Application of layered zinc-copper composite belt material

Abstract

The invention provides application of a layered zinc-copper composite strip, and relates to the technical field of energy storage batteries. The thickness of the layered zinc-copper composite strip is 0.01-0.2 mm, the thickness of the copper layer is 0.01-0.05 mm, the thickness of the zinc layer is 0.01-0.2 mm, and the thickness of the copper layer accounts for 20-30% of the total thickness of the layered zinc-copper composite strip. According to the invention, the layered zinc-copper composite strip is applied to the negative electrode material of the water-based zinc battery, and excellent conductivity and ductility of copper are utilized; a substrate is provided for zinc deposition in the charging process, and battery failure caused by electrode pulverization is prevented. In addition, copper has relatively high zinc affinity, so that uniform deposition of zinc is facilitated, generation and volume change of zinc dendrites are reduced, and the composite zinc metal negative electrode material with long cycle life is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of energy storage batteries, and in particular relates to the application of a layered zinc-copper composite strip material. Background Art

[0002] With the vigorous development of my country's emerging green industries, the new energy industry has developed rapidly, and the demand for related materials has also increased. Lithium-ion batteries are currently the most widely used battery system with high energy density and cycle life. However, lithium resources are limited, and the high price of lithium-related materials has also increased the cost of batteries. In addition, the organic electrolyte used in lithium-ion batteries is flammable, which brings safety risks of fire and explosion to the battery.

[0003] In contrast, metallic zinc has the advantages of low price, abundant reserves and high theoretical capacity. Aqueous zinc batteries are low-cost and highly safe, and have broad application prospects in the fields of large-scale energy storage and wearable products. However, zinc metal negative electrodes have the problem of uneven deposition and dissolution of zinc ions at the negative electrode, which brings serious dendrite problems and volume changes to the battery. At present, aqueous zinc batteries directly use zinc strips as negative electrodes. Zinc metal not only serves as an active substance, but also as a current collector, which greatly reduces the utilization rate of zinc metal. In addition, at a higher depth of discharge, a large amount of zinc dissolves, the zinc strip structure collapses and shatters, and the lack of a current collector as a substrate for zinc deposition leads to battery failure.

[0004] In order to improve the utilization rate of zinc metal anode and extend the battery life, constructing a composite zinc anode with a heterogeneous current collector is the main direction to promote the application of aqueous zinc batteries. By introducing a current collector, a better substrate can be provided for zinc deposition, zinc dendrite-free deposition can be achieved during the charging process, and the volume change during zinc deposition can be reduced. The traditional method is to deposit zinc as an active material on the current collector by electroplating to obtain a composite zinc anode. However, the method of preparing a composite zinc metal anode by electrodeposition has high energy consumption, serious pollution, and the electrode structure of the zinc metal anode is not easy to control. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an application of a layered zinc-copper composite strip. The layered zinc-copper composite strip provided by the present invention has high cycle performance, can solve the electrode pulverization problem faced by the zinc strip negative electrode, and can better alleviate the electrode volume expansion.

[0006] In order to achieve the above object, the present invention provides the following technical solutions.

[0007] The invention discloses an application of a layered zinc-copper composite strip, wherein the layered zinc-copper composite strip is used as a negative electrode material of an aqueous zinc battery.

[0008] The present invention applies the layered zinc-copper composite strip to the negative electrode material of the aqueous zinc battery, and utilizes the excellent conductivity and ductility of copper to provide a substrate for zinc deposition during the charging process, thereby preventing the electrode from pulverizing and causing battery failure. In addition, copper has a high affinity for zinc, which helps zinc to deposit uniformly, reduces zinc dendrite generation and volume changes, and obtains a composite zinc metal negative electrode material with a long cycle life.

[0009] Preferably, the thickness of the layered zinc-copper composite strip is 0.01-0.2 mm, wherein the thickness of the copper layer is 0.01-0.05 mm, the thickness of the zinc layer is 0.01-0.2 mm, and the thickness of the copper layer accounts for 20-30% of the total thickness of the layered zinc-copper composite strip.

[0010] The thickness of the layered zinc-copper composite strip is controlled within the above range, and the final performance is optimal. The thickness of the copper layer accounts for 20-30% of the total thickness. Copper and zinc are easily alloyed, and there is obvious alloying at the copper-zinc interface, making the combination more compact. In addition, copper has excellent electrical conductivity, which can improve the overall conductivity while playing a supporting role. If the copper layer is too thick, the energy density will be reduced.

[0011] In a preferred embodiment, the layered zinc-copper composite strip is produced by explosive composite.

[0012] The desired electrode structure can be obtained in a controllable manner through explosive compounding, and metallurgical bonding is formed between the layered zinc-copper composite strips through explosive compounding, thereby achieving good cycle stability.

[0013] According to a preferred embodiment, the preparation process of the layered zinc-copper composite strip is as follows: explosively composite a copper plate and a zinc plate to obtain a layered copper-zinc composite plate, anneal the layered copper-zinc composite plate, and then roll and cut the layered zinc-copper composite strip.

[0014] In the actual operation process, the surface of the copper plate and the zinc plate are first polished to remove the surface oxide layer and the passivation layer.

[0015] In a preferred embodiment, the thickness of the copper plate is 2-10 mm, the thickness of the zinc plate is 3-20 mm, and the thickness of the copper plate is 20-30% of the thickness of the layered copper-zinc composite plate.

[0016] In a preferred embodiment, the explosive composite process is as follows: placing a copper plate on a platform, evenly placing a support frame on its surface, placing a zinc plate on the support frame, and laying explosives on its surface to perform explosive composite to obtain a copper-zinc composite layered material, wherein the height of the support frame is 2-4 mm.

[0017] In the actual operation process, before the explosive compounding, the copper plate and the zinc plate are polished to remove the surface oxide layer and the passivation layer.

[0018] In a preferred embodiment, the explosives used in the explosive composite are composed, by mass percentage, of 80-85% expanded ammonium nitrate, 3-5% No. 2 rock ammonium nitrate explosive, 2-5% porous ammonium nitrate, 4-8% diesel, 4-6% powdered emulsion explosive, and 3-5% salt.

[0019] By using the above explosive formula and controlling the thickness of the copper plate to 20-30% of the thickness of the layered copper-zinc composite plate, copper and zinc can be easily alloyed. There is obvious alloying at the copper-zinc interface, making the combination tighter. In addition, copper has excellent electrical conductivity, which can improve the overall conductivity while playing a supporting role.

[0020] In a preferred embodiment, the annealing temperature is 250-350° C. and the annealing time is 1-3 hours.

[0021] In a preferred embodiment, the rolling process is to first perform 5-7 passes of rough rolling until the thickness of the rolled plate is 1-1.5 mm, and then perform 10-16 passes of finish rolling.

[0022] Benefits of the Invention (1) The zinc and copper composite is used as the composite negative electrode of the zinc battery. The excellent conductivity and ductility of copper provide a base for zinc deposition during the charging process, preventing the electrode from pulverizing and causing battery failure. In addition, copper has a high affinity for zinc, which helps zinc to deposit evenly, reduce zinc dendrite formation and volume change, and obtain a composite zinc metal negative electrode material with a long cycle life.

[0023] (2) Explosive bonding is a technique that uses explosives to weld metals. It can bond metals with very different properties such as melting point, strength, thermal expansion coefficient, etc., while avoiding the formation of brittle metal compounds. The materials bonded by explosive bonding are tightly bonded and are widely used. The present invention uses explosive bonding to bond copper and zinc and use them as composite metal negative electrode strips, achieving good cycle stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the cross-sectional structure of explosively composite copper-zinc composite strip. DETAILED DESCRIPTION

[0025] In order to make the technical problems to be solved, technical solutions and advantages of the present invention more clear, they are described in detail below in conjunction with specific embodiments.

[0026] Example 1 Copper and zinc plates with thicknesses of 2 mm and 5 mm were selected, and the surfaces of the copper and zinc plates were polished to remove impurities, oxide layers and passivation layers on the surfaces. The treated copper plates were placed on a platform, and support frames were evenly placed on their surfaces. The height of the support frames was 3 mm. Then the treated zinc plates were placed on the support frames. 85% expanded ammonium nitrate, 4% No. 2 rock ammonium nitrate explosives, 4% porous ammonium nitrate and diesel, 4% powdered emulsion explosives and 3% salt were laid on the zinc plates. The explosives were detonated to obtain explosively composited copper-zinc composite metal plates. The rolled copper-zinc composite plates were annealed and kept at 300℃ for 2 hours. Then the copper-zinc composite metal plates were rolled and cut. The rough rolling was repeated 5 times until the total thickness of the rolled plates was 1 mm, and then the fine rolling was repeated 12 times. Finally, the copper-zinc composite metal strips that met the requirements were obtained. The thickness was 0.1 mm, of which the copper plate thickness was 0.03 mm and the zinc plate thickness was 0.07 mm.

[0027] Example 2 Copper and zinc plates with thicknesses of 2 mm and 8 mm were selected, and the surfaces of the copper and zinc plates were polished to remove impurities, oxide layers and passivation layers on the surfaces. The treated copper plates were placed on a platform, and support frames were evenly placed on the surface. The height of the support frames was 3 mm. Then the treated zinc plates were placed on the support frames. 85% expanded ammonium nitrate, 4% No. 2 rock ammonium nitrate explosives, 4% porous ammonium nitrate and diesel, 4% powdered emulsion explosives and 3% salt were laid on the zinc plates. The explosives were detonated to obtain explosively composited copper-zinc composite metal plates. The rolled copper-zinc composite plates were annealed and kept at 300℃ for 2 hours. Then the copper-zinc composite metal plates were rolled and cut. The rough rolling was repeated 6 times until the total thickness of the rolled plates was 1.3 mm. The fine rolling was repeated 12 times. Finally, the copper-zinc composite metal strips that met the requirements were obtained. The thickness was 0.15 mm, of which the copper plate thickness was 0.03 mm and the zinc plate thickness was 0.12 mm.

[0028] Comparative Example 1 Pure zinc is used as the negative electrode.

[0029] Comparative Example 2 Copper and zinc plates with thicknesses of 3 mm and 4 mm, respectively, were selected, and the surfaces of the copper and zinc plates were polished to remove impurities, oxide layers and passivation layers on the surfaces. The treated copper plates were placed on a platform, and support frames were evenly placed on their surfaces. The height of the support frames was 3 mm. Then the treated zinc plates were placed on the support frames. 85% expanded ammonium nitrate, 4% No. 2 rock ammonium nitrate explosives, 4% porous ammonium nitrate and diesel, 4% powdered emulsion explosives and 3% salt were laid on the zinc plates. The explosives were detonated to obtain explosively composited copper-zinc composite metal plates. The rolled copper-zinc composite plates were annealed and kept at 300℃ for 2 hours. Then the copper-zinc composite metal plates were rolled and cut. The rough rolling was performed 6 times until the total thickness of the rolled plates was 1.2 mm, and then the fine rolling was performed 12 times. Finally, the copper-zinc composite metal strips that met the requirements were obtained. The thickness was 0.1 mm, of which the copper plate thickness was 0.04 mm and the zinc plate thickness was 0.06 mm.

[0030] The corrosion resistance and cycle performance of the obtained embodiments and comparative examples were tested under the following conditions: the current density was 5 mA / cm 2 , the single charge or discharge time is 1 hour, that is, 5mA h / cm 2 The capacity of the electrode is measured and the results are listed in Table 1. From the data in Table 1, it can be seen that the copper-zinc composite negative electrode obtained in the embodiment has excellent corrosion resistance and cycle life, while the comparative example has parameters that are not within the scope of the present invention, so the performance is worse than that of the embodiment.

[0031]

Claims

1. An application of a layered zinc-copper composite strip, characterized in that: The layered zinc-copper composite strip is used as a negative electrode material for an aqueous zinc battery.

2. The use of a layered zinc-copper composite strip according to claim 1, characterized in that: The thickness of the layered zinc-copper composite strip is 0.01-0.2 mm, wherein the thickness of the copper layer is 0.01-0.05 mm, the thickness of the zinc layer is 0.01-0.2 mm, and the thickness of the copper layer accounts for 20-30% of the total thickness of the layered zinc-copper composite strip.

3. The use of the layered zinc-copper composite strip according to claim 1 or 2, characterized in that: The layered zinc-copper composite strip is made by explosive composite.

4. The use of the layered zinc-copper composite strip according to claim 1 or 2, characterized in that: The preparation process of the layered zinc-copper composite strip is as follows: explosively composite a copper plate and a zinc plate to obtain a layered copper-zinc composite plate, anneal the layered copper-zinc composite plate, and then roll and cut to obtain the layered zinc-copper composite strip.

5. The use of the layered zinc-copper composite strip according to claim 1 or 2, characterized in that: The thickness of the copper plate is 2-10 mm, the thickness of the zinc plate is 3-20 mm, and the thickness of the copper plate is 20-30% of the thickness of the layered copper-zinc composite plate.

6. The use of the layered zinc-copper composite strip according to claim 1 or 2, characterized in that: The explosive composite process is as follows: placing a copper plate on a platform, evenly placing a support frame on the surface of the copper plate, placing a zinc plate on the support frame, and laying explosives on the surface of the copper plate to perform explosive composite to obtain a copper-zinc composite layered material, wherein the height of the support frame is 2-4 mm.

7. The use of the layered zinc-copper composite strip according to claim 1 or 2, characterized in that: The explosives used in the explosive composite are composed of the following by mass percentage: 80-85% expanded ammonium nitrate, 3-5% No. 2 rock ammonium nitrate explosive, 2-5% porous ammonium nitrate, 4-8% diesel, 4-6% powdered emulsion explosive, and 3-5% salt.

8. The use of the layered zinc-copper composite strip according to claim 1 or 2, characterized in that: The annealing temperature is 250-350° C., and the annealing time is 1-3 hours.

9. The use of the layered zinc-copper composite strip according to claim 1 or 2, characterized in that: The rolling process is to first perform 5-7 passes of rough rolling until the thickness of the rolled plate is 1-1.5 mm, and then perform 10-16 passes of finish rolling.

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