Multifunctional energy storage concrete, application thereof and energy storage concrete member

Abstract

The invention provides multifunctional energy storage concrete, application thereof and an energy storage concrete member, and belongs to the technical field of concrete. The multifunctional energy storage concrete is prepared from the following components in parts by weight: 300 to 600 parts of ordinary Portland cement, 30 to 100 parts of mineral admixture, 300 to 700 parts of quartz sand, 5 to 60 parts of conductive material, 4 to 8 parts of admixture and 120 to 250 parts of water. The conductive material is added into the concrete, and a conductive network can be formed in the concrete material, so that the concrete has electric energy storage and conduction functions. The energy storage concrete provided by the invention can be used as a structural member for energy storage, and can also be combined with other energy technologies (such as solar energy and wireless charging) to realize integration of power generation, storage and utilization.

Description

Technical Field

[0001] This invention relates to the field of concrete technology, and in particular to a multifunctional energy storage concrete and its application, and an energy storage concrete component. Background Technology

[0002] With the development of renewable energy and smart grids, integrating energy storage devices into civil engineering structures to achieve on-site energy storage and utilization has become a hot topic in interdisciplinary research between civil engineering and energy. Traditional energy storage methods (such as lithium batteries and lead-acid batteries) are installed independently in buildings, which not only increases system complexity and cost but also poses space occupation and safety hazards. Therefore, developing functionalized concrete that can both bear structural loads and store electrical energy is of great significance for achieving energy self-sufficiency in buildings and infrastructure.

[0003] Existing technologies have preliminarily explored the energy storage modification of concrete materials. For example, adding phase change materials to concrete can store thermal energy for regulating the thermal environment of buildings; combining concrete products with photovoltaic or wind power can achieve energy storage through thermal storage or gravitational potential energy. These are non-electrical energy storage methods with relatively limited functions. Regarding electrical energy storage, some studies have incorporated conductive components into cement-based materials to give them capacitor-like properties. For example, researchers have proposed incorporating steel fibers and dielectric materials into concrete to create capacitor-like concrete battery pavements for storing electrical energy and heating snow. These concrete battery pavements are reinforced with steel fibers and incorporate carbon nanomaterials to form a conductive network; however, steel fibers are prone to corrosion and are costly, and the amount of carbon materials added is limited, resulting in a significant decrease in strength as energy storage capacity increases.

[0004] Other solutions draw inspiration from battery principles, embedding electrode components within concrete to treat the entire structure as a battery cell. For example, US Patent 20210066749A1 proposes embedding galvanized steel bars as negative electrodes and stainless steel bars as positive electrodes within concrete, utilizing pore water in the concrete as the electrolyte to form a rechargeable "concrete battery." This design considers the matching of electrode materials with the thermal expansion and contraction of cement to mitigate interfacial stress caused by temperature differences. However, this type of solution requires embedding a large number of metal electrodes within the concrete, potentially affecting structural homogeneity. Furthermore, metal anodes, such as zinc, will slowly deplete, and long-term performance and safety still require verification. Recently, a prototype cement-based rechargeable battery was reported, using carbon fiber mesh loaded with Ni(OH)₂ and Fe as electrodes immersed in an alkaline electrolyte, achieving stable charge-discharge cycles with an upper limit energy density of approximately 7.6 Wh / m². While this type of cement-based battery has demonstrated feasibility, its implementation in conventional concrete pouring remains challenging due to the need for a liquid electrolyte and specific electrode coatings.

[0005] In summary, existing technologies have made some explorations in the field of energy storage concrete, but they generally have the following shortcomings: (1) Conductive filler incorporation method: Simply adding conductive phase will significantly weaken the mechanical strength and durability of concrete, and the dosage is limited; (2) Metal electrode embedding method: Special electrode materials need to be embedded, which is complicated to construct and has potential durability problems; (3) Single function: It only focuses on one mechanism of capacitor energy storage or battery energy storage, and does not fully combine multiple mechanisms to improve comprehensive performance; (4) Lack of multifunctionality: Energy storage concrete has not yet been applied in multiple scenarios in actual engineering, such as simultaneous use for load-bearing, energy storage, heating and de-icing, and structural health monitoring. Therefore, this study investigates a multifunctional energy storage concrete and its application, as well as an energy storage concrete component. Summary of the Invention

[0006] The purpose of this invention is to provide a multifunctional energy storage concrete and its application, as well as an energy storage concrete component, to solve the problems of limited functionality and application scenarios of energy storage concrete in the prior art.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a multifunctional energy storage concrete, comprising the following components in parts by weight: 300-600 parts of ordinary Portland cement 30-100 parts of mineral admixture 300-700 parts of quartz sand 5-60 parts of conductive material 4-8 parts of admixture 120-250 parts water.

[0008] Preferably, the conductive material comprises one or more of acetylene black, graphite powder, multi-walled carbon nanotubes, and graphene nanosheets.

[0009] Preferably, the multifunctional energy storage concrete further includes an active component; the active component is manganese dioxide micro powder.

[0010] Preferably, the mineral admixture is silica fume and / or fly ash; the multifunctional energy storage concrete also includes reinforcing fibers, wherein the reinforcing fibers are chopped carbon fibers, steel fibers or glass fibers.

[0011] The present invention provides an energy storage concrete component, the energy storage concrete component comprising a first electrode, an energy storage layer and a second electrode, wherein the energy storage layer is made of the multifunctional energy storage concrete described above.

[0012] Preferably, the first electrode is a carbon fiber electrode or a nickel foam electrode; the second electrode is a carbon fiber electrode or an iron electrode.

[0013] Preferably, the carbon fiber electrode is mainly made of carbon fiber cloth and conductive resin.

[0014] Preferably, when the first electrode and the second electrode are carbon fiber electrodes, the energy storage concrete component has a sandwich structure, with the energy storage layer located between the first electrode and the second electrode.

[0015] Preferably, the thickness of the first electrode and the second electrode is 1-3 mm, and the thickness of the energy storage layer is 18-22 mm.

[0016] The present invention also provides an application of the above-mentioned multifunctional energy storage concrete in road surface de-icing, road lighting, and self-energy storage.

[0017] The beneficial effects of this invention are: This invention adds conductive materials to concrete, which can form a conductive network in the concrete material, enabling the concrete to have the function of storing and conducting electrical energy.

[0018] The energy storage concrete of this invention can be used as a structural component for energy storage, and can also be combined with other energy technologies (such as solar energy and wireless charging) to achieve integrated generation, storage and utilization. Detailed Implementation

[0019] This invention provides a multifunctional energy storage concrete, comprising the following components in parts by weight: 300-600 parts of ordinary Portland cement 30-100 parts of mineral admixture 300-700 parts of quartz sand 5-60 parts of conductive material 4-8 parts of admixture 120-250 parts water.

[0020] In this invention, the weight parts of the ordinary silicate cement can be 300 parts, 350 parts, 400 parts, 450 parts, 500 parts, 550 parts, or 600 parts.

[0021] In this invention, the weight percentage of the mineral admixture can be 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 80 parts, 90 parts, or 100 parts.

[0022] In this invention, the specific weight percentages of the quartz sand can be 300 parts, 350 parts, 400 parts, 450 parts, 500 parts, 550 parts, or 600 parts. In this invention, the specific weight percentages of the conductive material can be 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, or 50 parts.

[0023] In this invention, the conductive material comprises one or more of acetylene black, graphite powder, multi-walled carbon nanotubes, and graphene nanosheets.

[0024] In this invention, the multifunctional energy storage concrete further includes an active component; the active component is manganese dioxide micro powder.

[0025] In this invention, the mineral admixture is silica fume and / or fly ash; the multifunctional energy storage concrete also includes reinforcing fibers, wherein the reinforcing fibers are chopped carbon fibers, steel fibers or glass fibers.

[0026] In this invention, the weight of the reinforcing fiber is preferably 5 to 10 parts, specifically 6, 7, 8, 9 or 10 parts.

[0027] In this invention, the particle size of the quartz sand is 0.1~0.6mm; the length of the chopped carbon fiber is 3~12mm, preferably 4~8mm, more preferably 6mm, and the diameter is 3~10μm, preferably 4~8μm, more preferably 5~7μm; the length of the steel fiber is 6~15mm, preferably 8~14mm, more preferably 10~13mm, and the diameter is 0.1~0.3mm, preferably 0.2mm.

[0028] The present invention provides an energy storage concrete component, the energy storage concrete component comprising a first electrode, an energy storage layer and a second electrode, wherein the energy storage layer is made of the multifunctional energy storage concrete described above.

[0029] In this invention, the first electrode is a carbon fiber electrode or a nickel foam electrode; the second electrode is a carbon fiber electrode or an iron electrode.

[0030] In this invention, the carbon fiber electrode is mainly made of carbon fiber cloth and conductive resin.

[0031] In this invention, when the first electrode and the second electrode are carbon fiber electrodes, the energy storage concrete component has a sandwich structure, with the energy storage layer located between the first electrode and the second electrode.

[0032] In this invention, the thickness of the first electrode and the second electrode is independently 1~3mm, preferably 2mm; the thickness of the energy storage layer is 18~22mm, preferably 19~21mm, and more preferably 20mm.

[0033] The present invention also provides an application of the above-mentioned multifunctional energy storage concrete in road surface de-icing, road lighting, and self-energy storage.

[0034] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0035] Example 1

[0036] The raw material composition of multifunctional energy storage concrete is as follows: 500 parts of ordinary silicate cement (grade 42.5), 50 parts of silica fume, 600 parts of quartz sand (particle size of 0.1~0.5mm), 25 parts of acetylene black, 25 parts of graphite powder, 7 parts of short carbon fiber (length of 6mm and diameter of 7μm), 6 parts of polycarboxylate superplasticizer, and 160 parts of water.

[0037] Acetylene black, graphite powder, and polycarboxylate superplasticizer were mixed with 20% water (32 parts) and ultrasonically dispersed for 15 minutes to obtain a conductive slurry. Ordinary silicate cement, silica fume, and quartz sand were dry-mixed in a mixer for 1 minute, and then the conductive slurry was added while stirring for 3 minutes. The remaining mixing water was then added, and stirring continued for 2 minutes. Finally, chopped carbon fibers were added and stirred for 2 minutes to obtain a concrete slurry with good fluidity and a slump of 180 mm. The concrete slurry was poured into 100 mm cube molds, vibrated to form the specimens, and covered with a plastic film for curing. After 24 hours, the molds were removed, and the resulting multifunctional energy storage concrete specimens were placed in a standard oxygen curing chamber at 20°C and 95% RH for 28 days.

[0038] After 28 days of curing, the surface of the multifunctional energy storage concrete specimen was dense and without cracks. The compressive strength, splitting tensile strength, resistivity and AC impedance spectrum of the specimen were tested.

[0039] The compressive strength of the multifunctional energy storage concrete specimen in Example 1 was 98.5 MPa. The present invention also prepared a concrete specimen without the addition of acetylene black and graphite powder, with a compressive strength of 110 MPa. This indicates that the addition of conductive materials has little effect on the strength of the concrete specimen.

[0040] The splitting tensile strength of the multifunctional energy storage concrete specimen in Example 1 was 8.6 MPa. The present invention also prepared concrete specimens without the addition of acetylene black and graphite powder. Compared with the concrete specimens without the addition of acetylene black and graphite powder, the splitting tensile strength of the multifunctional energy storage concrete specimen in Example 1 was increased by 15%, which is mainly because the short-cut carbon fiber has a bridging and toughening effect.

[0041] Resistivity was measured using the four-probe method. The results showed that the volume resistivity of the multifunctional energy storage concrete specimen in Example 1 was only 0.5 Ω·m, with fluctuations not exceeding ±10% between different specimens. This was compared to concrete specimens without added acetylene black and graphite powder (>10). 5 Compared to (Ω·m), the resistivity decreased by five orders of magnitude, indicating that a stable and interconnected conductive network has formed inside the multifunctional energy storage concrete of Example 1. Electrochemical impedance spectroscopy (EIS) testing shows that at 10... 3 ~10 5The impedance is flat in the Hz high-frequency region, indicating good contact of the conductive phase; at 10 0 ~10 2 The low-frequency region of Hz exhibits obvious capacitive characteristics.

[0042] The multifunctional energy storage concrete specimen from Example 1 was fabricated to dimensions of 100mm × 100mm × 10mm. A layer of copper foil was adhered to the top and bottom as current collector electrodes (effective electrode area 100mm²). The specimen was then immersed in a 3.5% sodium sulfate electrolyte solution, and its charge-discharge performance was tested using a two-electrode method. The constant current charge-discharge experiment showed that the electrodes of the aforementioned multifunctional energy storage concrete specimen achieved a current-to-discharge ratio of 1mA / cm². 2 It can be charged to a voltage of 0.9V at a given current density, corresponding to a surface capacitance of 0.15F / cm. 2 When three specimens of the above dimensions were connected in series, a 2 V / 5 mA LED was successfully lit, and the brightness remained stable. Cyclic life testing was conducted under a constant current charge-discharge window of 0–0.8 V. The results showed that after 10,000 cycles of constant current charge-discharge at 1 A, the discharge capacity retention rate of the multifunctional energy storage concrete specimen reached 96%, and the coulombic efficiency was 99%. This indicates that the conductive network constructed from acetylene black and carbon fiber has extremely high stability, and the concrete matrix provides good protection for the activated carbon material; no significant performance degradation was observed during cycling.

[0043] The multifunctional energy storage concrete of Example 1 can achieve resistance self-heating: a prism sample with dimensions of 40mm×40mm×160mm was prepared, and a 30V DC current was applied. The heating power was measured to be 8 W, and the surface temperature rose from room temperature to 65℃ within 15 minutes, proving that it is feasible as a heating element.

[0044] The multifunctional energy-storage concrete material from Example 1 was used to construct a simple energy-storage curb light: A spiral-shaped through-hole was pre-drilled inside a 150 mm high cylindrical concrete curb, and two 50 mm spaced steel wire mesh sheets were embedded as electrodes. The curb was then cast using the concrete slurry from Example 1. After curing, the curb concrete itself became a supercapacitor. During the day, a small solar panel on top charged the area between the two electrodes of the curb. At night, the solar panel was disconnected, and the curb electrodes were connected to an LED light, using the electrical energy released from the curb concrete to illuminate the LED light. Actual measurements showed that after 6 hours of charging under sunny conditions, each concrete curb could illuminate a 1W high-brightness LED light for approximately 4 hours. The internal energy storage performance of the curb remained stable after exposure to outdoor sun, rain, and sudden temperature changes, indicating that the multifunctional energy-storage concrete from Example 1 has good reliability in real-world environments.

[0045] Example 2

[0046] The raw material composition of multifunctional energy storage concrete is as follows: 400 parts of ordinary silicate cement (grade 42.5), 100 parts of fly ash, 500 parts of quartz sand (particle size 0.1~0.6mm), 40 parts of γ-MnO2 micro powder, 2 parts of multi-walled carbon nanotubes (length 10μm, diameter 20nm), 5 parts of graphene nanosheets, steel fiber (length 13mm, diameter 0.2mm), 4 parts of polycarboxylate superplasticizer, and 150 parts of water.

[0047] Carbon nanotubes, 0.5 parts water-reducing agent, and 20 parts water were mixed and ultrasonically dispersed for 20 minutes to form a slurry. Ordinary silicate cement, fly ash, quartz sand, γ-MnO2, and graphene nanosheets were placed in a mixer and dry-mixed for 2 minutes. The slurry and the remaining water-reducing agent were slowly poured in and mixed evenly. The remaining water was then added and the mixture was stirred for another 2 minutes. Finally, steel fibers were added and stirred evenly to obtain multifunctional energy storage concrete. Four 100mm×100mm×100mm cubic specimens and four 40mm×40mm×160mm prism specimens were poured into the concrete and vibrated to form the specimens. The surface was covered with a plastic film for curing. After 24 hours, the specimens were demolded and placed in a standard oxygen curing chamber at 20℃ and 95% relative humidity for 28 days.

[0048] The compressive strength and splitting tensile strength of the cubic specimen of Example 2 were tested. The results were as follows: the compressive strength of Example 2 was 72.4 MPa, which was basically the same as that of the specimen without γ-MnO2 micro powder and carbon nanotubes (75 MPa). The splitting tensile strength of the specimen prepared in Example 2 was 5.9 MPa, which was 30% higher than that of the concrete specimen without steel fiber. This is because steel fiber has a toughening effect.

[0049] The resistivity of the multifunctional energy storage concrete specimen (40mm × 40mm × 160mm) from Example 2 was measured using the four-probe method. The results showed that the volume resistivity of the multifunctional energy storage concrete specimen from Example 2 was only 2.3 Ω·m, which is significantly lower than that of the concrete specimen without carbon nanotubes and graphene nanosheets (10). 2 The Ω·m) is significantly reduced compared to the previous value because carbon nanotubes, graphene nanosheets and steel fibers form a multi-scale conductive network.

[0050] Electrochemical tests were performed on the prism specimen. A layer of copper foil was attached to each end face as electrodes, and the specimen was connected to a constant current charge-discharge device. Residual pore water was used as the electrolyte (some moisture remained inside the specimen even after sufficient curing). The specific capacitance of the specimen was 45 F / g, significantly higher than in Example 1, measured at a current density of 2 mA / cm². This indicates the pseudocapacitive contribution of γ-MnO₂: typical redox peak pairs appeared in the cyclic voltammetry curves within the 0.0–0.9 V range, with a peak potential of approximately 0.5 V, corresponding to the valence state transition of Mn. The charge-discharge curves showed a certain lag, but stabilized after 10 cycles, achieving a coulombic efficiency of 98%. After 1000 charge-discharge cycles at 1 A, the specimen retained 92% of its capacity, demonstrating good cycle life. Charge-discharge experiments were conducted at different rates: from 0.5 A to 5 A, the capacity decreased by only 20%, indicating good high-rate performance. This is thanks to the high-speed electron channels constructed from multi-walled carbon nanotubes / graphene, and the excellent ion accessibility of γ-MnO2. Example 2 demonstrates that introducing pseudocapacitive materials (γ-MnO2) into concrete, supplemented by conductive materials (CNTs, graphene), can significantly improve the energy storage capacity and power performance of concrete without significantly weakening its mechanical properties.

[0051] A 100mm×100mm×20mm rubber sand mold was selected. Two conductive carbon fiber fabrics (95mm×95mm) were placed at the bottom of the mold cavity as electrodes, separated by a 3mm thick PVC board with only the edges connected to prevent short circuits. Then, the concrete slurry from Example 2 was poured into the mold, with the two fabrics positioned close to the upper and lower surfaces of the tile. After compaction and curing, the resulting conductive tile had a layer of carbon fiber fabric electrodes on both the top and bottom, with γ-MnO2-containing energy storage concrete in the middle serving as the electrolyte and separating medium. Tests showed that each tile had an open-circuit voltage of 0.8V (between the two electrodes), and multiple tiles connected in series and parallel could serve as a low-voltage emergency power source. Connecting 10 tiles in series in pairs and then in parallel for 5 sets yielded an output voltage of approximately 4V, successfully lighting a mobile phone screen in darkness. Walking on the tile had no significant impact on its energy storage performance, and its compressive strength exceeded 50 MPa, making it suitable for use as a practical walkway material. By connecting multiple floor tiles in parallel, small fans and other equipment can be driven for a short time. It can be seen that the multifunctional energy storage concrete of Example 2 can be used to lay energy storage devices and can output electrical energy for emergency use when needed.

[0052] Example 3

[0053] The multifunctional energy storage concrete of Example 1 was made into a specimen with dimensions of 100mm×100mm×20mm. Carbon fiber cloth was impregnated with conductive resin to make a composite thin plate with a thickness of 2mm (the volume fraction of carbon fiber was 60%, and a small amount of graphene was added to the conductive resin to reduce contact resistance). Ni(OH)2 powder was added to the upper electrode thin plate during its fabrication as the active material of the positive electrode. Conductive copper foil leads were attached to the two electrodes for external circuit connection. One of the composite thin plates was laid flat at the bottom of the steel template, with the copper foil leads extending out of one side of the template. The concrete slurry of Example 1 (with a pouring thickness of 20mm) was poured and gently vibrated to spread the concrete slurry evenly. The upper layer (carbon fiber electrode plate with nickel hydroxide) was laid on the surface of the slurry, with the copper foil leads extending out of one side of the template. After standing and naturally hardening for 24 hours, the template was removed to obtain a sandwich-structured energy storage concrete specimen with dimensions of 100mm×100mm×25mm and a middle concrete layer thickness of 20mm.

[0054] The four sides of the above-mentioned energy storage concrete specimen were wrapped with a wet towel and covered with a film, and cured for 14 days. In order to improve the ionic conductivity of the inner concrete, the cured specimen was immersed in a saturated calcium hydroxide solution for 48 hours. Then it was taken out, dried, and all exposed surfaces were sealed with epoxy resin, leaving only the copper foil lead-out sheet, to obtain the sandwich energy storage concrete component.

[0055] The performance of the aforementioned sandwich-layered energy storage concrete member was tested, and the ultimate load reached 3.2 kN under three-point bending loading. The upper and lower carbon fiber plates effectively suppressed the crack propagation in the concrete layer, giving the member significant toughness. This indicates that the carbon fiber plates can not only serve as electrodes but also have a reinforcing effect, greatly improving the flexural performance of the concrete member.

[0056] The copper foil leads were connected to a potentiostat as positive and negative electrodes and tested in a 6 mol / L potassium hydroxide solution. The specific capacitance was 68 F / g. Cyclic tests were conducted at 0~0.5V. After 500 cycles, the capacity retention rate was 90%, showing good stability.

[0057] The aforementioned sandwich-layered energy storage concrete component can be used directly as a single energy storage structural unit. Multiple 100mm×100mm×25mm plates were connected in series and parallel with wires to form a 2V, approximately 5000F supercapacitor module, which was then embedded in a reinforced concrete beam (with pre-reserved slots for the module, followed by epoxy resin encapsulation). The beam measures 1000mm×200mm×150mm, is reinforced with ordinary steel bars, and the supercapacitor module is embedded at the mid-span. Actual measurements showed that the beam's flexural strength was comparable to that of a hollow beam, without any reduction in structural strength due to the embedded module. The energy storage module powered strain gauge sensors embedded in the mid-span, collecting stress data on the beam without requiring an external power source. Furthermore, the energy storage module continued to function normally even as the beam was subjected to loads leading to cracking and near-failure, demonstrating the supercapacitor module's good structural compatibility and robustness.

[0058] Application Example: The sandwiched energy storage concrete structure prepared in Example 1 can be further scaled up for use in bridge decks or floor slabs. For example, when manufacturing a 3-meter-long precast bridge deck, carbon fiber electrodes can be laid on the upper and lower surfaces of the slab and cast together with the energy storage concrete in the middle. This bridge deck is not only a load-bearing component but also equivalent to a giant parallel-plate capacitor. During the day, the bridge deck can store photovoltaic power, and at night, it can wirelessly transmit energy to vehicles through embedded induction coils. Simultaneously, the bridge deck itself can use its electric heating function to melt snow and remove ice, improving driving safety. Because the carbon fiber electrodes also serve a reinforcing function, the load-bearing capacity of this energy storage bridge deck is no less than that of traditional reinforced concrete slabs, but with the added functions of energy storage and heating. This will enable future bridges to have the ability to "self-generate power, self-store energy, and self-supply energy," potentially significantly improving the energy efficiency of infrastructure.

[0059] Example 4

[0060] The raw material composition of multifunctional energy storage concrete is as follows: 300 parts of ordinary Portland cement (42.5 grade), 30 parts of silica fume, 300 parts of quartz sand (particle size of 0.3~0.6mm), 15 parts of graphite powder, 6 parts of polycarboxylate superplasticizer, 15 parts of calcium chloride accelerator, and 135 parts of water.

[0061] Graphite powder and polycarboxylate superplasticizer were mixed with 20% water (27 parts) and ultrasonically dispersed for 15 minutes to obtain conductive slurry. Ordinary silicate cement, silica fume and quartz sand were placed in a mixer and dry-mixed for 1 minute. Then the conductive slurry was added while stirring, and stirred for 3 minutes. The remaining mixing water was added and stirred for another 2 minutes. Finally, calcium chloride accelerator was added to obtain concrete slurry.

[0062] Electrode materials: The positive electrode is a nickel foam sheet (50mm×50mm×2mm in size, with a porosity of 90%), which is electroplated with a layer of β-Ni(OH)2; the negative electrode is an iron rod (6mm in diameter and 50mm in length).

[0063] A positive electrode is placed at the bottom of a 70mm×70mm×70mm cubic steel mold, with a nickel-plated copper wire leading out from the side wall of the mold. An iron rod is suspended vertically in the center of the mold as the negative electrode, with its lower end 18mm away from the nickel foam. The concrete slurry is then poured into the steel mold, and the air is vented by vibration. The slurry can initially solidify and fix the electrode within 20 minutes. After 4 hours, the mold is removed, and the concrete specimen is cured at 100% RH humidity for 7 days. After curing, it is immersed in a 5% potassium hydroxide solution for 48 hours to fill the pores with potassium hydroxide electrolyte. After removal, the surface is wiped dry, and the concrete specimen is sealed with quick-drying epoxy resin, leaving only the head of the iron rod electrode and the nickel foam lead wire exposed as electrode terminals.

[0064] Electrochemical performance testing: The concrete specimen formed a nickel-iron rechargeable concrete battery with an open-circuit voltage of 1.30 V. Under constant current charging and discharging at 1 A, the initial discharge capacity was 150 mAh (cutoff voltage 1.0 V), subsequently increasing gradually and stabilizing at approximately 200 mAh after 10 cycles. The total volume of the specimen was 343 cm³, with a stored energy capacity of approximately 0.58 Wh, equivalent to an energy density of approximately 1.7 Wh / L (calculated based on the exposed electrode area of ​​the sample, which is 4.0 Wh / m²).

[0065] Cycle life test: After 100 cycles under 50% depth discharge conditions, the discharge capacity remained at 185 mAh, with a retention rate of 92.5%, and the coulombic efficiency was between 97% and 99%, with no obvious signs of degradation. This indicates that the electrode embedded in concrete has high reversibility and stability.

[0066] Structural performance testing: The specimen underwent a compressive strength test, with a failure load of 55 kN and an equivalent compressive strength of 16 MPa. Due to the use of high-porosity mortar and the presence of large-pore electrodes, this strength is consistent with that of general lightweight concrete, capable of bearing the self-weight of non-critical structures and minor loads.

[0067] In Example 4, calcium chloride was added as a setting accelerator during the preparation of the concrete specimens. The cement-based alkaline pore liquid provided a suitable working environment for the battery. Calcium chloride increased ion concentration and conductivity, while the addition of graphite powder reduced the contact resistance at the interface between the electrode plate and the slurry. The alkaline environment of the concrete inhibited the corrosion of the iron electrode, ensuring that only Fe corrosion occurred during repeated charge-discharge cycles. Fe(OH)2 FeOOH is converted and balanced by NiOOH / Ni(OH)2 cathode to achieve stable electrochemical cycling. The entire system does not require a diaphragm and has a robust structure. As long as the electrolyte moisture is maintained, it can work stably for a long time.

[0068] Several of the aforementioned concrete battery specimens are connected in series and parallel to form an energy storage unit. For example, using 1000 specimens to form a battery array can achieve an energy storage module of approximately 50 V and 20 Ah, equivalent to 1 kWh of energy. This module can be embedded in the foundation or walls of buildings to balance the diurnal variation of photovoltaic power generation or to provide emergency power.

[0069] In laboratory simulations, nine concrete batteries (3 series, 3 parallel configuration, output approximately 3.9 V, capacity 0.6 Ah) were embedded within a 1 m × 1 m reinforced concrete wall. Charged during the day with DC power and used to power LED lights at night, the system successfully illuminated nine LEDs (total power approximately 2 W) for up to 5 hours. The concrete wall did not cause cracking damage to the embedded battery modules, and the battery operation was unaffected by the concrete constraints. This demonstrates that the concrete batteries can be safely embedded in structural concrete to work collaboratively, providing long-life energy storage. Furthermore, due to the use of an aqueous electrolyte and passivated metal electrodes, the system offers high fire safety and is suitable for underground buildings, tunnels, and other locations with high fire protection requirements.

[0070] Example 5

[0071] A composite road panel with dimensions of 500mm × 500mm × 100mm was constructed using the concrete grout from Example 1 and C40 concrete. The upper layer used the concrete grout from Example 1, and the lower layer used C40 concrete, with each layer being 50mm thick. First, the C40 concrete was poured. Before initial setting, a layer of molybdenum wire mesh (20mm mesh spacing, 1mm diameter, serpentine arrangement) was laid as a heating element. Then, the concrete grout from Example 1 was poured, and the surface was smoothed. After the concrete hardened, grooves were cut into the upper surface to embed solar cells and supercapacitor modules. The exterior was sealed with sealant for waterproofing. Wiring connected the solar cells, capacitor modules, molybdenum wire mesh, LEDs, etc., to a microcontroller unit, which included charging / discharging and temperature control elements. Thin-film solar cells (125mm × 125mm, 6 cells in series, output approximately 18V) and supercapacitor modules (3 sets of 5V, 10F commercial capacitors) served as auxiliary energy harvesting and rapid buffering devices. The entire system is connected via control lines to function as follows: During the day, solar panels store electrical energy in the energy storage concrete layer (which itself acts as a capacitor) and the supercapacitor module; at night or when de-icing is needed, the control unit releases the stored DC power to the heating network, allowing the pavement panel to heat up itself. In addition, LED light strips are installed on the sides of the pavement panel, which can use the stored electrical energy for illumination and indication.

[0072] Test Scenario 1: Road De-icing: The composite road panel was placed in an environmental chamber at -5°C. Water was sprayed onto the surface of the composite road panel to form a thin layer of ice. The energy storage concrete layer was pre-charged indoors (approximately 15V DC, stored energy ≈ 30 Wh / m²). De-icing mode was activated, and the controller boosted the energy from the energy storage layer to 30V via DC / DC to power the molybdenum wire mesh. Using only the energy storage layer's own power (without an external power source), the road panel successfully raised its surface temperature from -5°C to 0.5°C within 20 minutes, and the ice began to melt. After 30 minutes, most of the ice melted into water and was expelled by the rough surface structure. It was measured that during the 30-minute de-icing process, the voltage of the energy storage concrete layer dropped by approximately 40%, releasing approximately 25 Wh of energy, primarily used for heating and dissipation. After the experiment, some charge remained inside the panel, which could be used for insulation or as a backup. Example 5: The energy storage concrete can be used as an energy storage medium for the road self-de-icing system, storing electricity during the day and discharging it at night to melt ice, reducing dependence on the power grid and realizing intelligent road safety.

[0073] Test Scenario 2: Road Surface Powered Lighting: The aforementioned road panel was placed outdoors for two days. During the day, the sun charged the energy storage layer, and at night, its ability to power LED lighting was tested. Calculations showed that two days of sunlight allowed the energy storage concrete layer within the panel to store approximately 50 Wh of energy (including solar power and some capacitor buffering due to ambient temperature changes during nighttime idleness). At 7:00 PM, the controller detected the darkness and automatically connected the energy storage layer to the LED light strips. A total of 4 m long LED light strips (approximately 4 W power consumption) were illuminated, operating in an intermittent flashing mode. The voltage of the energy storage concrete layer gradually decreased from 15 V, dropping to approximately 10 V by 10:00 PM. The light strip brightness decreased slightly but remained clearly visible until approximately 11:30 PM, when the energy storage layer voltage dropped to the set lower limit of 8 V. The controller then cut off the lighting to prevent over-discharge. The lighting lasted approximately 4.5 hours throughout the night. A new charging cycle began after sunrise the following day. This process demonstrates that the energy storage concrete of this invention can be used for nighttime lighting power supply in roads or squares, achieving a cycle of energy storage during the day and energy consumption at night. In practical applications, combined with road sensor control, an energy-saving mode can be achieved where "lights turn on when people and vehicles approach and dimly illuminate when they leave," significantly reducing municipal lighting energy consumption.

[0074] Durability Observation: After the composite pavement panel underwent 20 de-icing cycles and simulated 3 months of day-night cycle lighting, the energy storage concrete layer was disassembled and inspected. It was found that the concrete layer was tightly bonded to the heating network, with no peeling cracks caused by thermal expansion and contraction; the internal carbon fiber remained intact and uncorroded, its electrical properties remained stable, and its compressive strength showed no significant reduction. This indicates that the composite pavement panel of Example 5 maintained good performance after multiple electrothermal cycles and outdoor environmental conditions, demonstrating its potential for long-term use.

[0075] Through the above embodiments 1 to 5, it can be seen that the energy storage concrete material and system provided by the present invention can be flexibly applied to a variety of scenarios: it can be used as a structural component for energy storage, and it can also be combined with other energy technologies (such as solar energy and wireless charging) to achieve integrated generation-storage-use.

[0076] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A multifunctional energy storage concrete, characterized in that, It contains the following components in parts by weight: 300-600 parts of ordinary Portland cement 30-100 parts of mineral admixture 300-700 parts of quartz sand 5-60 parts of conductive material 4-8 parts of admixture 120-250 parts water.

2. The multifunctional energy storage concrete according to claim 1, characterized in that, The conductive material comprises one or more of acetylene black, graphite powder, multi-walled carbon nanotubes, and graphene nanosheets.

3. The multifunctional energy storage concrete according to claim 1 or 2, characterized in that, The multifunctional energy storage concrete also contains an active component; the active component is manganese dioxide micro powder.

4. The multifunctional energy storage concrete according to claim 3, characterized in that, The mineral admixture is silica fume and / or fly ash; the multifunctional energy storage concrete also includes reinforcing fibers, wherein the reinforcing fibers are chopped carbon fibers, steel fibers or glass fibers.

5. An energy storage concrete component, characterized in that, The energy storage concrete component includes a first electrode, an energy storage layer, and a second electrode, wherein the energy storage layer is made of the multifunctional energy storage concrete as described in any one of claims 1 to 4.

6. The energy storage concrete component according to claim 5, characterized in that, The first electrode is a carbon fiber electrode or a nickel foam electrode; the second electrode is a carbon fiber electrode or an iron electrode.

7. The energy storage concrete component according to claim 6, characterized in that, The carbon fiber electrode is mainly made of carbon fiber cloth and conductive resin.

8. The energy storage concrete component according to any one of claims 5 to 7, characterized in that, When the first electrode and the second electrode are carbon fiber electrodes, the energy storage concrete component has a sandwich structure, with the energy storage layer located between the first electrode and the second electrode.

9. The energy storage concrete component according to claim 8, characterized in that, The thickness of the first electrode and the second electrode is 1~3mm, which are independent; the thickness of the energy storage layer is 18~22mm.

10. The application of the multifunctional energy storage concrete according to any one of claims 1 to 4 in road surface de-icing, road lighting, and self-energy storage.