A solid-state electrolyte based on waste cement paste, and a preparation method and application thereof

Abstract

The application belongs to the field of solid waste resource utilization and electrochemical energy storage technology, and more particularly relates to a solid electrolyte based on waste cement paste as well as a preparation method and application thereof. Through directional conversion reaction between calcium-silicon-aluminum hydration phase in waste cement paste and zinc sulfate solution, a gypsum-alkali zinc sulfate composite phase (ZnCP composite material) with a layered crystal structure is in-situ constructed, and a collaborative breakthrough of high-value recycling of waste resources and development of high-performance solid electrolyte is realized. The structure-performance synergistic mechanism of the ZnCP composite material makes the solid electrolyte provided by the application maintain excellent electrochemical stability in a wide temperature range of-20-60 DEG C, the Zn / / polyaniline full battery assembled has a cycle life of more than 420 times, and the zinc / / zinc symmetric battery is stably operated for more than 1500 hours without dendrite and hydrogen evolution.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization and electrochemical energy storage technology, and more specifically relates to a solid electrolyte based on waste cement slurry, its preparation method and application. Background Technology

[0002] The cement industry is one of the most challenging basic industries to decarbonize, with its production process accounting for approximately 8% of global anthropogenic carbon dioxide emissions. The primary use of cement is in concrete production, the world's largest-volume building material, with an annual output exceeding 30 billion tons. With ongoing global urbanization and accelerated infrastructure upgrades, buildings and engineering structures generate massive amounts of construction and demolition waste (C&DW) after reaching their service life, exceeding 4.7 billion tons globally annually and continuing to increase at an annual growth rate of approximately 5%. Currently, a significant portion of this construction waste is not efficiently recycled and is often directly disposed of in landfills. This model not only consumes valuable land resources but also, combined with the high carbon emissions of cement production itself, creates a dual resource and environmental pressure of "high-carbon production - inefficient waste." Therefore, developing groundbreaking resource recycling technologies has become crucial to overcoming the industry's sustainable development bottleneck.

[0003] Concrete waste accounts for approximately 60% of the total weight of demolition waste, and its main components are aggregates and hardened cement paste. Currently, recycling technologies in the industry mostly focus on the mechanical recycling of aggregates to alleviate reliance on natural aggregate resources. In contrast, hardened cement paste, which loses its activity due to hydration reactions, has long been relegated to a low-value state, mostly being downgraded and used as backfill material. This disposal method fails to fully appreciate the rich mineral components contained in hardened cement paste, such as hydrated calcium silicate, calcium hydroxide, and incompletely reacted clinker phases; the potential functional value of these active components has not been effectively explored.

[0004] Meanwhile, cement-based energy storage devices, as an important direction for the integration of building structure and function, have shown promising application prospects in building-based energy storage. However, existing technologies generally adopt a composite configuration of "cement matrix + liquid electrolyte". This configuration relies on free water in the cement pores for ion transport, resulting in extremely low energy density of the devices, typically one to two orders of magnitude lower than commercial battery technology. This severely limits their large-scale application in practical engineering.

[0005] To address the aforementioned challenges, existing technological approaches mainly fall into two categories: one is to recover aggregates through mechanical sorting to achieve partial resource utilization, but this lacks high-value-added conversion strategies for hardened cement paste components; the other is to develop cement-based energy storage devices, but cement is typically treated merely as an inert structural framework, failing to effectively utilize its inherent ion conduction capabilities. The bottleneck lies in the fact that the microstructure of traditional cement hydration products lacks efficient ion transport channels. While directly introducing liquid electrolytes can improve ion conductivity to some extent, it compromises the structural stability and adaptability over a wide temperature range of the device.

[0006] Therefore, how to reconstruct the composition of materials to directionally transform the calcium, silicon, and aluminum phases in waste cement slurry into a composite phase with a layered crystal structure and containing water of crystallization channels, thereby constructing a cement-based solid electrolyte with both high ionic conductivity and a wide electrochemical stability window, has become a key technological requirement. This breakthrough is expected to simultaneously achieve the high-value utilization of waste resources and the development of high-performance energy storage devices, which is of great significance for promoting the green transformation of the cement industry and innovation in building energy storage technology. Summary of the Invention

[0007] The purpose of this invention is to provide a solid electrolyte based on waste cement slurry, its preparation method and application, in order to solve the resource waste and environmental burden caused by the low-value disposal of waste cement slurry, as well as the technical problems of low energy density and poor wide-temperature adaptability of traditional cement-based energy storage devices due to their reliance on liquid electrolytes.

[0008] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of the present invention is to provide a ZnCP composite material, wherein the ZnCP composite material comprises a gypsum phase and a basic zinc sulfate phase; The gypsum phase is CaSO4·2H2O; the basic zinc sulfate phase is Zn4SO4(OH)6·xH2O, where x is the number of water molecules of crystallization and x is not 0. The gypsum phase and the basic zinc sulfate phase have a layered crystal structure, with water of crystallization between the crystal lattice layers, and are Zn. 2+ Migration provides ion transport channels.

[0009] The second technical solution of the present invention provides a method for preparing the above-mentioned ZnCP composite material, comprising the following steps: Waste cement paste powder was mixed with a 1-4 mol / L zinc sulfate aqueous solution and stirred to obtain the ZnCP composite material.

[0010] Furthermore, the waste cement slurry powder is ball-milled to a particle size ≤75 μm after the hydration reaction of the waste cement slurry is terminated by isopropanol solvent exchange.

[0011] Furthermore, the solid-liquid mass ratio of the waste cement slurry powder and the zinc sulfate aqueous solution is 1:50.

[0012] Furthermore, the stirring reaction is carried out at a temperature of 20-30 °C for a duration of 18-30 h.

[0013] Furthermore, the reaction process includes vacuum filtration, washing, and drying.

[0014] Optionally, the drying temperature is 50-70 °C and the time is 20-28 h.

[0015] The third technical solution of the present invention provides an application of the above-mentioned ZnCP composite material in solid electrolytes.

[0016] The fourth technical solution of the present invention provides a solid electrolyte, wherein the solid electrolyte comprises the above-mentioned ZnCP composite material.

[0017] The solid electrolyte provided by this invention has an ionic conductivity ≥ 5 mS / cm. -1 Electrochemical stability window ≥3.5 V.

[0018] Furthermore, the solid electrolyte also includes a binder, and the mass ratio of the ZnCP composite material to the binder is (75-97):(3-25).

[0019] Optionally, the adhesive includes at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC), and sodium alginate (SA).

[0020] Optionally, the mass ratio of the ZnCP composite material to the binder is preferably 90:10.

[0021] Fifth technical solution of the present invention: A method for preparing the above-mentioned solid electrolyte, comprising the following steps: The solid electrolyte is obtained by uniformly mixing ZnCP composite material or ZnCP composite material and binder, followed by molding and drying.

[0022] Furthermore, the drying temperature is 50-70°C.

[0023] The sixth technical solution of the present invention is to provide an application of the above-mentioned ZnCP composite material or the above-mentioned solid electrolyte in a solid zinc-ion battery.

[0024] The seventh technical solution of the present invention: provides a solid zinc-ion battery, wherein the electrolyte of the solid zinc-ion battery is the above-mentioned solid electrolyte.

[0025] Furthermore, the solid-state zinc-ion battery also includes a zinc metal anode and a cathode material.

[0026] Optionally, the positive electrode material is one of polyaniline, manganese oxide, vanadium oxide, Prussian blue analogues, elemental sulfur and its derivatives, and elemental iodine and its derivatives.

[0027] In a solid-state zinc-ion battery, the solid electrolyte is placed between the zinc metal negative electrode and the positive electrode material as an ion conduction medium.

[0028] The present invention discloses the following technical effects: This invention achieves a synergistic breakthrough in the high-value recycling of waste resources and the development of high-performance solid electrolytes by directionally transforming the calcium-silica-alumina hydrated phase in waste cement slurry with zinc sulfate solution to construct a gypsum-basic zinc sulfate composite phase with a layered crystal structure in situ. At the microstructural level, the water of crystallization molecules embedded in the layered lattices of gypsum and basic zinc sulfate stabilize the interlayer structure through a hydrogen bond network, forming a sufficient interlayer spacing of 0.42–0.56 nm, which is conducive to the high-value recycling of waste resources. 2+ It provides a fast transport channel with low migration barriers (0.27 eV for gypsum phase and 0.47 eV for basic zinc sulfate phase). At the electrochemical level, this solid electrolyte exhibits a wide electrochemical stability window of 3.6 V. Its layered structure strongly adsorbs water molecules (gypsum -5.03 eV, basic zinc sulfate -9.06 eV), effectively inhibiting the migration of free water to the zinc anode interface, fundamentally blocking the hydrogen evolution side reaction, and simultaneously promoting Zn... 2+ The three-dimensional diffusion behavior enables dendrite-free uniform deposition / dissolution.

[0029] The structure-performance synergy mechanism of the ZnCP composite material enables the solid electrolyte provided by this invention to maintain excellent electrochemical stability in a wide temperature range of -20~60℃. The assembled Zn / / polyaniline full cell has a cycle life of more than 420 cycles, and the zinc / / zinc symmetric cell operates stably for more than 1500 hours without dendrites or hydrogen evolution.

[0030] The preparation process of this invention only requires simple stirring reaction, without the need for high-temperature calcination or complex equipment. The raw materials are widely available and inexpensive. It not only solves the industry pain point of resource utilization of waste cement slurry, but also provides an innovative solution for building structure integrated energy storage systems that combines high energy density, wide temperature range adaptability and integrated structural functions. It has significant environmental benefits, economic benefits and industrial application prospects. Attached Figure Description

[0031] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1Figure 1 shows the characterization results of the ZnCP composite material of the present invention. In the figure, A is a schematic diagram of the process flow of recycling waste cement slurry into solid electrolyte; B is an optical photograph of cement slurry and ZnCP composite material; C and D are schematic diagrams of the crystal structure of gypsum and basic zinc sulfate; E is a scanning electron microscope (SEM) morphology and elemental distribution map of ZnCP composite material; F and G are X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectra of ZnCP powder; H and I are the zinc K-edge X-ray absorption near-edge structure (XANES) spectrum and Fourier transform extended X-ray absorption fine structure (EXAFS) spectrum of metallic zinc, zinc oxide and ZnCP.

[0032] Figure 2 Figure 1 shows the characterization results of waste cement paste (CP). In this figure, A is an optical photograph of the CP block sample, B is a scanning electron microscope (SEM) morphology image of the CP powder, C is the nitrogen adsorption-desorption specific surface area (BET) test results of CP and ZnCP powder, D is the elemental content analysis of CP and ZnCP powder by inductively coupled plasma (ICP), E is the X-ray diffraction (XRD) pattern of the CP powder, and F is the Fourier transform infrared (FTIR) spectrum of the CP powder.

[0033] Figure 3 The graph shows the density functional theory (DFT) calculation results of ZnCP composites, where a represents the density of states (DOS) of gypsum, and b and c represent the Zn content in the interlayer channels of gypsum, respectively. 2+ The coordination structure of ions and their bulk diffusion barrier; d is the density of states (DOS) of basic zinc sulfate (ZHS); e and f are the Zn in the interlayer channels of basic zinc sulfate, respectively. 2+ The coordination structure and its bulk diffusion energy barrier.

[0034] Figure 4 Figure 1 shows the characterization and electrochemical performance test results of ZnCP-SSE. Figures a and b show the optical photograph and scanning electron microscope (SEM) morphology of ZnCP-SSE, respectively; figure c shows the three-dimensional spatial distribution configuration of various secondary ions in ZnCP-SSE; figures d, e, and f show the ionic conductivity, Nyquist impedance spectrum, and Zn ion conductivity of CP-SSE and ZnCP-SSE, respectively. 2+ The activation energy of migration; g, h, and i are the linear sweep voltammetry (LSV), Tafel polarization, and chronoamperometry (CA) curves of ZnCP-SSE and 2.0 M ZnSO4 electrolyte, respectively; j is the Zn / / Zn symmetric cell using ZnCP-SSE and ZnSO4 electrolyte at 0.5 mA cm⁻¹. -2Long-cycle performance at current density; k is the quantitative result of differential electrochemical mass spectrometry (DEMS) of hydrogen evolution behavior of zinc metal anode during deposition / dissolution when using ZnCP-SSE.

[0035] Figure 5 The figures show the characterization results of ZnCP-SSE and CP-SSE. a) is an optical photograph of the ZnCP-SSE sheet-like sample measured with vernier calipers; b) is a comparison of optical photographs of CP-SSE and ZnCP-SSE; c) is a scanning electron microscope (SEM) morphology image of CP-SSE; d) is the depth profile result of time-of-flight secondary ion mass spectrometry (TOF-SIMS) of ZnCP-SSE; e) is the F content in ZnCP-SSE. - With SO4 2- The three-dimensional spatial distribution configuration of ionic species.

[0036] Figure 6 Figure 1 shows the electrochemical performance test results of ZnCP-SSE and CP-SSE. A and B are the Nyquist impedance spectra of the Zn / / Zn symmetric cells using ZnCP-SSE and CP-SSE respectively at different temperatures; C is the current-time curve and corresponding Nyquist impedance spectrum of the ZnCP-SSE-based Zn / / Zn symmetric cell during the initial activation process; D is the current-time curve of the CP-SSE-based Zn / / Zn symmetric cell at 0.5 mA cm⁻¹. -2 Current density and 0.1 mAh cm⁻¹ -2 Long-cycle performance under areal capacity conditions.

[0037] Figure 7 Figure 1 shows the characterization results of ZnCP-SSE suppressing side reactions. In this figure, A is the differential electrochemical mass spectrometry (DEMS) quantitative test result of hydrogen evolution behavior of zinc metal anode during deposition / dissolution using 2.0 M ZnSO4 electrolyte; B is the comparison of X-ray diffraction (XRD) patterns of zinc metal anode after 50 cycles of Zn / / Zn symmetric cells in ZnCP-SSE and ZnSO4 electrolyte systems; C and D are scanning electron microscope (SEM) morphology images of zinc metal anode surface after 50 cycles of Zn / / Zn symmetric cells in ZnCP-SSE and ZnSO4 electrolyte systems.

[0038] Figure 8 The figures show the electrochemical performance test results of solid-state zinc-ion batteries. In the figure, A is a schematic diagram of the solid-state zinc-ion battery structure; BE shows the rate performance, constant current charge-discharge curve, self-discharge suppression capability, and long-cycle stability of the Zn / / polyaniline (PAN) battery using ZnCP-SSE; F is a schematic diagram of the solid-state pouch battery structure; and GI shows the long-cycle performance, physical optical photograph, and mechanical flexibility test results of the solid-state Zn / / PAN pouch battery.

[0039] Figure 9 The figure shows the electrochemical performance test results of Zn / / polyaniline (PAN) batteries, where A represents the Zn / / PAN battery using ZnCP-SSE at 0.1 mV s⁻¹. -1 Cyclic voltammetry (CV) curves at scan rates; B represents the Zn / / PAN cell using ZnCP-SSE and 2.0 M ZnSO4 electrolyte at 0.2, 0.5, 1.0, 2.0, 3.0, and 5.0 A g. -1 Comparison of rate performance at current density; C shows the constant current charge-discharge curves of Zn / / PAN batteries using ZnSO4 electrolyte at different current densities; D shows the test results of self-discharge suppression capability of Zn / / PAN batteries using ZnSO4 electrolyte; E shows the comparison of long-cycle performance of Zn / / PAN batteries using ZnCP-SSE and ZnSO4 electrolyte at room temperature.

[0040] Figure 10 The results of thermogravimetric analysis of CP and ZnCP are shown.

[0041] Figure 11 The graph shows the electrochemical performance test results of ZnCP-C. In this graph, A compares the ionic conductivity of CP-C, CP-SSE, ZnCP-C, and ZnCP-SSE; B and C show the Nyquist impedance spectra of the Zn / / Zn symmetric cell using ZnCP-C at different temperatures and the Zn conductivity calculated based on Arrhenius fitting. 2+ The activation energy of migration; DF represents the Tafel polarization curve, electrochemical stability window obtained by linear sweep voltammetry (LSV) and chronoamperometry (CA) curve of the Zn / / Zn symmetric cell in the ZnCP-C and 2.0 M ZnSO4 electrolyte system; G represents the activation energy of the ZnCP-C based Zn / / Zn symmetric cell at 0.5 mA cm⁻¹. -2 Current density and 0.1 mAh cm⁻¹ -2 Long-cycle performance under areal capacity conditions.

[0042] Figure 12 The Fourier transform extended X-ray absorption fine structure (EXAFS) fitting results for ZnCP are shown, where A is the r-space fitting diagram of the near-edge structure spectrum of zinc K-edge X-ray absorption, and B is the k-space fitting diagram of the near-edge structure spectrum of zinc K-edge X-ray absorption.

[0043] Figure 13 The adsorption configurations of H2O and their corresponding adsorption energies are shown on Zn(002) crystal planes, gypsum and ZHS surfaces. Detailed Implementation

[0044] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0045] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0046] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0047] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0048] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0049] Unless otherwise specified, room temperature and normal temperature in the specific embodiments of this invention refer to 20-30℃.

[0050] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0051] Unless otherwise specified, all raw materials and reagents involved in the specific embodiments of this invention are commercially available products.

[0052] The main components of waste cement slurry are as follows: Figure 2 As shown in E in the figure.

[0053] In some specific embodiments, the present invention provides a method for preparing a solid electrolyte based on waste cement slurry, the steps of which include: S1. Pretreatment of waste cement slurry: After cutting, the waste cement slurry is terminated by isopropanol solvent exchange, ball milled and sieved to obtain waste cement slurry powder with a particle size ≤75 μm. S2, Dissolution-precipitation reaction: Prepare a 1~4 mol / L zinc sulfate aqueous solution (preferably 2 mol / L), add the waste cement slurry powder obtained in step S1 to the zinc sulfate solution at a solid-liquid mass ratio of 1:50, and stir continuously at 20-30℃ for 18-30h to allow the calcium-silica-alumina phase in the waste cement slurry to undergo a dissolution-precipitation reaction with zinc sulfate to generate a composite phase of gypsum and basic zinc sulfate; S3. Post-processing: The reaction product of step S2 is vacuum filtered, washed with deionized water, and dried at 50-70℃ for 20-28 hours to obtain ZnCP composite powder. S4. The ZnCP composite material powder obtained in step S3 or the ZnCP composite material powder is mixed with a binder (at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC) and sodium alginate (SA)) at a mass ratio of (75-97):(3-25), and then rolled, dried (50-70℃) and cut into sheets to obtain a solid electrolyte.

[0054] The solid electrolyte provided by this invention uses waste cement slurry powder and zinc sulfate aqueous solution as raw materials, and prepares a ZnCP composite material containing gypsum and basic zinc sulfate layered phases through a simple stirring reaction; the crystal water in its layered structure forms sufficient ion transport channels between the lattice layers, significantly reducing Zn 2+ Migration barrier. This ZnCP solid electrolyte exhibits a wide electrochemical stability window of 3.6 V. When applied to zinc metal symmetric cells, it achieves over 1500 hours of stable operation without dendrite deposition / dissolution and without hydrogen evolution side reactions; the assembled Zn / / polyaniline full cell demonstrates a cycle life exceeding 420 cycles over a wide temperature range of -20 to 60 °C. This invention realizes the high-value recycling of waste cement slurry, providing a new path for the development of cement-based solid-state energy storage devices.

[0055] Example 1 The preparation steps of solid electrolyte based on waste cement slurry include: S1. Pretreatment of waste cement slurry: The waste cement slurry (CP) is a cement slurry with a water-cement ratio of 0.23 that has been cured for 28 days. After curing, the cubic specimen is sliced ​​using a water-lubricated cutting saw, the outer layer (about 1 mm thick) in contact with water is removed, and the specimen is immersed in isopropanol for 7 days. Then it is placed in an oven to dry for 1 day. Finally, the resulting block is ground to obtain CP powder with a particle size ≤75 μm. S2, Dissolution-precipitation reaction: Prepare a 2 mol / L zinc sulfate aqueous solution, add the CP powder obtained in step S1 to the zinc sulfate solution at a solid-liquid mass ratio of 1:50, and stir continuously at 25℃ for 24 hours to allow the calcium-silicon-aluminum phase in the waste cement slurry to undergo a dissolution-precipitation reaction with zinc sulfate. After stirring, use a circulating water vacuum pump to vacuum filter the suspension. The obtained solid product is repeatedly washed with deionized water and filtered again. Finally, place the powder in a 60℃ oven to dry for 24 hours to obtain grayish-white ZnCP composite powder. S3. The ZnCP composite material powder obtained in step S2 is mixed with the binder (polytetrafluoroethylene emulsion) at a mass ratio of 90:10. After being rolled and dried (60℃, 12h), it is cut into circular solid electrolytes with a diameter of 16 mm and a thickness of 0.25 mm, and is denoted as ZnCP-SSE.

[0056] Example 2 The preparation steps of solid electrolytes include: S1. Pretreatment of waste cement slurry: The waste cement slurry (CP) is a cement slurry with a water-cement ratio of 0.23 that has been cured for 28 days. After curing, the cubic specimen is sliced ​​using a water-lubricated cutting saw, the outer layer (about 1 mm thick) in contact with water is removed, and the specimen is immersed in isopropanol for 7 days. Then it is placed in an oven to dry for 1 day. Finally, the resulting block is ground to obtain CP powder with a particle size ≤75 μm. S2, Dissolution-precipitation reaction: Prepare a 2 mol / L zinc sulfate aqueous solution, add the CP powder obtained in step S1 to the zinc sulfate solution at a solid-liquid mass ratio of 1:50, and stir continuously at 25℃ for 24 hours to allow the calcium-silicon-aluminum phase in the waste cement slurry to undergo a dissolution-precipitation reaction with zinc sulfate. After stirring, use a circulating water vacuum pump to vacuum filter the suspension. The obtained solid product is repeatedly washed with deionized water and filtered again. Finally, place the powder in a 60℃ oven to dry for 24 hours to obtain grayish-white ZnCP composite powder. S3. The ZnCP composite powder obtained in step S2 is cold-pressed into a disc-shaped solid electrolyte with a diameter of 16 mm and a thickness of 0.25 mm, denoted as ZnCP-C.

[0057] Comparative Example 1 The preparation steps of solid electrolytes include: S1. Pretreatment of waste cement slurry: The waste cement slurry (CP) is a cement slurry with a water-cement ratio of 0.23 that has been cured for 28 days. After curing, the cubic specimen is sliced ​​using a water-lubricated cutting saw, the outer layer (about 1 mm thick) in contact with water is removed, and the specimen is immersed in isopropanol for 7 days. Then it is placed in an oven to dry for 1 day. Finally, the resulting block is ground to obtain CP powder with a particle size ≤75 μm. S2. The CP powder obtained in step S1 is mixed with the binder (polytetrafluoroethylene emulsion) at a mass ratio of 90:10. After being rolled and dried (60℃, 12h), it is cut into circular solid electrolytes with a diameter of 16 mm and a thickness of 0.25 mm, and is denoted as CP-SSE.

[0058] Comparative Example 2 The preparation steps of solid electrolytes include: S1. Pretreatment of waste cement slurry: The waste cement slurry (CP) is a cement slurry with a water-cement ratio of 0.23 that has been cured for 28 days. After curing, the cubic specimen is sliced ​​using a water-lubricated cutting saw, the outer layer (about 1 mm thick) in contact with water is removed, and the specimen is immersed in isopropanol for 7 days. Then it is placed in an oven to dry for 1 day. Finally, the resulting block is ground to obtain CP powder with a particle size ≤75 μm. S2. The CP powder obtained in step S1 is cold-pressed into a circular solid electrolyte with a diameter of 16 mm and a thickness of 0.25 mm, denoted as CP-C.

[0059] Test case Glass fiber separators impregnated with 2.0 M ZnSO4 electrolyte were selected as the control group electrolyte.

[0060] Zn / / Zn symmetric cell: Zinc foil is cut into 12 mm diameter discs; the prepared ZnCP solid electrolyte membrane is cut into 16 mm diameter discs; two zinc foil electrodes are placed on opposite sides of the ZnCP membrane, ensuring tight contact between the electrodes and the electrolyte interface. The assembled cell is transferred to a CR2025 stainless steel button cell casing, and after placing spring sheets and gaskets, it is packaged using a button cell packaging machine to obtain the Zn / / Zn symmetric cell.

[0061] Zn / / polyaniline full cell: The polyaniline positive electrode is cut into 40 mm × 40 mm square plates; the zinc foil is cut into 45 mm × 45 mm square plates; the prepared ZnCP solid electrolyte membrane is cut into 45 mm × 45 mm square sheets (larger than the positive and negative electrodes to ensure complete coverage). Positive electrode tab: Aluminum tabs with a width of 4 mm and a thickness of 0.2 mm are used. Ultrasonic spot welding is used to weld the tabs to the aluminum foil current collector, with ≥3 weld points. After welding, polyimide tape is used to wrap the weld points and the base to prevent short circuits from contact with the aluminum-plastic film. Negative electrode tab: Nickel tabs (or copper-plated nickel tabs) with a width of 4 mm and a thickness of 0.2 mm are used. They are also ultrasonically welded to the reserved positions on the zinc foil, and then wrapped with insulating tape. The Zn / / polyaniline full cell is assembled using a single-piece stacking method.

[0062] Figure 1Figure 1 shows the characterization results of the ZnCP composite material prepared in Example 1 of this invention. In the figure, A is a schematic diagram of the process flow for recycling waste cement slurry into solid electrolyte; B is an optical photograph of cement slurry and ZnCP composite material; C and D are schematic diagrams of the crystal structure of gypsum and basic zinc sulfate; E is a scanning electron microscope (SEM) morphology and elemental plane distribution diagram of ZnCP composite material; F and G are X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectra of ZnCP powder; H and I are the zinc K-edge X-ray absorption near-edge structure (XANES) spectrum and Fourier transform extended X-ray absorption fine structure (EXAFS) spectrum of metallic zinc, zinc oxide and ZnCP.

[0063] Figure 2 Figure 1 shows the characterization results of waste cement paste (CP). In this figure, A is an optical photograph of the CP block sample, B is a scanning electron microscope (SEM) morphology image of the CP powder, C is the nitrogen adsorption-desorption specific surface area (BET) test result of the CP and ZnCP composite powder, D is the inductively coupled plasma (ICP) elemental content analysis of the CP and ZnCP composite powder, E is the X-ray diffraction (XRD) pattern of the CP powder, and F is the Fourier transform infrared (FTIR) spectrum of the CP powder.

[0064] Depend on Figures 1-2 It can be seen that, Figure 1 The process shown in A enables the directional conversion of waste cement slurry from inert waste into a functional solid electrolyte. Figure 1 B shows that the ZnCP composite powder is significantly lighter in color than the original CP powder, as indicated by XRD and FTIR characterization. Figure 1 The results from F and G confirm that its main phases are gypsum and basic zinc sulfate. Figure 2 The B-value shows that the ZnCP powder consists of particles with a diameter of 3–10 μm. The ZnCP sample contains two types of particles: rod-shaped and irregularly shaped. Figure 1 The elemental distribution results show that S and Ca are uniformly distributed in the rod-shaped particles, while the irregular particles are mainly composed of S and Zn, with a small amount of Si in some areas. Figure 1 As shown in C and D, both gypsum and basic zinc sulfate exhibit typical layered crystal structures. The water of crystallization molecules embedded in the interlayer lattice stabilize the interlayer configuration through a hydrogen bond network, forming a sufficient interlayer spacing of 0.42–0.56 nm, which is suitable for Zn. 2+ The migration constructs a fast transport channel with low energy barriers (0.27 eV for the gypsum phase and 0.47 eV for the basic zinc sulfate phase). This layered structure has a strong adsorption effect on water molecules (5.03 eV for gypsum and 9.06 eV for basic zinc sulfate), effectively inhibiting the migration of free water to the zinc anode interface and fundamentally blocking the hydrogen evolution side reaction.

[0065] The specific surface area of ​​CP, determined by the Brunauer-Emmett-Teller (BET) method, is 2.64 m² g⁻¹. Figure 2 The C in ZnCP powder significantly increased its BET specific surface area to 38.32 m² g⁻¹. Figure 2 The C in CP). Inductively coupled plasma mass spectrometry (ICP-MS) analysis showed that the mass fractions of Ca, Zn, and Si in CP were 32.80%, 0%, and 8.00%, respectively. Figure 2 In ZnCP, the mass fractions of Ca, Zn, and Si are 17.26%, 17.91%, and 5.02%, respectively. Figure 2 The X-ray diffraction (XRD) pattern shows that CP has a complex phase composition, including hydration products calcium hydroxide, calcite, and ettringite, as well as incompletely hydrated raw materials tricalcium silicate and tetracalcium aluminoferrite. Figure 2 In the E), gypsum and basic zinc sulfate are the main crystalline phases of ZnCP ( Figure 1 The F in the figure. Fourier transform infrared spectroscopy (FTIR) further confirmed the presence of water of crystallization and carbonate (CO3). 2- ), gypsum (SO4) 2- The presence of amorphous hydrated calcium silicate (CSH) gel (SiO4 tetrahedron) and its characteristic absorption peaks correspond to the vibrations of HOH, CO, SO and Si-O bonds, respectively. Figure 2 The detection of vibrational signals of HOH, SO, and Si-O bonds in F and ZnCP indicates the presence of water of crystallization and sulfate (SO4) in the material. 2- ) and amorphous silicon oxide ( Figure 1 (G in the middle).

[0066] Given the close Zn / Ca mass ratio in ZnCP and the weak XRD diffraction signal of basic zinc sulfate, it can be inferred that a large amount of Zn exists in the amorphous basic zinc sulfate phase. To further analyze the coordination environment and electronic structure of Zn in ZnCP, X-ray absorption spectroscopy (XAS) was used for characterization. The Zn K-edge absorption edge position in ZnCP closely matches that of ZnO, indicating that the oxidation state of Zn is +2 (…). Figure 1 The extended X-ray absorption fine structure (EXAFS) spectrum of ZnCP and its fitting results show two characteristic peaks at 1.65 Å and 2.33 Å, which are attributed to the scattering paths of Zn-O and Zn-Zn in basic zinc sulfate, respectively. Figure 1 I and Figure 12 Based on the above characterization results, it can be confirmed that ZnCP mainly consists of two phases: gypsum and basic zinc sulfate.

[0067] like Figure 2As shown in J, a Zn / / Zn symmetric cell using ZnCP-SSE at 0.5 mA cm⁻¹ -2 It can achieve stable cycling for over 1500 hours at current density, maintaining stable voltage polarization without short circuits, while symmetrical cells using liquid ZnSO4 electrolyte fail within 200 hours; Figure 2 K and Figure 7 As shown in A, differential electrochemical mass spectrometry (DEMS) tests confirmed that the ZnCP-SSE system produced almost no hydrogen evolution during zinc deposition / dissolution, while the liquid electrolyte system was accompanied by significant hydrogen evolution side reactions.

[0068] Figure 3 The graph shows the density functional theory (DFT) calculation results of ZnCP composites, where a represents the density of states (DOS) of gypsum, and b and c represent the Zn content in the interlayer channels of gypsum, respectively. 2+ The coordination structure of ions and their bulk diffusion barrier; d is the density of states (DOS) of basic zinc sulfate (ZHS); e and f are the Zn in the interlayer channels of basic zinc sulfate, respectively. 2+ The coordination structure and bulk diffusion barrier of gypsum and zinc sulfate (ZHS) are shown in the figure. Both gypsum and ZHS exhibit layered crystal structures with interlayer spacings of approximately 4.2 Å and 5.6 Å, respectively. In both materials, the interlayer structure is stabilized by hydrogen bonding interactions between embedded water molecules and sulfate / hydroxysulfate anions. Figure 3 (c and d in the text). During the conversion of CP to ZnCP, free Zn... 2+ Pre-embedded interlayer channels act as migratable charge carriers during battery charging and discharging. This further elucidates the role of Zn in ZnCP. 2+ The coordination configuration and conduction mechanism of gypsum and basic zinc sulfate were systematically studied using density functional theory (DFT) calculations. DOS calculations showed that the band gaps of gypsum and basic zinc sulfate were as high as 8.3 eV and 3.0 eV, respectively. Figure 3 (a) and (d) in the figure confirm that both are electronic insulators, which helps to suppress electron leakage and ensure the selectivity of ion conduction. Molecular dynamics (MD) simulations further analyzed the free Zn in the interlayer channel between gypsum and basic zinc sulfate. 2+ The coordination environment, optimized solvation structure, radial distribution function (RDF), and average coordination number N(r) Figure 3 (b and e in the text). The results show that, in both materials, Zn... 2+ The first solvation shell of both zinc sulfate and zinc sulfonate is primarily coordinated by four oxygen atoms, but the specific coordination configurations differ: in gypsum, one oxygen atom originates from interlayer sulfate and three from water of crystallization molecules; while in basic zinc sulfate, three oxygen atoms originate from sulfonate groups and one from water of crystallization molecules. Bulk diffusion barrier and corresponding Zn 2+The migration path is also obtained through DFT calculation. Figure 3 (c and f in the text). It is worth noting that the water of crystallization molecules in the layered structure are not static, but actively participate in the Zn... 2+ The diffusion process of Zn reduces migration resistance through dynamic hydrogen bond network reconstruction. 2+ Ultra-low diffusion barriers of 0.27 eV and 0.47 eV were achieved between the gypsum and basic zinc sulfate layers, respectively. These characterizations and theoretical calculations together confirm that ZnCP, with its unique layered crystal water channel structure, can facilitate the diffusion of Zn... 2+ It provides a fast, low-resistance three-dimensional migration path and is a promising solid-state zinc-ion battery electrolyte material.

[0069] Figure 4 Figure 1 shows the characterization and electrochemical performance test results of ZnCP-SSE. Figures a and b show the optical photograph and scanning electron microscope (SEM) morphology of ZnCP-SSE, respectively; figure c shows the three-dimensional spatial distribution configuration of various secondary ions in ZnCP-SSE; figures d, e, and f show the ionic conductivity, Nyquist impedance spectrum, and Zn ion conductivity of CP-SSE and ZnCP-SSE, respectively. 2+ The activation energy of migration; g, h, and i are the linear sweep voltammetry (LSV), Tafel polarization, and chronoamperometry (CA) curves of ZnCP-SSE and 2.0 M ZnSO4 electrolyte, respectively; j is the Zn / / Zn symmetric cell using ZnCP-SSE and ZnSO4 electrolyte at 0.5 mA cm⁻¹. -2 Long-cycle performance at current density; k is the quantitative result of differential electrochemical mass spectrometry (DEMS) of hydrogen evolution behavior of zinc metal anode during deposition / dissolution when using ZnCP-SSE.

[0070] Figure 5 The figures show the characterization results of ZnCP-SSE and CP-SSE. a) is an optical photograph of the ZnCP-SSE sheet-like sample measured with vernier calipers; b) is a comparison of optical photographs of CP-SSE and ZnCP-SSE; c) is a scanning electron microscope (SEM) morphology image of CP-SSE; d) is the depth profile result of time-of-flight secondary ion mass spectrometry (TOF-SIMS) of ZnCP-SSE; e) is the F content in ZnCP-SSE. - (Fluoride ions, from the binder PTFE) and SO4 2- The three-dimensional spatial distribution configuration of ionic species.

[0071] Figure 6Figure 1 shows the electrochemical performance test results of ZnCP-SSE and CP-SSE. A and B are the Nyquist impedance spectra of the Zn / / Zn symmetric cells using ZnCP-SSE and CP-SSE respectively at different temperatures; C is the current-time curve and corresponding Nyquist impedance spectrum of the ZnCP-SSE-based Zn / / Zn symmetric cell during the initial activation process; D is the current-time curve of the CP-SSE-based Zn / / Zn symmetric cell at 0.5 mA cm⁻¹. -2 Current density and 0.1 mAh cm⁻¹ -2 Long-cycle performance under areal capacity conditions.

[0072] Figure 7 Figure 1 shows the characterization results of ZnCP-SSE suppressing side reactions. In this figure, A is the differential electrochemical mass spectrometry (DEMS) quantitative test result of hydrogen evolution behavior of zinc metal anode during deposition / dissolution using 2.0 M ZnSO4 electrolyte; B is the comparison of X-ray diffraction (XRD) patterns of zinc metal anode after 50 cycles of Zn / / Zn symmetric cells in ZnCP-SSE and ZnSO4 electrolyte systems; C and D are scanning electron microscope (SEM) morphology images of zinc metal anode surface after 50 cycles of Zn / / Zn symmetric cells in ZnCP-SSE and ZnSO4 electrolyte systems.

[0073] Depend on Figures 4-7 The display shows that: To evaluate the electrochemical performance of the solid electrolytes, the electrochemical performance of the solid electrolytes in Example 1 and Comparative Example 1 was systematically tested. It can be seen from the optical micrographs and scanning electron microscope (SEM) images of ZnCP-SSE and CP-SSE that their surface morphology is smooth and dense. Figure 4 a and b in Figure 5 (b and c in the text). Time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used to perform in-depth analysis of the chemical composition and spatial distribution of various secondary ion species in ZnCP-SSE. Figure 4 c and Figure 5 The sputtering depth distribution curves and the three-dimensional (3D) reconstruction results of the corresponding sputtering volumes of ZnO (d and e) show that... - ZnOH - ZnSO4 - CaO - CaOH - CaSO4 - SO4 2- Characteristic ionic species and characteristic F of PTFE - The signal is uniformly distributed throughout the entire electrolyte cross section, confirming that basic zinc sulfate (ZHS), gypsum, and PTFE binder achieve macroscopic uniform distribution in ZnCP-SSE.

[0074] Based on key indicators such as ionic conductivity and migration activation energy, the Zn in ZnCP-SSE was analyzed. 2+ The migration ability of Zn was systematically evaluated and compared with that of CP-SSE. First, the ionic conductivity was tested using electrochemical impedance spectroscopy (EIS) through a stainless steel symmetric cell; ZnCP-SSE exhibited a high conductivity of 7.21 mS / cm. -1 Its ionic conductivity is significantly better than that of CP-SSE (0.70 mS / cm). -1 () Figure 4 (d) The activation energy of migration was determined by temperature-dependent impedance testing of Zn / / Zn symmetric cells. At 30℃, the interfacial impedance of ZnCP-SSE (271.0 Ω) was significantly lower than that of CP-SSE (462.5 Ω). Figure 4 (e) in ZnCP-SSE. 2+ The activation energy for migration is 35.24 kJ / mol. -1 Compared to CP-SSE's 49.60 kJ mol -1 Significantly reduced ( Figure 4 f and Figure 6 (A and B in the text). This result indicates that Zn in ZnCP-SSE... 2+ The migration barrier is significantly reduced, which is in high agreement with the low diffusion barrier (0.27~0.47 eV) calculated by the aforementioned DFT, directly giving it excellent ion migration dynamics performance.

[0075] The electrochemical performance of ZnCP-SSE was systematically characterized using linear sweep voltammetry (LSV), Tafel polarization, chronoamperometry (CA), and mobility number assay, with a conventional 2.0 M liquid ZnSO4 electrolyte as a control. First, the electrochemical stability window of ZnCP-SSE was evaluated using LSV testing. Figure 4 The results showed that ZnSO4 electrolyte underwent significant oxidative decomposition at approximately 2.15 V, while ZnCP-SSE remained stable over a wide potential range of -0.6 to 3.0 V, effectively suppressing the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER).

[0076] Tafel polarization curves were used to compare the corrosion behavior of zinc metal in ZnCP-SSE and ZnSO4 electrolytes. Figure 4 The corrosion potential (Ecorr) of the ZnCP-SSE system was measured to be 0 mV, slightly lower than the 13.5 mV of the ZnSO4 electrolyte system, indicating that ZnCP-SSE can significantly improve the interfacial stability of the zinc anode. CA technology was used to analyze Zn in different electrolytes. 2+ diffusion patterns ( Figure 4(i) In the ZnCP-SSE system, the current density rapidly stabilizes after the initial transient decay, exhibiting typical three-dimensional (3D) diffusion characteristics. This 3D diffusion behavior, combined with high ionic conductivity and high mobility number, ensures the uniform distribution of zinc ions during deposition, thus achieving a dendrite-free, dense zinc coating. In contrast, the current density-time curve of the ZnSO4 electrolyte system continuously decreases, exhibiting obvious two-dimensional (2D) diffusion characteristics, which easily leads to uneven zinc deposition and the formation of dendritic structures.

[0077] To further investigate the electrochemical reversibility of the zinc anode in Example 1, the voltage-time curve of the symmetrical cell was obtained through a constant current long-cycle test. Figure 3 (j) The symmetric cell using ZnCP-SSE exhibits excellent cycle reversibility and stability under conditions of 0.5 mA cm⁻² current density and 0.1 mAh cm⁻² areal capacity. After more than 1500 hours of continuous charge-discharge, the voltage polarization remains stable, and its cycle life is approximately five times that of the 2.0 M ZnSO₄ electrolyte system formed by the control electrolyte. Simultaneously, its overpotential is significantly lower than that of the CP-SSE system (j). Figure 6 The D in the figure fully demonstrates the superior ability of ZnCP-SSE to maintain long-term stable electrochemical performance. Hydrogen evolution reaction (HER) is the most significant side reaction during the deposition / dissolution of zinc anodes. To quantitatively evaluate the HER suppression ability of ZnCP-SSE, differential electrochemical mass spectrometry (DEMS) was used for in-situ monitoring. The results showed that almost no hydrogen release signal was detected in the ZnCP-SSE system. Figure 4 The ZnSO4 electrolyte system showed a rapid increase in the hydrogen signal (k); while the ZnSO4 electrolyte system showed a rapid increase in the hydrogen signal (k). Figure 7 The presence of A in the figure indicates significant water decomposition behavior in the aqueous electrolyte. Phase and morphological characterization of the zinc anode surface after 50 cycles further confirmed this conclusion: XRD patterns and SEM images showed that a large number of by-reaction products (such as basic zinc sulfate) were generated on the zinc metal surface in the ZnSO4 electrolyte system, while the zinc anode surface in the ZnCP-SSE system remained smooth and dense, with no obvious corrosion or by-product deposition. Figure 7 The density functional theory (DFT) calculations revealed the microscopic mechanism of HER inhibition: the adsorption energies of gypsum and basic zinc sulfate (ZHS) for water molecules are -5.03 eV and -9.06 eV, respectively, which are much higher than the -0.87 eV of the zinc (002) crystal plane. Figure 13Therefore, the water of crystallization and potential free water molecules in ZnCP-SSE are thermodynamically difficult to migrate to the zinc anode interface and undergo reduction reactions, fundamentally blocking the hydrogen evolution pathway. In summary, electrochemical experiments and theoretical calculations jointly confirm that ZnCP-SSE not only ensures efficient and uniform deposition / dissolution of Zn²⁺ and rapid bulk diffusion, but also effectively suppresses hydrogen evolution side reactions and the formation of zinc dendrites, providing a key material foundation for constructing highly stable and long-life solid-state zinc-ion batteries.

[0078] Figure 8 The figures show the electrochemical performance test results of solid-state zinc-ion batteries. In the figure, A is a schematic diagram of the solid-state zinc-ion battery structure; BE shows the rate performance, constant current charge-discharge curve, self-discharge suppression capability, and long-cycle stability of the Zn / / polyaniline (PAN) battery using ZnCP-SSE; F is a schematic diagram of the solid-state pouch battery structure; and GI shows the long-cycle performance, physical optical photograph, and mechanical flexibility test results of the solid-state Zn / / PAN pouch battery.

[0079] Figure 9 The figure shows the electrochemical performance test results of Zn / / polyaniline (PAN) batteries, where A represents the Zn / / PAN battery using ZnCP-SSE at 0.1 mV s⁻¹. -1 Cyclic voltammetry (CV) curves at scan rates; B represents the Zn / / PAN cell using ZnCP-SSE and 2.0 M ZnSO4 electrolyte at 0.2, 0.5, 1.0, 2.0, 3.0, and 5.0 A g. -1 Comparison of rate performance at current density; C shows the constant current charge-discharge curves of Zn / / PAN batteries using ZnSO4 electrolyte at different current densities; D shows the test results of self-discharge suppression capability of Zn / / PAN batteries using ZnSO4 electrolyte; E shows the comparison of long-cycle performance of Zn / / PAN batteries using ZnCP-SSE and ZnSO4 electrolyte at room temperature.

[0080] Depend on Figures 8-9 It can be seen that, Figure 8 The BE results show that Zn / / polyaniline full cells range from 0.2 to 5.0 A g. -1 It exhibits excellent rate performance over a wide current density range, retains 86.3% capacity after 420 cycles at room temperature, and maintains stable electrochemical behavior even at extreme temperatures of -20°C and 60°C. Figure 8 The data from GI shows that the pouch cells based on ZnCP-SSE can withstand repeated bending without failure, making them suitable for building-integrated energy storage scenarios.

[0081] The battery performance of Example 1 and the control group was tested, with commercially available polyaniline (PAN) as the positive electrode and zinc foil as the negative electrode. The cyclic voltammetry (CV) curves showed clear redox peak pairs during both anodic and cathodic scans, indicating that the ZnCP-SSE battery possesses excellent electrochemical reversibility. Figure 9 A). Zn / / PAN batteries exhibit different rate performance in ZnCP-SSE and liquid ZnSO4 electrolyte systems ( ). Figure 8 B and Figure 9 (B and C in the text). ZnCP-SSE system at concentrations of 0.2, 0.5, 1.0, 2.0, 3.0 and 5.0 Ag. -1 At current densities, they provide 193.8, 144.1, 110.8, 82.6, 60.7, and 41.8 mAh g, respectively. -1 The reversible specific capacity; when the current density recovers to 0.2 A g -1 At that time, the capacity can be restored to 193.5 mAh g. -1 This fully demonstrates the excellent rate recovery capability of the ZnCP-SSE battery. The liquid ZnSO4 electrolyte system performs well at low current densities (0.2 and 0.5 A g). -1 The discharge capacity at low current densities (1.0~5.0 A g) is similar to that of the ZnCP-SSE system, while at high current densities (1.0~5.0 A g), it is significantly higher. -1 The ZnCP-SSE battery exhibits a slightly higher specific capacity, which can be attributed to its lower interfacial impedance. It demonstrates excellent self-discharge suppression. After 24 hours of rest, its specific capacity remains at 144 mAh g⁻¹. -1 The coulomb efficiency is as high as 96.3% ( Figure 8 D and Figure 9 In contrast, the liquid ZnSO4 electrolyte system retained only 130.3 mAh g⁻¹. -1 The capacity and coulombic efficiency decreased to 83.5% ( Figure 9 (D) Performance degradation mainly stems from inherent interfacial side reactions in the liquid electrolyte. At 0.5 A g -1 In long-cycle testing at current density ( Figure 8 E and Figure 9 The ZnCP-SSE battery retains 125 mAh g after 420 cycles (E), -1 The reversible specific capacity of the liquid electrolyte system was 85.2%, while the capacity of the liquid electrolyte system rapidly declined due to irreversible side reactions at the zinc anode and dissolution of the PAN cathode in the liquid phase, with a capacity retention of only 56.7% after 420 cycles. Further long-cycle testing was conducted under extreme conditions of low temperature (-20℃) and high temperature (60℃). Figure 8Both the E and ZnCP-SSE batteries exhibited stable cycle performance. This excellent wide-temperature adaptability fully demonstrates that ZnCP-SSE can effectively broaden the operating temperature range of solid-state zinc-ion batteries, providing key support for their practical application in complex environments.

[0082] Example 1 was assembled and tested. Figure 8 The Zn / / PAN pouch cell prepared by F in the process exhibits a stable open-circuit voltage (OCV) of 1.26V and retains a reversible capacity of 10 mAh after 75 cycles. Figure 8 (G and H in the figure). It is noteworthy that the charge-discharge curves of this battery not only exhibit stability in the initial state, but also remain highly consistent after undergoing severe bending and returning to its original shape. Even under extreme conditions where a corner of the battery was sheared off, no significant distortion occurred. These results fully demonstrate that cement-based batteries based on ZnCP-SSE possess excellent structural integrity and electrochemical stability under harsh operating conditions and dynamic mechanical stress, laying a solid foundation for their practical application in scenarios with stringent mechanical robustness requirements, such as integrated building energy storage and wearable electronic devices.

[0083] Figure 10 The thermogravimetric analysis (TG) results for CP and ZnCP are shown in the figure. As can be seen from the figure, the TG curve of CP exhibits three distinct weight loss steps: 25–250℃, 400–500℃, and 600–800℃, corresponding to the removal of water of crystallization, the dehydroxylation of CH4, and the decarbonation of calcite, respectively. Based on the TG analysis results, the contents of water of crystallization, CH4, and calcite in CP are calculated to be approximately 100.1, 8.2, and 8.3 mg / g, respectively. -1 The DTG curve of ZnCP also exhibits three distinct weight loss steps: 25–250℃, 250–380℃, and 725–910℃, corresponding to the removal of water of crystallization from gypsum and basic zinc sulfate, the decomposition of basic zinc sulfate after dehydration, and the thermal decomposition of sulfate groups, respectively. Based on the thermogravimetric (TG) analysis results, the water of crystallization content in ZnCP is calculated to be approximately 140.6 mg / g. -1 .

[0084] Figure 11 The graph shows the electrochemical performance test results of ZnCP-C. In this graph, A compares the ionic conductivity of CP-C, CP-SSE, ZnCP-C, and ZnCP-SSE; B and C show the Nyquist impedance spectra of the Zn / / Zn symmetric cell using ZnCP-C at different temperatures and the Zn conductivity calculated based on Arrhenius fitting. 2+The activation energy of migration; DF represents the Tafel polarization curve, electrochemical stability window obtained by linear sweep voltammetry (LSV) and chronoamperometry (CA) curve of the Zn / / Zn symmetric cell in the ZnCP-C and 2.0 M ZnSO4 electrolyte system; G represents the activation energy of the ZnCP-C based Zn / / Zn symmetric cell at 0.5 mA cm⁻¹. -2 Current density and 0.1 mAh cm⁻¹ -2 Long-cycle performance under areal capacity conditions.

[0085] As shown in the figure, ZnCP-C exhibits poor interparticle contact and a significantly increased grain boundary resistivity due to the lack of a binder. Consistent with this, the Zn content in ZnCP-C... 2+ Activation energy for migration (39.06 kJ mol) -1 It is also higher than ZnCP-SSE (35.24 kJ mol). -1 This reflects an increase in interfacial impedance. Figure 11 (B and C in the text). However, in terms of key interface stability indicators, ZnCP-C and ZnCP-SSE show a high degree of consistency: the Tafel polarization, linear sweep voltammetry (LSV), and chronoamperometry (CA) test results are basically consistent ( Figure 11 The DF in the figure indicates that the binder-free system can still maintain the electrochemical stability of the zinc anode interface. Furthermore, the Zn / / Zn symmetric cell assembled using ZnCP-C was tested at 0.5 mA cm⁻¹. -2 Stable deposition / dissolution cycles of 120 hours can be achieved at current density. Figure 11 (G in the text). The above results indicate that even under binder-free conditions, the intrinsic layered crystal water channel structure of ZnCP materials can still effectively support Zn. 2+ The conductivity and interface stability further validate the practicality and structural robustness of ZnCP as a solid electrolyte for zinc-ion batteries.

[0086] Figure 12 The Fourier transform extended X-ray absorption fine structure (EXAFS) fitting results for ZnCP are shown, where A is the r-space fitting diagram of the near-edge structure spectrum of zinc K-edge X-ray absorption, and B is the k-space fitting diagram of the near-edge structure spectrum of zinc K-edge X-ray absorption.

[0087] Figure 13 The adsorption configurations of H2O and their corresponding adsorption energies are shown on Zn(002) crystal planes, gypsum and ZHS surfaces.

[0088] comprehensive Figures 1-13This invention presents a simple and efficient strategy for upgrading and reprocessing waste cement slurry (CP) into a solid electrolyte (SSE) for zinc-ion batteries (ZIBs). Simply stirring the waste cement slurry powder in a zinc sulfate solution yields ZnCP powder composed of layered gypsum and basic zinc sulfate phases. Density functional theory (DFT) calculations show that the water of crystallization embedded in the layered structure stabilizes the interlayer configuration through a hydrogen bond network, forming sufficient interlayer spacing (4.2–5.6 Å) and promoting Zn... 2+ The rapid migration of ZnCP-SSE results in bulk diffusion barriers as low as 0.27 eV and 0.47 eV in gypsum and basic zinc sulfate, respectively. Electrochemical testing confirmed that ZnCP-SSE exhibits a wide electrochemical stability window of 3.6 V. Zn / / Zn symmetric cells constructed based on this electrolyte achieve highly reversible operation for over 1500 hours, with no dendrite zinc deposition / dissolution behavior and almost no hydrogen evolution side reactions. The assembled Zn / / polyaniline full cell exhibits a cycle life exceeding 420 cycles over a wide temperature range of -20 to 60 °C, with a capacity retention of 85.2%. Furthermore, laboratory-grade solid-state pouch cells maintain stable electrochemical performance under dynamic mechanical stresses such as severe bending and shearing. This work not only establishes an innovative paradigm for the high-value resource utilization of waste cement slurry but also provides important technical support for the practical application of cement-based solid-state energy storage devices in scenarios such as integrated energy storage in building structures.

[0089] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0090] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A ZnCP composite material, characterized in that, The ZnCP composite material comprises a gypsum phase and a basic zinc sulfate phase; The gypsum phase is CaSO4·2H2O; the basic zinc sulfate phase is Zn4SO4(OH)6·xH2O, where x is the number of water molecules of crystallization and x is not 0. The gypsum phase and the basic zinc sulfate phase have a layered crystal structure, and the interlayer of the crystal lattice contains water of crystallization.

2. A method for preparing the ZnCP composite material according to claim 1, characterized in that the step... include: Waste cement paste powder was mixed with a 1-4 mol / L zinc sulfate aqueous solution and stirred to obtain the ZnCP composite material.

3. The preparation method according to claim 2, characterized in that, The waste cement slurry powder was ball-milled to a particle size ≤75 μm after the hydration reaction of the waste cement slurry was terminated by isopropanol solvent exchange.

4. The preparation method according to claim 2, characterized in that, The solid-liquid mass ratio of the waste cement slurry powder and the zinc sulfate aqueous solution is 1:

50.

5. The preparation method according to claim 2, characterized in that, The stirring reaction is carried out at a temperature of 20-30 ℃ for 18-30 h. And / or, the stirring reaction may further include vacuum filtration, washing and drying.

6. The application of the ZnCP composite material according to claim 1 in a solid electrolyte.

7. A solid electrolyte, characterized in that, The solid electrolyte includes the ZnCP composite material as described in claim 1.

8. A method for preparing a solid electrolyte according to claim 7, characterized in that, step include: The solid electrolyte is obtained by uniformly mixing ZnCP composite material or ZnCP composite material and binder, followed by molding and drying.

9. The application of the ZnCP composite material of claim 1 or the solid electrolyte of claim 7 in a solid zinc-ion battery.

10. A solid-state zinc-ion battery, characterized in that, The electrolyte of the solid zinc-ion battery is the solid electrolyte described in claim 7.

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