Aqueous zinc ion battery dual-additive electrolyte, preparation method and application thereof

Abstract

The present disclosure provides a kind of double additive electrolyte for aqueous zinc ion battery, double additive electrolyte preparation method and the application of double additive electrolyte.The electrolyte includes solvent water and electrolyte;The electrolyte includes zinc salt, mannose and biomass organic salt;The biomass organic salt is sodium lignosulfonate.The double additive electrolyte for aqueous zinc ion battery provided by the present disclosure, wherein, mannose and sodium lignosulfonate can change zinc ion solvent sheath structure, improve zinc ion desolvation speed.Under the action of electric field, mannose and lignosulfonate root are alternately adsorbed on the electrode surface, and form dynamic reversible adsorption layer.Lignosulfonate root transports zinc ion around negative electrode under the action of electric field, speeds up the zinc ion transport speed of negative electrode near surface, ensures uniform and fast charge transfer kinetics, ensures that zinc negative electrode has very high reversibility and stability in the process of cycle, so as to improve the cycle performance of aqueous zinc ion battery.

Description

Technical Field

[0001] This disclosure relates to the field of aqueous zinc-ion battery materials technology, and more particularly to the field of aqueous zinc-ion battery dual-additive electrolyte technology. Background Technology

[0002] The escalating environmental problems and volatile global energy market have heightened the importance of improving the energy structure. While the demand for energy is increasing, currently, most energy comes from the combustion of fossil fuels, leading to substantial carbon dioxide emissions and a range of environmental and social problems. Therefore, developing renewable energy sources (such as solar, wind, and tidal power) is of great significance. Lithium-ion batteries have gained considerable attention due to their light weight, high energy density, and long cycle life, and have been widely used in various electronic devices. However, the limited availability of lithium resources, the flammable organic electrolytes, and the high reactivity of lithium metal can easily cause safety accidents, hindering the wider application of lithium-ion batteries. Aqueous zinc-ion batteries have attracted widespread attention in the field of electrochemical energy storage due to their high safety, simple manufacturing process, low electrode potential, and high theoretical capacity. However, zinc metal anodes still face serious problems such as dendrite growth, hydrogen evolution, and electrode corrosion, which severely affect the coulombic efficiency and cycle stability of aqueous zinc-ion batteries.

[0003] Researchers have long focused on mitigating dendrite growth and side reactions, employing methods including, but not limited to, adjusting negative electrode alloying, designing 3D structural frameworks, constructing electrode surface coatings, modifying separators, and adjusting electrolyte composition. Among these strategies, adjusting electrolyte composition is considered an economical and effective method for improving the reversibility of zinc anodes and suppressing side reactions due to its simplicity, low cost, and excellent performance. For the negative electrode, additives can regulate the zinc deposition process through interfacial adsorption and the formation of a solid electrolyte layer, or alter the zinc ion solvation structure to induce uniform zinc nucleation and reduce side reactions. The electrochemical behavior of the zinc negative electrode in aqueous solution depends primarily on the stability of the electrode / electrolyte interface. An unstable interface exacerbates side reactions and dendrite growth, thereby reducing battery cycle life. Therefore, regulating the distribution, migration, and deposition kinetics of zinc ions at the interface is crucial for improving the stability of zinc metal anodes. Constructing a solid electrolyte layer between zinc metal and the electrolyte is also a widely used protective technology for zinc anodes; however, the solid electrolyte layer formed by additives is relatively thin and may break or detach after prolonged cycling, resulting in limited improvement in battery performance. In contrast, constructing an in-situ anode / electrolyte interface with strong interactions with zinc metal and achieving dynamic acceleration of ion transport is a practical solution for interface regulation. Current research largely focuses on using only one additive, which may not simultaneously and efficiently achieve the functions of constructing a stable anode / electrolyte interface, guiding zinc ion desolvation, accelerating ion transport, promoting uniform nucleation, and directional deposition. Therefore, designing a synergistic electrolyte additive that can simultaneously construct a stable anode / electrolyte interface, regulate high-speed zinc ion desolvation, accelerate ion transport, promote uniform nucleation, and facilitate directional deposition is crucial. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this disclosure provides a dual-additive electrolyte for aqueous zinc-ion batteries, a method for preparing the dual-additive electrolyte, and applications of the dual-additive electrolyte.

[0005] According to a first aspect of this disclosure, an aqueous zinc-ion battery dual-additive electrolyte is provided, characterized in that...

[0006] The electrolyte includes water as a solvent and an electrolyte.

[0007] The electrolytes include zinc salts, mannose, and biomass organic salts;

[0008] The biomass organic salt is sodium lignosulfonate.

[0009] Preferably, the concentration of the zinc salt is 1-3 mol / L.

[0010] Preferably, the zinc salt is at least one of zinc sulfate, zinc trifluoromethanesulfonate, zinc chloride, or zinc perchlorate.

[0011] Preferably, in the electrolyte, the concentration of mannose is 0.001-0.2 mol / L, and the concentration of sodium lignosulfonate is 1 g / L-40 g / L.

[0012] According to a second aspect of this disclosure, a method for preparing a dual-additive electrolyte for an aqueous zinc-ion battery is provided, characterized in that...

[0013] Weigh out the zinc salt, the mannose, and the biomass organic salt, dissolve each component in water, and obtain the electrolyte.

[0014] According to a third aspect of this disclosure, an application of a dual-additive electrolyte for aqueous zinc-ion batteries is provided, characterized in that...

[0015] An aqueous zinc-ion battery was constructed using the aforementioned aqueous zinc-ion battery dual-additive electrolyte.

[0016] The principle of this disclosed technical solution is as follows:

[0017] Mannose and sodium lignin sulfonate can alter the zinc ion solvent sheath structure, increasing the zinc ion desolvation rate. During electroplating, the adsorption energy of lignin sulfonate ions on the negative electrode weakens. Due to the dipole effect, mannose preferentially adsorbs onto the negative electrode surface, causing lignin sulfonate ions to detach from the electrode surface and interact with zinc ions in the solution, forming alternating adsorption and a dynamically reversible adsorption layer. After entering the two zinc ion solvent sheath structures, the lignin sulfonate ions carry a positive charge. When the zinc ions carried by the lignin sulfonate ions are deposited on the negative electrode surface, they are accelerated away from the negative electrode under the influence of the electric field, accelerating the near-surface zinc ion transport rate and ensuring uniform and rapid charge transfer kinetics. The hydrophobic -CH3 group in the lignin sulfonate ion also acts as a water barrier, reducing water reactivity and inhibiting side reactions.

[0018] The beneficial effects of this disclosure are as follows:

[0019] The dual-additive electrolyte of the aqueous zinc-ion battery disclosed herein can accelerate the desolvation of zinc ions at the anode / electrolyte interface, speed up zinc ion transport, further promote nucleation and inhibit dendrite formation and growth, refine grains, and ensure that the zinc anode has high reversibility and stability during cycling, thereby improving the cycle performance and cycle life of the aqueous zinc-ion battery. Attached Figure Description

[0020] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. The drawings are provided for a better understanding of the present invention and are not intended to limit the scope of this disclosure. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0021] Figure 1 Morphology of zinc dendrite growth on the surface of the zinc electrode after 500 hours of cycling in the electrolyte of Experiment Example 1;

[0022] Figure 2 Morphology of zinc dendrite growth on the surface of the zinc electrode after 100 hours of cycling in the electrolyte of Comparative Example 1;

[0023] Figure 3 Cyclic performance test of zinc-copper half-cell in electrolyte of Experiment Example 1;

[0024] Figure 4 The zinc electrode was subjected to Tafel testing in a standard symmetrical cell with the electrolyte composition of Experiment Example 1.

[0025] Figure 5 The zinc electrode was subjected to electrochemical impedance spectroscopy (EIS) testing in a symmetrical cell with the standard electrolyte composition in Experiment Example 1.

[0026] Figure 6 The zinc electrode was tested using the chronoamperometry (CA) method in a standard symmetrical cell with the electrolyte composition of Experiment Example 1.

[0027] Figure 7 The zinc electrode in Experiment Example 1, using a standard symmetrical cell with a sodium lignosulfonate electrolyte, operates at 10 mA cm⁻¹. -2 Current density cyclic constant current charge-discharge test for 10,000 cycles (voltage-cycle count curve);

[0028] Figure 8 Zinc electrode and carbon cloth loaded Zn x MnO2 was tested in a standard aqueous zinc-ion full cell with the electrolyte composition of Experimental Example 1 using cyclic voltammetry (CV) at 0.1 mV s⁻¹.

[0029] Figure 9 Zinc electrode and carbon cloth loaded Zn x MnO2 was used in an aqueous zinc-ion full cell with a standard electrolyte composition in Experimental Example 1 for electrochemical impedance spectroscopy (EIS) testing.

[0030] Figure 10 Zinc electrode and carbon cloth loaded Zn x MnO2 in the electrolyte composition of Experimental Example 1 A standard aqueous zinc-ion full cell at 0.5 A g -1 Cyclic stability test at current density. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0032] Example 1

[0033] The preparation process of the aqueous zinc-ion battery dual-additive electrolyte disclosed herein is as follows:

[0034] The specific composition of the aqueous zinc-ion battery dual-additive electrolyte is water and electrolyte. The electrolyte is composed of zinc salt and electrolyte additives, wherein the zinc salt is zinc sulfate and the electrolyte additives are mannose and sodium lignin sulfonate.

[0035] In Example 1, the preparation method of the aqueous zinc-ion battery dual-additive electrolyte is as follows: weigh each component according to the amount of zinc sulfate concentration 2 mol / L, mannose concentration 10 mmol / L, and sodium lignosulfonate concentration 10 g / L, dissolve them in water, and thus obtain the aqueous zinc-ion battery dual-additive electrolyte.

[0036] Example 2

[0037] In Example 2, the preparation method of the aqueous zinc-ion battery dual-additive electrolyte is as follows: weigh each component according to the amount of zinc sulfate concentration 2 mol / L, mannose concentration 1 mmol / L, and sodium lignosulfonate concentration 1 g / L, dissolve them in water, and thus obtain the aqueous zinc-ion battery dual-additive electrolyte.

[0038] Example 3

[0039] In Example 3, the preparation method of the aqueous zinc-ion battery dual-additive electrolyte is as follows: weigh each component according to the amount of zinc sulfate concentration 2 mol / L, mannose concentration 1 mmol / L, and sodium lignosulfonate concentration 40 g / L, dissolve them in water, and thus obtain the aqueous zinc-ion battery dual-additive electrolyte.

[0040] Example 4

[0041] In Example 4, the preparation method of the aqueous zinc-ion battery dual-additive electrolyte is as follows: weigh each component according to the amount of zinc sulfate concentration 2 mol / L, mannose concentration 0.2 mol / L, and sodium lignosulfonate concentration 1 g / L, dissolve them in water, and thus obtain the aqueous zinc-ion battery dual-additive electrolyte.

[0042] Example 5

[0043] In Example 5, the preparation method of the aqueous zinc-ion battery dual-additive electrolyte is as follows: weigh each component according to the amount of zinc sulfate concentration 2 mol / L, mannose concentration 0.2 mol / L, and sodium lignosulfonate concentration 40 g / L, dissolve them in water, and thus obtain the aqueous zinc-ion battery dual-additive electrolyte.

[0044] Comparative Example 1

[0045] To compare the effects of the aqueous zinc-ion battery dual-additive electrolyte and the additive-free electrolyte on inhibiting zinc dendrites, an additive-free aqueous electrolyte was prepared. Its specific composition is water and electrolyte, with the electrolyte consisting of a zinc salt, specifically zinc sulfate. The preparation method is as follows: the zinc sulfate is dissolved in water at a concentration of 2 mol / L, and it is labeled as an additive-free electrolyte.

[0046] Table 1 shows the full-cell long-cycle test performance data of Examples 1-5 and Comparative Example 1.

[0047]

[0048] Table 1

[0049] As can be seen from the full-cell long-cycle test performance data in Table 1, compared with Comparative Example 1, the battery using the aqueous zinc-ion battery dual-additive electrolyte described in this disclosure exhibits superior coulombic efficiency and cycle performance.

[0050] Taking Example 1 as an example, the morphology characterization of the zinc electrode after cycling and the electrochemical performance characterization results of the material are further compared.

[0051] (1) Comparison of morphological characterization of zinc electrodes after cycling.

[0052] The dual-additive electrolyte described in this disclosure and the additive-free electrolyte in Comparative Example 1 were respectively applied to zinc-zinc symmetrical coin cells, using 1 mA / cm 2 The batteries were charged and discharged at a current density of 0.5 hours per charge-discharge cycle. After the batteries with the dual-additive electrolyte of this disclosure were added were cycled for 500 hours, and the batteries with the additive-free electrolyte of Comparative Example 1 were cycled for 100 hours, the batteries were disassembled and the dendrite growth on the zinc sheet surface was observed using a scanning electron microscope.

[0053] Scanning electron microscopy observation results as follows Figure 1 and Figure 2 As shown, Figure 1 The image shows the zinc sheet produced using the electrolyte described in this disclosure, which is a dual-additive electrolyte. Figure 2 The image shows the results using zinc sheets from Comparative Example 1 without added electrolyte. Figure 1 and Figure 2The results showed that the zinc surface using the dual-additive electrolyte described in this disclosure was smooth with no obvious dendrites and only a small amount of byproducts. In contrast, the zinc surface using the additive-free electrolyte in Comparative Example 1 had severely stacked sheet-like zinc dendrites. These protrusions caused by the "point effect" further led to uneven nucleation of zinc ions, resulting in rapid dendrite growth and exacerbating surface side reactions.

[0054] (2) Comparison of the electrochemical performance characterization results of the materials.

[0055] The dual-additive electrolyte described in this disclosure and the additive-free electrolyte of Comparative Example 1 were respectively applied to zinc-copper symmetrical coin cells. The charging cutoff voltage of the zinc-copper half-cell was 0.5V, and the charging speed was 1mA cm⁻¹. -2 0.5mAh cm -2 Under the conditions of zinc deposition / dissolution reversibility test;

[0056] The symmetrical cell with the dual-additive electrolyte described in this disclosure and zinc as the working electrode is used at 1 mV s. -1 The scanning speed was tested using Tafel.

[0057] The symmetrical cell with zinc as the working electrode in the dual-additive electrolyte described in this disclosure was subjected to electrochemical impedance spectroscopy (EIS) testing in the frequency range of 100 kHz to 10 mHz.

[0058] The symmetrical cell with zinc as the working electrode in the dual-additive electrolyte described in this disclosure was tested by chronoamperometry (CA) at a voltage of -150mV.

[0059] The symmetrical cell with the dual-additive electrolyte described in this disclosure and zinc as the working electrode was subjected to a 10 mA cm⁻¹ test. -2 Current density cyclic constant current charge-discharge test (voltage-time curve) for 10,000 cycles;

[0060] The dual-additive electrolyte described in this disclosure is used, with zinc as the negative electrode and Zn loaded on carbon cloth. x MnO2 electrode was used as the positive electrode of the battery to form a standard aqueous zinc-ion full cell for electrochemical testing.

[0061] The dual-additive electrolyte described in this disclosure is used, with zinc as the negative electrode and Zn loaded on carbon cloth. x The MnO2 electrode is used as the positive electrode of the battery, forming a standard aqueous zinc-ion full cell at 0.1 mV s. -1 Cyclic voltammetry (CV) tests were performed at a scan rate of [missing value].

[0062] The dual-additive electrolyte described in this disclosure is used, with zinc as the negative electrode and Zn loaded on carbon cloth. xUsing MnO2 as the positive electrode, a standard aqueous zinc-ion full cell was constructed and subjected to electrochemical impedance spectroscopy (EIS) testing in the frequency range of 100 kHz to 10 mHz.

[0063] The dual-additive electrolyte described in this disclosure is used, with zinc as the negative electrode and Zn loaded on carbon cloth. x The MnO2 electrode is used as the positive electrode of the battery, forming a standard aqueous zinc-ion full cell placed at 0.5 A g. -1 Cyclic stability tests were conducted for 400 cycles at a current density.

[0064] Figure 3 The diagram shows a comparison of the cycle counts when the dual-additive electrolyte described in this disclosure and the additive-free electrolyte of Comparative Example 1 are applied to zinc-copper half-cells. It can be seen that the dual-additive electrolyte described in this disclosure can significantly improve the coulombic efficiency in the first 10 cycles, and the coulombic efficiency of the zinc-copper half-cell rapidly increases to 99.3% in the tenth cycle, while the coulombic efficiency of the zinc-copper half-cell using the additive-free electrolyte of Comparative Example 1 only increases to 89.5% in the tenth cycle. Figure 4 The effects of the dual-additive electrolyte described in this disclosure and the additive-free electrolyte of Comparative Example 1 on the corrosion rate of the zinc anode are shown. It can be seen that the symmetrical cell using the dual-additive electrolyte described in this disclosure has the lowest corrosion current density and the highest corrosion potential, and the anode / electrolyte interface formed by the dual additives has a significant inhibitory effect on the corrosion reaction. Figure 5 To compare the impedance of the symmetrical battery using the dual-additive electrolyte described in this disclosure and the additive-free electrolyte symmetric battery of Comparative Example 1, the charge transfer resistance of the dual-additive electrolyte symmetric battery was approximately 41.8 Ω, while the charge transfer resistance of the additive-free electrolyte symmetric battery of Comparative Example 1 was approximately 215.4 Ω. This demonstrates that the dual-additive electrolyte battery of this disclosure has a faster ion transport rate than the additive-free electrolyte battery of Comparative Example 1. Figure 6 The results show that the current density of the additive-free electrolyte battery in Comparative Example 1 increases rapidly and continuously, while the current density of the dual-additive electrolyte battery described in this disclosure stabilizes after a short nucleation process of 40 seconds, indicating a stable and continuous three-dimensional diffusion process. The stable low current density implies uniform zinc deposition, and the rapid ion transport dynamics reduce diffusion polarization, thus regulating zinc deposition. Figure 7 The test results of the symmetrical battery shown can be seen that the symmetrical battery using the dual-additive electrolyte described in this disclosure achieves a performance of 10 mA cm⁻¹. -2 Current density, 0.5mAh cm⁻¹ -2 At its areal capacity, it exhibits no significant voltage hysteresis during a 10,000-cycle test. In contrast, the additive-free electrolyte symmetric cell in Comparative Example 1 rapidly exhibits severe voltage hysteresis at the very beginning of the test. Figure 8This illustrates a Zn battery using the dual-additive electrolyte described in this disclosure, with zinc as the negative electrode and carbon cloth-loaded Zn. x Using MnO2 as the positive electrode, the aqueous zinc-ion full cell exhibits a voltage range of 1-1.8V and a velocity of 0.1mV / s. -1 The test curves were obtained using the specified scan rate. The reduction peak of the battery redox curve appeared at 1.39V, while the oxidation peak appeared at 1.60V. Figure 9 In the frequency range of 100kHz to 10mHz, using the dual-additive electrolyte described in this disclosure, zinc as the negative electrode, and carbon cloth-loaded Zn... x A comparison of the electrochemical impedance spectroscopy (EIS) of an aqueous zinc-ion battery using MnO2 as the positive electrode and that of a battery using the additive-free electrolyte in Comparative Example 1. From... Figure 9 As can be seen, the charge transfer resistance of the full cell assembled using the dual-additive electrolyte described in this disclosure is only 24.1Ω. In contrast, the charge transfer resistance of the full cell using the additive-free electrolyte in Comparative Example 1 is as high as 139Ω. The small charge transfer resistance indicates that the full cell with the dual-additive electrolyte described in this disclosure has a fast ion transport rate. Figure 10 It uses the dual-additive electrolyte described in this disclosure, with zinc as the negative electrode and Zn loaded on carbon cloth. x A water-based zinc-ion full cell, with MnO2 as the positive electrode, is placed at 0.5 A g. -1 Cyclic curves at current densities. From Figure 10 As can be seen from this, at a current density of 0.5Ag -1 When using the dual-additive electrolyte described in this disclosure, zinc is used as the negative electrode of the battery, and Zn is loaded onto carbon cloth. x Using MnO2 as the positive electrode, the aqueous zinc-ion full cell exhibited excellent average coulombic efficiency of ≈99.7%, and capacity retention of 81.6% (≈213.9 mAh g⁻¹) after 400 cycles. -1 The performance tests above all demonstrate that using the dual-additive electrolyte described in this disclosure, i.e., simultaneously using mannose and sodium lignosulfonate as electrolyte additives, can significantly improve the cycle performance and cycle life of aqueous zinc-ion batteries. The method of this disclosure can also be extended to other energy storage battery systems, providing new methods and ideas for electrolyte design.

[0065] The above embodiments are preferred embodiments of this disclosure, but the embodiments of this disclosure are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of this disclosure shall be considered equivalent substitutions and shall be included within the protection scope of this disclosure.

Claims

1. A dual-additive electrolyte for aqueous zinc-ion batteries, characterized in that: The electrolyte includes water as a solvent and an electrolyte. The electrolytes include zinc salts, mannose, and biomass organic salts; The biomass organic salt is sodium lignosulfonate; The concentration of mannose is 0.001–0.2 mol / L, and the concentration of sodium lignosulfonate is 1 g / L–40 g / L.

2. The electrolyte according to claim 1, characterized in that: The concentration of the zinc salt is 1-3 mol / L.

3. The electrolyte according to claim 1, characterized in that: The zinc salt is at least one of zinc sulfate, zinc trifluoromethanesulfonate, zinc chloride, or zinc perchlorate.

4. The method for preparing the aqueous zinc-ion battery dual-additive electrolyte according to any one of claims 1-3, characterized in that: Weigh the zinc salt, the mannose, and the biomass organic salt, dissolve them in water, and obtain the electrolyte.

5. The application of the aqueous zinc-ion battery dual-additive electrolyte according to any one of claims 1-3, characterized in that: An aqueous zinc-ion battery was constructed using the aforementioned aqueous zinc-ion battery dual-additive electrolyte.

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