High-conductivity ion uniformly-distributed porous solid waste-fiber composite electrolyte as well as preparation and application thereof

Abstract

The invention belongs to the technical field of solid waste recycling and electricity storage, and particularly relates to a high-conductivity ion uniformly-distributed porous solid waste-fiber composite electrolyte as well as preparation and application thereof. At present, an electrolyte prepared based on cement is low in ionic conductivity, small in pore structure and poor in connectivity. Fiber is wound to form an aggregate with a chain structure, and then the aggregate is bridged on two copper nets to form a three-dimensional frame; the preparation method comprises the following steps: preparing mixed slurry from steel slag, mineral powder and polymer microspheres, filling the mixed slurry into a three-dimensional frame, and removing the polymer microspheres to form pores with uniformly distributed pore diameters, thereby obtaining the solid waste-fiber composite electrolyte. According to the invention, the electrolyte matrix is prepared from industrial solid wastes, fibers are introduced to form short-distance communicated ion channels, and soluble polymer microspheres are doped to form a pore structure with controllable pore diameter and uniform distribution in the solid waste-fiber composite electrolyte, so that the ionic conductivity of the electrolyte is improved. The prepared composite electrolyte can be used for assembling a structure supercapacitor, and performance optimization is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of solid waste resource utilization and electricity storage technology, and particularly relates to a highly ion-conductive, uniformly distributed porous solid waste-fiber composite electrolyte and its preparation and application. Background Art

[0002] The construction industry is undergoing a comprehensive transformation from traditional high-energy consumption and high-emissions to green and low-carbon development. To this end, the construction industry urgently needs new energy storage technologies to achieve efficient energy utilization and reduce carbon emissions. In recent years, by combining building materials with energy storage technologies, the development of structural supercapacitors with both mechanical and electrochemical properties has gradually become a research hotspot in the construction field. This type of structural supercapacitor can be used as a building component to achieve "load-bearing + energy storage" integration. In structural supercapacitors, the electrolyte serves as the medium for ion conduction and directly affects the capacitor's ionic conductivity, charge and discharge efficiency, and service life.

[0003] Research on electrolytes for existing structural supercapacitors mainly focuses on the use of cement materials to prepare electrolytes. These electrolytes have good mechanical properties, but the cement production process is energy-intensive and emits large amounts of emissions. In addition, the ionic conductivity of electrolytes prepared from cement is low, and the pore structure is small and the connectivity is poor. Therefore, there is an urgent need for low-carbon materials to prepare electrolytes with high ionic conductivity. At present, my country's industrial solid waste stockpiles urgently need effective recycling and utilization measures. Some industrial solid wastes have similar compositions to cement and have potential advantages in preparing electrolytes. However, some industrial solid wastes have a single composition and can replace cement to prepare electrolytes after synergistic utilization. However, its structure and composition need to be further optimized to improve ionic conductivity.

[0004] At present, the optimization of the structure and performance of electrolytes 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 the amount of hydrogel added is too much, 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 effective and uniform distribution of the constructed channels, which in turn limits the effective transmission 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 and increase the porosity, thereby providing more channels for ion transmission and improving the ionic conductivity. However, since the distribution of reactants and the reaction rate during the redox reaction are difficult to accurately control, 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, the formation of a pore structure with uniform pore size in the electrolyte through redox reaction still faces great preparation difficulties. Summary of the Invention

[0005] In response to the above problems, the primary purpose of the present invention is to provide a highly ion-conductive, uniformly distributed, porous solid waste-fiber composite electrolyte. The second purpose of the present invention is to provide a method for preparing the solid waste-fiber composite electrolyte. The third purpose of the present invention is to provide the application of the solid waste-fiber composite electrolyte material in structural supercapacitors.

[0006] The highly ion-conductive, uniformly distributed, porous solid waste-fiber composite electrolyte of the present invention is composed of an electrolyte body, fibers, and a copper mesh. The two ends of each of the multiple fibers are entangled on two opposing copper meshes, so that the fibers and the 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 the copper meshes. The electrolyte body is mainly composed of steel slag, mineral powder and pores; each fiber has a number of entangled aggregates "knots", and each fiber is a chain-like aggregate.

[0007] The mass ratio of steel slag to mineral powder in the electrolyte body is (20-40): (60-80); the pores are formed by dissolving and removing polymer microspheres contained in the electrolyte body, and the pore diameter is 20nm-50µm; the polymer microspheres include polystyrene microspheres, polymethyl methacrylate microspheres, or polyethylene microspheres.

[0008] The diameter of the fiber is 1 mm to 10 mm, preferably 1 mm to 5 mm; the fiber has a hydrophilic functional group, which includes a carboxyl group or a hydroxyl group; cotton fiber is preferred; each fiber preferably has 4 to 6 entangled aggregates "knots"; one fiber is entangled every 1 to 3 grids; the mesh number of the copper mesh is 10 mesh to 100 mesh, preferably 10 mesh to 50 mesh.

[0009] The method for preparing the highly ion-conductive, uniformly distributed, porous solid waste-fiber composite electrolyte of the present invention comprises the following steps: (1) Fiber pretreatment: Take several fibers, remove impurities on the fiber surface, and entangle and cross-link each fiber into several aggregates "knots". Each fiber is a chain aggregate; (2) Fiber-bridged copper mesh: The treated fibers in step (1) are entangled with the bridged copper mesh to form a three-dimensional frame, which is then inserted parallely and vertically into the mold to construct an ion transport channel; (3) Slurry preparation and injection molding: Steel slag, mineral powder, activator, and polymer microspheres are mixed and stirred evenly, and water is added to obtain a slurry for preparing the electrolyte matrix; the mixed slurry is poured into a mold with a three-dimensional frame inserted, and cured and hardened to obtain a composite electrolyte matrix; (4) Demolding and post-processing: After the composite electrolyte matrix is ​​demolded, it is immersed in an organic solvent to dissolve and remove the polymer microspheres, thereby forming a pore structure with uniform pore size inside the composite electrolyte matrix to obtain the solid waste-fiber composite electrolyte.

[0010] In step (1), the method for removing impurities on the fiber surface is as follows: the fiber is immersed in an alkaline potassium hydroxide solution with a pH of 10-14 for 1 hour to 2 hours, and then taken out and dried at a drying temperature of 60°C to 80°C for 1 hour to 2 hours, thereby removing hydrophobic impurities such as wax and pectin on the fiber surface and making the fiber surface more hydrophilic.

[0011] In step (2), the bridging method is: two copper meshes are placed opposite to each other, one end of the fiber is entangled on the grid of one copper mesh, and the other end is horizontally entangled on the grid of another copper mesh; the higher the mesh count of the copper mesh, the smaller the mesh size, in order to facilitate fiber entanglement, increase the number of entangled fibers, and improve the ion transmission channel in the electrolyte.

[0012] In step (3), the mass ratio of the steel slag to the mineral powder is (20-40): (60-80), the mass of the polymer microspheres is 10%-20% of the total mass of the steel slag, the mineral powder, and the polymer microspheres, and the mass of the activator is 4%-6% of the total mass of the steel slag, the mineral powder, and the polymer microspheres; the activator includes at least one of an alkaline activator and a sulfate activator.

[0013] In step (3), the mixing method is mechanical stirring, and the mixture is stirred in a mixer at 800 rpm to 1200 rpm for 5 min to 10 min to ensure that the powder is fully mixed; the water-cement ratio of the slurry is 0.3 to 0.6, preferably 0.5 to 0.6; and the curing is performed by standing at 40°C to 60°C and humidity > 95% for 24 h to 48 h.

[0014] In step (4), the composite electrolyte matrix is ​​first soaked in a saturated sodium sulfate solution or a saturated 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, and high temperatures can accelerate the dissolution process; the polymer microspheres include at least one of polystyrene microspheres, polymethyl methacrylate microspheres, and polyethylene microspheres, and have a particle size of 20 nm to 50 µm.

[0015] When the polymer microspheres are polystyrene microspheres, the immersion temperature is 60°C to 80°C, the immersion time is 24h to 48h, and the organic solvent is at least one of limonene, benzene, toluene, and xylene; when the polymer microspheres are polymethyl methacrylate microspheres, the immersion temperature is 40°C to 60°C, the immersion time is 6h to 12h, and the organic solvent is at least one of acetone, chloroform, dichloromethane, and ethyl acetate; when the polymer microspheres are polyethylene microspheres, the immersion temperature is 60°C to 100°C, the immersion time is 1h to 6h, and the organic solvent is at least one of benzene, toluene, and xylene.

[0016] The solid waste-fiber composite electrolyte of the present invention can be used to assemble a structural supercapacitor, and the specific method is as follows: Method 1, in step (3), the mixed slurry is poured into a mold into which a fiber bridge copper mesh has been inserted, and a graphene-loaded copper mesh electrode is inserted parallely and vertically on the outside of the two bridge copper meshes. The other steps are the same as the preparation method of the solid waste-fiber composite electrolyte, and finally a structural supercapacitor assembled with a solid waste-fiber composite electrolyte is obtained.

[0017] Method 2: A graphene-loaded copper mesh electrode is assembled parallely and vertically on the outside of the two bridging copper meshes of the final solid waste-fiber composite electrolyte to obtain a structural supercapacitor assembled with a solid waste-fiber composite electrolyte.

[0018] Compared with the prior art, the present invention has achieved the following significant results: (1) The proposed cross-linked and entangled fibers arranged at a fixed distance show significant structural and functional advantages in constructing ion transmission channels. By regulating the fiber arrangement and entanglement density, the precise design of ion transmission channels can be achieved. The aggregates formed by fiber entanglement can significantly increase the contact area between the fiber and the pores in the electrolyte. This structure provides more transmission paths for ions, facilitates the rapid migration of ions to the fiber surface, and thus effectively improves the ion 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 transmission efficiency. (2) The abundant hydrophilic functional groups such as hydroxyl / carboxyl groups on the fiber surface can effectively adsorb the electrolyte, ensure the wettability of the electrolyte, and improve the ion 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, which have high chemical stability, water resistance, acid and alkali resistance. During the slurry solidification process, the presence of microspheres will occupy a certain amount of space. The microspheres are then removed by heating in an organic solvent, leaving pores of uniform and controllable size 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 incorporation of activators as external admixtures 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 reinforcement effect, synergistically promoting the improvement of ion mobility. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The figure is a schematic diagram of the process of preparing a highly ion-conductive, uniformly distributed, porous solid waste-fiber composite electrolyte according to the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is clearly and completely described below in conjunction with the embodiments and drawings. It should be noted that the embodiments described in the present invention are only used to further explain and illustrate, and are not intended to limit the scope of its application. Based on the present invention, all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of the present invention.

[0021] To better demonstrate the performance, the mold size in the embodiment is a 20mm×20mm×20mm cube mold with an upper opening, and the copper mesh used for bridging is 10 mesh and 20mm×30mm in size. The prepared solid waste electrolyte was subjected to impedance spectroscopy (EIS) testing using an electrochemical workstation with a test frequency of 0.01Hz~1000000Hz; the assembled structural supercapacitor was subjected to a constant current charge and discharge test (GCD) with a test current density of 0.5mA / cm 2 .

[0022] Example 1 The mass ratio of steel slag, mineral powder, activator and polystyrene microspheres in the materials for preparing the electrolyte body is 6:12:0.8:2. The pores have a pore diameter of 20nm and are formed by the dissolution of the polystyrene microspheres in the electrolyte body material. Cotton fibers are used, with a diameter of 1mm and each fiber having 4 aggregate "knots". One fiber is entangled every other grid.

[0023] The preparation method of the solid waste-fiber composite electrolyte and the structural supercapacitor is as follows: Step 1: Fiber Pretreatment. 1 mm diameter cotton fibers were soaked in a potassium hydroxide solution with a pH of 12 for 1.5 hours to remove surface impurities. The fibers were then dried at 60°C for 2 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with four aggregate "knots" prepared for each fiber.

[0024] Step 2: Fiber Bridging Copper Mesh. The chain aggregates are entangled and bridged onto two opposing copper meshes, entwining one strand every other mesh and distributing them evenly across the meshes. Once entangled, the fibers and meshes are bridged to form a three-dimensional framework, which is then inserted into the mold for later use.

[0025] Step 3: Slurry preparation and injection molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (20 nm) were mixed in a mass ratio of 6:12:0.8:2 and manually stirred for 2 minutes to achieve uniform dispersion. Subsequently, water was added and stirred in a blender at 1200 rpm for 5 minutes to prepare a slurry with a water-cement ratio of 0.3. The slurry was poured into a mold with a fiber-bridged copper mesh inserted. The mold was allowed to stand for 24 hours at 60°C and humidity >95% to harden and form the solid waste-fiber composite electrolyte matrix.

[0026] At the same time, the structural supercapacitor is assembled: the slurry is poured into another mold with the same fiber bridge copper mesh inserted, and a 200-mesh copper mesh electrode loaded with graphene is inserted parallel and vertically on the outside of the two bridge copper meshes. The mold is cured and hardened under the same conditions to assemble into a structural supercapacitor.

[0027] Step 4: Demolding and post-processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled structural supercapacitor, place them in a saturated potassium sulfate solution and soak for 28 days before taking them out. At 60°C, place them in a limonene solution to dissolve the polystyrene microspheres in the electrolyte matrix. After soaking for 48 hours, take them out to obtain the solid waste-fiber composite electrolyte and the assembled structural supercapacitor. The preparation process is as follows: Figure 1 shown.

[0028] The ionic conductivity of the prepared solid waste-fiber composite electrolyte is 11.02mS / cm, and the surface capacitance of the assembled structural supercapacitor is 9.71mF / cm 2 .

[0029] Example 2 The mass ratio of steel slag, mineral powder, activator, and polystyrene microspheres in the materials for preparing the electrolyte body is 4:14:1.2:2. The pores have a pore diameter of 20 nm and are formed by the dissolution of the polystyrene microspheres in the electrolyte body material. Cotton fibers are used, with a diameter of 1 mm and each fiber having 5 aggregate "knots." One fiber is entangled every other grid.

[0030] The preparation method of the solid waste-fiber composite electrolyte and the structural supercapacitor is as follows: Step 1: Fiber Pretreatment. 1 mm diameter cotton fibers were soaked in a potassium hydroxide solution with a pH of 10 for 2 hours to remove surface impurities. The fibers were then dried at 80°C for 1 hour. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with five aggregate "knots" prepared for each fiber.

[0031] Step 2: Fiber Bridging Copper Mesh. The chain aggregates are entangled and bridged onto two opposing copper meshes, entwining one strand every other mesh and distributing them evenly across the meshes. Once entangled, the fibers and meshes are bridged to form a three-dimensional framework, which is then inserted into the mold for later use.

[0032] Step 3: Slurry preparation and injection molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (20 nm) were mixed in a mass ratio of 4:14:1.2:2 and manually stirred for 2 minutes to achieve uniform dispersion. Subsequently, water was added and stirred in a blender at 800 rpm for 10 minutes to prepare a slurry with a water-cement ratio of 0.35. The slurry was poured into a mold with a fiber-bridged copper mesh inserted. The mold was allowed to stand at 40°C and humidity >95% for 48 hours to cure and harden, resulting in a solid waste-fiber composite electrolyte matrix.

[0033] At the same time, the structural supercapacitor is assembled: the slurry is poured into another mold with the same fiber bridge copper mesh inserted, and a 200-mesh copper mesh electrode loaded with graphene is inserted parallel and vertically on the outside of the two bridge copper meshes. The mold is cured and hardened under the same conditions to assemble into a structural supercapacitor.

[0034] Step 4: Demolding and Post-Processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled structural supercapacitor, each was placed in a saturated potassium sulfate solution for 7 days of soaking and curing. Then, each was placed in a limonene solution at 80°C to dissolve the polystyrene microspheres in the electrolyte matrix. After soaking for 24 hours, the solid waste-fiber composite electrolyte and the assembled structural supercapacitor were obtained.

[0035] The ionic conductivity of the prepared solid waste-fiber composite electrolyte is 14.77mS / cm, and the surface capacitance of the assembled structural supercapacitor is 14.16mF / cm2 .

[0036] Example 3 The mass ratio of steel slag, mineral powder, activator and polystyrene microspheres in the materials for preparing the electrolyte body is 5:13:1:2. The pore diameter is 50nm, which is formed by the dissolution of the polystyrene microspheres in the electrolyte body material. Cotton fibers are used, the fiber diameter is 1mm, and each fiber has 6 aggregate "knots"; one fiber is entangled every other grid.

[0037] The preparation method of the solid waste-fiber composite electrolyte and the structural supercapacitor is as follows: Step 1: Fiber Pretreatment. 1 mm diameter cotton fibers were soaked in a potassium hydroxide solution with a pH of 14 for 1 hour to remove surface impurities. The fibers were then dried at 70°C for 1.5 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with six aggregate "knots" prepared for each fiber.

[0038] Step 2: Fiber Bridging Copper Mesh. The chain aggregates are entangled and bridged onto two opposing copper meshes, entwining one strand every other mesh and distributing them evenly across the meshes. Once entangled, the fibers and meshes are bridged to form a three-dimensional framework, which is then inserted into the mold for later use.

[0039] Step 3: Slurry preparation and injection molding. Mix steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (100 nm) in a mass ratio of 5:13:1:2 and stir manually for 2 minutes to evenly disperse them. Subsequently, add water and stir in a blender at 1000 rpm for 6 minutes to prepare a slurry with a water-cement ratio of 0.4. Pour the slurry into a mold with a fiber-bridged copper mesh inserted, and let it stand for 36 hours at 50°C and humidity >95% to harden and form a solid waste-fiber composite electrolyte matrix.

[0040] At the same time, the structural supercapacitor is assembled: the slurry is poured into another mold with the same fiber bridge copper mesh inserted, and a 200-mesh copper mesh electrode loaded with graphene is inserted parallel and vertically on the outside of the two bridge copper meshes. The mold is cured and hardened under the same conditions to assemble into a structural supercapacitor.

[0041] Step 4: Demolding and Post-Processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled structural supercapacitor, each was placed in a saturated potassium sulfate solution for 14 days of soaking and curing. The resulting solid waste-fiber composite electrolyte and assembled structural supercapacitor were then removed from the mold. The resulting solid waste-fiber composite electrolyte and assembled structural supercapacitor were then placed in a limonene solution at 70°C to dissolve the polystyrene microspheres in the electrolyte matrix. After soaking for 36 hours, the resulting solid waste-fiber composite electrolyte and assembled structural supercapacitor were obtained.

[0042] The ionic conductivity of the prepared solid waste-fiber composite electrolyte is 13.44mS / cm, and the surface capacitance of the assembled structural supercapacitor is 12.96mF / cm 2 .

[0043] Example 4 The mass ratio of steel slag, mineral powder, activator and polystyrene microspheres in the materials for preparing the electrolyte body is 7:11:0.8:2. The pore diameter is 50nm, which is formed by the dissolution of the polystyrene microspheres in the electrolyte body material. Cotton fibers are used, the fiber diameter is 3mm, and each fiber has 5 aggregate "knots"; one fiber is entangled every 3 grids.

[0044] The preparation method of the solid waste-fiber composite electrolyte and the structural supercapacitor is as follows: Step 1: Fiber Pretreatment. 3mm diameter cotton fibers were soaked in a potassium hydroxide solution with a pH of 10 for 2 hours to remove surface impurities. The fibers were then dried at 70°C for 2 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with five aggregate "knots" prepared for each fiber.

[0045] Step 2: Fiber Bridging Copper Mesh. The chain aggregates are entangled and bridged onto two opposing copper meshes, with one strand entangled every three meshes, evenly distributed across the meshes. Once entangled, the fibers and meshes are bridged to form a three-dimensional framework, which is then inserted into the mold for later use.

[0046] Step 3: Slurry preparation and injection molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (50 nm) were mixed in a mass ratio of 7:11:0.8:2 and manually stirred for 2 minutes to achieve uniform dispersion. Subsequently, water was added and stirred in a blender at 1000 rpm for 6 minutes to prepare a slurry with a water-cement ratio of 0.45. The slurry was poured into a mold with a fiber-bridged copper mesh inserted. The mold was allowed to stand for 24 hours at 55°C and humidity >95% to harden and form the solid waste-fiber composite electrolyte matrix.

[0047] At the same time, the structural supercapacitor is assembled: the slurry is poured into another mold with the same fiber bridge copper mesh inserted, and a 200-mesh copper mesh electrode loaded with graphene is inserted parallel and vertically on the outside of the two bridge copper meshes. The mold is cured and hardened under the same conditions to assemble into a structural supercapacitor.

[0048] Step 4: Demolding and Post-Processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled structural supercapacitor, each was placed in a saturated potassium sulfate solution for 14 days of soaking and curing. Then, each was placed in a limonene solution at 75°C to dissolve the polystyrene microspheres in the electrolyte matrix. After soaking for 28 hours, the solid waste-fiber composite electrolyte and the assembled structural supercapacitor were obtained.

[0049] The ionic conductivity of the prepared solid waste-fiber composite electrolyte is 18.15mS / cm, and the surface capacitance of the assembled structural supercapacitor is 20.92mF / cm 2 .

[0050] Example 5 The mass ratio of steel slag, mineral powder, activator and polystyrene microspheres in the materials used to prepare the electrolyte body is 5:13:1:2. The pore diameter is 100nm, which is formed by the dissolution of the polystyrene microspheres in the electrolyte body material. Cotton fibers are used, with a diameter of 5mm and each fiber having 6 aggregate "knots". One fiber is entangled every 2 grids.

[0051] The preparation method of the solid waste-fiber composite electrolyte and the structural supercapacitor is as follows: Step 1: Fiber Pretreatment. 5mm diameter cotton fibers were soaked in a potassium hydroxide solution with a pH of 12 for 2 hours to remove surface impurities. The fibers were then dried at 60°C for 2 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with six aggregate "knots" prepared for each fiber.

[0052] Step 2: Fiber Bridging Copper Mesh. The chain aggregates are entangled and bridged onto two opposing copper meshes, with one strand entangled every two meshes, evenly distributed across the meshes. Once entangled, the fibers and meshes are bridged to form a three-dimensional framework, which is then inserted into the mold for later use.

[0053] Step 3: Slurry preparation and injection molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (100 nm) were mixed in a mass ratio of 5:13:1:2 and manually stirred for 2 minutes to achieve uniform dispersion. Subsequently, water was added and stirred in a blender at 900 rpm for 9 minutes to prepare a slurry with a water-cement ratio of 0.5. The slurry was poured into a mold with a fiber-bridged copper mesh inserted. The mold was allowed to stand at 50°C and humidity >95% for 36 hours to cure and harden, resulting in a solid waste-fiber composite electrolyte matrix.

[0054] At the same time, the structural supercapacitor is assembled: the slurry is poured into another mold with the same fiber bridge copper mesh inserted, and a 200-mesh copper mesh electrode loaded with graphene is inserted parallel and vertically on the outside of the two bridge copper meshes. The mold is cured and hardened under the same conditions to assemble into a structural supercapacitor.

[0055] Step 4: Demolding and Post-Processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled structural supercapacitor, each was placed in a saturated potassium sulfate solution for 28 days of soaking and curing. Then, each was placed in a limonene solution at 60°C to dissolve the polystyrene microspheres in the electrolyte matrix. After soaking for 48 hours, the solid waste-fiber composite electrolyte and the assembled structural supercapacitor were obtained.

[0056] The ionic conductivity of the prepared solid waste-fiber composite electrolyte is 16.52mS / cm, and the surface capacitance of the assembled structural supercapacitor is 16.22mF / cm 2 .

[0057] Example 6 The mass ratio of steel slag, mineral powder, activator, and polystyrene microspheres in the materials used to prepare the electrolyte body is 6:11:0.8:3. The pores have a pore diameter of 100 nm and are formed by the dissolution of the polystyrene microspheres in the electrolyte body material. Cotton fibers are used, with a diameter of 3 mm and each fiber having 5 aggregate "knots." One fiber is entangled every 2 grids.

[0058] The preparation method of the solid waste-fiber composite electrolyte and the structural supercapacitor is as follows: Step 1: Fiber Pretreatment. 3mm diameter cotton fibers were soaked in a potassium hydroxide solution with a pH of 11 for 1.8 hours to remove surface impurities. The fibers were then dried at 65°C for 1.5 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with five aggregate "knots" prepared for each fiber.

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

[0060] Step 3: Slurry preparation and injection molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (100 nm) were mixed in a mass ratio of 6:11:0.8:3 and manually stirred for 2 minutes to uniformly disperse them. Subsequently, water was added and stirred in a blender at 1000 rpm for 8 minutes to prepare a slurry with a water-cement ratio of 0.55. The slurry was poured into a mold with a fiber-bridged copper mesh inserted and allowed to stand for 48 hours at 55°C and humidity >95% to harden and form the solid waste-fiber composite electrolyte matrix.

[0061] At the same time, the structural supercapacitor is assembled: the slurry is poured into another mold with the same fiber bridge copper mesh inserted, and a 200-mesh copper mesh electrode loaded with graphene is inserted parallel and vertically on the outside of the two bridge copper meshes. The mold is cured and hardened under the same conditions to assemble into a structural supercapacitor.

[0062] Step 4: Demolding and Post-Processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled structural supercapacitor, they were each immersed in a saturated potassium sulfate solution for 56 days and then removed. At 65°C, they were then placed in a limonene solution to dissolve the polystyrene microspheres in the electrolyte matrix. After immersion for 36 hours, the solid waste-fiber composite electrolyte and the assembled structural supercapacitor were obtained.

[0063] The ionic conductivity of the prepared solid waste-fiber composite electrolyte is 22.40mS / cm, and the surface capacitance of the assembled structural supercapacitor is 29.97mF / cm 2 .

[0064] Example 7 The mass ratio of steel slag, mineral powder, activator and polystyrene microspheres in the materials for preparing the electrolyte body is 6:10:0.8:4. The pore diameter is 50μm, which is formed by the dissolution of polystyrene microspheres in the electrolyte body material. Cotton fibers are used, the fiber diameter is 3mm, and each fiber has 5 aggregate "knots"; one fiber is entangled every other grid.

[0065] The preparation method of the solid waste-fiber composite electrolyte and the structural supercapacitor is as follows: Step 1: Fiber Pretreatment. 3mm diameter cotton fibers were soaked in a potassium hydroxide solution with a pH of 13 for 1.5 hours to remove surface impurities. The fibers were then dried at 60°C for 2 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with five aggregate "knots" prepared for each fiber.

[0066] Step 2: Fiber Bridging Copper Mesh. The chain aggregates are entangled and bridged onto two opposing copper meshes, entwining one strand every other mesh and distributing them evenly across the meshes. Once entangled, the fibers and meshes are bridged to form a three-dimensional framework, which is then inserted into the mold for later use.

[0067] Step 3: Slurry preparation and injection molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (50 μm) were mixed in a mass ratio of 6:10:0.8:4 and manually stirred for 2 minutes to achieve uniform dispersion. Subsequently, water was added and stirred in a blender at 1200 rpm for 6 minutes to prepare a slurry with a water-cement ratio of 0.6. The slurry was poured into a mold with a fiber-bridged copper mesh inserted. The mold was allowed to stand at 60°C and humidity >95% for 48 hours to cure and harden, resulting in a solid waste-fiber composite electrolyte matrix.

[0068] At the same time, the structural supercapacitor is assembled: the slurry is poured into another mold with the same fiber bridge copper mesh inserted, and a 200-mesh copper mesh electrode loaded with graphene is inserted parallel and vertically on the outside of the two bridge copper meshes. The mold is cured and hardened under the same conditions to assemble into a structural supercapacitor.

[0069] Step 4: Demolding and Post-Processing. After demolding the solid waste-fiber composite electrolyte matrix and the assembled structural supercapacitor, each was placed in a saturated potassium sulfate solution for 56 days of soaking and curing. Then, they were placed in a limonene solution at 70°C to dissolve the polystyrene microspheres in the electrolyte matrix. After soaking for 36 hours, the solid waste-fiber composite electrolyte and the assembled structural supercapacitor were obtained.

[0070] The ionic conductivity of the prepared solid waste-fiber composite electrolyte is 18.28mS / cm, and the surface capacitance of the assembled structural supercapacitor is 24.38mF / cm 2 .

[0071] Comparative Example 1 The comparative example does not have a three-dimensional framework formed by the fiber and copper mesh bridge, and the electrolyte body does not have pores formed by the dissolution of polystyrene microspheres. The mass ratio of steel slag, mineral powder, and activator in the electrolyte body material is 6:14:0.8.

[0072] The preparation method of the solid waste composite electrolyte and the structural supercapacitor is as follows: Step 1: No fiber pre-treatment step.

[0073] Step 2: No fiber bridging copper mesh step.

[0074] Step 3: Slurry preparation and injection molding. Mix steel slag, mineral powder and potassium sulfate in a mass ratio of 6:14:0.8 and stir manually for 2 minutes to make them evenly dispersed. Subsequently, add water and stir in a blender at a speed of 1000 rpm for 5 minutes to prepare a slurry with a water-cement ratio of 0.6. Pour the slurry into a mold and let it stand for 24 hours at 60°C and humidity >95% to harden and form a solid waste electrolyte matrix.

[0075] At the same time, the structural supercapacitor is assembled: the slurry is poured into another mold of the same model, and a 200-mesh copper mesh electrode loaded with graphene is inserted parallely and vertically at both ends of the mold. The mold is cured and hardened under the same conditions to assemble into a structural supercapacitor.

[0076] Step 4: Demolding and Post-processing: After demolding the solid waste electrolyte matrix and the assembled structural supercapacitor, they were immersed in a saturated potassium sulfate solution and cured for 28 days, respectively, to obtain the solid waste electrolyte and structural supercapacitor.

[0077] The ionic conductivity of the solid waste electrolyte was measured to be 4.15 mS / cm, and the surface capacitance of the assembled structural supercapacitor was 3.00 mF / cm 2 .

[0078] Comparative Example 2 The electrolyte body of this comparative example does not have pores formed by the dissolution of the polystyrene microspheres.

[0079] The mass ratio of steel slag, mineral powder and activator in the materials for preparing the electrolyte body is 6:14:0.8; cotton fiber is used, the fiber diameter is 1 mm, and each fiber has 4 aggregate "knots"; one fiber is entangled every other grid.

[0080] The preparation method of the solid waste-fiber composite electrolyte and the structural supercapacitor is as follows: Step 1: Fiber Pretreatment. 1 mm diameter cotton fibers were soaked in a potassium hydroxide solution with a pH of 12 for 2 hours to remove surface impurities. The fibers were then dried at 60°C for 2 hours. The dried fibers were then entangled and cross-linked to form chain-like aggregates, with four aggregate "knots" prepared for each fiber.

[0081] Step 2: Fiber Bridging Copper Mesh. The chain aggregates are entangled and bridged onto two opposing copper meshes, entwining one strand every other mesh and distributing them evenly across the meshes. Once entangled, the fibers and meshes are bridged to form a three-dimensional framework, which is then inserted into the mold for later use.

[0082] Step 3: Slurry preparation and injection molding. Mix steel slag, mineral powder and potassium sulfate in a mass ratio of 6:14:0.8 and stir manually for 2 minutes to make them evenly dispersed. Then add water and stir in a blender at a speed of 1000 rpm for 5 minutes to prepare a slurry with a water-cement ratio of 0.6. Pour the slurry into a mold with a fiber-bridged copper mesh inserted, and let it stand for 24 hours at 60°C and humidity >95% to cure and harden the mold to obtain a solid waste-fiber composite electrolyte matrix.

[0083] At the same time, the structural supercapacitor is assembled: the slurry is poured into another mold with the same fiber bridge copper mesh inserted, and a 200-mesh copper mesh electrode loaded with graphene is inserted parallel and vertically on the outside of the two bridge copper meshes. The mold is cured and hardened under the same conditions to assemble into a structural supercapacitor.

[0084] Step 4: Demolding and Post-processing: After demolding the solid waste-fiber composite electrolyte matrix and the assembled structural supercapacitor, they were immersed in a saturated potassium sulfate solution and cured for 28 days, respectively, to obtain the solid waste composite electrolyte and the assembled structural supercapacitor.

[0085] The ionic conductivity of the prepared solid waste composite electrolyte is 7.67mS / cm, and the surface capacitance of the assembled structural supercapacitor is 5.59mF / cm 2 .

[0086] Comparative Example 3 The comparative example does not have a three-dimensional frame formed by fibers and copper mesh. The mass ratio of steel slag, mineral powder, activator, and polystyrene microspheres in the materials for preparing the electrolyte body is 6:12:0.8:2.

[0087] The preparation method of the solid waste composite electrolyte and the structural supercapacitor is as follows: Step 1: No fiber pre-treatment step.

[0088] Step 2: No fiber bridging copper mesh step.

[0089] Step 3: Slurry Preparation and Injection Molding. Steel slag, mineral powder, potassium sulfate powder, and polystyrene microspheres (50µm) were mixed in a mass ratio of 6:12:0.8:2 and manually stirred for 2 minutes to achieve uniform dispersion. Subsequently, water was added and stirred in a blender at 1000 rpm for 5 minutes to prepare a slurry with a water-cement ratio of 0.6. The slurry was poured into a mold and allowed to stand for 24 hours at 60°C and humidity >95% to harden and form the solid waste electrolyte matrix.

[0090] At the same time, the structural supercapacitor is assembled: the slurry is poured into a mold of the same model, and a 200-mesh copper mesh electrode loaded with graphene is inserted parallel and vertically on the outside of the two bridging copper meshes. The molds are cured and hardened under the same conditions to assemble into a structural supercapacitor.

[0091] Step 4: Demolding and Post-Processing. After demolding the solid waste electrolyte matrix and the assembled structural supercapacitor, each was placed in a saturated potassium sulfate solution for 28 days of soaking and curing. Then, each was placed in a limonene solution at 60°C to dissolve the polystyrene microspheres in the electrolyte matrix. After soaking for 24 hours, the solid waste electrolyte and the assembled structural supercapacitor were obtained.

[0092] The ionic conductivity of the prepared solid waste electrolyte is 6.91mS / cm, and the surface capacitance of the assembled structural supercapacitor is 4.35mF / cm 2 .

[0093] The test values ​​of the electrolytes and structural supercapacitors prepared in various embodiments and comparative examples are shown in Table 1.

[0094] Table 1 Test values ​​of electrolytes and structural supercapacitors prepared in various embodiments and comparative examples: Group Name Electrolyte ion 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 ion-conductive, 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 a copper mesh. The two ends of each of the multiple fibers are entangled on two opposing copper meshes, so that the fibers and the 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 the copper meshes. The electrolyte body is mainly composed of steel slag, mineral powder and pores; each fiber has a number of entangled aggregates "knots", and each fiber is a chain-like aggregate.

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

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

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

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

6. The method for preparing a highly ion-conductive, 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 on the fiber surface, and entangle and cross-link each fiber into several aggregates "knots". Each fiber is a chain aggregate; (2) Fiber bridging copper mesh: The fibers processed in step (1) are entangled and bridged on the copper mesh to form a three-dimensional frame, and the three-dimensional frame is inserted parallely and vertically into the mold; (3) Slurry preparation and injection molding: Steel slag, mineral powder, activator, polymer microspheres and water are mixed to form a slurry, which is then poured into a mold with a three-dimensional frame inserted, cured and hardened to obtain a composite electrolyte matrix; (4) Demolding and post-processing: removing the polymer microspheres in the composite electrolyte matrix, forming a pore structure with uniform pore size inside the composite electrolyte matrix, and obtaining the solid waste-fiber composite electrolyte.

7. The method for preparing a highly ion-conductive, 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: soaking the fiber in an alkaline solution with a pH of 10 to 14 for 1 to 2 hours, taking it out and drying it at a temperature of 60°C to 80°C for 1 to 2 hours; In step (2), the bridging method is: two copper meshes are placed opposite to each other, one end of the fiber is entangled on one copper mesh, and the other end is horizontally entangled on the other copper mesh; In step (3), the mass ratio of the steel slag to the mineral powder is (20-40): (60-80), the mass of the polymer microspheres is 10%-20% of the total mass of the steel slag, mineral powder, and polymer microspheres, and the mass of the activator is 4%-6% of the total mass of the steel slag, mineral powder, and polymer microspheres; 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 solution or a saturated 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 ion-conductive, 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 an alkaline activator and a sulfate activator; the water-cement ratio of the slurry is 0.5-0.6; the curing conditions are 40°C-60°C, humidity>95% and the slurry is allowed to stand for 24h-48h; In step (4), when the polymer microspheres are polystyrene microspheres, the immersion temperature is 60°C to 80°C, the immersion time is 24h to 48h, and the organic solvent is at least one of limonene, benzene, toluene, and xylene; when the polymer microspheres are polymethyl methacrylate microspheres, the immersion temperature is 40°C to 60°C, the immersion time is 6h to 12h, and the organic solvent is at least one of acetone, chloroform, dichloromethane, and ethyl acetate; when the polymer microspheres are polyethylene microspheres, the immersion temperature is 60°C to 100°C, the immersion time is 1h to 6h, and the organic solvent is at least one of benzene, toluene, and xylene.

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

10. The use of a highly ion-conductive, 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, and the usage is as follows: a graphene-loaded copper mesh electrode is assembled parallely and vertically on the outside of 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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