Method for improving cycle stability of water-based zinc battery negative electrode by ultrasonic vibration pressing

Abstract

The application discloses a method for improving the cycle stability of a water-based zinc battery negative electrode through ultrasonic vibration pressing, and belongs to the technical field of water-based zinc battery energy storage. The cycle life of the untreated zinc electrode is only 140 hours, while the cycle life of the zinc electrode after ultrasonic vibration pressing treatment can reach 970 hours, which is nearly 6 times higher (as shown in FIG. 6). Excellent cycle stability is exhibited under different current densities, such as the cycle life of 850 hours under a current density of 1 A / g in Example 2, and the cycle life of 1050 hours under a current density of 0.2 A / g in Example 3, proving that the method is simple, efficient and low in cost, and can effectively cope with different working scenarios.

Description

Technical Field

[0001] This invention relates to an aqueous zinc battery energy storage system, and more particularly to a method for improving the cycle stability of the negative electrode of an aqueous zinc battery through ultrasonic vibration and pressure, belonging to the field of aqueous zinc battery energy storage technology. Background Technology

[0002] The most common method in existing technologies is to plate a layer of dissimilar metals, such as copper, indium, or tin, onto the zinc foil surface. These metals' affinity for zinc guides uniform zinc deposition and inhibits dendrite growth. Other methods utilize non-metallic materials such as graphene and carbon nanotubes to construct a protective layer on the zinc anode. Carbon-based materials provide abundant nucleation sites for zinc, promoting the migration and deposition of zinc ions on the electrode surface, thus effectively inhibiting zinc dendrite growth. Another method involves alloying the zinc anode with heat treatment, using materials such as tin or copper, to optimize the electronic structure of zinc and improve its stability. Additionally, alloying followed by dealloying yields a porous structure, which further enhances the stability of the zinc electrode.

[0003] These methods are all based on interface design and involve processes such as magnetron sputtering, heat treatment, and smelting. These methods are complex and require a lot of time and cost, ranging from a few hours to several days or even dozens of days, which is extremely unfavorable for mass production of aqueous zinc batteries. Therefore, a method is designed to improve the cycle stability of the negative electrode of aqueous zinc batteries by ultrasonic vibration and pressure to solve the above problems. Summary of the Invention

[0004] The main objective of this invention is to provide a method for improving the cycle stability of the negative electrode of an aqueous zinc battery through ultrasonic vibration and pressure.

[0005] The objective of this invention can be achieved by adopting the following technical solution:

[0006] A method for improving the cycle stability of the negative electrode of an aqueous zinc battery by ultrasonic vibration and pressure includes the following steps:

[0007] A silver foil is placed on top of a zinc foil, and the silver foil and zinc foil are subjected to ultrasonic vibration and pressure treatment. The ultrasonic vibration frequency is 40KHz, and the ultrasonic trigger pressure is set to 22N.

[0008] When the ultrasonic punch contacts the sample and generates a force of 22N, it begins to release ultrasonic waves. The ultrasonic waves are released for about 2 seconds, which completes the process of silver penetrating into the zinc foil and forming a ZnAg alloy, thus completing the silver-modified zinc anode foil.

[0009] Preferably, the ultrasonic vibration and compression treatment time is 1-3 seconds or can be manually adjusted.

[0010] Preferably, the maximum pressure during the ultrasonic vibration and compression process is less than 100N.

[0011] Preferably, the ultrasonic frequency of the ultrasonic vibration compression treatment is 20-100kHz.

[0012] Preferably, the thickness of the silver foil is 5-50 μm.

[0013] Preferably, the zinc foil has a purity of ≥99.9%.

[0014] Preferably, the ultrasonic vibration compression treatment is performed at room temperature and in a vacuum environment.

[0015] Preferably, after ultrasonic vibration and pressing treatment, the silver foil is removed, and the silver content in the zinc matrix of the resulting silver-modified zinc anode foil is 15%-25%, with a penetration depth exceeding 200nm.

[0016] Preferably, the silver-modified zinc anode foil prepared by the method is used in aqueous zinc batteries.

[0017] Beneficial technical effects of the present invention:

[0018] This invention provides a method for improving the cycle stability of the negative electrode in an aqueous zinc battery through ultrasonic vibration and pressure treatment. The untreated zinc electrode has a cycle life of only 140 hours, while the zinc electrode treated with ultrasonic vibration and pressure treatment can achieve a cycle life of 970 hours, an improvement of nearly 6 times (e.g., Figure 6 (As shown). It exhibits excellent cycling stability at different current densities. For example, Example 2 has a cycle life of 850 hours at a current density of 1 A / g, and Example 3 has a cycle life of 1050 hours at a current density of 0.2 A / g, proving that the method can effectively cope with different working scenarios.

[0019] By infiltrating elemental silver into the zinc foil and forming an alloy phase, uniform nucleation sites are provided for zinc ion deposition, altering the deposition behavior of zinc ions. This effectively inhibits the growth of zinc dendrites, prevents dendrites from piercing the separator and causing a short circuit in the battery, and improves the stability of the battery during cycling.

[0020] The entire ultrasonic vibration compression process takes only 1-3 seconds (2 seconds for Example 1), which greatly improves production efficiency compared to traditional interface-based design methods (which take several hours to tens of days), and is extremely beneficial for mass production of aqueous zinc batteries.

[0021] No complex magnetron sputtering, heat treatment, or smelting processes are required. The silver foil can be placed on zinc foil using an ultrasonic vibration pressing device. The operation is simple and the equipment requirements are relatively low.

[0022] Elemental silver is recyclable, reducing material waste and lowering production costs. Compared to traditional methods, it eliminates the need for expensive equipment and significant time investment, offering clear advantages in both material and process costs.

[0023] X-ray diffraction (XRD) results showed that new diffraction peaks appeared on the surface of the zinc anode after ultrasonic compression treatment, which did not match the characteristic peaks of either zinc or silver, strongly proving that silver had penetrated into the zinc and formed an alloy phase (such as...). Figure 3 (As shown).

[0024] Energy-dispersive X-ray spectroscopy (EDS) elemental analysis revealed the presence of silver (e.g., 0.05%) on the zinc electrode surface. Figure 4 As shown); transmission electron microscopy (TEM) elemental analysis revealed that silver has penetrated into the zinc matrix at the nanoscale, with a silver content of approximately 15%-25% and a penetration depth exceeding 200 nanometers (as shown). Figure 5 As shown in the figure, this uniform distribution and sufficient penetration depth ensure that silver modification effectively improves the performance of zinc anodes. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the ultrasonic compression treatment of a zinc electrode material anode according to a preferred embodiment of a method for improving the cycle stability of an aqueous zinc battery anode by ultrasonic compression according to the present invention.

[0026] Figure 2 This is a real-time pressure and temperature curve during ultrasonic vibration compression, according to a preferred embodiment of a method for improving the cycle stability of an aqueous zinc battery negative electrode by ultrasonic vibration compression according to the present invention.

[0027] Figure 3 This is an XRD diagram depicting the silver diffusion on the zinc electrode surface, according to a preferred embodiment of a method for improving the cycle stability of an aqueous zinc battery negative electrode by ultrasonic vibration and pressure according to the present invention.

[0028] Figure 4 This is an elemental distribution diagram of the zinc electrode surface according to a preferred embodiment of a method for improving the cycle stability of the negative electrode of an aqueous zinc battery by ultrasonic vibration and pressure according to the present invention.

[0029] Figure 5 The image shows the elemental characterization of the zinc electrode surface under a transmission electron microscope according to a preferred embodiment of a method for improving the cycle stability of the negative electrode of an aqueous zinc battery by ultrasonic vibration and pressure according to the present invention.

[0030] Figure 6 This is a test graph of the battery cycle life according to a preferred embodiment of a method for improving the cycle stability of the negative electrode of an aqueous zinc battery by ultrasonic vibration and pressure according to the present invention. Detailed Implementation

[0031] To enable those skilled in the art to understand the technical solution of the present invention more clearly, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0032] This method employs ultrasonic vibration and pressing, using elemental silver to surface-modify the zinc foil of the aqueous zinc battery negative electrode. The silver foil is placed on top of the zinc foil and subjected to ultrasonic vibration and pressing, allowing the elemental silver to penetrate into the zinc foil. After vibration, the silver foil is removed, yielding a silver-modified zinc negative electrode foil sheet. The entire process takes only 2 seconds, with a maximum pressure below 100 N. Figure 2 This process is efficient and simple. Most importantly, elemental silver is recyclable, significantly reducing costs. To verify that elemental silver had successfully diffused into the zinc foil, we performed comprehensive characterization on the treated samples. X-ray diffraction (XRD) results showed that new diffraction peaks appeared on the surface of the zinc anode after ultrasonic pressure treatment. Figure 3 (Solid line). The illustration magnifies the new peak, clearly showing that its position does not match the characteristic peaks of either zinc or silver, strongly proving that silver has penetrated into the zinc and formed an alloy phase.

[0033] In addition, energy-dispersive X-ray spectroscopy (EDS) elemental analysis ( Figure 4 This indicates that silver was detected on the surface of the zinc electrode, further confirming that the ultrasonic vibration pressing treatment successfully diffused silver to the zinc electrode surface.

[0034] More in-depth transmission electron microscopy (TEM) elemental analysis Figure 5 The study revealed that silver has penetrated into the zinc matrix at the nanoscale, with the silver content in the zinc matrix being approximately 20% and the penetration depth exceeding 200 nanometers.

[0035] In summary, these characterization results consistently confirm that ultrasonic vibration and compression treatment not only promotes the diffusion of elemental silver into the zinc interior but also induces the formation of alloy phases, thereby effectively improving the performance of the zinc anode.

[0036] Battery cycle performance is one of the key indicators for measuring battery performance. Test results clearly show that the untreated zinc electrode has a cycle life of only 140 hours, while the zinc electrode treated with ultrasonic compression has a significantly extended cycle life of up to 970 hours. This significant improvement fully demonstrates the advantages of ultrasonic compression treatment of zinc electrodes.

[0037] Example 1;

[0038] The steps are as follows: Prepare zinc foil with a purity of 99.95%, a size of Φ10cm, and a thickness of 100μm; prepare silver foil with a thickness of 50μm and the same size as the zinc foil.

[0039] Place the silver foil flat on top of the zinc foil and put it into the ultrasonic vibration and pressing device.

[0040] Set the ultrasonic vibration parameters: ultrasonic frequency of 30kHz, processing time of 2 seconds, maximum applied pressure of 80N, and process at room temperature (25℃).

[0041] After ultrasonic compression treatment, the silver foil is carefully removed to obtain a silver-modified zinc anode foil.

[0042] Characterization and performance testing;

[0043] XRD characterization: The results showed a new diffraction peak at approximately 40.8° 2θ, confirming that silver and zinc formed an alloy phase.

[0044] EDS elemental analysis: The atomic fraction of silver on the zinc electrode surface is approximately 20%.

[0045] TEM elemental analysis showed that the penetration depth of silver in the zinc matrix was approximately 220 nm, and the silver content was approximately 20%.

[0046] Battery cycle life test: At a current density of 0.5 A / g, the cycle life can reach 970 hours.

[0047] Example 2;

[0048] The steps involve selecting zinc foil with a purity of 99.99%, a size of Φ15cm, and a thickness of 80μm; and silver foil with a thickness of 5μm and the same size as the zinc foil.

[0049] The silver foil is placed over the zinc foil and then placed in an ultrasonic vibration and pressing device.

[0050] The ultrasonic frequency was set to 20kHz, the processing time to 1 second, the maximum pressure to 50N, and the ultrasonic vibration and pressure treatment was carried out at room temperature (23℃).

[0051] After processing, the silver foil is removed to obtain a silver-modified zinc anode foil.

[0052] Characterization and performance testing;

[0053] XRD analysis revealed new alloy phase diffraction peaks, located in positions similar to those in Example 1.

[0054] EDS analysis showed that the atomic fraction of silver on the zinc electrode surface was approximately 18%.

[0055] TEM observation: The penetration depth of silver in the zinc matrix is ​​approximately 200 nm, and the silver content is approximately 18%.

[0056] Cyclic performance: Cyclic life reaches 850 hours at a current density of 1 A / g.

[0057] Example 3;

[0058] The steps are as follows: Prepare zinc foil with a purity of 99.9%, a size of 8cm, and a thickness of 150μm; silver foil with a thickness of 20μm and the same size.

[0059] Place the silver foil on top of the zinc foil and put it into an ultrasonic vibration and pressing device.

[0060] The ultrasonic frequency was set to 50kHz, the processing time to 3 seconds, the maximum pressure to 100N, and the treatment was carried out at room temperature (28℃).

[0061] After processing, the silver foil is removed, yielding a silver-modified zinc anode foil.

[0062] Characterization and performance testing;

[0063] XRD results: The diffraction peaks of the alloy phase are clearly visible, consistent with expectations.

[0064] EDS analysis showed that the atomic fraction of silver on the zinc electrode surface was approximately 22%.

[0065] TEM characterization: The penetration depth of silver in the zinc matrix exceeds 250 nm, and the silver content is approximately 22%.

[0066] Battery cycle test: At a current density of 0.2A / g, the cycle life can reach 1050 hours.

[0067] Example 4;

[0068] The steps involve taking zinc foil with a purity of 99.98%, measuring 2.5cm × 2.5cm and 50μm in thickness; and silver foil with a thickness of 30μm, with matching dimensions.

[0069] The silver foil is placed over the zinc foil and then placed in an ultrasonic vibration and pressing device.

[0070] The ultrasonic frequency was set to 80kHz, the processing time to 2.5 seconds, the maximum pressure to 70N, and the ultrasonic vibration and compression treatment was carried out at room temperature (26℃).

[0071] After processing, the silver foil is removed, yielding a silver-modified zinc anode foil.

[0072] Characterization and performance testing;

[0073] XRD analysis: The diffraction peaks of the alloy phase are obvious, consistent with the results of other examples.

[0074] EDS analysis showed that the atomic fraction of silver on the zinc electrode surface was approximately 21%.

[0075] TEM observation: The penetration depth of silver in the zinc matrix is ​​approximately 230 nm, and the silver content is approximately 21%.

[0076] Cyclic performance: The cycle life reaches 920 hours at a current density of 0.8 A / g.

[0077] Example 5;

[0078] The steps involve preparing zinc foil with a purity of 99.96%, a size of Φ10cm, and a thickness of 120μm; and silver foil with a thickness of 50μm and the same size.

[0079] Place the silver foil on top of the zinc foil and put it into the ultrasonic vibration and pressing device.

[0080] The ultrasonic frequency was set to 100kHz, the processing time to 1.5 seconds, the maximum pressure to 60N, and the treatment was carried out at room temperature (24℃).

[0081] After processing, the silver foil is removed, yielding a silver-modified zinc anode foil.

[0082] Characterization and performance testing;

[0083] XRD characterization: The diffraction peaks of the alloy phase are clearly visible.

[0084] EDS elemental analysis: The atomic fraction of silver on the zinc electrode surface is approximately 19%.

[0085] TEM elemental analysis showed that the penetration depth of silver in the zinc matrix was approximately 210 nm, with a silver content of approximately 19%.

[0086] Battery cycle life test: At a current density of 1.2 A / g, the cycle life can reach 780 hours.

[0087] Example 6;

[0088] The steps involve preparing zinc foil with a purity of 99.96%, a size of Φ10cm, and a thickness of 120μm; and copper foil with a thickness of 50μm and the same size.

[0089] Place the copper foil on top of the zinc foil and put it into the ultrasonic vibration and pressing device.

[0090] The ultrasonic frequency was set to 100kHz, the processing time to 1.5 seconds, the maximum pressure to 60N, and the treatment was carried out at room temperature (24℃).

[0091] After processing, the copper foil is removed to obtain copper-modified zinc negative electrode foil.

[0092] Characterization and performance testing;

[0093] XRD characterization: The diffraction peaks of the alloy phase are clearly visible.

[0094] EDS elemental analysis: The atomic fraction of copper on the zinc electrode surface is approximately 10%.

[0095] TEM elemental analysis showed that copper penetrated to a depth of approximately 150 nm in the zinc matrix, with a copper content of about 10%.

[0096] Battery cycle life test: At a current density of 1.2 A / g, the cycle life can reach 880 hours.

[0097] The above description is merely a further embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A method for improving the cycle stability of the negative electrode of an aqueous zinc battery by ultrasonic vibration and pressure, characterized in that: Includes the following steps: A silver foil is placed on top of a zinc foil, and the silver foil and zinc foil are subjected to ultrasonic vibration and pressure treatment. The ultrasonic vibration frequency is 20-100kHz, and the ultrasonic trigger pressure is set to 50-100N. When the ultrasonic punch contacts the sample and generates a force of 50-100N, it begins to release ultrasonic waves. The ultrasonic wave release time is 1-3s, which completes the process of silver penetrating into the zinc foil and forming a ZnAg alloy. After the ultrasonic vibration and pressing treatment is completed, the silver foil is removed to obtain a silver-modified zinc negative electrode foil. The thickness of the silver foil is 5-50 μm.

2. The method for improving the cycle stability of the negative electrode of an aqueous zinc battery by ultrasonic vibration and pressure according to claim 1, characterized in that: The ultrasonic vibration and compression treatment takes 2 seconds.

3. The method for improving the cycle stability of the negative electrode of an aqueous zinc battery by ultrasonic vibration and pressure according to claim 1, characterized in that: The trigger pressure during the ultrasonic vibration and compression process is 80N.

4. The method for improving the cycle stability of the negative electrode of an aqueous zinc battery by ultrasonic vibration and pressure according to claim 1, characterized in that: The ultrasonic frequency of the ultrasonic vibration compression treatment is 40kHz.

5. The method for improving the cycle stability of the negative electrode of an aqueous zinc battery by ultrasonic vibration and pressure according to claim 1, characterized in that: The zinc foil has a purity of ≥99.9%.

6. The method for improving the cycle stability of the negative electrode of an aqueous zinc battery by ultrasonic vibration and pressure according to claim 1, characterized in that: The ultrasonic vibration compression treatment was carried out at room temperature and in a vacuum environment.

7. The method for improving the cycle stability of the negative electrode of an aqueous zinc battery by ultrasonic vibration and pressure according to claim 1, characterized in that: After ultrasonic vibration and pressure treatment, the silver foil is removed, and the silver content in the zinc matrix of the resulting silver-modified zinc anode foil is 15%-25%, with a penetration depth of more than 200nm.

8. The application of the silver-modified zinc anode foil prepared by the method of improving the cycle stability of the anode of an aqueous zinc battery by ultrasonic vibration and pressure as described in claim 1 in an aqueous zinc battery.

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