacitors prepared in each embodiment and comparative example are shown in Table 1.

[0120] Table 1. Test values ​​of electrolytes and structural supercapacitors prepared in each embodiment and comparative example:

[0121] Group Name Electrolyte ionic conductivity (mS / cm) <![CDATA[Capacitor surface capacitance (mF / cm 2 ).]]> Comparative Example 1 4.15 3.00 Comparative Example 2 7.67 5.59 Comparative Example 3 6.91 4.35 Example 1 11.02 9.71 Example 2 14.77 14.16 Example 3 13.44 12.96 Example 4 18.15 20.92 Example 5 16.52 16.22 Example 6 22.40 29.97 Example 7 18.28 24.38

Claims

1. A highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte, characterized in that, The solid waste-fiber composite electrolyte is composed of an electrolyte body, fibers, and copper mesh. Several fibers are wound at both ends on two opposing copper meshes, so that the fibers and copper meshes are bridged to form a three-dimensional frame. The electrolyte body is filled in the three-dimensional frame formed by the fibers and copper mesh. The electrolyte matrix is ​​mainly composed of steel slag, mineral powder and pores; each fiber has several entangled aggregates called "knots", and each fiber is a chain-like aggregate.

2. The highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte according to claim 1, characterized in that, The mass ratio of steel slag to mineral powder is (20~40):(60~80), and the pores are formed after the polymer microspheres contained in the electrolyte body are removed.

3. The highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte according to claim 2, characterized in that, The pore size is 20 nm to 50 µm, and the polymer microspheres include polystyrene microspheres, polymethyl methacrylate microspheres, or polyethylene microspheres.

4. The highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte according to claim 1, characterized in that, The fiber has hydrophilic functional groups, a diameter of 1mm to 10mm, and each fiber has 4 to 6 entangled aggregates "knots"; the copper mesh has a mesh count of 10 to 100, and one fiber is entangled every 1 to 3 meshes.

5. The highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte according to claim 4, characterized in that, The fiber is cotton fiber with a diameter of 1mm to 5mm, and the hydrophilic functional group includes carboxyl or hydroxyl groups; the copper mesh has a mesh size of 10 to 50 mesh.

6. A method for preparing a highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte according to any one of claims 1 to 5, characterized in that, Includes the following: (1) Fiber pretreatment: Take several fibers, remove impurities from the fiber surface, and cross-link each fiber into several aggregates "knots". Each fiber is a chain aggregate; (2) Fiber bridging copper mesh: The fiber entanglement treated in step (1) is bridged on the copper mesh to form a three-dimensional frame. The three-dimensional frame is inserted into the mold in a parallel and vertical manner. (3) Slurry preparation and molding: steel slag, mineral powder, activator, polymer microspheres and water are mixed to make slurry. The slurry is poured into a mold with a three-dimensional frame, cured and hardened to obtain a composite electrolyte matrix. (4) Demolding and post-processing: Remove the polymer microspheres in the composite electrolyte matrix and form a pore structure with uniform pore size inside the composite electrolyte matrix to obtain the solid waste-fiber composite electrolyte.

7. The method for preparing a highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte according to claim 6, characterized in that, In step (1), the method for removing impurities from the fiber surface is as follows: the fiber is soaked in an alkaline solution with a pH of 10 to 14 for 1 to 2 hours, then removed and dried at a temperature of 60°C to 80°C for 1 to 2 hours. In step (2), the bridging method is as follows: two copper meshes stand opposite each other, one end of the fiber is wrapped around one copper mesh, and the other end is horizontally wrapped around the other copper mesh; In step (3), the mass ratio of steel slag to mineral powder is (20~40):(60~80), the mass of polymer microspheres is 10%~20% of the total mass of steel slag, mineral powder, and polymer microspheres, the mass of activator is 4%~6% of the total mass of steel slag, mineral powder, and polymer microspheres, and the water-cement ratio of the slurry is 0.3~0.6; In step (4), the composite electrolyte matrix is ​​first soaked in a saturated sodium sulfate or potassium sulfate solution for 7 to 56 days and then soaked in an organic solvent to remove the polymer microspheres.

8. The method for preparing a highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte according to claim 7, characterized in that, In step (3), the activator includes at least one of alkaline activator and sulfate activator; the water-cement ratio of the slurry is 0.5~0.6; the curing conditions are 40℃~60℃ and humidity>95% for 24h~48h of standing. In step (4), when the polymer microspheres are polystyrene microspheres, the soaking temperature is 60℃~80℃, the soaking time is 24h~48h, and the organic solvent is at least one of limonene, benzene, toluene, and xylene; when the polymer microspheres are polymethyl methacrylate microspheres, the soaking temperature is 40℃~60℃, the soaking time is 6h~12h, and the organic solvent is at least one of acetone, chloroform, dichloromethane, and ethyl acetate; when the polymer microspheres are polyethylene microspheres, the soaking temperature is 60℃~100℃, the soaking time is 1h~6h, and the organic solvent is at least one of benzene, toluene, and xylene.

9. The application of a highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte prepared according to claim 6, characterized in that, The solid waste-fiber composite electrolyte is used to assemble a structural supercapacitor. The method of use is as follows: In step (3), the slurry is poured into a mold with the three-dimensional frame inserted. A copper mesh electrode loaded with graphene is inserted parallel and vertically on the outside of the two bridging copper meshes. The other steps are the same as the preparation method of the solid waste-fiber composite electrolyte. Finally, a structural supercapacitor assembled with the solid waste-fiber composite electrolyte is obtained.

10. The application of the highly conductive, ion-uniformly distributed porous solid waste-fiber composite electrolyte according to claim 1, characterized in that, The solid waste-fiber composite electrolyte is used to assemble a structural supercapacitor. The method of use is as follows: two copper mesh electrodes loaded with graphene are assembled parallel and vertically on the outside of the two bridging copper meshes of the solid waste-fiber composite electrolyte to obtain a structural supercapacitor assembled with the solid waste-fiber composite electrolyte.

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