A solid gel concrete-based zinc-manganese battery and a preparation method and application thereof

Abstract

This application provides a solid-state gel concrete-based zinc-manganese battery and its preparation method. The solid-state gel concrete-based zinc-manganese battery is assembled from a manganese dioxide positive electrode, a zinc negative electrode, and a solid-state gel concrete-based electrolyte. The solid-state gel concrete-based electrolyte is composed of porous alkali-activated concrete and a gel polymer. The porous alkali-activated concrete is constructed using discontinuous gradation and natural stacking of single-size aggregates to create a non-destructive interconnected pore structure. The gel polymer fills the interconnected pores to form the solid-state gel concrete-based electrolyte. This application is the first to construct a solid-state concrete-based battery that combines high mechanical properties with excellent electrical storage performance. It provides an innovative approach for developing low-cost, simple-process, and high-performance concrete energy storage devices, and is expected to promote the transformation of related technologies from laboratory research to large-scale engineering applications.

Description

Technical Field

[0001] This invention relates to the field of battery manufacturing and energy storage device technology, specifically to a solid gel concrete-based zinc-manganese battery, its preparation method, and its application. Background Technology

[0002] Currently, while traditional commercial batteries possess high energy storage capabilities, they require expensive rigid protective casings and independent operating spaces. More importantly, commercial batteries pose potential risks such as spontaneous combustion and explosion. As the primary sites of human activity and energy conversion, urban buildings have long been relegated to a passive role, merely providing strength, durability, and load-bearing capacity. Due to safety, economic, and space considerations, traditional batteries are not suitable for integration into building materials. With further compression of urban space, the installation space required for energy storage devices in widely distributed renewable energy collection systems faces land resource depletion and the intractable "NIMBY" effect in high-density urban areas. These dilemmas have prompted researchers to explore cement-based energy storage materials with load-bearing capacity and energy storage capabilities. Cement-based energy storage materials can be integrated into building structures, thus solving the problem of distributed energy storage. One research focus in cement-based energy storage materials is using cement-based materials as electrolytes. Because cement has insulating properties, it is often necessary to combine it with highly conductive electrolytes, where cement provides strength support and the electrolyte promotes ion conduction.

[0003] However, ion transport is severely hampered in dense cement-based materials. To address this, some studies have employed strategies such as adding foaming agents, chemical air-entraining agents, etching, and ice templates to create porous structures. While these methods can improve ion transport efficiency, the resulting pores are small in size and spatially uneven, leading to high tortuosity. More importantly, these methods are essentially destructive modifications to cement-based materials, often resulting in a significant decrease in their mechanical properties. Furthermore, these modification techniques are typically complex, parameter-sensitive, and require precise control, thus posing significant challenges for large-scale engineering applications.

[0004] Therefore, there is an urgent need for a concrete energy storage device that can combine high mechanical properties with excellent electrical storage performance, and is low-cost, simple to manufacture, and high-performance. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a solid-state gel concrete-based zinc-manganese battery, its preparation method, and its application.

[0006] The technical solution provided in this application is as follows.

[0007] In a first aspect, a method for preparing a solid gel concrete-based electrolyte is provided, comprising: Dry porous alkali-activated concrete is immersed in a polymer solution under negative pressure to allow the polymer solution to fully fill the pores of the porous alkali-activated concrete; then, after freezing and thawing, solid gel concrete is obtained; the solid gel concrete is immersed in an inorganic electrolyte to obtain solid gel concrete-based electrolyte. The porous alkali-activated concrete is obtained by alkali activator, fly ash, mineral powder and aggregate through alkali activation reaction; The polymer solution includes a polyvinyl alcohol solution and sodium alginate; The inorganic electrolyte includes zinc sulfate solution and manganese sulfate solution.

[0008] In one possible implementation, the raw material composition of the porous alkali-activated concrete, by mass parts, includes: 105-315 parts fly ash, 35-245 parts mineral powder, 1600-1900 parts aggregate, 15-16 parts sodium hydroxide, and 120-130 parts sodium silicate.

[0009] In one possible implementation, the polymer solution comprises, by mass parts: Polyvinyl alcohol 25-100 parts, sodium alginate 5-20 parts, deionized water 220-880 parts.

[0010] Furthermore, in the polymer solution, the concentration of polyvinyl alcohol is 10-15 wt%; the mass ratio of polyvinyl alcohol to sodium alginate is 5:1.

[0011] In one possible implementation, the inorganic electrolyte is a mixed solution of zinc sulfate and manganese sulfate; wherein, in the mixed solution, the concentration of zinc sulfate is 1-3 mol / L and the concentration of manganese sulfate is 0.2-0.5 mol / L.

[0012] In one possible implementation, the freezing temperature is below -20°C, and the freeze-thaw cycle is repeated at least three times.

[0013] In one possible implementation, the solid gel concrete is soaked for at least 6 hours.

[0014] In a second aspect, a solid gel concrete-based electrolyte is provided, which is prepared using the method described in the first aspect.

[0015] Thirdly, a solid-state gel concrete-based zinc-manganese battery is provided, comprising a manganese dioxide positive electrode, a zinc negative electrode, and the solid-state gel concrete-based electrolyte described in the second aspect.

[0016] Fourthly, the solid-state gel concrete-based zinc-manganese battery described in the third aspect is provided as an application of concrete energy storage devices.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This application presents an optimized design for the electrolyte in solid gel concrete. Unlike traditional methods that create destructive pores in a dense cement matrix, this application constructs undamaged, millimeter-sized interconnected pores within the concrete using a discontinuous gradation and natural packing strategy of single-size aggregates. An alkali-activated paste with high bonding properties is used as a binder between aggregates to ensure continuous load transfer. Further filling of the interconnected pores with the gel electrolyte not only establishes an efficient ion transport network but also provides supplementary strength support for the porous alkali-activated concrete.

[0018] (2) This application uses polyvinyl alcohol and sodium alginate dual-network hydrogel as gel electrolyte to improve the conductivity and mechanical properties of the battery.

[0019] (3) The solid gel concrete-based zinc-manganese battery prepared in the embodiments of this application has both high mechanical properties and excellent electrical storage performance, providing an innovative idea for developing low-cost, simple process and high-performance concrete energy storage devices, and is expected to promote the transformation of related technologies from laboratory research to large-scale engineering applications. Attached Figure Description

[0020] Figure 1 A schematic diagram illustrating the fabrication process of a solid gel concrete-based zinc-manganese battery according to an embodiment of the present invention; Figure 2 The porosity and fractal dimension distribution along the height of the porous alkali-activated concrete prepared in this embodiment of the invention are obtained by X-ray computed tomography. Figure 3 The image shows a three-dimensional reconstruction of the internal isolated pores and connected pores of the porous alkali-activated concrete prepared according to an embodiment of the present invention, obtained using AVIZO software. Figure 4 This is a flow path diagram of the electrolyte inside the porous alkali-activated concrete prepared according to an embodiment of the present invention. Figure 5 The image shows the compressive strength of porous alkali-activated concrete obtained in an embodiment of the present invention. Figure 6 The electrochemical impedance spectroscopy of porous alkali-activated concrete prepared in an embodiment of the present invention is shown. Figure 7 The image shows a constant current charge-discharge diagram of a solid gel concrete-based zinc-manganese battery prepared according to an embodiment of the present invention. Figure 8 The rate performance of the solid gel concrete-based zinc-manganese battery prepared according to an embodiment of the present invention is shown. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid unnecessarily obscuring the description of this application. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0023] See Figure 1 The present application provides a method for preparing a solid gel concrete-based electrolyte, comprising the following steps: Dry porous alkali-activated concrete is immersed in a polymer solution under negative pressure, so that the polymer mixed electrolyte fully fills the pores of the porous alkali-activated concrete; then, after freezing and thawing, solid gel concrete is obtained; the solid gel concrete is immersed in an inorganic electrolyte to obtain solid gel concrete-based electrolyte. The porous alkali-activated concrete is obtained by alkali activator, fly ash, mineral powder and aggregate through alkali activation reaction; The polymer solution includes a polyvinyl alcohol solution and sodium alginate.

[0024] The inorganic electrolyte includes zinc sulfate solution and manganese sulfate solution.

[0025] In one possible implementation, the raw material composition of the porous alkali-activated concrete, by mass parts, includes: 105-315 parts fly ash, 35-245 parts mineral powder, 1600-1900 parts aggregate, 15-16 parts sodium hydroxide, and 120-130 parts sodium silicate.

[0026] Furthermore, the aggregates include limestone, granite, basalt, and similar aggregates.

[0027] In one possible implementation, the method for preparing the porous alkali-activated concrete includes: Sodium hydroxide, sodium silicate, and deionized water are mixed to obtain an alkali activator solution. Fly ash, mineral powder, and aggregate are added to a mixer and mixed for 3-5 minutes. Then, the alkali activator solution is gradually added and mixed for another 2-3 minutes. The mixture is then poured into a mold and manually tamped in layers. After solidification and molding, the mixture is demolded and placed in an environment with a temperature of 20-25℃ and a relative humidity of 90%-95% for 28 days. After cleaning and drying, the final product is obtained.

[0028] In one possible implementation, the polymer solution comprises, by mass parts: Polyvinyl alcohol 25-100 parts, sodium alginate 5-20 parts, deionized water 220-880 parts.

[0029] Furthermore, in the polymer solution, the concentration of polyvinyl alcohol is 10-15 wt%; the mass ratio of polyvinyl alcohol to sodium alginate is 5:1.

[0030] In one possible implementation, the inorganic electrolyte is a mixed solution of zinc sulfate and manganese sulfate; wherein, in the mixed solution, the concentration of zinc sulfate is 1-3 mol / L and the concentration of manganese sulfate is 0.2-0.5 mol / L.

[0031] It is understandable that the hydroxyl groups on the polyvinyl alcohol molecular chain can bond to Zn through a hydrogen bond network. 2+ Zinc sulfate provides the migration pathway, and provides Zn. 2+ Sodium alginate can enhance mechanical strength and fix anions to improve Zn content. 2+ The transport number, as a charge transport carrier, is Mn in manganese sulfate. 2+ It can effectively inhibit the dissolution of MnO2 cathode material.

[0032] In one possible implementation, the freezing temperature is below -20°C.

[0033] Furthermore, the freezing time is not less than 8 hours.

[0034] In one possible implementation, the thawing is carried out in an air environment at a temperature of 20°C-30°C.

[0035] In one possible implementation, the freeze-thaw cycle is repeated at least three times. Preferably, the freeze-thaw cycle is repeated three times.

[0036] Understandably, the reason for employing multiple freeze-thaw cycles is to promote the physical cross-linking of polyvinyl alcohol (PVA) molecular chains. During freezing, PVA molecular chains locally aggregate and form microcrystalline regions, serving as physical cross-linking points; these structures are retained after thawing. Multiple cycles increase the number and perfection of microcrystalline structures, thereby enhancing the mechanical strength and stability of the gel. Simultaneously, the presence of sodium alginate can further assist in the formation of the network structure through hydrogen bonding or complexation with PVA. This application provides a solid-state gel concrete-based zinc-manganese battery and its preparation method, which constructs a non-destructive, interconnected porous structure through a discontinuous gradation and natural stacking strategy of single-size aggregates. The aggregates act as a rigid framework within the material, bearing the main compressive load, while simultaneously forming a highly interconnected porous structure through stacking. An alkali-activated material acts as a binder between the aggregates, ensuring the integrity and structural stability of the system.

[0037] The alginate chains in the polymer gel contain many hydroxyl and carboxyl groups, and transition metal cations can help crosslink alginate through coordination bonds. Polyvinyl alcohol is a polymer sensitive to hydrophilic anions and will also crosslink in the presence of sulfate ions. Therefore, when polyvinyl alcohol and alginate are immersed in an aqueous solution of zinc sulfate, polyvinyl alcohol and alginate will crosslink and entangle with each other, ultimately forming a double-network hydrogel with excellent mechanical properties.

[0038] Based on this, the polymer electrolyte fills the interconnected pores inside the porous alkali-activated concrete under negative pressure. After a freeze-thaw cycle, a polymer gel is formed, which is then soaked in an inorganic electrolyte to attach electrolytes, thus forming a highly efficient ion transport network.

[0039] This application also provides a solid gel concrete-based zinc-manganese battery, comprising a manganese dioxide positive electrode, a zinc negative electrode, and a solid gel concrete-based electrolyte prepared by the aforementioned method.

[0040] In one possible implementation, the method for preparing the solid gel concrete-based zinc-manganese battery includes: placing a solid gel concrete-based electrolyte between a manganese dioxide positive electrode and a zinc negative electrode, encapsulating the entire battery in a flexible packaging shell made of aluminum-plastic film, and then vacuum sealing it.

[0041] The present application will be further described below with reference to specific embodiments, but these are not intended to limit the scope of the application.

[0042] A unified description of some of the materials mentioned in the embodiments: The fly ash is a secondary low-calcium fly ash sourced from Gongyi Borun Refractory Materials Co., Ltd., and its main components include Al2O3 and SiO2. The mineral powder is S95 grade granulated high-grade mineral powder, sourced from Gongyi Borun Refractory Materials Co., Ltd., and its main components include Al2O3, SiO2, and CaO. The aggregate is limestone aggregate with a particle size of 3-5 mm. Sodium hydroxide, in analytical grade solid particles; Sodium silicate, modulus 2.3; Polyvinyl alcohol (powder), type 1799; sodium alginate (powder), reagent grade, purity 90%; the mass ratio of polyvinyl alcohol to sodium alginate is 5:1.

[0043] Example 1 This embodiment provides a solid-state gel concrete-based zinc-manganese battery, the fabrication process of which is as follows: Figure 1 As shown, the preparation steps include the following: (1) Preparation of porous alkali activated concrete: 125.3g sodium silicate, 15.4g sodium hydroxide and 41.3g deionized water were mixed evenly and used as alkali activator. 315g fly ash, 35g mineral powder and 1750g limestone aggregate were weighed and placed in a mixer and mixed for 4 min. The alkali activator was added gradually and the mixture was stirred for 3 min. The mixture was then poured into a 100×100×100 mm mold, manually tamped, and demolded after hardening. The concrete was then cured in a curing room at 25℃ and 90% relative humidity for 28 days. (2) Preparation of polymer mixed electrolyte: Mix 100g polyvinyl alcohol, 20g sodium alginate and 880g deionized water, and heat to 90°C while stirring until the powder is fully dissolved to form a polymer solution; (3) Preparation of solid gel concrete: After cleaning the porous alkali-activated concrete in an ultrasonic cleaner for 10 min, it was placed in a forced-air drying oven and dried at 60℃ for 24 h. The dried concrete was placed in a polymer mixed electrolyte and impregnated under vacuum for 12 h. It was then transferred to a freezer and frozen at -20℃ for 12 h. After thawing in the air for 6 h, the freezing-thawing process was repeated three times to obtain solid gel concrete. It was then cut into 50×60×10 mm size using a cutting machine.

[0044] (4) Preparation of solid gel concrete-based electrolyte: Solid gel concrete was soaked in an inorganic electrolyte containing 2 mol / L zinc sulfate and 0.2 mol / L manganese sulfate for 6 h to obtain solid gel concrete-based electrolyte.

[0045] (5) Assembly of solid gel concrete-based zinc-manganese battery: The solid gel concrete-based electrolyte is placed between the manganese dioxide positive electrode and the zinc negative electrode, and the whole assembly is placed in a flexible packaging shell made of aluminum-plastic film. After vacuum sealing, the solid gel concrete-based zinc-manganese battery is obtained.

[0046] Figure 2This is a distribution map of porosity and fractal dimension along the height of porous alkali-activated concrete obtained by X-ray computed tomography. It can be seen that the curves for total porosity and connected pores are basically consistent, indicating that isolated pores account for a small proportion, and the pore system is dominated by connected pores. The porosity and fractal dimension show little variation along the height direction, indicating that the number and size of pores are relatively uniform.

[0047] Figure 3 This is a 3D reconstruction image of the internal isolated pores and connected pores of porous alkali-activated concrete obtained using AVIZO software. It can be seen that a rich pore network has been successfully constructed inside the concrete, which can be fully filled by the polymer-mixed electrolyte. Figure 4 The flow path of the polymer solution inside porous alkali-activated concrete is visually demonstrated.

[0048] Mechanical property testing and electrochemical impedance spectroscopy were performed on porous alkali-activated concrete, such as... Figure 5 and Figure 6 As shown, the compressive strength of the porous alkali-activated concrete was 18.9 MPa, and the ionic conductivity was 14.2 mS / cm.

[0049] Example 2 Solid-state gel concrete-based zinc-manganese batteries were prepared according to the method in Example 1, except that the mass of fly ash in step (1) was 245g and the mass of mineral powder was 105g. The compressive strength of the porous alkali-activated concrete was 24.3 MPa and the ionic conductivity was 13.4 mS / cm.

[0050] Example 3 Solid gel concrete-based zinc-manganese batteries were prepared according to the method in Example 1, except that the mass of fly ash and mineral powder in step (1) was 175g. The compressive strength of the porous alkali-activated concrete was 32.7 MPa and the ionic conductivity was 11.7 mS / cm.

[0051] Example 4 Solid-state gel concrete-based zinc-manganese batteries were prepared according to the method in Example 1, except that the mass of fly ash in step (1) was 105g and the mass of mineral powder was 245g. The compressive strength of the porous alkali-activated concrete was 38.9 MPa and the ionic conductivity was 9.6 mS / cm.

[0052] Example 5 Solid gel concrete-based zinc-manganese batteries were prepared according to the method in Example 1, except that in step (2), the mass of polyvinyl alcohol was 25g, the mass of sodium alginate was 5g, and the mass of deionized water was 220g.

[0053] Example 6 Solid gel concrete-based zinc-manganese batteries were prepared according to the method in Example 1, except that in step (2), the mass of polyvinyl alcohol was 50g, the mass of sodium alginate was 10g, and the mass of deionized water was 440g.

[0054] Example 7 Solid gel concrete-based zinc-manganese batteries were prepared according to the method in Example 1, except that in step (2), the mass of polyvinyl alcohol was 60g, the mass of sodium alginate was 12g, and the mass of deionized water was 528g.

[0055] The electrochemical performance test results of the zinc-manganese batteries prepared in the examples are described below.

[0056] The electrochemical performance of the solid gel concrete-based zinc-manganese battery prepared in Example 1 was tested. Constant current charge-discharge tests were conducted within a working voltage window of 1–1.7 V and a current density range of 0.1–1.6 A / g.

[0057] Depend on Figure 7 As can be seen, all curves exhibit similar characteristics, with two consecutive discharge plateaus observed at approximately 1.4 V and 1.2 V, and two charging plateaus at approximately 1.55 V and 1.6 V. These two plateaus correspond to the H+ in the manganese dioxide electrode, respectively. + and Zn 2+ The embedding and extraction process forms Mn 2+ And ZnMn2O4. Furthermore, the former exhibits a higher reaction rate than the latter, as evidenced by a single, distinct plateau segment observed at higher discharge rates. Therefore, proper control of the discharge rate is crucial for achieving high specific capacity. The zinc-manganese battery assembled based on this electrolyte achieved a maximum specific capacity of 157.5 mAh / g and an energy density of 205.6 Wh / kg at a power density of 130.4 W / kg, demonstrating promising potential for structural energy storage applications.

[0058] Figure 8 The rate performance at different current densities was demonstrated, with the solid-state gel concrete-based zinc-manganese battery cycling five times at each current density. Discharge capacities of 157.5, 119.4, 88.4, 62.5, and 34.8 mAh / g were exhibited at current densities of 0.1, 0.2, 0.4, 0.8, and 1.6 A / g, respectively. Furthermore, after high-rate cycling, the battery's discharge capacity recovered to its initial value.

[0059] The above tests fully demonstrate that the solid-state gel concrete-based zinc-manganese battery and its fabrication method provided in this application have achieved significant breakthroughs in terms of mechanical and electrochemical performance. This provides an innovative approach for developing low-cost, simple-process, and high-performance concrete energy storage devices.

[0060] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for preparing a solid gel concrete-based electrolyte, characterized in that, include: Dry porous alkali-activated concrete is immersed in a polymer solution under negative pressure to allow the polymer solution to fully fill the pores of the porous alkali-activated concrete; then, after freezing and thawing, solid gel concrete is obtained; the solid gel concrete is immersed in an inorganic electrolyte to obtain solid gel concrete-based electrolyte. The porous alkali-activated concrete is obtained by alkali activator, fly ash, mineral powder and aggregate through alkali activation reaction; The polymer solution comprises polyvinyl alcohol and sodium alginate; The inorganic electrolyte includes zinc sulfate and manganese sulfate.

2. The preparation method according to claim 1, characterized in that, The raw material composition of the porous alkali-activated concrete, by mass, includes: 105-315 parts fly ash, 35-245 parts mineral powder, 1600-1900 parts aggregate, 15-16 parts sodium hydroxide, and 120-130 parts sodium silicate.

3. The preparation method according to claim 1, characterized in that, The polymer solution comprises, by mass parts: Polyvinyl alcohol 25-100 parts, sodium alginate 5-20 parts, deionized water 220-880 parts.

4. The preparation method according to claim 3, characterized in that, In the polymer solution, the concentration of polyvinyl alcohol is 10-15 wt%; the mass ratio of polyvinyl alcohol to sodium alginate is 5:

1.

5. The preparation method according to claim 1, characterized in that, The inorganic electrolyte is a mixed solution of zinc sulfate and manganese sulfate; wherein, in the mixed solution, the concentration of zinc sulfate is 1-3 mol / L and the concentration of manganese sulfate is 0.2-0.5 mol / L.

6. The preparation method according to claim 1, characterized in that, The freezing temperature is below -20°C, and the freezing-thawing process is repeated at least three times.

7. The preparation method according to claim 1, characterized in that, The solid gel concrete must be soaked for at least 6 hours.

8. A solid gel concrete-based electrolyte, characterized in that, Prepared using the method of any one of claims 1-7.

9. A solid-state gel concrete-based zinc-manganese battery, characterized in that, It includes a manganese dioxide positive electrode, a zinc negative electrode, and the solid gel concrete-based electrolyte as described in claim 8.

10. The application of the solid gel concrete-based zinc-manganese battery of claim 9 as a concrete energy storage device.

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