Electrodes and batteries utilizing geopolymer alkali-activated materials

Abstract

The invention discloses an electrode material using a geopolymer alkali-activated material. The electrode material is prepared by the following steps: uniformly mixing ground geopolymer powder, transition metal oxide powder and a conductive agent according to a mass ratio of (3-100): (3-30): 2 to obtain a positive electrode mixture; fully mixing the obtained positive electrode mixture with a solvent and an alkali activator to obtain electrode slurry, and carrying out hydration reaction molding in a mold to obtain a positive electrode material; uniformly mixing the ground geopolymer powder, a carbon material and a conductive agent according to a mass ratio of (3-100): (3-30): 2 to obtain a negative electrode mixture; fully mixing the obtained negative electrode mixture with a solvent and an alkali activator to obtain electrode slurry, and carrying out hydration reaction molding in a mold to obtain a negative electrode material; the geopolymer, the electrode active material and the conductive agent are used as main materials, the hydration activity of the geopolymer is activated through the alkali activator, the positive electrode, the negative electrode and the cement-based battery are manufactured, and resource utilization of solid waste is achieved while electric energy storage is achieved.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, specifically relating to an electrode and battery that utilizes a geopolymer alkali-excited material. Background Technology

[0002] As China places increasingly higher demands on high-quality and high-level modernization, the resource utilization and large-scale energy storage of industrial solid waste have become crucial issues that urgently need to be addressed. Statistics show that my country's annual industrial solid waste production amounts to 3 billion tons. This massive accumulation of solid waste poses a significant threat to the ecological environment and occupies a large amount of valuable land resources. Meanwhile, renewable energy sources are characterized by their timeliness, instability, and difficulty in storage; therefore, developing large-scale energy storage technologies to ensure my country's energy security is equally important. Thus, developing and utilizing solid waste to manufacture large-scale energy storage devices is of great significance.

[0003] Geopolymers are prepared from industrial solid waste (fly ash, blast furnace slag powder, etc.) through an alkali-activated reaction. They have the potential to replace traditional cement and can be applied in building materials, solid waste treatment, and high-temperature coatings. Blast furnace slag powder is a hydraulically active cementitious material obtained during pig iron smelting in blast furnaces. It is a potential hydraulic industrial byproduct with a glassy phase as its main component. Through alkali activators, it generates low Ca / Si CSH and layered magnesium-aluminum phases, thereby improving the long-term strength and durability of concrete. Aqueous energy storage systems have attracted significant attention due to their low cost, high conductivity, and high safety. Although their relatively low energy density makes them unsuitable for commercial use as power batteries, aqueous batteries show great potential for large-scale energy storage.

[0004] With the increasing demands for high-level infrastructure construction, the importance of combining the resource utilization of industrial solid waste geopolymers with aqueous electrochemical energy storage has gradually been recognized. Utilizing blast furnace slag powder in conjunction with aqueous electrochemical energy storage can not only solve the problem of large-scale accumulation of solid waste but also achieve large-scale electrical energy storage, contributing to my country's high-quality modernization and development. Summary of the Invention

[0005] The purpose of this invention is to prepare electrodes and cement-based batteries using geopolymer alkali-activated materials. Geopolymers, electrode active materials, and conductive agents are the main materials. The hydration activity of geopolymers is activated by alkali activators to produce positive and negative electrodes and cement-based batteries, thereby achieving energy storage and resource utilization of solid waste.

[0006] To achieve the above objectives, the following technical solution is adopted: The electrode material, which utilizes geopolymer base excitation material, is prepared using the following method: The ground geopolymer powder, transition metal oxide powder, and conductive agent are uniformly mixed at a mass ratio of (3~100):(3~30):2 to obtain a positive electrode mixture; the obtained positive electrode mixture is thoroughly mixed with a solvent and an alkaline activator to obtain an electrode slurry, which is then hydrated and molded in a mold to obtain a positive electrode material; The ground geopolymer powder, carbon material, and conductive agent are uniformly mixed at a mass ratio of (3~100):(3~30):2 to obtain a negative electrode mixture; the obtained negative electrode mixture is fully mixed with solvent and alkaline activator to obtain an electrode slurry, which is then hydrated and molded in a mold to obtain a negative electrode material.

[0007] According to the above scheme, the geopolymer powder is one or a mixture of blast furnace slag powder, fly ash, red mud, and silica fume; the particle size is ≤20μm. In the optimized scheme, blast furnace slag powder containing low-hydration-activity silica is used.

[0008] According to the above scheme, the transition metal oxide is one of δ-MnO2, Fe2O3, VO2(B), and NiO.

[0009] According to the above scheme, the carbon material is one of activated carbon, superconducting graphite, onion carbon, graphene, and carbon nanotubes.

[0010] According to the above scheme, the conductive agent is one of Super P, acetylene black, Ketjen black, and carbon nanotubes.

[0011] According to the above scheme, the alkali activator is one or a mixture of sodium hydroxide, potassium hydroxide, sodium silicate, potassium silicate, sodium carbonate, sodium sulfate, and Portland cement; the dosage of the alkali activator is 5-15% of the mass of the geopolymer powder.

[0012] According to the above scheme, the solvent is one or a mixture of tap water, seawater, deionized water, and recycled water, and the amount used is 0.3~5 times the water-cement ratio.

[0013] According to the above scheme, the hydration reaction temperature is 20~50℃ and the hydration reaction time is 3~72 h.

[0014] The present invention also provides a cement-based battery that utilizes a geopolymer alkali-activated material, using the above-mentioned positive electrode material and negative electrode material as electrodes, and further comprising an electrolyte and a battery separator to form a coin cell.

[0015] According to the above scheme, the battery separator is one of glass fiber separator, polyethylene separator, naphthol separator, and polypropylene separator.

[0016] According to the above scheme, the electrolyte is a ZnSO4 solution with a concentration of 2~4 M.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes a combination of geopolymer materials and aqueous electrochemical energy storage materials to fabricate electrodes, resulting in a cement-based battery with good mechanical strength and long-term continuous charge-discharge capability. By combining infrastructure materials with large-scale energy storage while simultaneously utilizing industrial solid waste, this invention addresses the environmental and land occupation problems caused by large-scale solid waste accumulation. It also provides a new approach to large-scale energy storage and power security, possessing significant environmental and social implications.

[0018] The compressive strength of the electrode material obtained by this invention is not less than 1 MPa; the charge / discharge current density of the cement-based battery reaches 3 mA / cm². 2 It can be charged and discharged more than 1,000 times. Attached Figure Description

[0019] Figure 1 : Schematic diagram of the cement-based electrode preparation process of this invention.

[0020] Figure 2 Example 1: Constant current charge-discharge images and impedance diagrams.

[0021] Figure 3 Example 2: Constant current charge-discharge images and impedance diagrams.

[0022] Figure 4 Example 3: Constant current charge-discharge images and impedance diagrams. Detailed Implementation

[0023] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] A specific embodiment provides a method for preparing a cement-based battery using geopolymer alkali-activated materials, as shown in the attached figure. Figure 1As shown: A positive electrode mixture is obtained by uniformly mixing ground geopolymer powder, transition metal oxide powder, and conductive agent at a mass ratio of (3~100):(3~30):2; the resulting positive electrode mixture is then thoroughly mixed with a solvent and an alkaline activator to obtain an electrode slurry, which is then hydrated and molded in a mold to obtain the positive electrode material; a negative electrode mixture is obtained by uniformly mixing ground geopolymer powder, carbon material, and conductive agent at a mass ratio of (3~100):(3~50):2; the resulting negative electrode mixture is then thoroughly mixed with a solvent and an alkaline activator to obtain an electrode slurry, which is then hydrated and molded in a mold to obtain the positive electrode material, which is then combined with an electrolyte and a battery separator to form a button cell. The battery separator uses one of the following: a glass fiber separator with a diameter of 17 mm, a polyethylene separator, a naphthol separator, or a polypropylene separator; the aqueous electrolyte is a ZnSO4 solution with a concentration of 2-4 M; the electrode is a circular electrode with a thickness of 2 mm and a diameter of 16 mm, directly adapted to the CR2032 battery casing.

[0025] The specific implementation method uses blast furnace slag powder as the geopolymer. Blast furnace slag powder (<20 μm) is obtained from the molten material mainly composed of silicates and aluminosilicates, which is formed during pig iron smelting in a blast furnace. The resulting glassy substance is then crushed. δ-MnO2 (<20 μm) is sourced from Dalian Tongmanganese New Material Technology Co., Ltd. Activated carbon (<20 μm) and Super P are sourced from Shanghai Aladdin Biochemical Technology Co., Ltd. All other raw materials, unless otherwise specified, were obtained commercially.

[0026] Example 1 First, finely ground blast furnace slag powder, δ-MnO2 powder, and Super P powder in a mass ratio of 3:3:2 are weighed and mixed evenly to obtain a positive electrode mixture; finely ground blast furnace slag powder, activated carbon powder, and Super P powder in a mass ratio of 3:3:2 are weighed and mixed evenly to obtain a negative electrode mixture.

[0027] Then, weigh out 10% of the alkali activator NaOH powder by mass of blast furnace slag powder, add it to deionized water to dissolve it, and the water-cement ratio is 3. That is, weigh out 3 times the mass of the positive electrode mixture and the negative electrode mixture respectively, and then add them to the positive electrode mixture and the negative electrode mixture. Stir thoroughly to obtain positive electrode slurry and negative electrode slurry.

[0028] Then, the positive electrode slurry and the negative electrode slurry were poured into a rubber electrode mold with a thickness of 2 mm and a diameter of 16 mm. The electrode surface was polished smooth and shaped. The electrode mold was wrapped with plastic wrap and placed in a constant temperature biochemical incubator at 40℃ for hydration time of 24 h. After demolding, the positive and negative electrodes of the cement battery were obtained.

[0029] The positive and negative electrodes of the cement battery were then immersed in 2 M ZnSO4 electrolyte and placed in a vacuum oven at 20°C. The oven was then evacuated to a vacuum state to fill the electrode pore structure with electrolyte, thus obtaining the positive and negative electrodes of the cement battery that can be pre-treated.

[0030] Then, the coin cell is assembled in the following order: CR2032 positive electrode shell, current collector, cement battery positive electrode, glass fiber separator, cement battery negative electrode, current collector, and CR2032 negative electrode shell. A schematic diagram of the overall fabrication process is shown below. Figure 1 As shown. The battery capacity and cycle stability were tested using a battery testing system; the mechanical strength of the positive and negative electrodes of the cement battery was tested using an integrated bending and compression testing machine. The constant current charge / discharge images and impedance diagrams of the battery obtained in this embodiment are attached. Figure 2 As shown.

[0031] Example 2 The preparation process in this embodiment is basically the same as in Example 1, except that: finely ground blast furnace slag powder, δ-MnO2 powder, and Super P powder in a mass ratio of 5:3:2 are uniformly mixed to obtain a positive electrode mixture; finely ground blast furnace slag powder, activated carbon powder, and Super P powder in a mass ratio of 5:3:2 are weighed and uniformly mixed to obtain a negative electrode mixture. The constant current charge-discharge image and impedance diagram of the battery obtained in this embodiment are attached. Figure 3 As shown.

[0032] Example 3 The preparation process in this embodiment is basically the same as in Example 1, except that: finely ground blast furnace slag powder, δ-MnO2 powder, and Super P powder in a mass ratio of 8:3:2 are uniformly mixed to obtain a positive electrode mixture; finely ground blast furnace slag powder, activated carbon powder, and Super P powder in a mass ratio of 8:3:2 are weighed and uniformly mixed to obtain a negative electrode mixture. The constant current charge-discharge image and impedance diagram of the battery obtained in this embodiment are attached. Figure 4 As shown.

[0033] Example 4 The preparation process in this embodiment is basically the same as that in Example 1, except that the hydration temperature is 20°C and the electrode mold is wrapped in plastic wrap and placed in a constant temperature biochemical incubator at 20°C.

[0034] Example 5 The preparation process in this embodiment is basically the same as that in Example 1, except that the hydration time is 3 hours.

[0035] Example 6 The preparation process in this embodiment is basically the same as that in Example 1, except that the hydration time is 48 h.

[0036] Example 7 The preparation process in this embodiment is basically the same as that in Example 1, except that the electrode is immersed under normal pressure.

[0037] Example 8 The preparation process in this embodiment is basically the same as that in Example 1, except that the water-cement ratio is 2.

[0038] Example 9 The preparation process in this embodiment is basically the same as that in Example 1, except that the water-cement ratio is 5.

[0039] Example 10 The preparation process of this embodiment is basically the same as that of Example 1, except that: the finely ground blast furnace slag powder, δ-MnO2 powder and Super P powder in a mass ratio of 10:3:2 are uniformly mixed to obtain a positive electrode mixture; the finely ground blast furnace slag powder, activated carbon powder and Super P powder in a mass ratio of 10:3:2 are weighed and uniformly mixed to obtain a negative electrode mixture.

[0040] Example 11 The preparation process of this embodiment is basically the same as that of Example 1, except that: the finely ground blast furnace slag powder, δ-MnO2 powder and Super P powder in a mass ratio of 20:3:2 are uniformly mixed to obtain a positive electrode mixture; the finely ground blast furnace slag powder, activated carbon powder and Super P powder in a mass ratio of 20:3:2 are weighed and uniformly mixed to obtain a negative electrode mixture.

[0041] Example 12 The preparation process of this embodiment is basically the same as that of Example 1, except that: the finely ground blast furnace slag powder, δ-MnO2 powder and Super P powder in a mass ratio of 50:3:2 are uniformly mixed to obtain a positive electrode mixture; the finely ground blast furnace slag powder, activated carbon powder and Super P powder in a mass ratio of 50:3:2 are weighed and uniformly mixed to obtain a negative electrode mixture.

[0042] Example 13 The preparation process of this embodiment is basically the same as that of Example 1, except that: the finely ground blast furnace slag powder, δ-MnO2 powder and Super P powder in a mass ratio of 100:3:2 are uniformly mixed to obtain a positive electrode mixture; the finely ground blast furnace slag powder, activated carbon powder and Super P powder in a mass ratio of 100:3:2 are weighed and uniformly mixed to obtain a negative electrode mixture.

[0043] Example 14 The preparation process of this embodiment is basically the same as that of Example 1, except that: the finely ground blast furnace slag powder, δ-MnO2 powder and Super P powder in a mass ratio of 3:10:2 are uniformly mixed to obtain a positive electrode mixture; the finely ground blast furnace slag powder, activated carbon powder and Super P powder in a mass ratio of 3:10:2 are weighed and uniformly mixed to obtain a negative electrode mixture.

[0044] Example 15 The preparation process of this embodiment is basically the same as that of Example 1, except that: the finely ground blast furnace slag powder, δ-MnO2 powder and Super P powder in a mass ratio of 3:20:2 are uniformly mixed to obtain a positive electrode mixture; the finely ground blast furnace slag powder, activated carbon powder and Super P powder in a mass ratio of 3:20:2 are weighed and uniformly mixed to obtain a negative electrode mixture.

[0045] Example 16 The preparation process of this embodiment is basically the same as that of Example 1, except that: the finely ground blast furnace slag powder, δ-MnO2 powder and Super P powder in a mass ratio of 3:30:2 are uniformly mixed to obtain a positive electrode mixture; the finely ground blast furnace slag powder, activated carbon powder and Super P powder in a mass ratio of 3:30:2 are weighed and uniformly mixed to obtain a negative electrode mixture.

[0046] Example 17 The preparation process of this embodiment is basically the same as that of Example 1, except that: the finely ground blast furnace slag powder, δ-MnO2 powder and Super P powder in a mass ratio of 3:50:2 are uniformly mixed to obtain a positive electrode mixture; the finely ground blast furnace slag powder, activated carbon powder and Super P powder in a mass ratio of 3:50:2 are weighed and uniformly mixed to obtain a negative electrode mixture.

[0047] Example 18 The preparation process in this embodiment is basically the same as that in Example 1, except that the mass ratio of the external alkali activator is 5% of the blast furnace slag powder.

[0048] Example 19 The preparation process in this embodiment is basically the same as that in Example 1, except that the mass ratio of the external alkali activator is 15% of the blast furnace slag powder.

[0049] Example 20 The preparation process in this embodiment is basically the same as that in Example 1, except that the geopolymer is replaced with fly ash. Example 21 The preparation process in this embodiment is basically the same as that in Example 1, except that the geopolymer is replaced with red mud. Example 22 The preparation process in this embodiment is basically the same as that in Example 1, except that the geopolymer is replaced with silica fume.

[0050] The compressive strength of the positive and negative electrodes and the energy density of the cement-based battery obtained in the examples are shown in Table 1.

[0051] Table 1

[0052] Table 1 shows that in Examples 1-3 and 10-13, the compressive strength of the positive and negative electrodes increases with the increase of the proportion of blast furnace slag powder, while the energy density of the battery decreases. This proves that controlling the proportion of cementitious material can regulate the porosity, strength, and energy density of the electrode system, and a suitable proportion can obtain a more reasonable compressive strength and energy density. Meanwhile, in Examples 4-9 and 20-22, factors such as the type of cementitious material, curing temperature, and curing time all affect the compressive strength and energy density of the electrodes.

[0053] Figure 2 The constant current charge-discharge test of the positive electrode in Example 1 is shown at 1 mA / cm. 2 The discharge time and impedance plots at the current density show that the charge-discharge time of the positive electrode reaches 2700 s and the impedance is 3.5 Ω, proving the conductivity of the system.

[0054] Figure 3 The constant current charge-discharge test of the positive electrode in Example 2 is shown at 1 mA / cm². 2 The discharge time and impedance diagrams at current density were obtained, and the results showed that the charge-discharge time of the positive electrode reached 1500 s and the impedance was 3.8 Ω, which proved the conductivity of the system. The strength and capacity of the electrode can be adjusted by adjusting the proportion of cementing material.

[0055] Figure 4 The constant current charge-discharge test of the positive electrode in Example 3 is shown at 1 mA / cm². 2 The discharge time and impedance diagrams at current density were obtained, and the results showed that the charge-discharge time of the positive electrode reached 500 s and the impedance was 4 Ω, which proved the conductivity of the system. The strength and capacity of the electrode can be adjusted by adjusting the proportion of cementing material.

Claims

1. An electrode material that utilizes a geopolymer base to excite the material, characterized in that... It is prepared using the following method: The ground geopolymer powder, transition metal oxide powder, and conductive agent are uniformly mixed at a mass ratio of (3~100):(3~30):2 to obtain a positive electrode mixture; the obtained positive electrode mixture is thoroughly mixed with a solvent and an alkaline activator to obtain an electrode slurry, which is then hydrated and molded in a mold to obtain a positive electrode material; The ground geopolymer powder, carbon material, and conductive agent are uniformly mixed at a mass ratio of (3~100):(3~30):2 to obtain a negative electrode mixture; the obtained negative electrode mixture is fully mixed with solvent and alkaline activator to obtain an electrode slurry, which is then hydrated and molded in a mold to obtain a negative electrode material.

2. The electrode material utilizing the geopolymer base-excited material as described in claim 1, characterized in that... The geopolymer powder is one or a mixture of blast furnace slag powder, fly ash, red mud, and silica fume; with a particle size ≤20μm.

3. The electrode material using geopolymer base excitation material as described in claim 1, characterized in that... The transition metal oxide is one of δ-MnO2, Fe2O3, VO2(B), and NiO.

4. The electrode material using geopolymer base-excited material as described in claim 1, characterized in that... The carbon material is one of activated carbon, superconducting graphite, onion carbon, graphene, and carbon nanotubes.

5. The electrode material using geopolymer base-excited material as described in claim 1, characterized in that... The conductive agent is one of Super P, acetylene black, Ketjen black, and carbon nanotubes.

6. The electrode material using geopolymer base-excited material as described in claim 1, characterized in that... The alkali activator is one or a mixture of sodium hydroxide, potassium hydroxide, sodium silicate, potassium silicate, sodium carbonate, sodium sulfate, and Portland cement; the dosage of the alkali activator is 5-15% of the mass of the geopolymer powder.

7. The electrode material utilizing the geopolymer base-excited material as described in claim 1, characterized in that... The solvent used is one or a mixture of tap water, seawater, deionized water, and recycled water, with a water-cement ratio of 0.3 to 5.

8. The electrode material using geopolymer base-excited material as described in claim 1, characterized in that... The hydration reaction temperature is 20~50℃, and the hydration reaction time is 3~72 h.

9. A cement-based battery utilizing geopolymer alkali-activated materials, characterized in that... The battery uses the electrode material described in any one of claims 1-9 as the electrode, and further includes an electrolyte and a battery separator to form a coin cell.

10. The cement-based battery using geopolymer alkali-activated materials as described in claim 9, characterized in that... The battery separator is one of glass fiber separator, polyethylene separator, naphthol separator, and polypropylene separator; the electrolyte is ZnSO4 solution with a concentration of 2~4 M.

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