阅读说明：本技术 一种锂电池极耳材料及其加工工艺 (Lithium battery tab material and processing technology thereof ) 是由 覃超 郑楠 何在专 于 2020-12-21 设计创作，主要内容包括：本发明涉及材料轧制技术领域,公开了一种锂电池极耳材料及其加工工艺,其中,极耳材料的加工工艺包括以下步骤：原材料选取、复合处理、抛光处理、第一次扩散退火处理、压延处理。本发明提供的一种锂电池极耳材料的加工工艺,通过一定的机械咬合将纯镍带、SPCC钢带和纯铜带复合为一体,通过上述加工工艺生产出的极耳材料综合了镍、钢和铜的性能特点,不但具有很好的导电性能,还有一定的强度和韧性,而且还具有很好的焊接性能,同时电阻率低,生产成本低。(The invention relates to the technical field of material rolling, and discloses a lithium battery tab material and a processing technology thereof, wherein the processing technology of the tab material comprises the following steps: selecting raw materials, carrying out composite treatment, polishing treatment, carrying out first diffusion annealing treatment and calendaring treatment. According to the processing technology of the lithium battery tab material, the pure nickel strip, the SPCC steel strip and the pure copper strip are compounded into a whole through certain mechanical engagement, and the tab material produced through the processing technology integrates the performance characteristics of nickel, steel and copper, has good conductivity, certain strength and toughness, good welding performance, low resistivity and low production cost.)

1. The processing technology of the lithium battery tab material is characterized by comprising the following steps:

selecting raw materials: selecting a pure nickel strip with the thickness of 0.5-1.0mm and the width of 100-; wherein the hardness of the pure nickel strip is 90-110HV1.0, the hardness of the SPCC steel strip is 100-140HV1.0, and the hardness of the pure copper strip is 70-80HV 1.0;

performing composite treatment: calendering and compounding the selected pure nickel strip, the SPCC steel strip and the pure copper strip, and simultaneously providing certain heat energy for the pure nickel strip, the SPCC steel strip and the pure copper strip respectively so as to control the temperature of the pure nickel strip to be 200-plus-300 ℃, the temperature of the SPCC steel strip to be 150-plus-300 ℃, the temperature of the pure copper strip to be 150-plus-200 ℃, and compounding the pure nickel strip, the SPCC steel strip and the pure copper strip into a whole to obtain a composite strip;

polishing treatment: polishing the surface of the composite strip obtained after the composite treatment to remove impurities generated on the surface of the composite strip in the composite process;

first diffusion annealing treatment: performing primary diffusion annealing treatment on the polished composite strip at the annealing temperature of 700-900 ℃;

rolling treatment: and rolling the composite strip subjected to diffusion annealing treatment for multiple times by using a multi-roll rolling mill until the composite strip is rolled to the thickness of 0.05-0.30 mm.

2. The process for manufacturing a tab material for a lithium battery as claimed in claim 1, wherein the process further comprises the steps of, before the step of compounding:

cleaning treatment: and respectively cleaning the surfaces of the selected pure nickel strip, the SPCC steel strip and the pure copper strip.

3. The processing technology of the tab material for the lithium battery as claimed in claim 2, wherein the cleaning treatment specifically comprises the steps of:

carrying out surface polishing, impurity removal and deoxidization on the selected pure nickel strip, SPCC steel strip and pure copper strip through polishing equipment;

and carrying out surface drying treatment on the polished, impurity-removed and oxidized pure nickel strip, the SPCC steel strip and the pure copper strip by drying equipment.

4. The process for manufacturing a tab material for a lithium battery as claimed in claim 1, wherein in the step of the composite treatment:

and (2) calendering and compounding the pure nickel strip, the SPCC steel strip and the pure copper strip through a pressure compounding machine, wherein an inert gas or an ammonia decomposition gas (N2, H2) is introduced into the pressure compounding machine so that the pure nickel strip, the SPCC steel strip and the pure copper strip are calendered and compounded in an inert atmosphere or a reducing atmosphere.

5. The process for manufacturing a tab material for a lithium battery as claimed in claim 1, wherein in the step of the rolling treatment,

performing one or more times of softening annealing treatment on the composite strip between any two times of rolling the composite strip, wherein the annealing temperature is 800-; the multi-roll rolling mill produces work hardening when the composite strip is rolled for multiple times, and the softening annealing treatment is used for eliminating the work hardening produced in the rolling treatment process of the composite strip.

6. The process for manufacturing a tab material for a lithium battery as claimed in claim 1, further comprising the steps of, after the step of calendering:

and (3) second diffusion annealing treatment: and performing second diffusion annealing treatment on the finished product strip subjected to the rolling treatment, wherein the annealing temperature is 700-900 ℃, so that the hardness of the finished product strip meets the required hardness requirement.

7. The process for manufacturing a tab material for a lithium battery as claimed in claim 1, further comprising the steps of, after the step of calendering:

surface treatment: removing rolling oil on the surface of the finished product strip and drying;

cutting and packaging: the finished strip is cut into the desired size and packaged.

8. A tab material for a lithium battery, wherein the tab material is processed by the processing technology of any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of material rolling, in particular to a lithium battery tab material and a processing technology thereof.

Background

With the development of new energy industry, lithium ion batteries are widely applied to new energy vehicles, electric tools, electric toys and other objects requiring large electric quantity. The lithium ion battery has four main materials, which are respectively: the lithium ion battery comprises a positive electrode material, a negative electrode material, a diaphragm and electrolyte, and further comprises a positive electrode lug, a negative electrode lug, a shell and the like besides four main materials. The positive and negative pole lugs are conductor parts for leading out electric energy. In the prior art, the production process of the lithium ion battery is mature, an aluminum strip is generally adopted as a positive electrode tab material, and a nickel strip is generally adopted as a negative electrode tab material.

The nickel strap has the characteristics of good conductivity, excellent welding performance, strong corrosion resistance and the like, and is generally applied to a negative pole tab material in the market. However, pure nickel has a high resistivity, which has a great influence on a large-capacity battery. The copper-nickel composite strip which is developed at present reduces the resistivity of the material, replaces a pure nickel strip in a high-capacity battery, but has higher cost.

Disclosure of Invention

The invention aims to provide a lithium battery tab material and a processing technology thereof, and aims to solve the problem that the resistivity of the tab material in a lithium battery is high in the prior art.

The invention is realized in such a way that in a first aspect, the invention provides a processing technology of a lithium battery tab material, which comprises the following steps:

selecting raw materials: selecting a pure nickel strip with the thickness of 0.5-1.0mm and the width of 100-; wherein the hardness of the pure nickel strip is 90-110HV1.0, the hardness of the SPCC steel strip is 100-140HV1.0, and the hardness of the pure copper strip is 70-80HV 1.0;

performing composite treatment: calendering and compounding the selected pure nickel strip, the SPCC steel strip and the pure copper strip, and simultaneously providing certain heat energy for the pure nickel strip, the SPCC steel strip and the pure copper strip respectively so as to control the temperature of the pure nickel strip to be 200-plus-300 ℃, the temperature of the SPCC steel strip to be 150-plus-300 ℃, the temperature of the pure copper strip to be 150-plus-200 ℃, and compounding the pure nickel strip, the SPCC steel strip and the pure copper strip into a whole to obtain a composite strip;

polishing treatment: polishing the surface of the composite strip obtained after the composite treatment to remove impurities generated on the surface of the composite strip in the composite process;

first diffusion annealing treatment: performing primary diffusion annealing treatment on the polished composite strip at the annealing temperature of 700-900 ℃;

rolling treatment: and rolling the composite strip subjected to diffusion annealing treatment for multiple times by using a multi-roll rolling mill until the composite strip is rolled to the thickness of 0.05-0.30 mm.

Further, before the step of the composite treatment, the processing technology further comprises the following steps:

cleaning treatment: and respectively cleaning the surfaces of the selected pure nickel strip, the SPCC steel strip and the pure copper strip.

Further, the cleaning process specifically includes the steps of:

carrying out surface polishing, impurity removal and deoxidization on the selected pure nickel strip, SPCC steel strip and pure copper strip through polishing equipment;

and carrying out surface drying treatment on the polished, impurity-removed and oxidized pure nickel strip, the SPCC steel strip and the pure copper strip by drying equipment.

Further, in the step of the composite processing:

and (2) calendering and compounding the pure nickel strip, the SPCC steel strip and the pure copper strip through a pressure compounding machine, wherein an inert gas or an ammonia decomposition gas (N2, H2) is introduced into the pressure compounding machine so that the pure nickel strip, the SPCC steel strip and the pure copper strip are calendered and compounded in an inert atmosphere or a reducing atmosphere.

Further, in the step of the rolling treatment,

performing one or more times of softening annealing treatment on the composite strip between any two times of rolling the composite strip, wherein the annealing temperature is 800-; the multi-roll rolling mill produces work hardening when the composite strip is rolled for multiple times, and the softening annealing treatment is used for eliminating the work hardening produced in the rolling treatment process of the composite strip.

Further, after the step of calendering, the method further comprises the following steps:

and (3) second diffusion annealing treatment: and performing secondary diffusion annealing treatment on the finished product strip subjected to the rolling treatment, wherein the annealing temperature is 700-900 ℃, so that the hardness of the finished product strip meets the required hardness requirement.

Further, after the step of calendering, the method further comprises the following steps:

surface treatment: removing rolling oil on the surface of the finished product strip and drying;

cutting and packaging: the finished strip is cut into the desired size and packaged.

In a second aspect, the invention further provides a lithium battery tab material, and the tab material is processed by the processing technology.

Compared with the prior art, the processing technology of the lithium battery tab material provided by the invention fully utilizes the plastic deformation of metal and the intermetallic atom diffusion principle, combines the pure nickel strip, the SPCC steel strip and the pure copper strip into a whole through certain mechanical engagement, and the tab material produced by the processing technology integrates the performance characteristics of nickel, steel and copper, has good conductivity, certain strength and toughness, good welding performance, low resistivity and low production cost.

Drawings

Fig. 1 is a schematic flow chart of a processing process of a tab material of a lithium battery according to a first embodiment of the present invention;

fig. 2 is a schematic flow chart of a process for manufacturing a tab material of a lithium battery according to a second embodiment of the present invention;

fig. 3 is a schematic flow chart of a process for manufacturing a tab material of a lithium battery according to a third embodiment of the present invention;

fig. 4 is a schematic flow chart of a process for manufacturing a tab material of a lithium battery according to a fourth embodiment of the present invention;

fig. 5 is a schematic structural diagram of a tab material of a lithium battery according to an embodiment of the present invention.

Reference numerals: 1-nickel band layer, 2-SPCC steel band layer and 3-copper band layer.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The same or similar reference numerals in the drawings of the present embodiment correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. based on the orientation or positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but it is not intended to indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and are not to be construed as limiting the present patent, and the specific meaning of the terms may be understood by those skilled in the art according to specific circumstances.

The following describes the implementation of the present invention in detail with reference to specific embodiments.

A processing process of a lithium battery tab material according to a first embodiment of the present invention is shown in fig. 1, and referring to fig. 2, the processing process of the lithium battery tab material includes the following steps:

step S10, selecting raw materials: selecting a pure nickel strip with the thickness of 0.5-1.0mm (such as 0.5mm, 0.8mm or 1.0mm) and the width of 100-150mm (such as 100mm, 125mm or 150mm), selecting an SPCC steel strip with the thickness of 0.7-3.0mm (such as 0.7mm, 2.0mm or 3.0mm) and the width of 100-150mm (such as 100mm, 125mm or 150mm), and selecting a pure copper strip with the thickness of 1.0-2.0mm (such as 1.0mm, 1.5mm or 2.0mm) and the width of 100-150mm (such as 100mm, 125mm or 150 mm); wherein the hardness of the pure nickel strip is 90-110HV1.0 (such as 90HV1.0, 100HV1.0 or 110HV1.0), the hardness of the SPCC steel strip is 100-140HV1.0 (such as 100HV1.0, 120HV1.0 or 140HV1.0), and the hardness of the pure copper strip is 70-80HV1.0 (such as 70HV1.0, 75HV1.0 or 80HV 1.0).

Step S20, composite processing: calendering and compounding the selected pure nickel strip, the SPCC steel strip and the pure copper strip, and simultaneously respectively providing certain heat energy for the pure nickel strip, the SPCC steel strip and the pure copper strip so as to control the temperature of the pure nickel strip to be 200-300 ℃ (such as 200 ℃, 250 ℃ or 300 ℃), control the temperature of the SPCC steel strip to be 150-300 ℃ (such as 150 ℃, 200 ℃ or 300 ℃), control the temperature of the pure copper strip to be 150-200 ℃ (such as 150 ℃, 175 ℃ or 200 ℃), and compound the pure nickel strip, the SPCC steel strip and the pure copper strip into a whole to obtain a compound strip; the composite strip obtained after compounding is broken back and forth at 90 degrees, and the end face is not separated to serve as the qualified standard of compounding.

Preferably, the pure nickel strip, the SPCC steel strip and the pure copper strip are subjected to rolling compounding through a pressure compounding machine, and in order to ensure the cleanliness among the selected nickel strip, SPCC steel strip and pure copper strip, an inert gas or an ammonia decomposition gas (N2, H2) is introduced into the pressure compounding machine so that the pure nickel strip, the SPCC steel strip and the pure copper strip are subjected to rolling compounding in an inert atmosphere or a reducing atmosphere; therefore, impurities (such as oxides) between the two materials can be prevented, the cleanliness between the materials is ensured, and substances with poor plasticity are not generated, so that the bonding strength between different materials is influenced.

Step S30, polishing: and polishing the surface of the composite strip obtained after the composite treatment by using a polishing machine, and removing impurities generated on the surface of the composite strip in the composite process so as to eliminate defects (such as scratches, indentations, pits and the like) generated on the surface of a product in the processing process.

Step S40, first diffusion annealing: performing first diffusion annealing treatment on the polished composite strip, wherein the annealing temperature is 700-900 ℃ (for example, 700 ℃, 800 ℃ or 900 ℃); different annealing temperatures can be selected through different deformation amounts, and the annealing mainly aims to enable the composite interface of the composite strip to be bonded more tightly through diffusion of atoms between materials, so that the composite strength of a product is enhanced.

Step S50, rolling: and rolling the composite strip subjected to diffusion annealing treatment for multiple times by using a multi-roll rolling mill until the composite strip is rolled to the thickness of 0.05-0.30 mm.

Preferably, the composite strip is subjected to one or more softening annealing treatments between any two rolling of the composite strip, the annealing temperature being 800-; the multi-roll rolling mill produces work hardening when the composite strip is rolled for multiple times, and the softening annealing treatment is used for eliminating the work hardening produced in the rolling treatment process of the composite strip.

According to the processing technology of the lithium battery tab material, the principle of plastic deformation of metal and intermetallic atomic diffusion is fully utilized, the pure nickel strip, the SPCC steel strip and the pure copper strip are compounded into a whole through certain mechanical engagement, and the tab material produced through the processing technology integrates the performance characteristics of nickel, steel and copper, has good conductivity, certain strength and toughness, good welding performance, low resistivity and low production cost.

Based on the first embodiment of the present invention, a second embodiment of the present invention is provided, and fig. 2 is a schematic flow chart of a processing process of a lithium battery tab material according to the second embodiment of the present invention, please refer to fig. 2, before the step S20, the processing process further includes the following steps:

step S101, cleaning: and respectively cleaning the surfaces of the selected pure nickel strip, the SPCC steel strip and the pure copper strip.

After the cleaning treatment in the step S101, and then the step S2 is performed, the composite strength between the pure nickel strip, the SPCC steel strip and the pure copper strip can be greatly improved, and the composite effect of the composite strip can be improved.

It should be noted that step S101 specifically includes the following steps:

step S1011: carrying out surface polishing, impurity removal and deoxidization on the selected pure nickel strip, SPCC steel strip and pure copper strip through polishing equipment; thus, impurities and metal oxides on the surfaces of the pure nickel strip, the SPCC steel strip and the pure copper strip can be removed.

Step S1012: carrying out surface drying treatment on the polished, impurity-removed and oxidized pure nickel strip, the SPCC steel strip and the pure copper strip through drying equipment; therefore, the surfaces of the pure nickel strip, the SPCC steel strip and the pure copper strip can be kept dry, and potential quality hazards such as water stains/water spots are avoided.

Based on the first embodiment of the present invention, a third embodiment of the present invention is provided, fig. 3 is a schematic flow chart of a processing process of a lithium battery tab material provided by the third embodiment of the present invention, please refer to fig. 3, after the step S50, the processing process further includes the following steps:

step S501, second diffusion annealing: and carrying out secondary diffusion annealing treatment on the finished strip subjected to the rolling treatment, wherein the annealing temperature is 700-900 ℃ (such as 700 ℃, 800 ℃ or 900 ℃) so as to enable the hardness of the finished strip to reach the required hardness requirement, and the hardness of the finished strip is the same at different annealing temperatures.

Based on the first embodiment of the present invention, a fourth embodiment of the present invention is provided, fig. 4 is a schematic flow chart of a processing process of a lithium battery tab material according to the fourth embodiment of the present invention, please refer to fig. 4, after the step S50, the processing process further includes the following steps:

step S502, surface treatment: and removing the rolling oil on the surface of the finished product strip and drying the rolling oil, thereby ensuring the smoothness of the surface of the finished product strip.

Step S503, slitting and packaging: cutting the finished strip into required sizes and packaging; specifically, the finished strips of different specifications are cut according to the sizes of the finished strips, and the cut finished strips are subjected to vacuum packaging.

In a specific embodiment, the processing technology of the tab material comprises the following steps,

step S10, selecting raw materials:

nickel strip: 0.5X 115mm, HV1.0:160,

copper strip: 2.0X 115mm, HV1.0:80,

SPCC steel belt: 1.0X 115mm, HV1.0: 110;

step S101, cleaning: polishing the surfaces of the three strips by using a polishing machine, washing the surfaces by using hot water after polishing, and drying the surfaces by using hot air to ensure that the surfaces have no impurities, water spots and the like;

step S20, composite processing: the composite is carried out on a two-roller rolling composite machine, wherein the upper layer is a nickel strip, the middle layer is an SPCC steel strip, the lower layer is a copper strip, and the three strips are compounded together. The temperature of the nickel strip at the roll gap is controlled to be 180 ℃, the temperature deviation is +/-5 ℃, the temperature of the SPCC steel strip at the roll gap is controlled to be 250 ℃, the temperature deviation is +/-5 ℃, the temperature of the copper strip at the roll gap is controlled to be 180 ℃, the temperature deviation is +/-5 ℃, ammonia decomposition gases (N2 and H2) are introduced into a rolling mill for protecting the strip before the strip enters a roll, the gas flow rate is controlled to be 7Nm3/H, the thickness of a rolling outlet of a compound machine is 2.0mm, so that the thickness of the compound strip after compounding is 2.0mm, the compound strip is broken at 90 degrees after compounding, the section has no separation phenomenon, and the compound strength is qualified;

step S30, polishing: and cleaning black impurities, scraps, lines and the like on the surface of the compounded strip by using a polishing machine, and simultaneously drying by using hot water and a drying facility.

Step S40, first diffusion annealing: after cleaning, carrying out heat treatment in a bright annealing furnace at 850 ℃ and 1m/min, after annealing, enabling the composite interface of the composite strip to be more tightly combined, enhancing the composite strength of the product, eliminating the processing hardness of the strip and facilitating the later cold processing;

step S50, rolling: carrying out back and forth rolling on a four-roller rolling machine after annealing for 20 times, and carrying out softening annealing on the semi-finished product and then rolling until the thickness of the product is 0.08mm in the rolling process;

step S501, second diffusion annealing: annealing the rolled finished strip at 830 ℃, and keeping the hardness of the nickel strip controlled at HV1.0: 80;

step S502, surface treatment: carrying out surface degreasing and drying on the finished product strip on a cleaning machine to ensure that the surface of the finished product strip has no quality defect;

step S503, slitting and packaging: and slitting and packaging the finished strip according to the size requirement.

Referring to fig. 5, the invention further provides a lithium battery tab material, which is obtained by processing the processing technology and comprises a nickel strip layer 1, an SPCC steel strip layer 2 and a copper strip layer 3 which are sequentially stacked from top to bottom.

According to the lithium battery tab material, the pure nickel strip, the SPCC steel strip and the pure copper strip are compounded into a whole through certain mechanical engagement, so that the tab material integrates the performance characteristics of nickel, steel and copper, has good conductivity, certain strength and toughness, good welding performance, low resistivity and low production cost.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.