Battery detection method

Abstract

The application discloses a battery detection method, comprising the following steps: providing a test battery, the test battery comprising a first shell, a first positive electrode and a first negative electrode; providing a reference voltage range and measuring a detection voltage between the first positive electrode and the first shell of the test battery, judging that the detection voltage is located in the reference voltage range, then the battery is normal; wherein the reference voltage range is obtained by the following steps: providing a reference battery, measuring a voltage between the first positive electrode and the first shell of the reference battery to obtain V1; providing a three-electrode battery, measuring a voltage between the second positive electrode and the reference electrode of the three-electrode battery to obtain V2; connecting resistors with different resistance values between one of the electrodes of all the reference batteries and the first shell, and measuring the voltage between the first positive electrode and the first shell to obtain V3; the reference voltage range V=V3+(V1-V2). The reference voltage range obtained by the method has high accuracy, and the accuracy of the detection of the battery failure can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery detection method. BACKGROUND

[0002] In the process of battery production or use, the positive and negative electrodes of the battery can be in direct contact with the shell, causing lithium ions to preferentially embed into the aluminum shell through the electrolyte during charging and discharging, producing lithium-embedded compounds, and causing corrosion of the battery shell to liquid leakage, affecting the normal and safe use of the battery.

[0003] Currently, the battery generally adopts a structure in which the positive electrode is in electrical conduction with the shell and the negative electrode is insulated from the shell, i.e., the battery is a single-insulation battery. The single-insulation battery determines whether the shell is corroded by real-time monitoring of the voltage between the positive electrode and the shell. If the voltage exceeds the voltage boundary value when the shell is corroded, it means that the battery is corroded. The voltage boundary value when the shell is corroded is determined by measuring the voltage between the positive electrode and the shell of a plurality of batteries when corrosion occurs, and determining the range of the voltage boundary value according to the measured voltage. Since there is almost no potential between the shell and the electrolyte of the single-insulation battery, the measured voltage between the positive electrode and the shell is not affected.

[0004] For a battery in which both the positive electrode and the negative electrode are insulated from the shell, i.e., a double-insulation battery, there is an ion channel between the electrode, the electrolyte and the shell, and there is a potential between the shell and the electrolyte. The voltage between the positive electrode and the shell of the double-insulation battery directly monitored may include the potential between the shell and the electrolyte. If the above-mentioned voltage boundary value determination method for the single-insulation battery is still used to determine the voltage boundary value range when the shell is corroded, the positive electrode and the shell of the double-insulation battery need to be electrically connected first, and then the voltage between the positive electrode and the shell of a plurality of double-insulation batteries when corrosion occurs is monitored in real time, and the range of the voltage boundary value is determined according to the measured voltage. However, since the positive electrode and the shell of the double-insulation battery are electrically connected, it is equivalent to the battery becoming a single-insulation battery in which the positive electrode is in electrical conduction with the shell and the negative electrode is insulated from the shell. Therefore, the voltage between the positive electrode and the shell of the double-insulation battery measured in the test does not include the potential between the shell and the electrolyte. Therefore, the voltage boundary value range obtained by using the above-mentioned method for the battery with this structure may be smaller, and the battery that has not corroded but exceeds the voltage boundary value range may be determined as corroded, reducing the accuracy of the detection. SUMMARY

[0005] The purpose of the embodiment of the present application is to provide a battery detection method which can effectively improve the accuracy of battery corrosion failure detection.

[0006] To achieve the above purpose, the present application adopts the following technical solution:

[0007] A battery detection method is provided, comprising the following steps:

[0008] A test battery is provided, comprising a first shell and an electrode, the electrode comprising a first positive electrode and a first negative electrode, both of which are arranged in insulation with the first shell;

[0009] A reference voltage range is provided;

[0010] A detection voltage between the first positive electrode and the first shell of the test battery is measured, and it is determined whether the detection voltage is within the reference voltage range, if the detection voltage is within the reference voltage range, the test battery is normal;

[0011] The reference voltage range is obtained by the following steps:

[0012] Step S1, a plurality of reference batteries consistent with the structure of the test battery are provided, and the voltage between the first positive electrode and the first shell of all the reference batteries is measured to obtain the voltage range V1 of the reference battery when it is normal;

[0013] Step S2, a plurality of three-electrode batteries are provided, the three-electrode battery comprising a second shell, a second positive electrode, a second negative electrode and a reference electrode, all of which are insulated with the second shell, and the material of the reference electrode is the same as that of the first shell;

[0014] The voltage between the second positive electrode and the reference electrode of all the three-electrode batteries is measured to obtain the voltage range V2 of the three-electrode battery when it is normal;

[0015] Step S3, a resistor with different resistance is connected between one of the electrodes of all the reference batteries and the first shell, and the voltage between the first positive electrode and the first shell is measured to obtain the voltage range V3 between the first positive electrode and the first shell when the reference battery is not corroded;

[0016] Step S4, the reference voltage range V=V3+(V1-V2).

[0017] As a preferred scheme of the battery detection method, the step S2 specifically comprises the following steps:

[0018] Step S201, the first shell of the reference battery that passes the detection is provided, the first shell is cut into a strip-shaped piece, and then the piece is polished;

[0019] Step S202, a first diaphragm is wrapped outside the piece;

[0020] Step S203, providing a core package of the reference battery, inserting one end of the sheet into the core package to form the reference electrode;

[0021] Step S204, providing a second shell and an electrolyte, installing the core package into the second shell, then injecting the electrolyte into the second shell, and packaging the second shell; wherein the reference electrode extends to the outside of the second shell away from one end of the core package, and the three-electrode battery is prepared.

[0022] As a preferred solution of the battery detection method, the second shell is made of an aluminum plastic film.

[0023] As a preferred solution of the battery detection method, in the step S201, the sheet is cut into a first section and a second section with an included angle, in the step S204, the second shell is provided with a through hole, the core package includes a positive electrode sheet, a negative electrode sheet, and a second separator between the negative electrode sheet and the positive electrode sheet, and the first section is inserted into the second shell through the through hole away from one end of the second section and vertically inserted between the negative electrode sheet and the second separator.

[0024] As a preferred solution of the battery detection method, after the step S204, it further includes a step S205 of filling an insulating seal between the first section and the hole wall of the through hole.

[0025] As a preferred solution of the battery detection method, the length of the second section is 3-5 cm, the width is 1-2 cm, and the thickness is 0.05-0.1 cm.

[0026] As a preferred solution of the battery detection method, the step S3 specifically includes the following steps:

[0027] Step S301, all the reference batteries are subjected to charge-discharge cycle operation;

[0028] Step S302, connecting batteries with different resistance values between the first positive electrode of a part of the reference batteries and the first shell, and connecting batteries with different resistance values between the first negative electrode of a part of the reference batteries and the first shell, to simulate the corrosion failure of the reference batteries respectively;

[0029] Step S303, after a period of time, disassembling the reference batteries, and observing and judging whether the first shell is corroded, and measuring the voltage between the first positive electrode and the first shell of the reference batteries when the reference batteries are disassembled, to obtain the voltage range V3 between the first positive electrode and the first shell when the reference batteries are not corroded.

[0030] As a preferred solution of the battery detection method, in the step S303, after the reference battery is disassembled, whether the first shell is corroded is observed by a scanning electron microscope and an energy spectrometer.

[0031] As a preferred solution of the battery detection method, the reference voltage range is less than 1.3V.

[0032] As a preferred solution of the battery detection method, the voltage range V1 of the reference battery when it works normally is 0.5-0.7V, the voltage range V2 of the three-electrode battery when it works normally is 0.35-0.5V, and the voltage range V3 between the first positive electrode and the first shell when the reference battery does not corrode is less than 1.15V.

[0033] The present application has the following advantages: since the material of the reference electrode is the same as that of the first shell, the second electrode is equivalent to the first electrode, the voltage range V2 measured between the second positive electrode and the reference electrode is equivalent to the voltage between the first positive electrode and the first shell of the reference battery, V2 does not contain the potential between the electrolyte and the first shell, V1 and V2 can be compared to determine whether the voltage between the first positive electrode and the first shell of the reference battery directly measured contains the potential between the first shell and the electrolyte, and the potential between the first shell and the electrolyte can be obtained according to the difference between V1 and V2, and the voltage range V3 between the first positive electrode and the first shell of the reference battery when the reference battery is simulated to be short-circuited and fails does not contain the potential between the electrolyte and the shell, therefore, the potential between the first shell and the electrolyte can be compensated by modifying the voltage range V3, the reference voltage range V of the double-insulated battery shell when it corrodes is obtained, the accuracy of the reference voltage range V is improved, and the failure detection of the double-insulated battery is more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0034] The present application will be further described in detail below according to the drawings and embodiments.

[0035] Figure 1 The flowchart of the determination method of the reference range according to the embodiments of the present application.

[0036] Figure 2 The structure diagram of the three-electrode battery according to the embodiments of the present application.

[0037] Figure 3 The SEM image of the first shell when it is not corroded according to the embodiments of the present application.

[0038] Figure 4 The SEM image of the first shell when it is corroded according to the embodiments of the present application.

[0039] In the drawings:

[0040] 1, second housing; 2, second positive electrode; 3, second negative electrode; 4, reference electrode; 41, first section; 42, second section; 5, core package. DETAILED DESCRIPTION

[0041] In order to make the technical problems solved by the present application, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the embodiments of the present application will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0042] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] The present application provides a battery detection method for detecting whether the battery is corroded and invalid. The battery detection method comprises the following steps:

[0044] A test battery is provided, which comprises a first housing and an electrode, the electrode comprising a first positive electrode and a first negative electrode, both of which are insulated from the first housing, i.e. the test battery is a double-insulated battery;

[0045] A reference voltage range is provided;

[0046] The detection voltage between the first positive electrode and the first housing of the test battery is measured, and it is judged whether the detection voltage is within the reference voltage range. If the detection voltage is within the reference voltage range, it means that the test battery is normal, and if the detection voltage exceeds the reference voltage range, it means that the first housing of the test battery is corroded and invalid. This method can monitor the change of the detection voltage between the first positive electrode and the first housing of the battery in real time, detect whether the battery housing is corroded and invalid, and timely issue an alarm, so as to avoid the threat to the personal safety of the user due to the failure of the battery to work normally.

[0047] Among them, the reference Figure 1 and Figure 2 The reference voltage range is obtained by the following steps:

[0048] Step S1, providing a plurality of reference batteries consistent with the structure of the test battery, measuring the voltage between the first positive electrode and the first shell of all reference batteries to obtain the voltage range V1 of the reference battery when it works normally,

[0049] Step S2, providing a plurality of three-electrode batteries, the three-electrode battery comprising a second shell 1, a second positive electrode 2 insulated from the second shell 1, a second negative electrode 3 and a reference electrode 4, the material of the reference electrode 4 being the same as that of the first shell, and the structure of the three-electrode battery being the same as that of the test battery except for the reference electrode 4 and the second shell 1;

[0050] Measuring the voltage between the second positive electrode 2 and the reference electrode 4 of all three-electrode batteries to obtain the voltage range V2 of the three-electrode battery when it works normally;

[0051] Since the material of the reference electrode 4 is the same as that of the first shell, the second positive electrode 2 is equivalent to the first positive electrode, and the voltage range V2 measured between the second positive electrode 2 and the reference electrode 4 is equivalent to measuring the voltage between the first positive electrode and the first shell of the reference battery, and V2 does not include the potential between the electrolyte and the first shell;

[0052] Step S3, connecting resistors with different resistances between one of the electrodes of all reference batteries and the first shell to simulate the short-circuit failure caused by the contact between the battery shell and the electrode, and measuring the voltage between the first positive electrode and the first shell to obtain the voltage range V3 between the first positive electrode and the first shell of the reference battery when it is not corroded;

[0053] Connecting one of the electrodes of the reference battery and the first shell to the resistor and electrically connecting them, and keeping the other electrode insulated from the first shell, which is equivalent to changing the double-insulated reference battery into a single-insulated reference battery, therefore, the measured V3 does not include the potential between the electrolyte and the shell;

[0054] Step S4, the reference voltage range V = V3 + (V1-V2);

[0055] In the above method, the difference between V1 and V2 can be used to determine whether the potential between the first shell and the electrolyte is included when measuring the voltage between the first positive electrode and the first shell of the reference battery, if there is a difference between V1 and V2, it means that the voltage between the first positive electrode and the first shell of the reference battery directly measured contains the potential between the first shell and the electrolyte, and the potential between the first shell and the electrolyte of the reference battery needs to be added to V3 to correct the reference voltage range V; if V1 and V2 are equal, it means that the voltage between the first positive electrode and the first shell of the reference battery directly measured does not contain the potential between the first shell and the electrolyte. Therefore, the reference voltage range obtained by the above method is more accurate, which reduces the situation of judging the double-insulated battery that has not corroded as corroded, thereby improving the accuracy of the detection.

[0056] Specifically, the voltage range V1 of the reference battery when working normally is 0.5-0.7V, and the voltage range V2 of the three-electrode battery when working normally is 0.35-0.5V. The inventors have found through experiments that there is indeed a difference between V1 and V2, and therefore, when testing the double-insulated battery, the voltage directly measured between the first positive electrode and the first shell includes the potential between the first shell and the electrolyte.

[0057] Specifically, in step S3, the voltage range V3 between the first positive electrode and the first shell of the reference battery when not corroded is less than 1.15V.

[0058] According to the test data described above, the reference voltage range is less than 1.3V, i.e., the reference voltage range of the double-insulated battery is less than 1.3V, and if the monitored test voltage of the double-insulated battery exceeds 1.3V, it indicates that the battery is corroded.

[0059] Optionally, the first shell is an aluminum shell or a steel shell.

[0060] Specifically, step S2 specifically includes the following steps:

[0061] Step S201, providing the first shell of the reference battery that passes the test, cutting the first shell into a strip-shaped piece, and then polishing the piece with sandpaper to remove burrs;

[0062] Step S202, wrapping the first piece with a first diaphragm on the outside;

[0063] Step S203, providing the core package 5 of the reference battery as the core package 5 of the three-electrode battery, inserting one end of the piece into the core package 5 to form the reference electrode 4;

[0064] Step S204, providing the second shell 1 and the electrolyte, installing the core package 5 into the second shell 1, then injecting the electrolyte into the second shell 1, and packaging the second shell 1 to obtain the three-electrode battery; wherein the end of the reference electrode 4 away from the core package 5 extends to the outside of the second shell 1.

[0065] In the above method, the reference electrode 4 can be isolated from the core package 5 and the electrolyte through the first diaphragm, so as to ensure that the voltage measured between the reference electrode 4 and the second positive electrode 2 does not include the potential between the reference electrode 4 and the electrolyte, thereby preventing the potential between the reference electrode 4 and the electrolyte from interfering with the accuracy of the test structure.

[0066] Optionally, in step S202, the outside of the piece is completely wrapped with the first diaphragm; or, the part of the piece inserted into the second shell 1 is wrapped with the first diaphragm, so as to save the first diaphragm.

[0067] Specifically, the core pack 5 includes a positive electrode sheet, a negative electrode sheet, and a second separator arranged between the negative electrode sheet and the positive electrode sheet, and one end of the reference battery is located between the negative electrode sheet and the second separator. This design directly inserts the reference electrode 4 into the core pack 5, fully utilizes the existing components and structures of the three-electrode battery itself, and does not need to introduce other accessories, thereby greatly improving the assembly efficiency of the three-electrode battery, and avoiding the increase of interference factors caused by the introduction of other accessories.

[0068] Preferably, the three-electrode battery is a soft package battery, and the second shell 1 of the three-electrode battery is made of an aluminum plastic film. The three-electrode battery is packaged by the aluminum plastic film, which is convenient and fast to disassemble and assemble, and can improve the test efficiency.

[0069] Preferably, the core pack 5 includes a positive electrode tab and a negative electrode tab, the positive electrode tab is connected with the positive electrode sheet, and the negative electrode tab is connected with the negative electrode sheet. The positive electrode tab and the negative electrode tab both extend to the outside of the second shell 1 and form the second positive electrode 2 and the second negative electrode 3, thereby facilitating the connection of the positive electrode sheet and the negative electrode sheet with the external circuit for test work.

[0070] Preferably, the part of the reference electrode 4 extending to the outside of the second shell 1 is located on a different side of the second shell 1 from the positive electrode tab and the negative electrode tab. Since the three-electrode battery is packaged by the aluminum plastic film, the reference electrode 4 can be arranged on different sides of the second shell 1 by staggering the positive electrode tab and the negative electrode tab before packaging, thereby preventing the problem of increased packaging difficulty and overcrowding between components caused by arranging too many components on the same side of the second shell 1.

[0071] Optionally, in step S201, the sheet body is cut into a first segment 41 and a second segment 42 having an included angle. In this embodiment, the reference electrode 4 is in the shape of "L", and the first segment 41 and the second segment 42 are perpendicular. In step S204, the second shell 1 is provided with a through hole, and the core pack 5 is inserted into the second shell 1 through the through hole with one end of the first segment 41 away from the second segment 42, and is vertically inserted between the negative electrode sheet and the second separator, that is, the first segment 41 and the core pack 5 are vertically connected. At least part of the first segment 41 and the second segment 42 are located outside the second shell 1, the second segment 42 is used to connect with the external circuit, and the length of the second segment 42 is parallel to the length of the end face of the second shell 1 provided with the through hole. This design helps to increase the exposed connection area of the reference electrode 4, so as to facilitate the clamping of the reference electrode 4 and the external circuit.

[0072] Preferably, the second section 42 has a length of 3-5 cm, a width of 1-2 cm, and a thickness of 0.05-0.1 cm. Optionally, the second section 42 has a length of 3 cm, 3.5 cm, 4 cm, 4.5 cm, 5 cm, etc., a width of 1 cm, 1.5 cm, 2 cm, etc., and a thickness of 0.05 cm, 0.06 cm, 0.07 cm, 0.08 cm, 0.09 cm, 0.1 cm, etc. This design can make the second section 42 as flat as possible, which can ensure the connection area of the second section 42 and make the second section 42 thinner to facilitate connection.

[0073] Specifically, after step S204, step S205 of filling an insulating sealant (not shown in the figure) between the first section 41 and the hole wall of the through hole is further included. For example, the insulating sealant is a tab rubber, which can fill the gap between the first section 41 and the hole wall of the through hole to ensure the sealing of the second shell 1 and prevent electrolyte leakage, and can also insulate and isolate the gap between the reference electrode 4 and the hole wall of the through hole to prevent the reference electrode 4 from being affected by the potential between the reference electrode 4 and the second shell 1 to interfere with the accuracy of the detection data.

[0074] Specifically, step S3 specifically includes the following steps:

[0075] Step S301: all reference batteries are subjected to charge-discharge cycle operation;

[0076] Step S302: a part of the reference batteries are connected with batteries having different resistance values between the first positive electrode and the first shell, and a part of the reference batteries are connected with batteries having different gradient resistance values between the first negative electrode and the first shell, so as to simulate short-circuit failure of the reference batteries in different cases, so that the voltage between the first positive electrode and the first shell of all the reference batteries changes to different degrees;

[0077] Step S303: after the reference batteries are subjected to charge-discharge cycle for a period of time, the reference batteries are disassembled, and it is observed and judged whether the first shell is corroded, and the voltage between the first positive electrode and the first shell of all the reference batteries when disassembled is measured, and the voltage range V3 between the first positive electrode and the first shell of the reference batteries when not corroded is obtained.

[0078] In the embodiment, after the reference battery is disassembled in step S303, whether the first shell is corroded is observed by a scanning electron microscope (SEM) and an energy dispersive spectrometer (EDS). The scanning electron microscope is an observation means between a transmission electron microscope and an optical microscope, which uses a focused very narrow high-energy electron beam to scan a sample, excites various physical information through the interaction between the light beam and the substance, collects, amplifies and re-images the information to achieve the purpose of micro-morphology characterization of the first shell. The energy dispersive spectrometer is an instrument for analyzing the elements of a substance. The combination of the scanning electron microscope and the energy dispersive spectrometer can analyze the composition of the micro area of the substance while observing the micro morphology, so as to accurately judge whether the first shell is corroded.

[0079] Embodiment:

[0080] The following is the change of the voltage between the first positive electrode and the first shell of the reference battery measured by the above-mentioned method by the inventors of the present application on several reference batteries with an additional resistance:

[0081]

[0082] In the above table, different resistance values are applied between the electrodes and the first shell of several reference batteries, and the batteries are disassembled after six months of storage to observe and judge the corrosion state of the first shell of each of the several batteries and the voltage between the first shell and the first positive electrode of each reference battery at the time of disassembly.

[0083] In the embodiment, whether the first shell is corroded is observed by a scanning electron microscope and an energy dispersive spectrometer, wherein, Figure 3 the SEM image of the first shell that is not corroded, Figure 4 the SEM image of the first shell that is corroded.

[0084] According to the data in the above table, the first positive electrode and the first shell of the reference battery are corroded between 1.16V and 1.3V. Considering the inevitable errors in the measurement, in order to make the voltage range V3 more accurate and reliable, the inventors of the present application repeated the experiment several times and found that when the voltage range V3 between the first positive electrode and the first shell of the reference battery is less than 1.15V, the first shell will not be corroded.

[0085] In the description herein, it should be understood that the terms "upper", "lower", "left", "right", and the like orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only used to distinguish in the description, and have no special meaning.

[0086] In the description of the specification, the description referring to the terms "one embodiment", "an example", and the like means that the particular feature, structure, material, or characteristic following the term is included in at least one embodiment or example of the present application. The illustrative expressions are not necessarily referring to the same embodiment or example.

[0087] In addition, it should be understood that although the specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

[0088] The technical principles of the present application are described above in combination with specific embodiments. These descriptions are only for the purpose of explaining the principles of the present application, and cannot be interpreted in any way as a limitation on the scope of protection of the present application. Based on the explanations here, those skilled in the art can think of other specific embodiments of the present application without creative labor, and these ways will fall within the scope of protection of the present application.

Claims

1. A battery detection method, characterized by, The method comprises the following steps: providing a test battery, the test battery comprising a first shell and electrodes, the electrodes comprising a first positive electrode and a first negative electrode, the first positive electrode and the first negative electrode are both arranged in insulation with the first shell; providing a reference voltage range; measuring a detection voltage between the first positive electrode and the first shell of the test battery, and determining whether the detection voltage is within the reference voltage range, if the detection voltage is within the reference voltage range, the test battery is normal; wherein the reference voltage range is obtained by the following steps: step S1, providing a plurality of reference batteries consistent with the structure of the test battery, measuring the voltage between the first positive electrode and the first shell of all the reference batteries, and obtaining the voltage range V1 of the reference battery when it is working normally; step S2, providing a plurality of three-electrode batteries, the three-electrode battery comprising a second shell, a second positive electrode, a second negative electrode and a reference electrode which are all insulated with the second shell, the material of the reference electrode is the same as that of the first shell; measuring the voltage between the second positive electrode and the reference electrode of all the three-electrode batteries, and obtaining the voltage range V2 of the three-electrode battery when it is working normally; step S3, connecting resistors with different resistance values between one of the electrodes of all the reference batteries and the first shell, and measuring the voltage between the first positive electrode and the first shell, so as to obtain the voltage range V3 between the first positive electrode and the first shell when the reference battery does not corrode; step S4, the reference voltage range V=V3+(V1-V2).

2. The battery detection method of claim 1, wherein, The step S2 specifically comprises the following steps: step S201, providing the first shell of the reference battery which passes the detection, cutting the first shell into a strip-shaped piece, and then polishing the piece; step S202, coating a first diaphragm on the outer side of the piece; step S203, providing a core package of the reference battery, inserting one end of the piece into the core package and forming the reference electrode; step S204, providing a second shell and an electrolyte, installing the core package into the second shell, injecting the electrolyte into the second shell, and packaging the second shell; wherein the reference electrode extends to the outside of the second shell away from one end of the core package, and the three-electrode battery is prepared.

3. The battery detection method of claim 2, wherein, The second shell is made of an aluminum plastic film.

4. The battery detection method of claim 2, wherein, In the step S201, the piece is cut into a first segment and a second segment which have an included angle, in the step S204, the second shell is provided with a through hole, the core package comprises a positive electrode piece, a negative electrode piece and a second diaphragm arranged between the negative electrode piece and the positive electrode piece, and one end of the first segment away from the second segment is inserted into the second shell through the through hole and vertically inserted between the negative electrode piece and the second diaphragm.

5. The battery detection method of claim 4, wherein, After the step S204, the step S205 of filling an insulating sealing member between the first segment and the hole wall of the through hole is further included.

6. The battery detection method of claim 4, wherein, The length of the second segment is 3-5 cm, the width is 1-2 cm, and the thickness is 0.05-0.1 cm.

7. The battery detection method according to any one of claims 1 to 6, characterized by, The step S3 specifically comprises the following steps: Step S301, all the reference batteries are subjected to charge-discharge cycle operation; Step S302, a part of the reference batteries are connected with batteries of different resistance values between the first positive electrode and the first shell, and a part of the reference batteries are connected with batteries of different resistance values between the first negative electrode and the first shell, so as to simulate the corrosion failure of the reference batteries respectively; Step S303, after a period of time, the reference batteries are disassembled, and it is observed and judged whether the first shell is corroded, and meanwhile, the voltage between the first positive electrode and the first shell of the reference batteries when the reference batteries are disassembled is measured, so as to obtain the voltage range V3 between the first positive electrode and the first shell when the reference batteries are not corroded.

8. The battery detection method of claim 7, wherein, In the step S303, after the reference batteries are disassembled, it is observed by a scanning electron microscope and an energy spectrometer whether the first shell is corroded.

9. The battery detection method according to any one of claims 1 to 6, characterized by, The reference voltage range is less than 1.3 V.

10. The battery detection method of claim 9, wherein, The voltage range V1 of the reference battery when the reference battery is normally operated is 0.5-0.7 V, the voltage range V2 of the three-electrode battery when the three-electrode battery is normally operated is 0.35-0.5 V, and the voltage range V3 between the first positive electrode and the first shell when the reference battery is not corroded is less than 1.15 V.

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