Zinc battery electrolyte, zinc ion battery and electric device

Abstract

The invention belongs to the field of batteries, and provides a zinc battery electrolyte, a zinc ion battery and an electric device. The battery electrolyte comprises water, and a zinc salt and an additive dissolved in the water, the additive comprises at least one organic matter having a general formula represented by a formula 1, Cy represents a substituted or unsubstituted bridged cycloalkyl group, a substituent group is an alkyl group having 1-4 carbon atoms, and L represents a single bond or an alkylene group having 1-4 carbon atoms. When the electrolyte is applied to the zinc ion battery, the cycle life of the battery can be effectively prolonged, and the coulombic efficiency of the battery can be effectively improved. O = Cy-L-SO3H in the formula 1.

Description

Technical Field

[0001] This invention belongs to the field of batteries, specifically, it provides a zinc battery electrolyte, a zinc-ion battery, and an electrical device. Background Technology

[0002] As the mainstream electrochemical energy storage device, lithium-ion batteries have been widely used in consumer electronics and electric vehicles due to their high energy density and good cycle performance. However, as application scenarios gradually expand to large-scale grid energy storage, backup power, and other fields, the limitations of this technology system are becoming increasingly prominent. On the one hand, the core materials of lithium-ion batteries (such as lithium, cobalt, and nickel) are unevenly distributed, with weak supply stability and continuously rising costs. On the other hand, the organic electrolyte system used in these batteries has inherent flammable and explosive properties, bringing significant safety risks and increasing the system complexity and maintenance costs when used in large-scale integrated applications. Against this backdrop, aqueous zinc-ion batteries (AZIBs) are considered a feasible alternative for large-scale energy storage systems. AZIBs use metallic zinc as the negative electrode and an aqueous electrolyte, which not only has abundant and low-cost raw materials but also fundamentally eliminates the risk of combustion and explosion due to its aqueous electrolyte system, possessing intrinsic safety. In particular, the zinc metal negative electrode has a lower redox potential and higher theoretical specific capacity compared to the standard hydrogen electrode (SHE), exhibiting significant advantages. Therefore, conducting in-depth research on rechargeable aqueous zinc-ion batteries is of great significance.

[0003] However, traditional aqueous electrolytes are prone to problems such as zinc dendrite growth, severe hydrogen evolution reaction (HER), and electrode / electrolyte interface instability during battery charging and discharging, which severely limit the battery's cycle life and other performance characteristics. Specifically, zinc anodes undergo continuous side reactions in aqueous environments, especially the HER reaction, resulting in low coulombic efficiency of zinc deposition / stripping, uncontrolled dendrite growth, and continuous electrolyte consumption. Currently, achieving highly reversible and stable zinc metal cycling remains difficult, thus limiting the application of AZIBs. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, the present invention aims to provide a zinc battery electrolyte, a zinc-ion battery, and an electrical device. The electrolyte of the present invention, when applied to a zinc-ion battery, can effectively improve the battery's cycle life and coulombic efficiency.

[0005] In a first aspect, the present invention provides a zinc battery electrolyte comprising water and zinc salts and additives dissolved therein, wherein the additives comprise at least one organic compound of the general formula shown in Formula 1: O=Cy-L-SO3H Equation 1, In Formula 1, Cy represents a substituted or unsubstituted bridged cycloalkyl group, wherein the substituent is an alkyl group with 1 to 4 carbon atoms, and L represents a single bond or an alkylene group with 1 to 4 carbon atoms.

[0006] The zinc battery electrolyte of this invention is an aqueous electrolyte containing an organic additive of the general formula shown in Formula 1. This additive's molecular structure contains both sulfonic acid groups (-SO3H) and carbonyl groups (C=O), which can act as bifunctional sites to stabilize the electrode / electrolyte interface through chemisorption and participate in the formation of a sulfur-rich solid electrolyte interphase (SEI) layer. This SEI layer helps guide zinc ions (Zn... 2+ Uniform deposition inhibits the formation and growth of zinc dendrites and repels water molecules at the interface, thereby suppressing water-induced hydrogen evolution side reactions and other interfacial side reactions. This can improve the overall performance of zinc-ion batteries, such as cycle life and coulombic efficiency.

[0007] In some embodiments of the present invention, in Formula 1, Cy is a 7-10-membered bridged cycloalkyl group substituted with at least one methyl group, and L is a single bond or a methylene group.

[0008] In some embodiments of the present invention, the additive is camphor sulfonic acid. Camphor sulfonic acid, as an additive, can more effectively participate in the formation of the sulfur-rich electrolyte interphase (SEI) layer, significantly inhibiting zinc dendrites and side reactions. Further, the additive is L-camphor sulfonic acid.

[0009] In some embodiments of the present invention, the concentration of the additive in the zinc battery electrolyte is 5~30 mmol / L.

[0010] Furthermore, in the zinc battery electrolyte, the concentration of the additive is 8~12 mmol / L.

[0011] In some embodiments of the present invention, the zinc salt is selected from at least one of zinc sulfate, zinc chloride, zinc trifluoromethanesulfonate, zinc acetate, and zinc perchlorate.

[0012] In some embodiments of the present invention, the concentration of the zinc salt in the zinc battery electrolyte is 1~3 mol / L.

[0013] In some embodiments of the present invention, the molar ratio of the additive to the zinc salt is (0.25~1.5):100.

[0014] In a second aspect, the present invention provides a zinc-ion battery, wherein the zinc-ion battery includes the zinc battery electrolyte described in the first aspect of the present invention.

[0015] Thirdly, the present invention provides an electrical device, the electrical device comprising the zinc-ion battery described in the second aspect of the present invention.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 The batteries assembled using the electrolytes of Example 1 and Comparative Examples 1-3 were tested at 1 mA / cm². 2 1mAh / cm 2 A comparison of voltage-time curves under the test parameters; Figure 2 The batteries assembled using the electrolytes of Examples 1-4 and Comparative Examples 1-3 were tested at 10 mA / cm². 2 1mAh / cm 2 A comparison of voltage-time curves under the test parameters; Figure 3 The batteries assembled using the electrolytes of Examples 1-4 and Comparative Examples 1-3 were tested at 10 mA / cm². 2 10mAh / cm 2 A comparison of voltage-time curves under the test parameters; Figure 4 A comparison graph showing the coulombic efficiency changes of batteries assembled using the electrolytes of Example 1 and Comparative Example 1 during cycling. Figure 5 A comparison of cyclic voltammetry (CV) curves of batteries assembled using the electrolytes of Example 1 and Comparative Example 1; Figure 6 A comparison graph of chronocurrent (CA) curves of batteries assembled using the electrolytes of Example 1 and Comparative Example 1; Figure 7 A comparison of linear sweep voltammetry (LSV) curves for CSA electrolyte and 2M Na2SO4 aqueous solution; Figure 8 Comparative images of in-situ optical microscopy observations at the cross-section of the zinc electrode during zinc deposition using the electrolytes of Example 1 and Comparative Example 1. Figure 9 Comparison of 1H NMR spectra of deuterated water and 2M ZSO solutions with or without different concentrations of CSA. Detailed Implementation

[0018] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0019] The "scope" disclosed in this invention is defined in the form of a lower limit and / or an upper limit, whereby a given scope is defined by selecting a lower limit and / or an upper limit. This scope may or may not include endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form an undefined scope, and any lower limit can be combined with other lower limits to form an undefined scope, similarly, any upper limit can be combined with any other upper limit to form an undefined scope. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and can be combined with any other point or single value, or with other lower or upper limits, to form an undefined scope.

[0020] Unless otherwise specified, all embodiments and optional embodiments of the present invention may be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present invention.

[0021] During repeated deposition / stripping processes, zinc metal anodes are prone to uncontrolled dendrite growth and hydrogen evolution, among other side reactions. These problems not only reduce battery coulombic efficiency and rapidly decay capacity, but can also lead to internal short circuits and safety risks in severe cases. Key factors affecting the stability of zinc anodes include: interfacial polarization caused by uneven electrolyte concentration distribution, exacerbated side reactions due to zinc / electrolyte interface instability, and parasitic reactions resulting from the continuous consumption of active materials and electrolyte. Effectively suppressing zinc dendrite growth and improving anode reversibility has become a core issue that must be addressed to promote the practical application of zinc-ion batteries. Current improvement strategies mainly focus on optimizing electrolyte composition, constructing artificial interface layers, and designing three-dimensional current collectors. Among these, optimizing electrolyte composition, with its advantages of ease of operation, low cost, and ease of large-scale production, can achieve control over the electrode-electrolyte interface. This strategy typically involves adjusting zinc salt concentration, introducing functional additives, or developing mixed aqueous electrolyte systems to suppress dendrite growth and side reactions (such as hydrogen evolution and corrosion). However, current electrolyte systems still face problems such as insufficient long-term effectiveness of additives and difficulty in effectively maintaining the long-term cycle life of batteries.

[0022] Therefore, a first aspect of the present invention provides a zinc battery electrolyte that, by optimizing the electrolyte composition, significantly inhibits the growth of zinc dendrites and reduces the degree of side reactions such as hydrogen evolution. Specifically, the electrolyte of the present invention comprises water and zinc salts and additives dissolved therein, wherein the additives comprise at least one organic compound of the general formula shown in Formula 1: O=Cy-L-SO3H, Equation 1 Wherein, Cy represents a substituted or unsubstituted bridged cycloalkyl group, wherein the substituent is an alkyl group with 1 to 4 carbon atoms (e.g., methyl, ethyl, n-propyl, isopropyl, etc.), and L represents a single bond or an alkylene group with 1 to 4 carbon atoms (e.g., methylene, ethylene, n-propylene, etc.).

[0023] In this invention, the bridged cycloalkyl group can be selected from 7- to 15-membered bridged cycloalkyl groups, such as 7-, 8-, 10-, 11-, or 12-membered bridged cycloalkyl groups. When the bridged cycloalkyl group is substituted, the number of substituents can be one or more.

[0024] In some embodiments, in Formula 1, Cy is a 7- to 10-membered bridged cycloalkyl group substituted with at least one (e.g., two or three) methyl groups, and L is a single bond or a methylene group.

[0025] In some embodiments, the additive is camphor sulfonic acid. It should be understood that the camphor sulfonic acid includes all its stereoisomers, specifically (1S)-(+)-camphor-10-sulfonic acid (L-camphor sulfonic acid, CAS No.: 3144-16-9), (1R)-(-)-camphor-10-sulfonic acid (D-camphor sulfonic acid, CAS No.: 35963-20-3), and mixtures thereof in any proportion, such mixtures being, for example, racemic mixtures (CAS No.: 5872-08-2). Preferably, the additive is L-camphor sulfonic acid.

[0026] In this invention, the concentration of the additive in the zinc battery electrolyte can be 5~30 mmol / L, for example, 5 mmol / L, 7 mmol / L, 8 mmol / L, 9 mmol / L, 10 mmol / L, 12 mmol / L, 15 mmol / L, 18 mmol / L, 20 mmol / L, 25 mmol / L, 30 mmol / L, etc. When the amount of additive is too small, it is difficult to form a stable organic protective layer on the surface of the zinc electrode, and zinc ions still mainly use water molecules as the solvation structure, leading to severe hydrogen evolution side reactions, intensified dendrite growth, and reduced cycle efficiency, thus reducing cycle life. Conversely, when the amount of additive is too high, the acidity of the system increases, and Zn... 2+ Excessive complexation with additives can lead to decreased ionic conductivity and interfacial passivation, hindering zinc ion deposition and stripping processes and ultimately weakening electrochemical performance. Preferably, the concentration of the additive in the zinc battery electrolyte is 8-12 mmol / L. Controlling the amount of additive within this range can further improve the battery's cycle life and coulombic efficiency.

[0027] In this invention, the zinc salt, as the electrolyte, can be selected from various soluble zinc salts. According to some embodiments, the zinc salt is selected from at least one of zinc sulfate, zinc chloride, zinc trifluoromethanesulfonate, zinc acetate, and zinc perchlorate.

[0028] In some embodiments, the concentration of zinc salt in the zinc battery electrolyte is 1~3 mol / L, such as 1 mol / L, 1.5 mol / L, 2 mol / L, 2.2 mol / L, 2.5 mol / L, 3 mol / L, etc. Controlling the concentration within this range can effectively reduce the risk of increased side reactions and uneven dendrite growth on the zinc electrode surface under low concentration conditions; on the other hand, it can also avoid the problems of restricted ion migration and excessive viscosity in high-concentration electrolytes, thereby maintaining high ion transport efficiency and rate performance while suppressing side reactions.

[0029] This invention does not particularly limit the preparation method of the zinc battery electrolyte, as long as all components (including zinc salts and additives) can be dissolved in water to form a homogeneous solution. As some specific examples, the zinc battery electrolyte can be prepared according to the following method: (1) Dissolve the zinc salt in water to form a homogeneous zinc salt aqueous solution; (2) Mix the additive with the zinc salt aqueous solution to fully dissolve the additive and obtain an aqueous electrolyte (i.e., zinc battery electrolyte).

[0030] In step (1), the zinc salt raw material can be anhydrous zinc salt or its hydrate form, and the dissolution temperature can be 20~80℃, preferably room temperature. In step (2), the mixing temperature can be 20~80℃, preferably room temperature.

[0031] A second aspect of the present invention provides a zinc-ion battery, comprising an electrolyte, wherein the electrolyte is the zinc battery electrolyte described in the first aspect of the present invention.

[0032] In this invention, the zinc-ion battery further includes a positive electrode and a negative electrode. The zinc-ion battery stores and releases electrochemical energy through the reversible insertion / extraction or deposition / dissolution of zinc ions between the positive and negative electrodes. Specifically, during discharge, zinc in the negative electrode undergoes an oxidation reaction to form zinc ions and release electrons. The zinc ions migrate through the electrolyte to the positive electrode and are inserted into the positive electrode material. Simultaneously, electrons are transferred through an external circuit to the positive electrode and received by the active material. The charging process is the opposite: zinc ions are extracted from the positive electrode, return to the negative electrode via the electrolyte, and undergo a reduction reaction on the surface of the negative electrode to deposit as metallic zinc.

[0033] In this invention, the positive electrode may include a positive electrode current collector and an active film layer located on the positive electrode current collector. The active film layer comprises a positive electrode active material, a conductive agent, and a binder. The positive electrode active material may be selected from one or more of manganese-based oxides (such as MnO2), vanadium-based compounds (such as V2O5), Prussian blue and its analogues, layered transition metal sulfides, layered transition metal oxides, etc. Specific examples of the positive electrode current collector include, but are not limited to, carbon paper, carbon cloth, titanium foil, stainless steel mesh, etc.

[0034] In this invention, the negative electrode can typically be selected from zinc foil, three-dimensional porous zinc substrate or other forms of zinc negative electrode, and may also include a surface modification layer or protective coating (such as a polymer coating or artificial interface layer) for suppressing dendrites and side reactions.

[0035] The zinc-ion battery of this invention benefits particularly from the high ionic conductivity, wide electrochemical stability window, and good interfacial stability of the electrolyte in the first aspect of this invention, thus exhibiting excellent rate performance and cycle life. Furthermore, this battery system offers high safety and is suitable for applications requiring high safety and cost control, such as large-scale energy storage and flexible electronic devices.

[0036] In this invention, the zinc-ion battery may further include a separator disposed between the positive and negative electrodes. The separator may be, for example, a glass fiber separator, a non-woven fabric separator, or a porous polymer membrane (such as a polypropylene or polyethylene membrane), and its surface may optionally be coated with a ceramic or metal oxide coating to further enhance mechanical strength and thermal stability.

[0037] In this invention, the zinc-ion battery can be assembled into different physical forms, including cylindrical and square batteries, and can be further integrated to form a battery module or battery pack.

[0038] A third aspect of the present invention provides an electrical device comprising the zinc-ion battery described in the second aspect of the present invention. The zinc-ion battery is particularly suitable for fields with high requirements for safety, cost, and environmental adaptability. The electrical device includes, but is not limited to: large-scale energy storage power stations, home energy storage systems, low-speed electric vehicles, smart wearable devices, medical electronic devices, and other portable electronic devices. Due to the inherent safety and wide temperature range operating characteristics of zinc-ion batteries, they have significant advantages in wearable electronics, medical implants, and outdoor interactive devices.

[0039] The following describes embodiments of the present invention. These embodiments are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0040] In the following examples and comparative examples, for ease of description, "CSA" refers to L-camphor sulfonic acid; unless otherwise stated, the concentration unit "M" means "mol / L" and "mM" means "mmol / L".

[0041] Example 1 17.25 g (0.06 mol) of zinc sulfate heptahydrate powder was dissolved in 25 mL of deionized water and stirred until completely dissolved. The resulting solution was then brought to a final volume of 30 mL with deionized water and stirred until homogeneous, yielding a 2 M zinc sulfate aqueous solution. 0.07 g (0.3 mmol) of L-CSA was then added to the zinc sulfate aqueous solution and stirred until dissolved, yielding a 10 mM CSA aqueous electrolyte, denoted as CSA. 10 .

[0042] Example 2 An aqueous electrolyte was prepared according to the method in Example 1, except that the amount of L-CSA was adjusted to 0.035 g, thereby obtaining an aqueous electrolyte with an L-CSA concentration of 5 mM, denoted as CSA5.

[0043] Example 3 The aqueous electrolyte was prepared according to the method in Example 1, except that the amount of L-CSA was adjusted to 0.15 g, thereby obtaining an aqueous electrolyte with an L-CSA concentration of 20 mM, denoted as CSA. 20 .

[0044] Example 4 The aqueous electrolyte was prepared according to the method in Example 1, except that the amount of L-CSA was adjusted to 0.23 g, thereby obtaining an aqueous electrolyte with an L-CSA concentration of 30 mM, denoted as CSA. 30 .

[0045] Comparative Example 1 A 2M zinc sulfate aqueous solution (prepared as shown in Example 1) was used as the control aqueous electrolyte and denoted as ZSO.

[0046] Comparative Example 2 An aqueous electrolyte was prepared according to the method in Example 1, except that L-CSA was replaced with an equimolar amount of cyclohexanone, denoted as CyO.

[0047] Comparative Example 3 An aqueous electrolyte was prepared according to the method in Example 1, except that L-CSA was replaced with an equimolar amount of benzenesulfonic acid, denoted as BSA.

[0048] Test case The test examples are used to illustrate the performance of the aqueous electrolytes prepared in the above embodiments and comparative examples.

[0049] 1. Battery cycle life test Assembly of Zinc-ion Symmetrical Batteries: Cycle life of symmetric batteries was evaluated by assembling them using a CR2032 button cell casing. The battery assembly method involved using two identical zinc electrodes (1.2 cm in diameter, 0.2 mm thick, sanded) as working electrodes, separated by an electrolyte-wetted glass fiber separator (1.6 cm in diameter), and both encapsulated within a CR2032 battery casing. The electrolyte addition was 100 μL.

[0050] The zinc-ion symmetric battery was subjected to constant current cycling tests using a charge-discharge apparatus (Xinwei CT-ZWJ-4S-1U) at a constant temperature of 25°C. The specific procedure involved zinc deposition on the negative electrode at a set current density, with the deposition time determined based on the desired capacity (e.g., at a current density of 1 mA / cm²). 2 1 mAh / cm³ can be achieved by deposition for 1 hour. 2 The areal capacity is measured. Immediately after deposition, the same current density is applied in reverse for stripping until the voltage returns to near its original potential (approximately 0V), completing one deposition-stripping cycle. This deposition-stripping process is repeated continuously as one cycle until the battery experiences a short circuit (manifested as a voltage drop to near 0V). Throughout the test, the voltage-time curve is recorded in real time, allowing for analysis of the battery's cycle stability, zinc electrode reversibility, and coulombic efficiency changes.

[0051] To comprehensively evaluate the performance of the zinc anode, multiple test conditions were designed to simulate different application scenarios, ranging from conventional to demanding, by varying the current density and deposition areal capacity (which together determine the deposition amount and deposition rate). Specific conditions and corresponding test results are shown in Table 1. The current density and deposition areal capacity were 1 mA / cm². 2 1mAh / cm 2 The conditions represent the basic cycle stability under normal operating conditions, i.e., this condition represents a normal or light usage scenario; the current density and deposition capacity are 10 mA / cm². 2 1mAh / cm 2 The conditions represent high-rate application scenarios, and the high current density aims to verify the rapid migration and uniform nucleation ability of zinc ions under harsh conditions; the current density and deposition capacity are 10 mA / cm². 2 10mAh / cm 2 The conditions are relatively harsh, and it has both high current density and large deposition capacity, which can verify the structural stability and reversibility of zinc anode when a large amount of zinc is deposited at high speed.

[0052] Table 1

[0053] Based on the test results in Table 1, comparing Comparative Examples 1-3 with Examples 1-4, it can be seen that using CSA as an electrolyte additive can effectively improve the cycle stability of zinc batteries.

[0054] Figure 1 ZSO and CSA respectively 10 A comparison of voltage-time curves for batteries prepared with CSA electrolyte. The graph shows that, with CSA... 10 For batteries with electrolyte, under normal operating conditions (1mA / cm) 2 1mAh / cm 2 The battery did not experience a short circuit even after 6000 hours of cycling, while the cycle life of batteries using ZSO, CyO and BSA as electrolytes were approximately 95 hours, 446 hours and 720 hours, respectively.

[0055] Figure 2 Examples 1-4 and Comparative Examples 1-3 are shown in high current density applications (10 mA / cm²). 2 1mAh / cm 2 The figure shows the voltage-time curves of a symmetrical zinc battery under the same additive concentration (10 mM). As can be seen from the figure, under the same additive concentration conditions, both CyO and BSA additives exhibit significant voltage fluctuations and rapid short circuits within a short cycle time, indicating that they cannot effectively control the uniform deposition of Zn at high current densities and are unable to suppress dendrite growth. However, the introduction of CSA additive significantly improves the battery's cycle stability. 10 It has the longest cycle life, capable of stable cycling up to 4000 hours. Its voltage plateau is stable and its polarization voltage is low, indicating that CSA can form a stable and dense interface layer on the Zn surface, effectively improving Zn. 2+ The nucleation and deposition behavior of CSA is inhibited, thereby suppressing dendrite formation. Simultaneously, CSA can be observed... 20 It also exhibits a longer cycle life, but it is still lower than that of CSA. 10 The results show that appropriately increasing the CSA concentration can still maintain good interface regulation capabilities. When the CSA content is too low (e.g., CSA5), interface protection is insufficient, and the battery will short-circuit in a short time; while when the CSA content is too high (e.g., CSA5), the interface protection is insufficient, and the battery will short-circuit in a short time; 30 When using excessive additives, it may lead to Zn 2+ Transport obstruction or exacerbated side reactions can also lead to accelerated failure. These results demonstrate that CSA still significantly improves the stability of the Zn anode under high-rate conditions.

[0056] Figure 3 Examples 1-4 and Comparative Examples 1-3 were demonstrated under relatively harsh cycling conditions (10 mA / cm). 2 10mAh / cm 2The voltage-time curves of symmetrical zinc batteries are shown in the figure. As can be seen from the figure, compared to Comparative Examples 1-3 (ZSO, CyO, BSA), the different concentrations of CSA additives used in Examples 1-4 effectively extended the cycle life of the batteries, indicating that the CSA electrolyte system can maintain a relatively stable voltage plateau even under large areal capacity and high current density. This suggests that CSA can construct a more robust interfacial protective layer on the zinc surface, effectively controlling the Zn content. 2+ The nucleation and growth behavior of the zinc anode is controlled, thereby suppressing dendrite growth and interface rupture during large-area rapid deposition, significantly improving the structural stability and reversibility of the zinc anode.

[0057] Furthermore, comparing Examples 1 and Comparative Examples 1-3, it is evident that, compared to ZSO, under the same additive concentration conditions, although the introduction of cyclohexanone (Comparative Example 2) and benzenesulfonic acid (Comparative Example 3) as additives can also improve cycle stability, their effects are far less than those of Example 1. The reason for this may be that benzenesulfonic acid can adsorb onto the zinc surface via -SO3H, reducing water molecule activity and inhibiting hydrogen evolution and mitigating side reactions, but it is still difficult to form a stable protective layer. The carbonyl group in cyclohexanone induces the formation of an organic-rich, sulfur-free SEI layer through a strong zincophilic interaction, improving the Zn... 2+ While exhibiting good deposition uniformity, CSA suffers from insufficient ionic conductivity. CSA, on the other hand, contains both -SO3H and -C=O bipolar groups, which can both suppress hydrogen evolution and promote SEI construction, and induce the formation of a sulfur-rich gradient SEI in situ during cycling. The outer -SO3H residues enhance interfacial hydrophilicity and trap Zn. 2+ The inner ZnS layer provides high Zn content. 2+ The conductivity enables uniform ion transport from top to bottom, effectively suppressing dendrites and side reactions.

[0058] 2. Coulomb efficiency test To evaluate the coulombic efficiency of the electrolyte system, a Zn||Cu half-cell was assembled using a CR2032 button cell. The cell consisted of a copper sheet as the working electrode, a zinc sheet as the counter electrode, and a glass fiber membrane as the separator. Both the copper and zinc sheets were cut into 12mm diameter discs, each 0.2mm thick, and the glass fiber separator had a diameter of 16mm. During assembly, a suitable amount (100μL) of electrolyte was dropped onto the center of the separator to ensure thorough wetting, followed by the placement of gaskets and spring contacts, and then the cell was sealed.

[0059] The coulombic efficiency was tested in constant current mode using a charge-discharge device (Xinwei CT-ZWJ-4S-1U). Specifically, the operation involved first applying 1 mA·cm⁻¹. -2 Discharge current density up to 1 mAh·cm -2 The capacity is then charged to a cutoff voltage of 0.5 V at the same current density, and the charge-discharge capacity ratio is calculated by continuously cycling a certain number of times to obtain the coulombic efficiency.

[0060] Figure 4 These are ZSO and CSA respectively. 10 A comparison of the coulombic efficiency (CE) of batteries prepared using CSA electrolytes. The figure shows that, when using CSA... 10 In the electrolyte system, the battery operates at 1 mA / cm 2 Current density and 1mAh / cm 2 Under the areal capacity testing conditions, the average coulombic efficiency remained as high as 99.67% after 2000 cycles. In contrast, the ZnSO4 system (ZSO) without CSA additive showed significant coulombic efficiency fluctuations after 114 cycles, which is speculated to be related to the shedding of zinc dendrites or the accumulation of dead zinc. It is evident that functionalized interface regulation can effectively suppress dendrite growth and side reactions, indicating that the addition of CSA additive effectively suppressed side reactions, stabilized the electrode / electrolyte interface, improved the reversibility of electrode reactions, and thus significantly improved coulombic efficiency.

[0061] 3. Half-cell electrochemical performance testing Zn||Ti half-cells were assembled using a CR2032 coin cell casing. Cyclic voltammetry (CV) and chronoamperometry (CA) tests were performed on the half-cells using a Chenhua electrochemical workstation (CHI760E). The Zn||Ti half-cells were assembled as follows: titanium foil (1.2 cm in diameter, 0.2 mm in thickness) was used as the working electrode, and zinc foil (1.2 cm in diameter, 0.2 mm in thickness) was used as the counter electrode. The two electrodes were separated by an electrolyte-wetted glass fiber membrane (1.6 cm in diameter). The entire assembly was encapsulated in a CR2032 coin cell casing, with an electrolyte addition of 100 μL.

[0062] The battery assembly sequence is as follows: positive electrode shell / titanium electrode / separator / electrolyte / zinc electrode / gasket / spring sheet / negative electrode shell. The titanium and zinc electrodes are both 1.2 cm in diameter and 0.2 mm thick; the separator is made of 1.6 cm diameter glass fiber; and the electrolyte is added in an amount of 100 μL.

[0063] Cyclic voltammetry (CV) test: at 25°C, within a voltage range of -0.2 to 2.0 V (vs. Zn / Zn). 2+ The scan was performed within 1 mV·s. -1 .

[0064] Chronoampere (CA) test: At 25°C, the electrodes were stabilized at the open circuit potential (OCP) for 300 s, followed by the application of a -150 mV (vs. Zn / Zn) 2+ A potential step was applied and sustained for 600 seconds, and the transient response of the current was recorded.

[0065] Combination Figure 5It can be seen that, compared to electrolyte ZSO, CSA 10 The nucleation overpotential of the Zn electrode in this system is more negative. According to nucleation theory, the larger the nucleation overpotential, the smaller the nucleation radius. This result indicates that the additive CSA is beneficial to the preferential directional growth of nuclei and the uniform deposition of zinc, suggesting that this system is more conducive to the formation of dense and fine Zn deposition structures.

[0066] To further understand the initial nucleation behavior, chronoampere (CA) tests were performed on both systems, and the results are as follows: Figure 6 As shown, in ZnSO electrolyte, the response current of the Zn anode continuously increases within 500 s, indicating that it undergoes a long and random two-dimensional diffusion process, which easily induces the formation of zinc dendrites. In CSA... 10 In this system, the process is significantly shortened and rapidly transitions to a stable three-dimensional diffusion stage, reflecting the role of CSA molecules in regulating Zn. 2+ Capabilities related to diffusion behavior.

[0067] 4. Linear sweep voltammetry test Linear sweep voltammetry (LSV) was performed using a three-electrode method. Electrochemical performance testing of the hydrogen evolution reaction (HER) was conducted using a three-electrode system, with zinc metal as the working electrode, a platinum sheet as the counter electrode, and Ag / AgCl (saturated KCl) as the reference electrode. The electrolyte was a 2 M sodium sulfate solution, or a 2 M sodium sulfate solution with 10 mM camphor sulfonic acid (denoted as 1-CSA) added. 10 The test potential range is -2.3 V to -1.3 V (relative to Ag / AgCl), and the scan rate is 1 mV s. -1 .

[0068] Figure 7 The results show that at -10 mA·cm -2 At current density, 1-CSA 10 The overpotential of the zinc anode in the system was -1.13V (vs. Ag / AgCl), which was significantly higher than that of the NaSO4 system (-1.09V). This indicates that the introduction of CSA can effectively reduce the kinetic activity of HER, thereby inhibiting the occurrence of side reactions.

[0069] 5. Observation of zinc deposition To directly observe the nucleation and deposition behavior of zinc, in-situ optical microscopy was performed using a symmetrical Zn / / Zn battery structure. During the test, two identical zinc plates were used as the working electrode and counter electrode, respectively. The electrolyte was a 2M ZnSO solution (the ZnSO electrolyte of Comparative Example 1), or a solution with 10mM CSA (the CSA of Example 1) added. 10By applying a constant current to both ends of the battery to drive the deposition / dissolution process of zinc, the evolution of the cross-sectional morphology of the zinc electrode was recorded in real time using an optical microscope, thus visually revealing the differences in the nucleation, growth, and deposition morphology of zinc under different electrolyte systems. Specific tests were conducted at 10 mA / cm². 2 Dynamic process of zinc deposition at current density for 60 min.

[0070] like Figure 8 As shown, the zinc anode surface remained smooth during the initial deposition in ZSO electrolyte. However, after only 10 minutes, uneven nucleation points and protrusions appeared on the zinc anode surface (triggering the "tip effect"). Subsequently, these particles gradually grew, forming a thick and unevenly distributed zinc dendrite layer by 60 minutes. This process was accompanied by uneven deposition, bubble generation, and byproduct formation. In contrast, the zinc anode using CSA electrolyte remained smooth and uniform throughout the entire deposition process. This is mainly due to the uniform zinc ion deposition flux and the interface adaptive regulation function, fully demonstrating the role of CSA in inhibiting zinc dendrite growth.

[0071] 6. Nuclear magnetic resonance (NMR) test To investigate the effects of additives on the chemical environment of the electrolyte system, 2M ZnSO4 electrolyte and electrolyte samples with different concentrations (5mM, 10mM, 20mM, 30mM) of camphor sulfonic acid (CSA) were prepared, namely, the electrolyte samples of Comparative Example 1 and Examples 1-4. Approximately 10 vol% deuterated water (D2O) was added to a suitable amount of electrolyte sample to provide a magnetic field lock signal for chemical shift calibration. Nuclear magnetic resonance (NMR) measurements were performed on a 400 MHz NMR spectrometer, and data were collected... 1 H nuclear magnetic resonance spectrum.

[0072] Figure 9 The following are examples of electrolytes with different concentrations of CSA additive: 1 H NMR characterization results. The signals for all samples were around δ≈4.70 ppm, corresponding to the concentration of water molecules. 1 H signal. As the CSA concentration increases (from 5 mM to 30 mM), the spectral peak gradually shifts slightly towards the higher field (with a smaller chemical shift), indicating a change in the chemical environment of the water molecules. Compared to 2 M ZnSO4 electrolyte, the addition of CSA... 1 A slight shift in the H signal indicates that CSA molecules interact with Zn. 2+ This may be due to interactions between water molecules, leading to changes in the hydrogen bond structure or solvation environment of water molecules. These results indicate that the introduction of CSA can modulate Zn... 2+ The solvation structure affects the chemical shielding effect of water molecules in the electrolyte.

[0073] Finally, it should be noted that the above preparation examples are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing preparation examples, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing preparation examples, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the preparation examples of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the preparation examples can be combined in any way. The present invention is not limited to the specific preparation examples disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A zinc battery electrolyte, characterized in that, It comprises water and zinc salts dissolved therein, and additives, wherein the additives include at least one organic compound of the general formula shown in Formula 1: O=Cy-L-SO3H, Equation 1 In Formula 1, Cy represents a substituted or unsubstituted bridged cycloalkyl group, wherein the substituent is an alkyl group with 1 to 4 carbon atoms, and L represents a single bond or an alkylene group with 1 to 4 carbon atoms.

2. The zinc battery electrolyte according to claim 1, characterized in that, In Formula 1, Cy is a 7-10-membered bridged cycloalkyl group substituted with at least one methyl group, and L is a single bond or a methylene group.

3. The zinc battery electrolyte according to claim 1 or 2, characterized in that, The additive is camphor sulfonic acid; Preferably, the additive is L-camphorsulfonic acid.

4. The zinc battery electrolyte according to any one of claims 1-3, characterized in that, In the zinc battery electrolyte, the concentration of the additive is 5~30 mmol / L.

5. The zinc battery electrolyte according to any one of claims 1-3, characterized in that, In the zinc battery electrolyte, the concentration of the additive is 8~12 mmol / L.

6. The zinc battery electrolyte according to any one of claims 1-5, characterized in that, The zinc salt is selected from at least one of zinc sulfate, zinc chloride, zinc trifluoromethanesulfonate, zinc acetate, and zinc perchlorate.

7. The zinc battery electrolyte according to any one of claims 1-6, characterized in that, In the zinc battery electrolyte, the concentration of the zinc salt is 1~3 mol / L.

8. The zinc battery electrolyte according to any one of claims 1-7, characterized in that, The molar ratio of the additive to the zinc salt is (0.25~1.5):

100.

9. A zinc-ion battery, characterized in that, Includes the zinc battery electrolyte according to any one of claims 1-8.

10. An electrical device, characterized in that, Including the zinc-ion battery as described in claim 9.

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