Detection method for nickel-plated steel shell of battery

Abstract

The invention provides a method for detecting a nickel-plated steel shell of a battery, which comprises the following steps of: firstly, taking a heating device, setting the temperature of the heating device to be a preset temperature value which is set according to the thermal expansion coefficient of metal nickel, then, placing the nickel-plated steel shell to be detected into the heating device, and heating for a first preset time, and the nickel-plated steel shell is taken out of the heating device and put into room-temperature liquid to be quenched for second preset time, and finally whether the adhesion strength of the plating layer of the nickel-plated steel shell is qualified or not is detected according to the bubbling condition of the quenched nickel-plated steel shell. The method realizes effective detection of the adhesion strength of the steel shell nickel plating layer, can prevent battery scrapping caused by corrosion of the steel shell plating layer, can prevent battery scrapping caused by corrosion of the steel shell plating layer, and is high in plating layer adhesion strength detection efficiency and simple and feasible in detection mode.

Description

[Technical field]

[0001] The invention relates to the technical field of batteries, and in particular to a method for detecting a nickel-plated steel shell of a battery. [Background technology]

[0002] Cylindrical lithium batteries mostly use steel materials with strong physical stability as the shell material. In order to prevent the oxidation of the steel shell by the positive active material of the battery, nickel plating is usually used to protect the iron matrix of the steel shell. The adhesion strength of the nickel plating layer on the steel shell is one of the important bases for judging the quality of the nickel plating on the steel shell, but there is currently no detection method for the adhesion strength of the nickel plating layer on the steel shell in the market. If the adhesion strength of the nickel plating layer on the steel shell is not enough, the coating of the steel shell will fall off in the subsequent battery cell manufacturing process, resulting in corrosion of the steel shell, micro short circuit of the battery cell, etc., which will reduce the electrical performance of the battery or even cause it to fail and be scrapped.

[0003] In view of this, it is necessary to provide a new detection method for nickel-plated steel shell of battery to overcome the above defects. [Summary of the invention]

[0004] The purpose of the present invention is to provide a method for detecting nickel-plated steel shells of batteries to solve the above technical problems.

[0005] In order to achieve the above object, the present invention provides a method for detecting a nickel-plated steel shell of a battery, comprising the following steps:

[0006] Take a heating device and set the temperature of the heating device to a preset temperature value; the preset temperature value is set according to the thermal expansion coefficient of metal nickel;

[0007] Placing the nickel-plated steel shell to be tested in the heating device and heating it for a first preset time;

[0008] Taking out the nickel-plated steel shell from the heating device and placing it in a room temperature liquid to quench for a second preset time;

[0009] Whether the coating adhesion strength of the nickel-plated steel shell is qualified is detected according to the blistering condition of the nickel-plated steel shell after rapid cooling.

[0010] In a preferred embodiment, the preset temperature value is 290°C to 310°C.

[0011] In a preferred embodiment, the heating device is an electric constant temperature blast drying oven.

[0012] In a preferred embodiment, the step of taking a heating device and setting the temperature of the heating device to a preset temperature value comprises:

[0013] Turn on the electric constant temperature blast drying oven for preheating and set the temperature to 300℃.

[0014] In a preferred embodiment, the first preset time is 0.5-1 hour.

[0015] In a preferred embodiment, the room temperature liquid is water at 25°C.

[0016] In a preferred embodiment, the second preset time is 2-3 minutes.

[0017] In a preferred embodiment, the step of detecting whether the coating adhesion strength of the nickel-plated steel shell is qualified according to the blistering condition of the nickel-plated steel shell after quenching comprises:

[0018] If the coating on the surface of the nickel-plated steel shell does not bubble or fall off, the coating adhesion strength of the nickel-plated steel shell is qualified;

[0019] If the coating on the surface of the nickel-plated steel shell has bubble-like holes or falls off, the coating adhesion strength of the nickel-plated steel shell is unqualified.

[0020] Compared with the prior art, the method for detecting the nickel-plated steel shell of a battery provided by the present invention first takes a heating device and sets the temperature of the heating device to a preset temperature value, which is set according to the thermal expansion coefficient of metal nickel. The nickel-plated steel shell to be detected is then placed in the heating device and heated for a first preset time. The nickel-plated steel shell is then taken out of the heating device and placed in a room temperature liquid for rapid cooling for a second preset time. Finally, the coating adhesion strength of the nickel-plated steel shell is detected to be qualified according to the bubbling condition of the nickel-plated steel shell after rapid cooling. This realizes the effective detection of the adhesion strength of the nickel-plated layer of the steel shell, can prevent the battery from being scrapped due to the corrosion of the steel shell coating, can prevent the battery from being scrapped due to the corrosion of the steel shell coating, has high coating adhesion strength detection efficiency, and is simple and easy to detect.

Brief Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 The present invention is a flow chart of the method for detecting the nickel-plated steel shell of a battery.

[0023] Figure 2 This is a schematic diagram of the structure with qualified adhesion strength of the nickel-plated steel shell coating.

[0024] Figure 3 This is a schematic diagram of the structure in which the adhesion strength of the nickel-plated steel shell coating is unqualified. [Specific implementation method]

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0026] See also Figure 1 , which is a flow chart of the method for detecting the nickel-plated steel shell of a battery provided by the present invention. Specifically, there is no corresponding detection method for the adhesion strength of the nickel-plated layer of the steel shell in the prior art, and it is impossible to judge whether the nickel-plated layer of the steel shell meets the requirements of the battery cell process, which will cause inevitable losses and increase the manufacturing cost. The detection method for the adhesion strength of the nickel-plated layer of the steel shell of the present invention can simply and effectively detect whether the adhesion strength of the coating is qualified in advance, and prevent the loss caused by the mixing of bad steel shells into production.

[0027] The method for detecting the nickel-plated steel shell of a battery provided by the present invention comprises the following steps:

[0028] Step S10: Take a heating device, and set the temperature of the heating device to a preset temperature value; the preset temperature value is set according to the thermal expansion coefficient of metal nickel. Specifically, the heating device has a receiving space, which can accommodate the sample to be tested and can be heated to increase the temperature of the sample to be tested in the space, and the temperature of the heating device can be set by itself. In this embodiment, the temperature set by the heating device is set according to the thermal expansion coefficient of metal nickel. The thermal expansion coefficient is the volume change caused by a unit temperature change. Since the thermal expansion coefficients of the plated metal nickel and the steel shell body are different, the degree of deformation when the temperature rises is different. Therefore, the temperature corresponding to the deformation of the metal nickel and the non-deformation of the steel shell body is selected as the preset temperature value. The preset temperature value is 290℃~310℃, which can cause the nickel plating layer to deform while the steel shell body does not deform.

[0029] In some embodiments, the heating device is an electric constant temperature blast drying oven, which is a more common heating device, mainly used for baking, drying, heat treatment and heating of items. A reasonable hot air circulation channel is designed inside the oven to make the temperature distribution inside the oven more uniform and the temperature rise faster.

[0030] In this embodiment, step S10: taking a heating device and setting the temperature of the heating device to a preset temperature value comprises:

[0031] Preheat the electric constant temperature blast drying oven and set the temperature to 300°C. Preheat the electric constant temperature blast drying oven in advance and set the temperature to 300°C (±10°C). After reaching the set temperature, put the nickel-plated steel shell to be tested in. This can more accurately control the heating time and make the final temperature of the nickel-plated steel shell more accurate.

[0032] Step S20: placing the nickel-plated steel shell to be detected in the heating device and heating it for a first preset time. Specifically, after the nickel-plated steel shell to be detected is heated in the heating device for a certain period of time, the nickel-plated steel shell to be detected reaches a preset temperature value of the heating device, and the first preset time is 0.5-1 hour, that is, after the nickel-plated steel shell is placed in the heating device for 0.5-1 hour, the temperature of the nickel-plated steel shell reaches the temperature set by the heating device, that is, the preset temperature value.

[0033] Step S30: Take out the nickel-plated steel shell from the heating device, and put it into the room temperature liquid for rapid cooling for a second preset time. Specifically, after the nickel-plated steel shell is heated in the heating device for the first preset time, take out the nickel-plated steel shell, and quickly put it into the room temperature liquid for rapid cooling. The room temperature liquid is 25°C water, and the second preset time is 2-3 minutes. It can be understood that the temperature difference between the preset temperature value of the heating device and the room temperature liquid is 270°C to 290°C. The sample is subjected to a temperature alternation test in an environment with a certain temperature difference (270°C to 290°C), and the change in the bonding strength of the coating after the change in this different temperature environment is detected, so as to detect whether the coating adhesion strength is qualified.

[0034] Step S40: detecting whether the coating adhesion strength of the nickel-plated steel shell is qualified according to the blistering condition of the nickel-plated steel shell after rapid cooling.

[0035] In some embodiments, step S40: the step of detecting whether the coating adhesion strength of the nickel-plated steel shell is qualified according to the blistering condition of the nickel-plated steel shell after quenching, comprises:

[0036] If the coating on the surface of the nickel-plated steel shell does not bubble or fall off, the coating adhesion strength of the nickel-plated steel shell is qualified;

[0037] If the coating on the surface of the nickel-plated steel shell has bubble-like holes or falls off, the coating adhesion strength of the nickel-plated steel shell is unqualified.

[0038] Specifically, after the nickel-plated steel shell is heated and suddenly cooled, if the coating does not bubble or fall off, it means that the bonding between the coating and the steel shell body is strong and the coating adhesion strength is qualified. If the coating has bubble holes or falls off, it means that the bonding between the coating and the steel shell body is poor and the coating adhesion strength is unqualified.

[0039] The method 100 for detecting the nickel-plated steel shell of a battery provided by the present invention comprises the following steps: firstly taking a heating device, and setting the temperature of the heating device to a preset temperature value, wherein the preset temperature value is set according to the thermal expansion coefficient of metal nickel; then placing the nickel-plated steel shell to be detected in the heating device, heating it for a first preset time; then taking the nickel-plated steel shell out of the heating device, and placing it in a room temperature liquid for rapid cooling for a second preset time; finally, detecting whether the coating adhesion strength of the nickel-plated steel shell is qualified according to the bubbling condition of the nickel-plated steel shell after rapid cooling; thereby realizing effective detection of the adhesion strength of the nickel-plated layer of the steel shell, preventing the battery from being scrapped due to corrosion of the steel shell coating; and preventing the battery from being scrapped due to corrosion of the steel shell coating. The coating adhesion strength detection efficiency is high, and the detection method is simple and easy.

[0040] The following is an experiment on the detection method of the nickel-plated steel shell of the battery provided by the present invention:

[0041] 1) Preheat the electric constant temperature air drying oven in advance and set the temperature to 300℃ (±10℃);

[0042] 2) After reaching the set temperature, the temperature error is allowed to be ±10℃, and the sample steel shell to be tested is placed in the drying oven for 0.5h~1h;

[0043] 3) Take out the sample steel shell and quickly put it into room temperature water to quench for 2 minutes;

[0044] 4) Check whether the coating on the surface of the steel shell is bubbling or falling off.

[0045] Judgment criteria: Figure 2 As shown in the figure, if there is no blistering or peeling of the coating on the surface of the steel shell, the sample steel shell meets the requirements of the subsequent process and can be used; Figure 3 As shown in the figure, if bubble-like holes appear on the surface coating of the steel shell and fall off, the adhesion strength of the nickel plating layer of the sample steel shell is low. During the subsequent assembly and rolling groove, the coating may fall off due to excessive external impact force, causing a micro-short circuit inside the battery.

[0046] The battery nickel-plated steel shell detection method provided by the present invention has a detection principle based on the principle that the thermal expansion coefficient of the plated metal nickel and the steel shell is different and the deformation difference occurs. The sample is subjected to a temperature alternation test in an environment with a certain temperature difference (270°C to 290°C) to detect the change in the bonding strength of the coating after the change in the different temperature environments. The detection method of the adhesion strength of the nickel-plated steel shell of the present invention can be simple and effective for early detection, and prevent the loss caused by the mixing of bad steel shells into production.

[0047] The above description is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for detecting nickel-plated steel shell of a battery, characterized in that: The steps include: Take a heating device and set the temperature of the heating device to a preset temperature value; the preset temperature value is set according to the thermal expansion coefficient of metal nickel; Placing the nickel-plated steel shell to be tested in the heating device and heating it for a first preset time; Taking out the nickel-plated steel shell from the heating device and placing it in a room temperature liquid to quench for a second preset time; Whether the coating adhesion strength of the nickel-plated steel shell is qualified is detected according to the blistering condition of the nickel-plated steel shell after rapid cooling.

2. The method for detecting nickel-plated steel shell of a battery as claimed in claim 1, characterized in that: The preset temperature value is 290°C to 310°C.

3. The method for detecting nickel-plated steel shell of a battery as claimed in claim 1, characterized in that: The heating device is an electric constant temperature blast drying oven.

4. The method for detecting nickel-plated steel shell of a battery as claimed in claim 3, characterized in that: The step of taking a heating device and setting the temperature of the heating device to a preset temperature value comprises: Turn on the electric constant temperature blast drying oven for preheating and set the temperature to 300℃.

5. The method for detecting nickel-plated steel shell of a battery as claimed in claim 1, characterized in that: The first preset time is 0.5-1 hour.

6. The method for detecting nickel-plated steel shell of a battery as claimed in claim 1, characterized in that: The room temperature liquid is water at 25°C.

7. The method for detecting nickel-plated steel shell of a battery as claimed in claim 1, characterized in that: The second preset time is 2-3 minutes.

8. The method for detecting nickel-plated steel shell of a battery according to any one of claims 1 to 7, characterized in that: The step of detecting whether the coating adhesion strength of the nickel-plated steel shell is qualified according to the blistering condition of the nickel-plated steel shell after quenching comprises: If the coating on the surface of the nickel-plated steel shell does not bubble or fall off, the coating adhesion strength of the nickel-plated steel shell is qualified; If the coating on the surface of the nickel-plated steel shell has bubble-like holes or falls off, the coating adhesion strength of the nickel-plated steel shell is unqualified.

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