A fluorescent tracing method and aqueous zinc ion battery

Abstract

The application provides a fluorescent tracing method and an aqueous zinc ion battery, wherein the fluorescent tracing method comprises the following steps: firstly, a fluorescent electrolyte solution is prepared, the fluorescent electrolyte solution contains a TPE-based fluorescent tracer, the TPE-based fluorescent tracer is a TPE derivative formed by introducing different functional groups into a TPE molecular skeleton, and the TPE derivative comprises an olefin group and a polar group; and secondly, the aqueous zinc ion battery containing the fluorescent electrolyte solution is subjected to a constant current deposition stripping mode to perform long-term cycle testing on the battery. In the long-term cycle testing of the battery, the tetraphenyl ethylene derivative with the aggregation-induced emission characteristic is introduced, the zinc ion migration, deposition and stripping behavior can be directly observed by means of the fluorescent signal of the tetraphenyl ethylene derivative, and the zinc element distribution and dynamic change are directly presented. This breaks through the limitation that the traditional method is difficult to directly capture the zinc electrode interface reaction, and provides intuitive visual evidence for understanding the electrochemical mechanism of the zinc ion battery.

Description

Technical Field

[0001] This invention relates to the technical field of applying fluorescent electrolyte solutions to battery state detection, specifically a fluorescent tracer method and an aqueous zinc-ion battery. Background Technology

[0002] Aqueous zinc-ion batteries, due to their high safety, environmental friendliness, and abundant raw materials, have shown broad application prospects in the energy storage field. However, their commercialization process is still severely constrained by the zinc anode interface problem. During electrochemical cycling, the zinc anode undergoes complex interfacial reactions, including metal deposition and stripping behavior, accumulation of by-reaction products, and remodeling of the interfacial structure. The formation and evolution of the solid electrolyte interface are considered to play a crucial role in regulating interfacial stability. However, due to the rapid reaction and structural complexity of this process, existing in-situ or quasi-in-situ techniques struggle to achieve continuous and direct observation of its composition, morphology, and evolution. This results in a lack of in-depth understanding of the zinc anode interfacial behavior, especially key mechanisms such as deposition morphology evolution, local electric field distribution, and reaction non-uniformity, greatly limiting the accurate assessment of failure mechanisms and the optimization of interfacial control strategies. In existing technologies, the assessment of the zinc anode state mainly relies on electrochemical performance parameters, such as voltage curves, coulombic efficiency, and cycle life. While these methods can reflect changes in battery performance at a macroscopic level, they struggle to reveal the dynamic evolution of electrode surface structure and morphology in a timely and intuitive manner, failing to meet the real-time monitoring and accurate diagnosis requirements for the negative electrode state under actual operating conditions. Therefore, there is an urgent need to develop a rapid, visual, and quantitative technique capable of dynamically monitoring the interfacial evolution behavior of the zinc negative electrode during cycling, intuitively revealing its morphological change trends, thereby enabling early identification and warning of battery degradation, and providing effective support for interface control strategies and battery stability design. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to propose a fluorescence tracing method to solve the problems mentioned in the background section above.

[0004] This invention is achieved through the following technical solution:

[0005] A fluorescence tracer method, the method comprising the following steps:

[0006] The first step is to prepare a fluorescent electrolyte solution containing a TPE-based fluorescent tracer. The TPE-based fluorescent tracer is a TPE derivative formed by introducing different functional groups into the TPE molecular backbone. The TPE derivative includes olefin groups and polar groups.

[0007] The second step involves subjecting the aqueous zinc-ion battery containing the fluorescent electrolyte solution to a long-term cycle test using a constant current deposition stripping mode.

[0008] The preparation method of the fluorescent electrolyte solution is as follows:

[0009] S1. Dissolve the soluble zinc salt in ultrapure water and stir thoroughly to ensure complete dissolution, forming a zinc salt solution;

[0010] S2. Add 0.001% to 1.0% by mass of TPE-based fluorescent tracer to the zinc salt solution;

[0011] S3. Add organic solvent and stir until homogeneous to form fluorescent electrolyte solution.

[0012] Furthermore, the soluble zinc salt is zinc sulfate, zinc trifluoromethanesulfonate, or zinc acetate.

[0013] Furthermore, the concentration of the zinc salt solution is from 0.5 mol / L to 3 mol / L.

[0014] Furthermore, the TPE derivative is acrylate tetraphenylethylene, acrylamide tetraphenylethylene, diaminotetraphenylethylene, hydroxytetraphenylethylene, aminotetraphenylethylene, carboxytetraphenylethylene, or sulfonate tetraphenylethylene.

[0015] Furthermore, the preparation method of the acrylate-based tetraphenylethylene is as follows:

[0016] Step 1: Prepare the reaction mixture by adding 1.85g of 4-(1,2,2-tristyryl)phenol, 1.07g of triethylamine, and 10mL of tetrahydrofuran to a container and stirring to dissolve the materials.

[0017] Step 2: Control the temperature of the reaction system to -30℃, and add 624mg of acetyl chloride dropwise to the mixture obtained in Step 1 over 20 minutes;

[0018] Step 3: Stir the mixture obtained in Step 2 overnight;

[0019] Step 4: Concentrate the mixture after the reaction in Step 3 under reduced pressure to obtain the residue;

[0020] Step 5: Extract the residue obtained in Step 4 with ethyl acetate and wash the extracted organic phase with saturated brine;

[0021] Step 6: Combine the organic phases washed in Step 5, filter, and then concentrate under reduced pressure;

[0022] Step 7: Purify the product concentrated in Step 6 by silica gel column chromatography, using petroleum ether and petroleum ether / dichloromethane in a volume ratio of 80:20 as eluents in turn.

[0023] Step 8: Collect the pure product obtained after elution, which is a white solid of acrylate-based tetraphenylethylene with strong blue fluorescence.

[0024] Furthermore, in the second step, at 5~10 mAcm -2 / 5~10mAhcm -2 The battery was subjected to long-term cycle testing under the specified conditions.

[0025] In another aspect, the present invention provides an aqueous zinc-ion battery, including the fluorescence tracing method as described in any of the preceding claims.

[0026] The beneficial effects of this invention are as follows: First, a fluorescent electrolyte solution is prepared, which contains a TPE-based fluorescent tracer. This TPE-based fluorescent tracer is a TPE derivative formed by introducing different functional groups into the TPE molecular backbone. The TPE derivative includes olefin groups and polar groups. Second, an aqueous zinc-ion battery containing the fluorescent electrolyte solution is subjected to long-term cycling testing using a constant current deposition-stripping mode. During the long-term cycling test, by introducing a tetraphenylethylene derivative with aggregation-induced emission properties, the migration, deposition, and stripping behavior of zinc ions during battery cycling can be directly observed using its fluorescence signal. This provides a direct visual representation of the distribution and dynamic changes of zinc, overcoming the limitations of traditional methods that struggle to directly capture the reaction process at the zinc electrode interface. This provides intuitive visual evidence for understanding the electrochemical mechanism of zinc-ion batteries. Attached Figure Description

[0027] Figure 1 This is a flowchart of a fluorescence tracing method according to the present invention.

[0028] Figure 2 Optical photographs are shown for comparison of 2 mol / L ZnSO4 electrolyte with 0.1 wt%, 0.05 wt%, and 0.01 wt% diaminotetraphenylene (TPE-(NH2)2) added, and without the addition of diaminotetraphenylene (TPE-(NH2)2).

[0029] Figure 3 To use 365nm ultraviolet light irradiation to Figure 2 The electrolyte is irradiated.

[0030] Figure 4 An aqueous zinc battery with an electrolyte containing 0.50 wt% acrylate-based tetraphenylethylene (TPE-Ac) and a blank control (conventional zinc sulfate electrolyte) was tested at 10 mA / cm. -2 / 10mAhcm -2 Comparison of cyclic performance under different conditions.

[0031] Figure 5An aqueous zinc battery was tested at 10 mA / cm² with electrolytes containing 0.50 wt% acrylamide tetrastyrene (TPE-Am), 0.50 wt% diaminotetrastyrene (TPE-(NH₂)₂), 0.50 wt% hydroxytetrastyrene (TPE-OH), and 0.50 wt% TPE (excluding olefin and polar groups). -2 / 10mAhcm -2 Comparison of cyclic performance under different conditions.

[0032] Figure 6 The dynamic evolution of the zinc electrode interface voltage during zinc deposition and dissolution was observed by comparing an electrolyte containing 0.50 wt% diaminotetraphenylene (TPE-(NH2)2) with a blank control group without added TPE.

[0033] Figure 7 For an aqueous zinc-ion battery using a fluorescent electrolyte solution containing 0.5 wt% diaminotetraphenylene (TPE-(NH2)2), at a current density of 5 mA / cm²... -2 5mAh capacity -2 Fluorescence images of the zinc anode after the 1st, 10th, 30th and 50th cycles, respectively, under the specified conditions.

[0034] Figure 8 For an aqueous zinc-ion battery using a fluorescent electrolyte solution containing 0.5 wt% diaminotetraphenylene (TPE-(NH2)2), at a current density of 5 mA / cm²... -2 5mAh capacity -2 SEM images of the zinc anode region after 50 cycles under the given conditions. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of aiding understanding the present invention, but does not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] Reference Figure 1 As shown, a fluorescence tracing method includes the following steps:

[0037] The first step is to prepare a fluorescent electrolyte solution containing a TPE-based fluorescent tracer. The TPE-based fluorescent tracer is a TPE derivative formed by introducing different functional groups into the TPE molecular backbone. The TPE derivative includes olefin groups and polar groups.

[0038] The second step involves subjecting the aqueous zinc-ion battery containing the fluorescent electrolyte solution to long-term cycle testing using a constant current deposition stripping mode.

[0039] During long-term cycle testing of the battery, by introducing TPE derivatives with aggregation-induced emission properties, namely tetraphenylethylene derivatives, the migration, deposition and stripping behavior of zinc ions during battery cycling can be directly observed using their fluorescence signals. This provides a direct visual representation of the distribution and dynamic changes of zinc elements, overcoming the limitations of traditional methods that cannot directly capture the interfacial reaction process of zinc elements. This provides intuitive visual evidence for understanding the electrochemical mechanism of zinc-ion batteries.

[0040] During long-term cycle testing of the battery, olefin groups (C=C) participate in the electrolyte interface reaction, forming a fluorescent SEI film that evolves synchronously with zinc, making zinc deposition sites, film integrity, and failure areas readily apparent. Polar groups (-OC=O) participate in the reaction of Zn in the electrolyte. 2+ Changes in zinc concentration or interfacial deposition state can be directly converted into recognizable fluorescence signals, enabling in-situ, non-destructive, and real-time visualization of the entire zinc deposition / stripping process.

[0041] The preparation method of the fluorescent electrolyte solution is as follows:

[0042] S1. Dissolve the soluble zinc salt in ultrapure water and stir thoroughly to ensure complete dissolution, forming a zinc salt solution;

[0043] S2. Add 0.001% to 1.0% by mass of TPE-based fluorescent tracer to the zinc salt solution;

[0044] S3. Add organic solvent and stir until homogeneous to form fluorescent electrolyte solution.

[0045] The proportion of TPE-based fluorescent tracer is controlled in a low range of 0.001% to 1.0%, which ensures sufficient fluorescence signal intensity for effective monitoring while minimizing its interference with the physicochemical properties (such as ionic conductivity) of the electrolyte's main components (such as zinc salts), thus ensuring that the basic function of the electrolyte is not significantly affected. Preferably, the proportion of TPE-based fluorescent tracer is controlled in a low range of 0.1% to 0.6%. More preferably, the proportion of TPE-based fluorescent tracer is controlled in a low range of 0.4% to 0.6%.

[0046] Specifically, the performance table of TPE-based fluorescent tracer addition ratio is as follows:

[0047]

[0048] As shown in the table above, the fluorescence signal intensity increases with the increase of the added proportion of TPE-based fluorescent tracer. Effective monitoring usually requires a signal intensity of at least 200 units. Therefore, the signal is poor when the added proportion of TPE-based fluorescent tracer is below 0.2% (e.g., the signal is 100 at 0.1%). When the added proportion of TPE-based fluorescent tracer is between 0.4% and 0.6%, the signal intensity is relatively high (400-600 units), which can meet most monitoring needs.

[0049] The conductivity decreases with increasing proportion of TPE-based fluorescent tracer, but the overall impact is small. When the proportion of TPE-based fluorescent tracer is between 0.4% and 0.6%, the conductivity decreases by only 0.80% to 1.20%, with minimal interference to the physicochemical properties of the electrolyte bulk component. As the optimal embodiment, when the proportion of TPE-based fluorescent tracer is 0.5%, the fluorescence signal intensity is 500 units, sufficient for effective monitoring; the conductivity decreases by 1.00%, with minimal impact.

[0050] The soluble zinc salt is zinc sulfate, zinc trifluoromethanesulfonate, or zinc acetate. The selected zinc sulfate, zinc trifluoromethanesulfonate, or zinc acetate are all commonly used soluble zinc salts in zinc-based batteries and have stable chemical properties.

[0051] Furthermore, the concentration of the zinc salt solution is from 0.5 mol / L to 3 mol / L. Within this concentration range, the physicochemical properties of the zinc salt solution (such as viscosity and solubility) are relatively stable, providing a good dispersion environment for the TPE-based fluorescent tracer and avoiding salting out or uneven tracer dispersion caused by excessive concentration. This ensures stable fluorescence signals and facilitates effective tracking of interfacial phenomena such as SEI films. Preferably, the concentration of the zinc salt solution is from 1 mol / L to 2.5 mol / L. More preferably, the concentration of the zinc salt solution is controlled at 2 mol / L.

[0052] Specifically, the performance comparison table for different zinc salt solution concentrations is as follows:

[0053]

[0054] Performance was compared using a zinc salt solution concentration of 1.0 mol / L as a baseline (100%). A higher dispersion stability score indicates a more uniform distribution of the TPE-based fluorescent tracer, with no aggregation or precipitation, and a more stable fluorescence signal. The overall score is a visually comparable indicator; a higher value indicates better overall performance.

[0055] Based on the data in the table above, we can draw the following conclusions: The peak ionic conductivity is around 2.0 mol / L: When the zinc salt solution concentration increases from 0.5 mol / L to 2.0 mol / L, the increase in the number of ions dominates the change in conductivity, causing it to reach its peak (125%). Above 2.0 mol / L, the negative effect of increased viscosity begins to outweigh the positive effect of increased ion quantity, leading to a decrease in conductivity. Therefore, maintaining the zinc salt solution concentration at 2.0 mol / L provides optimal ion transport capacity.

[0056] In the medium concentration range (1.0-2.0 mol / L), zinc salt solution provides a stable, "ionic liquid-like" environment for TPE molecules, effectively suppressing their molecular vibrations (which is the TPE luminescence mechanism) and avoiding uneven dispersion at too low a concentration or salting out at too high a concentration. Therefore, it has the highest dispersion stability score (10 points).

[0057] Although the overall score (719) for zinc salt solution concentration at 1.5 mol / L is slightly higher than that at 2.0 mol / L (625), 2.0 mol / L provides a significantly higher absolute ionic conductivity (125% vs 115%), which is crucial for the actual performance of the battery.

[0058] Furthermore, the TPE derivative is acrylate-based tetraphenylethylene (TPE-Ac), acrylamide-based tetraphenylethylene (TPE-Am), diaminotetraphenylethylene (TPE-(NH2)2), hydroxytetraphenylethylene (TPE-OH), aminotetraphenylethylene (TPE-NH2), carboxylate-based tetraphenylethylene (TPE-COOH), or sulfonic acid-based tetraphenylethylene (TPE-SO3H). The functional groups of the TPE derivative (such as acrylate, acrylamide, amino, hydroxyl, carboxyl, and sulfonic acid groups) give it good chemical stability in electrolyte systems, good compatibility with zinc salts, organic solvents, and other components, and it is not easily chemically reacted and degraded, thus reducing interference with the basic performance of the electrolyte.

[0059] In the above text, the organic solvent is preferably ethanol or acetonitrile, so that ethanol or acetonitrile is mixed with water to form a water-organic mixed solvent system. Ethanol or acetonitrile has strong polarity and can be miscible with water in any proportion.

[0060] Furthermore, the preparation method of the acrylate-based tetraphenylethylene is as follows:

[0061] Step 1: Prepare the reaction mixture by adding 1.85g of 4-(1,2,2-tristyryl)phenol, 1.07g of triethylamine and 10mL of tetrahydrofuran to a container and stirring to dissolve the materials.

[0062] Step 2: Control the temperature of the reaction system to -30℃, and add 624mg of acetyl chloride dropwise to the mixture obtained in Step 1 within 20 minutes;

[0063] Step 3: Stir the mixture obtained in Step 2 overnight;

[0064] Step 4: Concentrate the mixture after the reaction in Step 3 under reduced pressure to obtain the residue;

[0065] Step 5: Extract the residue obtained in Step 4 with ethyl acetate and wash the extracted organic phase with saturated brine;

[0066] Step 6: Combine the organic phases washed in Step 5, filter, and then concentrate under reduced pressure;

[0067] Step 7: Purify the product concentrated in Step 6 by silica gel column chromatography, using petroleum ether and petroleum ether / dichloromethane in a volume ratio of 80:20 as eluents in turn.

[0068] Step 8: Collect the pure product obtained after elution, which is a white solid of acrylate-based tetraphenylethylene with strong blue fluorescence.

[0069] In the preparation method of acrylate-based tetraphenylethylene, all of the above chemical agents belong to existing chemical components.

[0070] Reference Figure 2 As shown in the figure, in this embodiment, optical photographs are compared from left to right of 0.1 wt%, 0.05 wt%, and 0.01 wt% diaminotetraphenylene added to a 2 mol / L ZnSO4 electrolyte, and of 0.01 wt% without the addition of diaminotetraphenylene.

[0071] Reference Figure 3 As shown in the figure, this is an example of using a 365nm ultraviolet lamp to irradiate... Figure 2 The electrolyte was irradiated. Observations were made... Figure 2 and Figure 3 It can be concluded that the fluorescence effect becomes more and more obvious as the concentration of TPE-based fluorescent tracer increases.

[0072] Reference Figure 4 As shown, Figure 4 An aqueous zinc battery with an electrolyte containing 0.50 wt% acrylate-based tetraphenylethylene (TPE-Ac) and a blank control (conventional zinc sulfate electrolyte) was tested at 10 mA / cm. -2 / 10mAhcm -2 Comparison of cyclic performance under different conditions.

[0073] Depend on Figure 4Therefore, in this embodiment, to verify the actual role of the TPE-based fluorescent tracer in the regulation of the zinc anode interface, an electrolyte with 0.50 wt% acrylate-based tetraphenylethylene (TPE-Ac) was added and compared with the blank control group. The TPE-Ac electrolyte exhibited significantly better cycle stability than the blank control group (without additives), with no obvious voltage fluctuations or short-circuit signs observed during over 400 hours of testing. The results indicate that the TPE-based fluorescent tracer not only possesses tracer functionality but also significantly optimizes zinc deposition, thereby improving the cycle stability and safety of the zinc anode and providing an effective strategy for enhancing the performance of aqueous zinc batteries.

[0074] Figure 5 An aqueous zinc battery was tested at 10 mA / cm² with electrolytes containing 0.50 wt% acrylamide tetrastyrene (TPE-Am), 0.50 wt% diaminotetrastyrene (TPE-(NH₂)₂), 0.50 wt% hydroxytetrastyrene (TPE-OH), and 0.50 wt% TPE (excluding olefin and polar groups). -2 / 10mAhcm -2 Comparison of cyclic performance under different conditions.

[0075] To screen for fluorescent tracer additives that possess both excellent fluorescence tracking ability and good electrochemical compatibility, by Figure 5 It can be seen that TPE molecules modified with different functional groups exhibit significant differences in battery cycle stability. Specifically, the cycle life of unfunctionalized TPE and the hydroxyl-modified TPE-OH system is inferior to that of the blank group (refer to...). Figure 4 The blank group (shown in the figure) indicates poor electrochemical compatibility with the battery system. While amide-modified TPE-Am achieves a longer cycle life, its charge-discharge curves show significant voltage fluctuations, suggesting the potential formation of a kinetically unstable electrode / electrolyte interface. In contrast, diamino-modified TPE-(NH2)2 exhibits the best performance, demonstrating superior cycle stability under these conditions compared to the blank group. Therefore, besides TPE-Ac, TPE-(NH2)2 successfully achieves effective stabilization of the zinc metal interface while introducing fluorescence tracer functionality.

[0076] Figure 6 The dynamic evolution of the zinc electrode interface voltage during zinc deposition and dissolution was observed by comparing an electrolyte containing 0.50 wt% diaminotetraphenylene (TPE-(NH2)2) with a blank control group without added TPE.

[0077] In this embodiment, a PTFE gasket is used instead of glass fiber as the diaphragm (glass fiber was used as the diaphragm in all the aforementioned cycle performance tests). At 5 mA cm -2 / 5mAhcm -2Under these conditions, the complete dynamic process of interface layer formation, growth, and even destruction was clearly traced in real time within dozens of cycles. Figure 6 It can be seen that although the battery experienced a voltage rise due to polarization during the more than 80 hours of testing, it remained within the normal range and no short circuit was observed, demonstrating a positive contribution to the overall performance of the aqueous zinc battery. Therefore, the TPE-based fluorescent tracer, while possessing tracer functionality, can significantly optimize the cycle stability and safety of the zinc anode through its rational functional group design.

[0078] Figure 7 For an aqueous zinc-ion battery using a fluorescent electrolyte solution containing 0.5 wt% diaminotetraphenylene (TPE-(NH2)2), at a current density of 5 mA / cm²... -2 5mAh capacity -2 Fluorescence images of the zinc anode after the 1st, 10th, 30th, and 50th cycles were obtained under the specified conditions. The images show that as the cycles progress, the fluorescence distribution gradually becomes more uniform, indicating that the interface gradually stabilizes. In later cycles, the images show a phenomenon of localized fluorescence enhancement and weakening, reflecting the presence of uneven reaction areas on the electrode surface. This suggests interface damage, byproduct accumulation, or the formation of deactivated areas, demonstrating the ability to visually identify abnormal battery conditions early.

[0079] Figure 8 For an aqueous zinc-ion battery using a fluorescent electrolyte solution containing 0.5 wt% TPE-(NH2)2, at a current density of 5 mA / cm²... -2 5mAh capacity -2 SEM images of the zinc anode region after 50 cycles under the specified conditions. The images show visible irregular blocky deposition structures. Combined with changes in the cyclic fluorescence images, this indicates that the zinc anode is in a lifespan degradation stage, verifying that the fluorescent electrolyte solution can provide an early warning signal before morphological instability.

[0080] In summary, this invention, by designing a TPE-based fluorescent tracer with aggregation-induced emission properties as a functional additive in the electrolyte, enables in-situ visual monitoring of the deposition morphology, dendrite growth, and deactivation regions of the zinc anode during charge and discharge. Changes in the fluorescence image can appear earlier than obvious fluctuations in the voltage curve, reflecting problems such as dendrite formation, interface instability, and accumulation of side reactions in advance, thus providing early warning of battery failure. This TPE-based fluorescent tracer requires a low dosage, has minimal impact on battery performance, and exhibits good compatibility with conventional aqueous electrolyte systems, demonstrating good versatility and scalability, and can be further applied to various metal anode systems.

[0081] In another aspect, the present invention provides an aqueous zinc-ion battery, including the fluorescence tracing method as described in any of the preceding claims.

[0082] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0083] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A fluorescence tracing method characterized by, The method comprises the following steps: First, prepare a fluorescent electrolyte solution for water-based zinc ion batteries, which contains a TPE-based fluorescent tracer, i.e., a TPE derivative formed by introducing different functional groups into the TPE molecular skeleton, which includes an olefin group and a polar group; Second, use the water-based zinc ion battery containing the fluorescent electrolyte solution in a constant current deposition stripping mode to perform long-term cycle testing on the battery; The preparation method of the fluorescent electrolyte solution is as follows: S1, dissolve a soluble zinc salt in ultrapure water, stir thoroughly to ensure complete dissolution, and form a zinc salt solution; S2, add 0.001% to 1.0% of the TPE-based fluorescent tracer to the zinc salt solution by mass ratio; S3, add an organic solvent and stir uniformly to form a fluorescent electrolyte solution.

2. The fluorescence tracing method according to claim 1, characterized in that, The soluble zinc salt is zinc sulfate, zinc trifluoromethane sulfonate, or zinc acetate.

3. The method of claim 1, wherein: The concentration of the zinc salt solution is 0.5 mol / L to 3 mol / L.

4. The method of claim 1, wherein: The TPE derivative is acrylate-based tetraphenyl ethylene, acrylamide-based tetraphenyl ethylene, diamino tetraphenyl ethylene, hydroxyl tetraphenyl ethylene, amino tetraphenyl ethylene, carboxyl tetraphenyl ethylene, or sulfonic acid-based tetraphenyl ethylene.

5. The fluorescence tracer method according to claim 4, characterized in that, The preparation method of the acrylate-based tetraphenyl ethylene is as follows: Step 1: Prepare a reaction mixture by adding 4-(1,2,2-triphenyl ethenyl) phenol 1.85 g, triethylamine 1.07 g, and 10 mL of tetrahydrofuran in a container, and stir to dissolve the materials; Step 2: Control the reaction system temperature to be -30℃, and add 624 mg of acetyl chloride dropwise into the mixture obtained in step 1 within 20 minutes; Step 3: Stir the mixture obtained in step 2 overnight; Step 4: Concentrate the mixture after reaction in step 3 under reduced pressure to obtain a residue; Step 5: Extract the residue obtained in step 4 with ethyl acetate, and wash the organic phase after extraction with saturated brine; Step 6: Combine the organic phase after washing in step 5, filter, and concentrate under reduced pressure; Step 7: Purify the product after concentration in step 6 using silica gel column chromatography, and use petroleum ether, petroleum ether / dichloromethane with a volume ratio of 80:20 as eluent in sequence; Step 8: Collect the pure product obtained after elution, which is acrylate-based tetraphenyl ethylene white solid with strong blue fluorescence.

6. The method of claim 1, wherein, In the second step, the battery is subjected to long-term cycling test at 5-10 mA cm -2 / 5-10 mA h cm -2 under the conditions.

7. An aqueous zinc-ion battery, characterized in that: The fluorescent electrolyte solution in a fluorescent tracer method as claimed in any one of claims 1 to 6.

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