Concrete matrix, battery electrode and structural energy storage integrated concrete matrix battery

Abstract

This invention provides a concrete matrix battery integrating a concrete matrix, battery electrodes, and structural energy storage. The concrete matrix is ​​formed of foamed concrete with short fibers incorporated, and has an internal porous structure. A surface coating layer is formed on the surface of the concrete matrix to seal the internal porous structure. The battery electrodes include a current collector, tabs, and the concrete matrix. The surface of the current collector is provided with an electrode active material, a conductive agent, and a binder. The tabs are located at one end of the current collector. The concrete matrix provides a space to accommodate the current collector, and an alkaline electrolyte is contained within the internal porous structure of the concrete matrix and sealed by the surface coating layer. The battery includes a positive electrode, a negative electrode, and a separator, with the separator disposed between the positive and negative electrodes. At least one of the positive and negative electrodes is the aforementioned battery electrode. This invention maintains the battery's energy storage performance while imparting excellent mechanical properties through the concrete matrix.

Description

Technical Field

[0001] This invention relates to the field of structural battery technology, specifically to a concrete matrix battery, battery electrodes, and a structural energy storage integrated concrete matrix battery. Background Technology

[0002] Structural batteries are divided into two categories: embedded integrated batteries and functional composite materials batteries. They achieve weight reduction and structural simplification by combining structural components with energy storage systems, and have already seen initial exploration and application in areas such as small aircraft, passenger planes, and new energy vehicles. Currently, the United States and the European Union are conducting extensive research in this field, mostly on structural batteries based on carbon fiber composite materials, gradually moving from the laboratory to industrialization. However, the fastest-growing lithium-ion structural batteries in recent years suffer from high costs, poor resistance to overcharging and over-discharging, and the flammability and toxicity of the organic electrolyte inside the battery pose a potential threat to battery safety.

[0003] Concrete, with its controllable properties, simple processing, good durability, low price, and wide availability, is an excellent container for alkaline electrolytes and can also directly serve as a structural component of batteries. The concrete itself in the battery does not participate in the electrochemical reaction but acts as a container for storing the electrolyte, a matrix for electrode active materials and current collectors, and provides support and protection. Unlike embedded integrated structural batteries, structural batteries made with a concrete matrix do not distinguish between structural components and battery components, resulting in a more continuous internal structure and tighter interface bonding. This helps improve force transmission efficiency and endows the battery with excellent mechanical properties while maintaining energy storage performance. Considering the large annual demand for concrete in the construction industry, structurally integrated concrete-matrix alkaline aqueous batteries are expected to see gradual development and application in the future.

[0004] The search revealed:

[0005] Chinese utility model patent CN216671715U discloses an integrated battery cell, battery pack, and flight device. The current collector, which forms a spacer to house the positive electrode, electrolyte, and negative electrode, serves as a structural support for the integrated battery cell. Because the current collector can have a porous structure, it not only functions as a structural support but also effectively increases the contact area between the active material and the current collector, providing a rapid electron transport channel and thus achieving better energy storage and structural performance. However, this patent still has the following problem: it improves the battery's structural form by forming a honeycomb structure using a template, but does not address the bottleneck of battery energy efficiency through material-level structural energy storage integration. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a concrete matrix battery that integrates a concrete matrix, battery electrodes, and structural energy storage.

[0007] According to a first aspect of the present invention, a concrete matrix for ion conduction is provided, the concrete matrix being formed of foamed concrete, short fibers being incorporated into the foamed concrete, the concrete matrix having an internal porous structure, and a surface covering layer for sealing the internal porous structure being formed on the surface of the concrete matrix.

[0008] Furthermore, the short fiber is at least one of PP fiber, PVA fiber, and PE fiber; the length of the short fiber is 5-15 mm; and the volume fraction of the short fiber is 0.3%-1.5%.

[0009] Furthermore, the concrete matrix increases the volume content of its internal pore structure through physical or chemical foaming methods, and the porosity of the concrete matrix is ​​10%-20%.

[0010] Furthermore, the surface covering layer is any one of stainless steel plate, epoxy resin and cement-based waterproof layer, and the thickness of the surface covering layer is 0.5-2mm.

[0011] According to a second aspect of the present invention, a battery electrode is provided, the battery electrode comprising:

[0012] A current collector, the surface of which is provided with an electrode active material, a conductive agent and a binder;

[0013] The electrode tab is located at one end of the current collector;

[0014] The aforementioned ion-conducting concrete matrix provides a space for accommodating the current collector. The internal porous structure of the concrete matrix contains an alkaline electrolyte, which is sealed by a surface covering layer.

[0015] Furthermore, the current collector is made of any one of carbon fiber mesh, iron mesh, copper mesh, copper sheet, aluminum sheet, and nickel foam.

[0016] Furthermore, the conductive agent is at least one of nano carbon black, carbon nanotubes, graphene, and nickel powder; the adhesive is at least one of PTEE, HPMC, and CMC.

[0017] Furthermore, the alkaline electrolyte includes at least one of KOH solution, NaOH solution and LiOH solution, and includes at least KOH solution. The alkaline electrolyte is injected into the internal pore structure of the concrete matrix by natural immersion method or vacuum infiltration method.

[0018] According to a third aspect of the present invention, a structural energy storage integrated concrete matrix battery is provided, the battery comprising a positive electrode, a negative electrode and a separator, the separator being disposed between the positive electrode and the negative electrode, wherein at least one of the positive electrode and the negative electrode is the aforementioned battery electrode.

[0019] Furthermore, the diaphragm is any one of polypropylene diaphragm, polyamide diaphragm, polytetrafluoroethylene diaphragm, and cement-based diaphragm.

[0020] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0021] The present invention provides a concrete matrix, battery electrodes, and a structural energy storage integrated concrete matrix battery. The ion-conducting concrete matrix is ​​formed by foamed concrete incorporating short fibers. The concrete matrix utilizes its internal porous structure to store alkaline electrolyte, which can maintain the energy storage performance of the battery while endowing it with excellent mechanical properties. Attached Figure Description

[0022] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0023] Figure 1 This is a schematic diagram of the composition of the battery electrodes in one embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of a structural energy storage integrated concrete matrix battery in one embodiment of the present invention.

[0025] In the diagram: 1-positive electrode, 2-negative electrode, 3-diaphragm, 11-current collector, 12-tab, 13-electrode active material, 14-concrete matrix, 15-conductive agent, 16-adhesive. Detailed Implementation

[0026] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0027] In the description of the embodiments of the present invention, concrete matrix and ion-conducting concrete matrix have the same meaning, and foamed concrete and ion-conducting foamed concrete have the same meaning.

[0028] This invention provides an ion-conducting concrete matrix for use as an electrode in a structural energy storage integrated battery. The concrete matrix is ​​formed of foamed concrete, which is used for ion conduction. Short fibers are incorporated into the foamed concrete. Because foam can form pores of arbitrary shapes within the concrete, the concrete matrix has an internal porous structure. A surface coating layer is formed on the surface of the concrete matrix to seal this internal porous structure. By incorporating short fibers into the foamed concrete, the mechanical properties of the concrete matrix can be improved, thereby imparting excellent mechanical properties to the battery while maintaining its energy storage performance.

[0029] In some embodiments, the short fibers are at least one of PP fibers, PVA fibers, and PE fibers; if too many short fibers are added, the fibers will clump together and cannot be dispersed, which will reduce their mechanical properties; under the same volume dosage, the longer the short fiber, the fewer the number, and the shorter the short fiber, the more the number. Preferably, the length of the short fiber is 5-15 mm; the volume dosage of the short fiber (i.e., the proportion of the volume of the short fiber to the total volume of the concrete matrix) is 0.3%-1.5%.

[0030] It should be noted that conductive fibers such as steel fibers and carbon fibers cannot be used as the incorporated short fibers, as these can cause short circuits in the battery's internal electrolyte, leading to self-discharge. Furthermore, the length and volumetric content of the short fibers can be appropriately adjusted based on the specific foamed concrete formulation to effectively improve the battery's mechanical properties.

[0031] In some embodiments, the volumetric content of the internal pore structure of the concrete matrix is ​​increased through physical or chemical foaming methods. Higher porosity results in lower compressive strength and lower resistivity. Preferably, the porosity of the concrete matrix is ​​10%-20%, achieving both good mechanical properties and electrical conductivity. It should be noted that, depending on specific circumstances and actual needs, such as higher conductivity requirements, the porosity can be appropriately increased while still meeting the basic compressive strength requirements, thereby further improving conductivity.

[0032] To achieve a surface seal, the surface covering layer should possess good sealing properties and sufficient strength and durability. In some embodiments, the surface covering layer is any one of stainless steel plate, epoxy resin, and cement-based waterproof layer. Considering both sealing and strength requirements as well as material costs, the thickness of the surface covering layer is preferably 0.5-2 mm. Of course, in other embodiments, other types of surface covering layers can also be used. Depending on the material used, the thickness of the surface covering layer can be adjusted accordingly, as long as the same function can be achieved.

[0033] Another embodiment of the present invention provides a battery electrode, referring to... Figure 1 The battery electrode includes a current collector 11, a tab 12, and the aforementioned ion-conducting concrete matrix 14, wherein: the surface of the current collector 11 is provided with an electrode active material 13, a conductive agent 15, and an adhesive 16; the tab 12 is located at one end of the current collector 11; the concrete matrix 14 provides a space for the current collector 11, and an alkaline electrolyte is provided in the internal pore structure of the concrete matrix 14, which stores the alkaline electrolyte and seals the alkaline electrolyte with a surface covering layer.

[0034] The current collector 11 is conductive and can also allow the particles of the electrode active material 13 and the conductive agent 15 to adhere. Preferably, the current collector 11 is any one of carbon fiber mesh, iron mesh, copper mesh, copper sheet, aluminum sheet and nickel foam. Among them, the mesh current collector and nickel foam have a larger surface area / volume ratio, which is beneficial to improving the discharge specific capacity of the electrode.

[0035] In some embodiments, the conductive agent 15 is filled between the electrode active material 13 and the current collector 11 to reduce resistance. Preferably, the conductive agent 15 is at least one of nano carbon black, carbon nanotubes, graphene and nickel powder. The conductive agent 15, electrode active material 13 and current collector 11 are bonded together by an adhesive 16 to form a conductive network. Preferably, the adhesive 16 is at least one of PTEE, HPMC and CMC.

[0036] In the above embodiments, when the electrochemical reaction principle of a zinc-manganese battery is adopted, the positive electrode active material 13 includes MnO2 powder, and the negative electrode active material 13 includes Zn powder; when the electrochemical reaction principle of a nickel-iron battery is adopted, the positive electrode active material 13 includes Ni(OH)2 powder, and the negative electrode active material 13 includes Fe and / or Fe3O4 powder; when the electrochemical reaction principle of a nickel-metal hydride battery is adopted, the positive electrode active material 13 includes Ni(OH)2 powder, and the negative electrode active material 13 includes hydrogen storage alloy powder.

[0037] In the above embodiments, when the current collector 11 is made of a mesh-like conductive material or foam metal, the electrode active material 13, the conductive agent 15 and the adhesive 16 can form a three-dimensional conductive network on the current collector 11 by bonding or dry powder pressing; when the current collector 11 is made of a metal sheet, the electrode active material 13, the conductive agent 15 and the adhesive 16 can form a three-dimensional conductive network on the current collector 11 by dry powder pressing.

[0038] In some embodiments, potassium hydroxide solution is used as an electrolyte because it has high conductivity and low freezing point, allowing the battery to maintain good performance at low temperatures. LiOH can inhibit the aggregation of impurities during the battery reaction cycle, thereby increasing the battery specific capacity and extending battery life. However, excessive concentration will significantly increase the electrolyte resistance. The alkaline electrolyte includes at least one of 4-8 mol / L KOH solution, 0-2 mol / L NaOH solution, and 0-1 mol / L LiOH solution, and includes at least KOH. The alkaline electrolyte is injected into the internal pore structure of the concrete matrix 14 by natural immersion or vacuum infiltration.

[0039] Specifically, the concrete matrix 14 is subjected to physical or chemical foaming to increase the volumetric content of its internal pore structure, resulting in a porosity of 10% to 20%. After 28 days of curing following demolding, an alkaline electrolyte is injected into it. When using the natural immersion method, the mass of the concrete matrix 14 is weighed daily; when using the vacuum infiltration method, the mass of the concrete matrix 14 is weighed hourly. Infiltration is considered complete when the mass change is less than 1%. The surface is then wiped clean and immediately sealed with a surface covering layer.

[0040] Another embodiment of the present invention provides a structural energy storage integrated concrete matrix battery, as shown in the reference. Figure 2 The battery includes a positive electrode 1, a negative electrode 2 and a separator 3. The separator 3 is disposed between the positive electrode 1 and the negative electrode 2. The separator 3 can reduce the thickness of the battery. At least one of the positive electrode 1 and the negative electrode 2 is the battery electrode mentioned above.

[0041] The function of the diaphragm is to allow ions to pass through but not electrons. In some embodiments, the diaphragm 3 is any one of a polypropylene diaphragm, a polyamide diaphragm, a polytetrafluoroethylene diaphragm, and a cement-based diaphragm. Among them, the use of a cement-based diaphragm can be compatible with electrodes made of concrete substrates, which is beneficial to improving the interfacial mechanical properties.

[0042] The concrete matrix, battery electrodes, and structural energy storage integrated concrete matrix battery in the above embodiments of the present invention are formed by using foamed concrete with short fibers incorporated into the concrete matrix. The concrete matrix utilizes its internal porous structure to store alkaline electrolyte. By incorporating short fibers into the foamed concrete, the mechanical properties of the concrete matrix can be improved, thereby maintaining the energy storage performance of the battery while endowing it with excellent mechanical properties through the concrete matrix.

[0043] Existing technologies use carbon fiber composite materials as the matrix. However, due to the high cost of carbon fiber composite materials and the typically small size of these batteries, they cannot meet the requirements of large-scale energy storage equipment. Compared to existing technologies, the concrete material used in the above embodiments of this invention has the advantages of controllable material properties, simple processing, good durability, low price, and wide availability. Due to its economic advantages, it can be used as a supporting energy storage device for power generation equipment such as thermal power and offshore wind power.

[0044] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention. The above preferred features can be used in any combination without conflict.

Claims

1. A battery electrode, characterized in that, include: A current collector, the surface of which is provided with an electrode active material, a conductive agent and a binder; The electrode tab is located at one end of the current collector; A concrete matrix for ion conduction, wherein the concrete matrix provides a space for accommodating the current collector, and an alkaline electrolyte is provided within the internal porous structure of the concrete matrix and sealed by a surface covering layer. The ion-conducting concrete matrix is ​​formed of foamed concrete, which is used for ion conduction. The porosity of the concrete matrix is ​​10%-20%. Short fibers with a length of 5-15 mm are incorporated into the foamed concrete. The volume fraction of the short fibers is 0.3%-1.5%, and the short fibers are at least one of PP fibers, PVA fibers, and PE fibers, used to improve the mechanical properties of the concrete matrix and prevent short circuits in the electrolyte inside the battery. The ion-conducting concrete matrix has an internal porous structure, and a surface covering layer for sealing the internal porous structure is formed on the surface of the ion-conducting concrete matrix. The surface covering layer is any one of stainless steel plate, epoxy resin, and cement-based waterproof layer, and the thickness of the surface covering layer is 0.5-2 mm.

2. The battery electrode according to claim 1, characterized in that, The current collector can be any one of carbon fiber mesh, iron mesh, copper mesh, copper sheet, aluminum sheet and nickel foam.

3. The battery electrode according to claim 1, characterized in that, The conductive agent is at least one of nano carbon black, carbon nanotubes, graphene and nickel powder; the binder is at least one of PTEE, HPMC and CMC.

4. The battery electrode according to claim 1, characterized in that, The concrete matrix increases the volumetric content of its internal pore structure through physical or chemical foaming methods.

5. The battery electrode according to claim 1, characterized in that, The alkaline electrolyte includes at least one of KOH solution, NaOH solution and LiOH solution, and at least includes KOH solution. The alkaline electrolyte is injected into the internal pore structure of the concrete matrix by natural immersion method or vacuum infiltration method.

6. A structural energy storage integrated concrete matrix battery, characterized in that, The battery includes a positive electrode, a negative electrode, and a separator, wherein the separator is disposed between the positive electrode and the negative electrode, and at least one of the positive electrode and the negative electrode is a battery electrode according to any one of claims 1-5.

7. The structural energy storage integrated concrete matrix battery according to claim 6, characterized in that, The diaphragm is any one of polypropylene diaphragm, polyamide diaphragm, polytetrafluoroethylene diaphragm, and cement-based diaphragm.

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