Cylindrical battery and electrolyte behavior detection method and system thereof

Abstract

The invention provides a cylindrical battery and an electrolyte behavior detection method and system thereof. The method comprises the following steps: step A1, introducing a position measuring floater into a central hole of a detected cylindrical battery roll core; a2, in the electrolyte detection process, an X-ray device is used for obtaining scanning images of the cylindrical battery under different charging and discharging degrees and different shelving time, and position information of a position measuring floater in a center hole of a cylindrical battery roll core is analyzed; and A3, obtaining the extrusion and backflow behaviors of the electrolyte according to the position information of the position measuring floater. By introducing the position measuring floater into the central hole of the battery roll core, the extrusion and backflow behaviors of the electrolyte can be known according to the position information of the position measuring floater, and the design of the battery is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of battery testing, and in particular to a cylindrical battery and an electrolyte behavior detection method and system thereof. Background Art

[0002] The cylindrical battery includes a shell, a battery cell and an electrolyte disposed in the shell. The battery cell includes a positive electrode sheet, a negative electrode sheet, a first diaphragm and a second diaphragm. The first diaphragm, the positive electrode sheet, the second diaphragm and the negative electrode sheet are stacked in sequence and then wound into a battery cell (i.e., a winding core). The electrolyte is injected from the injection port on the upper part of the battery cell, and the electrolyte is infiltrated downward by pressurization and vacuuming, so that the electrolyte is evenly distributed in the entire battery cell.

[0003] When a cylindrical battery is charged, the pole piece will expand. Since the expansion space is limited by the shell, the pole pieces will be squeezed, and the electrolyte between the pole piece and the diaphragm will be squeezed out. After discharge, the electrolyte needs to return to the gap between the pole piece and the diaphragm. However, it takes a long time for the electrolyte to return evenly between the pole piece and the diaphragm to restore the cylindrical battery to its original state. Therefore, after repeated charging and discharging, the electrolyte in the battery cell will be partially missing, and the battery capacity will gradually decrease, which will affect the service life of the battery cell.

[0004] The amount of electrolyte extrusion is related to the battery design, including group margin, electrode compaction, etc. The time it takes for the electrolyte to return to the inside of the core after discharge is related to the electrolyte path, diaphragm type, electrode thickness, etc.; since the cylindrical battery shell and core are non-transparent, the amount of electrolyte extrusion and reflux time are difficult to determine intuitively, resulting in no reference data for electrolyte extrusion and reflux when designing the battery cell, making it difficult to design the battery cell to meet usage requirements. Summary of the invention

[0005] Based on the above reasons, the present invention provides a cylindrical battery and an electrolyte behavior detection method and system thereof, which only solves the problem that it is difficult to obtain electrolyte extrusion and reflux reference data in the prior art.

[0006] A method for detecting the behavior of a cylindrical battery electrolyte, comprising:

[0007] Step A1, introducing a positioning float into the center hole of the cylindrical battery roll core to be measured;

[0008] Step A2, during the electrolyte detection process, using an X-ray device to obtain scanning images of cylindrical batteries at different charge and discharge levels and different shelf times, and analyzing the position information of the positioning float in the central hole of the cylindrical battery roll core;

[0009] Step A3, obtaining the extrusion and recirculation behaviors of the electrolyte according to the position information of the positioning float.

[0010] Furthermore, the material of the position measuring float is nano material, plastic or wood;

[0011] The surface of the position measuring float is plated with a metal layer.

[0012] Furthermore, the metal layer on the surface of the positioning float is made of copper, aluminum or titanium.

[0013] Furthermore, after step A1 and before step A2, step B1 is further performed: the cylindrical battery to be tested is subjected to capacity division.

[0014] Furthermore, in step A2, during the electrolyte detection process, when the charging degree reaches the battery charge state of 20%, 50%, 80% and 100%, respectively, an X-ray device is used to scan the cylindrical battery at a shelf time of 0h, 1h, 2h, 3h, 4h and 5h to obtain a scanned image.

[0015] Furthermore, in step A2, during the electrolyte detection process, when the discharge degree reaches the battery charge state of 80%, 50%, 20% and 0%, respectively, an X-ray device is used to scan the cylindrical battery at a shelf time of 0h, 1h, 2h, 3h, 4h and 5h to obtain a scanned image.

[0016] Furthermore, in step A2, the cylindrical battery is subjected to charge and discharge cycles, and an electrolyte detection process is performed after the number of charge and discharge cycles reaches a predetermined number.

[0017] Further, in step A2, after the number of charge and discharge cycles reaches 0, 20, 50, 100, 150 and 200 respectively, an electrolyte detection process is performed.

[0018] A cylindrical battery, wherein a positioning float is introduced into the central hole of the cylindrical battery roll core.

[0019] A cylindrical battery electrolyte behavior detection system, used to perform the aforementioned cylindrical battery electrolyte behavior detection method, comprising a positioning float, a charging and discharging device and an X-ray device;

[0020] The positioning float is introduced into the center hole of the cylindrical battery roll core to be measured;

[0021] The charging and discharging device performs intermediate charging and discharging of the cylindrical battery during the electrolyte detection process;

[0022] The X-ray device obtains scanning images of cylindrical batteries at different charge and discharge levels and different shelf times, and analyzes the position information of the positioning float in the central hole of the cylindrical battery roll core, so as to subsequently derive the extrusion and recirculation behavior of the electrolyte based on the position information of the positioning float.

[0023] The beneficial technical effect of the present invention is that: the present invention introduces a positioning float into the center hole of the battery coil core, and during the battery charging and discharging process, obtains the position information of the positioning float in various states through X-ray scanning, and understands the extrusion and recirculation behavior of the electrolyte based on the position information of the positioning float. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A flowchart of the steps of a cylindrical battery electrolyte behavior detection method of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the positioning float of the present invention being introduced into the center hole of a cylindrical battery;

[0026] in,

[0027] 1-Positioning float;

[0028] 2-electrolyte;

[0029] 3- Center hole. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0032] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0033] See also Figure 1-2 The present invention provides a method for detecting the behavior of a cylindrical battery electrolyte, comprising:

[0034] Step A1, introducing a positioning float (1) into the central hole (3) of the cylindrical battery roll core to be measured;

[0035] Step A2, during the electrolyte detection process, using an X-ray device to obtain scanning images of the cylindrical battery at different charge and discharge levels and different shelf times, and analyzing the position information of the positioning float (1) in the central hole (3) of the cylindrical battery roll core;

[0036] Step A3, obtaining the extrusion and recirculation behavior of the electrolyte (2) according to the position information of the positioning float (1).

[0037] See also Figure 2The present invention provides a cylindrical battery, wherein a positioning float is introduced into the central hole of the cylindrical battery roll core.

[0038] During the charging process, the electrolyte in the core is squeezed by the expansion of the pole piece, and flows out from the inside of the core into the center hole. The more electrolyte is squeezed out, the higher the electrolyte level in the center hole is. Under the action of buoyancy, the positioning float rises as the electrolyte level in the center hole rises. When the electrolyte flows into the core from the center hole during the discharge process, the electrolyte level in the center hole decreases, and the positioning float decreases with the electrolyte level. The extrusion and reflow behavior of the electrolyte are characterized by the position change of the positioning float. According to the position of the positioning float, the degree of electrolyte extrusion, the speed of electrolyte reflow over time and other information can be understood. Using this information as reference data is beneficial to the design of the battery. It can be seen that the present invention introduces a positioning float in the center hole of the battery core. During the battery charging and discharging process, the position information of the positioning float in various states is obtained by X-ray scanning, and the extrusion and reflow behavior of the electrolyte can be understood according to the position information of the positioning float.

[0039] Furthermore, the cylindrical battery is a lithium-ion battery.

[0040] Furthermore, the material of the positioning float (1) is nanomaterial, plastic or wood;

[0041] The surface of the position measuring float (1) is plated with a metal layer.

[0042] The internal material of the position measuring float is selected from materials with relatively light mass density such as nanomaterials, plastics or wood, so that the position measuring float can float on the surface of the electrolyte in the center hole, reducing the influence of gravity on the measurement of the real surface of the electrolyte in the center hole. It can be polyurethane foam material, copolymer foam material, composite foam material.

[0043] Furthermore, the positioning float (1) is spherical, hemispherical, square, etc., and may also be other shapes such as a cylinder.

[0044] Furthermore, the size of the positioning float (1) is smaller than the size of the central hole, and the maximum size is ≤4 mm. For example, when it is spherical or hemispherical, the diameter is ≤4 mm.

[0045] Furthermore, the material of the metal layer on the surface of the positioning float (1) is copper, aluminum or titanium.

[0046] Furthermore, the positioning float (1) is connected to the current collecting plate (or positive electrode) through a connecting wire, one end of which is connected to the positioning float (1), and the other end is fixed to the current collecting plate or positive electrode by welding, gluing, bundling, etc. The flexibility of the connecting wire must be good. If the flexibility of the wire is not good, it is likely that the rigidity of the wire will prevent the float from floating upward when the electrolyte is squeezed out, affecting the test. The material of the connecting wire is selected from polyester fiber, aramid fiber, ceramic fiber, polyamide fiber, polypropylene fiber, etc.

[0047] The surface of the positioning float is plated with a metal layer so that the X-ray device can distinguish the positioning float. The X-ray device is a CT scanning device. After obtaining the scanning image of the cylindrical battery, the position information of the positioning float in the cylindrical battery can be analyzed based on the recognition of the positioning float by the scanning image.

[0048] Furthermore, the positioning float (1) can be introduced into the center hole (3) of the cylindrical battery roll core by means of a center needle.

[0049] Furthermore, after step A1 and before step A2, step B1 is further performed: the cylindrical battery to be tested is subjected to capacity division.

[0050] Formation (also called formation or initial charging) is an important step in the production of lithium-ion batteries. The main purpose of this process is to activate the battery so that it can reach its designed performance. During the formation stage, the battery will undergo a series of charge and discharge cycles to ensure that the chemical reactions between the materials inside the battery can proceed correctly.

[0051] Furthermore, in step A2, during the electrolyte detection process, when the charging degree reaches the battery charge state of 20%, 50%, 80% and 100%, respectively, an X-ray device is used to scan the cylindrical battery at a shelf time of 0h, 1h, 2h, 3h, 4h and 5h to obtain a scanned image.

[0052] The state of charge of a battery is called SOC (State of Charge), which is the ratio of the current remaining power of the battery to the total capacity of the battery. SOC is a very important parameter because it helps us understand the remaining available energy of the battery. The SOC value is usually expressed as a percentage, ranging from 0 to 1 (or 0% to 100%): when SOC is 0, it means that the battery is fully discharged; when SOC is 1 (or 100%), it means that the battery is fully charged.

[0053] The cylindrical battery is charged, and when the battery SOC is 20%, 50%, 80% and 100%, an X-ray scan is performed after each charging level is reached and the shelf time is 0, 1 hour, 2 hours, 3 hours, 4 hours and 5 hours to obtain a scanned image, and the position information of the positioning float in the cylindrical battery is obtained through identification and analysis.

[0054] Furthermore, in step A2, during the electrolyte detection process, when the discharge degree reaches the battery charge state of 80%, 50%, 20% and 0 respectively, an X-ray device is used to scan the cylindrical battery at a shelf time of 0h, 1h, 2h, 3h, 4h and 5h to obtain a scanned image.

[0055] The cylindrical battery is discharged, and when the battery SOC is 80%, 50%, 20% and 0, and the shelf time after each discharge level is 0, 1 hour, 2 hours, 3 hours, 4 hours and 5 hours, an X-ray scan is performed to obtain a scanned image, and the position information of the positioning float in the cylindrical battery is obtained through identification and analysis.

[0056] Combined with the position information of the position measuring float under charging and discharging, the degree of electrolyte extrusion and the speed of reflux can be understood, thus providing a basis for battery design.

[0057] Furthermore, in step A2, the cylindrical battery is subjected to charge and discharge cycles, and an electrolyte detection process is performed after the number of charge and discharge cycles reaches a predetermined number.

[0058] Further, in step A2, after the number of charge and discharge cycles reaches 0, 20, 50, 100, 150 and 200 respectively, an electrolyte detection process is performed.

[0059] The battery is charged and discharged for different times: 0, 20, 50, 100, 150, 200, etc., and the electrolyte detection process is repeated. The electrolyte behavior verification is carried out during the cycle.

[0060] In step A3, the analysis can be performed manually, or an analysis algorithm can be designed to automatically analyze the position information of the positioning float to obtain the extrusion and recirculation behavior of the electrolyte. The automatic analysis involving the analysis algorithm not only quickly draws conclusions, but also can unify the standards and make the analysis more objective when facing the electrolyte analysis of a large number of batteries.

[0061] The present invention also provides a cylindrical battery electrolyte behavior detection system, which is used to execute the aforementioned cylindrical battery electrolyte behavior detection method, comprising a positioning float (1), a charging and discharging device and an X-ray device;

[0062] The positioning float (1) is introduced into the central hole (3) of the cylindrical battery winding core to be measured;

[0063] The charging and discharging device electrolyte detection process charges and discharges the cylindrical battery;

[0064] The X-ray device obtains scanning images of the cylindrical battery at different charge and discharge levels and different shelf times, and analyzes the position information of the positioning float (1) in the central hole (3) of the cylindrical battery roll core, so as to subsequently obtain the extrusion and recirculation behavior of the electrolyte (2) based on the position information of the positioning float (3).

[0065] During the charging process, the electrode sheet expands, causing the electrolyte to be squeezed into the center hole. The electrolyte squeezed into the center hole causes the position of the positioning float to rise. During the discharge and storage process, the electrolyte will gradually flow back, and the position of the positioning float will drop. Therefore, according to the position of the positioning float, the degree of electrolyte extrusion, the speed of electrolyte backflow over time and other information can be understood. Using this information as reference data is beneficial to the design of the battery. It can be seen that the present invention introduces a positioning float in the center hole of the battery coil core. During the battery charging and discharging process, the position information of the positioning float in various states is obtained through X-ray scanning, and the extrusion and backflow behavior of the electrolyte are understood according to the position information of the positioning float.

[0066] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting the behavior of a cylindrical battery electrolyte, characterized in that: include: Step A1, introducing a positioning float into the center hole of the cylindrical battery roll core to be measured; Step A2, during the electrolyte detection process, using an X-ray device to obtain scanning images of the cylindrical battery at different charge and discharge levels and different shelf times, and analyzing the position information of the positioning float in the central hole of the cylindrical battery roll core; Step A3, obtaining the extrusion and recirculation behaviors of the electrolyte according to the position information of the positioning float.

2. A cylindrical battery electrolyte behavior detection method as claimed in claim 1, characterized in that: The material of the positioning float is nano material, plastic or wood; The surface of the positioning float is plated with a metal layer.

3. A cylindrical battery electrolyte behavior detection method as claimed in claim 2, characterized in that: The material of the metal layer on the surface of the positioning float is copper, aluminum or titanium.

4. A cylindrical battery electrolyte behavior detection method as claimed in claim 1, characterized in that: After step A1 and before step A2, step B1 is further performed: the cylindrical battery to be tested is subjected to capacity division.

5. A cylindrical battery electrolyte behavior detection method as claimed in claim 1, characterized in that: In the step A2, during the electrolyte detection process, when the charging degree reaches the battery charge state of 20%, 50%, 80% and 100%, respectively, the cylindrical battery is scanned using the X-ray device at a shelf time of 0h, 1h, 2h, 3h, 4h and 5h to obtain a scanned image.

6. A cylindrical battery electrolyte behavior detection method as claimed in claim 1, characterized in that: In the step A2, during the electrolyte detection process, when the discharge degree reaches the battery charge state of 80%, 50%, 20% and 0 respectively, the cylindrical battery is scanned using the X-ray device at a shelf time of 0h, 1h, 2h, 3h, 4h and 5h to obtain a scanned image.

7. A cylindrical battery electrolyte behavior detection method as claimed in claim 1, characterized in that: In the step A2, the cylindrical battery is subjected to charge and discharge cycles, and the electrolyte detection process is performed once after the number of charge and discharge cycles reaches a predetermined number.

8. A cylindrical battery electrolyte behavior detection method as claimed in claim 7, characterized in that: In the step A2, the electrolyte detection process is performed once after the number of charge and discharge cycles reaches 0, 20, 50, 100, 150 and 200 respectively.

9. A cylindrical battery, characterized in that: A positioning float is introduced into the central hole of the cylindrical battery coil core.

10. A cylindrical battery electrolyte behavior detection system, characterized in that: Used to perform a cylindrical battery electrolyte behavior detection method as described in any one of claims 1 to 8, comprising a positioning float, a charging and discharging device and an X-ray device; The positioning float is introduced into the central hole of the cylindrical battery roll core to be measured; The charging and discharging device charges and discharges the cylindrical battery during the electrolyte detection process; The X-ray device obtains scanning images of the cylindrical battery at different charge and discharge levels and different storage times, and analyzes the position information of the positioning float in the central hole of the cylindrical battery roll core, so as to subsequently derive the extrusion and recirculation behavior of the electrolyte based on the position information of the positioning float.

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