Battery cell gas production rate detection system

Abstract

The utility model discloses a cell gas production rate detection system, and relates to the field of detection systems. The battery cell gas production rate detection system comprises a liquid storage tank, a tension sensor and a charging and discharging device, a battery cell comprises a battery cell body and a tab which are fixedly connected, a base solution is stored in the liquid storage tank, the battery cell body is immersed in the base solution, the tension sensor is arranged above the liquid storage tank, and the charging and discharging device comprises a charging and discharging wire. The upper end of the charge-discharge wire is fixedly connected with the tension sensor, the lower end of the charge-discharge wire is fixedly connected with the tab, the tension sensor is used for measuring the tension value borne by the charge-discharge wire, and the gas production rate of the battery cell can be obtained according to the change of the tension value borne by the charge-discharge wire measured by the tension sensor and the density of the base liquid. In the cell gas production rate detection process, the charging and discharging wire does not interfere with the measurement result of the tension sensor, so that the detection error of the tension sensor is reduced, and the detection precision of the cell gas production rate detection system on the cell gas production rate is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of detection systems, and in particular to a battery core gas production detection system. Background Art

[0002] A certain amount of gas will be generated inside the battery cell during manufacturing and use. The amount of gas produced by the battery cell is related to the material system and processing technology of the battery cell. During the research and development stage, it is necessary to test the gas production of the battery cell to verify the feasibility of the current material system and processing technology of the battery cell.

[0003] In the related art, the Archimedean principle is usually used to detect the gas production of the battery cell. The sensor needs to accurately measure the weight change of the battery cell before and after gas production. However, the battery cell also needs to be connected to wires for charge and discharge cycles. The wires are prone to pulling on the battery cell, causing the sensor to interfere with the measurement of the battery cell's weight. The sensor's measurement of the weight change before and after gas production has poor accuracy, and the battery cell's gas production detection accuracy is poor and the accuracy is low. Utility Model Content

[0004] The utility model aims to solve at least one of the above technical problems in the prior art to a certain extent. To this end, the utility model provides a battery cell gas production detection system, which can improve the detection accuracy of the battery cell gas production.

[0005] According to the battery cell gas production detection system of the embodiment of the utility model, the battery cell includes a battery cell body and a tab fixedly connected, and the battery cell gas production detection system includes: a liquid storage tank, in which a base liquid is stored; a tension sensor, which is arranged above the liquid storage tank; a charging and discharging device, which includes a charging and discharging wire, the upper end of the charging and discharging wire is fixedly connected to the tension sensor, and the lower end of the charging and discharging wire is fixedly connected to the tab; wherein the battery cell body is immersed in the base liquid in the liquid storage tank, and the tension sensor is used to measure the tension value exerted on the charging and discharging wire.

[0006] According to the battery cell gas production detection system of the embodiment of the utility model, the upper end of the charge and discharge wire is fixedly connected to the tension sensor, and the lower end of the charge and discharge wire is fixedly connected to the pole ear. The charge and discharge wire can charge and discharge the battery cell body through the pole ear to simulate the actual operating condition of the battery cell. At the same time, the battery cell body can be suspended in the base liquid of the liquid storage tank by the charge and discharge wire, and the gas production of the battery cell can be obtained according to the change in the tension value measured by the tension sensor and the density of the base liquid on the charge and discharge wire. During the battery cell gas production detection process, the charge and discharge wire will not interfere with the measurement result of the tension sensor, which is conducive to reducing the detection error of the tension sensor and improving the detection accuracy of the battery cell gas production detection system for the battery cell gas production.

[0007] According to some embodiments of the present invention, the charging and discharging equipment further includes a charging and discharging cabinet and an electrical connecting line, wherein the electrical connecting line is electrically connected between the charging and discharging line and the charging and discharging cabinet.

[0008] According to some embodiments of the present invention, the electrical connection line is in a relaxed state.

[0009] According to some other embodiments of the utility model, the charging and discharging equipment also includes a charging and discharging cabinet, the charging and discharging cabinet has a first coil, the charging and discharging line has a second coil, the first coil and the second coil are opposite to and spaced apart from each other, and the first coil and the second coil are suitable for wireless transmission of electrical energy.

[0010] According to some embodiments of the utility model, the battery cell gas production detection system further includes: a liquid replenishing device, and the liquid replenishing device is used to adjust the liquid level of the base liquid in the liquid storage tank.

[0011] According to some embodiments of the utility model, the fluid replenishment equipment includes: a fluid reservoir, in which the base fluid is stored; a pumping device, which is respectively connected to the fluid reservoir and the fluid storage tank, and is used to pump the base fluid between the fluid reservoir and the fluid storage tank.

[0012] According to some embodiments of the utility model, the fluid replenishing device also includes: a liquid level sensor, which is used to detect the liquid level height of the base liquid in the liquid storage tank; a controller, which is communicatively connected to the liquid level sensor and the pumping device respectively, and the controller is configured to pump the base liquid between the liquid reservoir and the liquid storage tank by controlling the pumping device to make the liquid level height of the base liquid in the liquid storage tank constant.

[0013] According to other embodiments of the present invention, the fluid replenishing device also includes: a depth sensor, which is used to detect the immersion depth of the battery cell body in the base liquid; a controller, which is communicatively connected to the depth sensor and the pumping device respectively, and the controller is configured to control the pumping device to pump the base liquid between the liquid reservoir and the liquid storage tank so that the immersion depth of the battery cell body in the base liquid is constant.

[0014] According to some embodiments of the utility model, the battery cell gas production detection system further includes: a mounting frame, and the liquid storage tank and the tension sensor are both fixedly connected to the mounting frame.

[0015] According to some embodiments of the present utility model, the battery cell gas production detection system further includes: a heater, the heater is installed in the liquid storage tank, and the heater is used to heat the base liquid in the liquid storage tank.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of a battery cell gas production detection system according to an embodiment of the utility model.

[0018] Reference numerals:

[0019] Mounting frame 1; test table 11; bracket 12; fixing plate 13;

[0020] Liquid storage tank 2;

[0021] Tension sensor 3;

[0022] Charging and discharging equipment 4; charging and discharging wires 41; charging and discharging cabinets 42; electrical connecting wires 43;

[0023] Fluid replenishing device 5; liquid reservoir 51; pumping device 52; liquid level sensor 53;

[0024] Battery cell gas production detection system 10. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0026] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "inside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0028] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] Combine the following Figure 1 The battery cell gas generation detection system 10 according to an embodiment of the present utility model is described in detail.

[0030] According to the battery cell gas production detection system 10 of the embodiment of the utility model, refer to Figure 1 As shown, the battery cell includes a battery cell body and a tab fixedly connected, and the battery cell gas production detection system 10 includes: a liquid storage tank 2, a tension sensor 3 and a charge and discharge device 4, the liquid storage tank 2 stores a base liquid, the tension sensor 3 is arranged above the liquid storage tank 2, the charge and discharge device 4 includes a charge and discharge wire 41, the upper end of the charge and discharge wire 41 is fixedly connected to the tension sensor 3, and the lower end of the charge and discharge wire 41 is fixedly connected to the tab, wherein the battery cell body is immersed in the base liquid in the liquid storage tank 2, and the tension sensor 3 is used to measure the tension value exerted on the charge and discharge wire 41.

[0031] Among them, the battery cell includes a battery cell body and a pole ear that are fixedly connected. The battery cell body is used to store and release electrical energy. The battery cell body is the main part of the battery cell gas production detection. The pole ear is fixed on the battery cell body. The tension sensor 3 is arranged above the liquid storage tank 2. The charging and discharging device 4 includes a charging and discharging line 41. The upper end of the charging and discharging line 41 is fixedly connected to the tension sensor 3, and the lower end of the charging and discharging line 41 is fixedly connected to the pole ear and is conductive. The tension sensor 3 can display the numerical value of the tension exerted on the charging and discharging line 41 in real time. The charging and discharging device 4 can charge and discharge the battery cell for multiple cycles through the conduction between the charging and discharging line 41 and the pole ear. The liquid storage tank 2 The base liquid inside can be a non-conductive liquid, and the base liquid can be distilled water, ethanol, silicone oil, etc. When the gas production of the battery cell is detected, the battery cell body is connected to the lower end of the charge and discharge wire 41 through the pole ear, and the battery cell is suspended by the charge and discharge wire 41. At the same time, the battery cell body is also immersed in the base liquid in the liquid storage tank 2. When the battery cell produces gas and causes the volume of the battery cell body to increase, the volume of the base liquid displaced by the battery cell body increases, and the buoyancy of the base liquid on the battery cell body increases. The tension value of the charge and discharge wire 41 detected by the tension sensor 3 decreases, so that the gas production of the battery cell can be measured according to the changes in the density of the base liquid and the tension value of the charge and discharge wire 41.

[0032] Specifically, the battery cell can be a soft-pack battery cell. When the battery cell produces gas, the volume of the battery cell body increases, and the gas production △V of the battery cell satisfies the following formula: F1-F2=△Vρg, wherein F1 is the tension value of the charge and discharge wire 41 detected by the tension sensor 3 at the beginning of the detection, F2 is the tension value of the charge and discharge wire 41 detected by the tension sensor 3 at the end of the detection, ρ is the base liquid density, and g is the ratio of gravity to mass (g can be 9.8N / kg). Therefore, the gas production △V of the battery cell can be obtained based on F1, F2, ρ and g, and then the feasibility of the material system matching and processing technology of the current battery cell can be evaluated and verified based on the gas production △V of the battery cell.

[0033] It should be noted that when the soft-pack battery is a lithium-ion battery, the gas generation is divided into normal gas generation and abnormal gas generation. Normal gas generation refers to the gas generated in the formation process of the battery production process. The gas generated during the formation of the SEI film (solid electrolyte interface film) is often called formation gas generation. The gas generated during the formation process will increase the distance between the positive electrode, the diaphragm, and the negative electrode, hindering the transmission of lithium ions from the positive electrode sheet to the negative electrode sheet. In addition, the presence of gas will also hinder the contact between the electrolyte and the positive and negative electrodes, making the local wetting performance of the negative electrode worse, and ultimately leading to a large number of unreacted dead areas on the negative electrode sheet. The appearance of dead areas will increase the possibility of lithium precipitation in the battery and will seriously affect the performance of the battery itself. Abnormal gas generation is due to excessive gas caused by abnormalities inside the battery during operation. At this time, the gas cannot be discharged, causing the battery cell to swell, which will cause performance deterioration of the battery cell. When the internal pressure is too high, it is easy to stretch the packaging aluminum foil, causing leakage, corrosion and other serious damage. Therefore, understanding the entire gas production process of the battery cell has certain guiding significance for the matching and selection of the battery cell material system and the optimization of process parameters. In addition, it is also crucial for monitoring abnormal gas production states and boundaries.

[0034] In the above embodiment, the upper end of the charge and discharge wire 41 is fixedly connected to the tension sensor 3, and the lower end of the charge and discharge wire 41 is fixedly connected to the pole ear. The charge and discharge wire 41 can charge and discharge the battery cell body through the pole ear to simulate the actual operating conditions of the battery cell. At the same time, the battery cell body can be suspended in the base liquid of the liquid storage tank 2 by the charge and discharge wire 41, and the gas production of the battery cell can be obtained according to the change in the tension value of the charge and discharge wire 41 measured by the tension sensor 3 and the density of the base liquid. During the gas production detection process of the battery cell, the charge and discharge wire 41 will not interfere with the measurement result of the tension sensor 3, which is beneficial to reduce the detection error of the tension sensor 3 and improve the detection accuracy of the battery cell gas production detection system 10 for the gas production of the battery cell.

[0035] According to some embodiments of the present invention, referring to Figure 1 As shown, the charging and discharging device 4 further includes a charging and discharging cabinet 42 and an electrical connection line 43 , and the electrical connection line 43 is electrically connected between the charging and discharging line 41 and the charging and discharging cabinet 42 .

[0036] Among them, the charging and discharging cabinet 42 is electrically connected to the pole ear through the electrical connecting line 43 and the charging and discharging line 41 in turn. The charging and discharging cabinet 42 can realize the charging and discharging of the battery cell to simulate the actual operating conditions of the battery cell to perform charging and discharging cycles, and verify the gas production of the battery cell to improve the accuracy of the gas production detection of the battery cell and improve the detection precision.

[0037] According to some embodiments of the present invention, referring to Figure 1 As shown, the electrical connection line 43 is in a relaxed state, wherein the distance between the charge and discharge cabinet 42 and the charge and discharge line 41 may be smaller than the length of the electrical connection line 43, so that the electrical connection line 43 is in a relaxed state, so as to reduce the effect of the electrical connection line 43 on the charge and discharge line 41. When the tension sensor 3 measures the tension value exerted on the charge and discharge line 41, the influence of the electrical connection line 43 on the measurement result of the tension sensor 3 is weakened, thereby facilitating reducing the detection error of the tension sensor 3 and improving the detection accuracy.

[0038] According to some other embodiments of the utility model (not shown in the figure), the charging and discharging device 4 also includes a charging and discharging cabinet 42, the charging and discharging cabinet 42 has a first coil, the charging and discharging line 41 has a second coil, the first coil is opposite to and spaced from the second coil, and the first coil and the second coil are suitable for wireless transmission of electrical energy.

[0039] Among them, the second coil on the charge and discharge line 41 can be set at any position of the charge and discharge line 41 above the base liquid level, and the charge and discharge cabinet 42 can perform wireless power transmission with the second coil on the charge and discharge line 41 through the first coil to simulate the actual use condition of the battery cell to perform charge and discharge cycles and verify the gas production of the battery cell. At the same time, the first coil and the second coil are relative to ensure the transmission efficiency of electric energy, and the first coil and the second coil are separated to avoid the second coil affecting the measurement result of the tension sensor 3.

[0040] In the above embodiment, electric energy is transmitted between the charge and discharge cabinet 42 and the charge and discharge line 41 through the first coil and the second coil which are relative and spaced apart. When the tension sensor 3 measures the tension value exerted on the charge and discharge line 41, the force exerted by the charge and discharge cabinet 42 and the first coil on the electrical connecting line 43 is eliminated, which is beneficial to reduce the detection error of the tension sensor 3 and improve the detection accuracy.

[0041] According to some embodiments of the present invention, referring to Figure 1 As shown, the battery cell gas production detection system 10 also includes a liquid replenishing device 5, which is used to adjust the liquid level of the base liquid in the liquid storage tank 2.

[0042] The fluid replenishment device 5 may include a fluid reservoir 51 and a pumping device 52, and the base fluid may be pumped between the fluid reservoir 51 and the fluid reservoir 2 by the pumping device 52 to adjust the liquid level of the base fluid in the fluid reservoir 2. In addition, in some embodiments not shown in the figures, the fluid replenishment device 5 may include a fluid replenishment pot and a pipette, and the base fluid may be added to the fluid reservoir 2 manually using the fluid replenishment pot or the base fluid in the fluid reservoir 2 may be sucked by the pipette, thereby adjusting the liquid level of the base fluid in the fluid reservoir 2.

[0043] In the above embodiment, the liquid level of the base liquid in the liquid storage tank 2 can be adjusted by the liquid replenishing device 5. When the gas production of battery cells of different sizes is detected, the liquid level of the base liquid in the liquid storage tank 2 can be adjusted by the liquid replenishing device 5 so that the battery cell body is immersed in the base liquid, that is, the battery cell body is completely located below the liquid level of the base liquid, so that the battery cell gas production detection system 10 can be adapted to detect battery cells of different specifications and ensure the measurement accuracy of the battery cell gas production detection system 10.

[0044] According to some embodiments of the present invention, referring to Figure 1 As shown, the fluid replenishing device 5 includes a fluid reservoir 51 and a pumping device 52. The fluid reservoir 51 stores base fluid. The pumping device 52 is connected to the fluid reservoir 51 and the fluid storage tank 2 respectively. The pumping device 52 is used to pump the base fluid between the fluid reservoir 51 and the fluid storage tank 2.

[0045] Among them, the pumping device 52 may include a connecting pipeline and a liquid pump arranged on the connecting pipeline. The liquid pump is connected to the liquid reservoir 51 and the liquid storage tank 2 respectively through the connecting pipeline. The pumping device 52 can pump the base liquid in both directions. That is, when the liquid level of the base liquid in the liquid storage tank 2 needs to be increased, the pumping device 52 can pump the base liquid from the liquid reservoir 51 to the liquid storage tank 2. When the liquid level of the base liquid in the liquid storage tank 2 needs to be lowered, the pumping device 52 can pump the base liquid from the liquid storage tank 2 to the liquid reservoir 51, so as to facilitate the adjustment of the liquid level of the base liquid in the liquid storage tank 2.

[0046] In the above embodiment, the pumping device 52 can pump the base liquid between the liquid reservoir 51 and the liquid storage tank 2 to adjust the liquid level of the base liquid in the liquid storage tank 2, reduce the debugging time of the battery cell gas production detection system 10, and improve the detection efficiency of the battery cell gas production detection system 10.

[0047] According to some embodiments of the present invention, referring to Figure 1 As shown, the fluid replenishing device 5 also includes: a liquid level sensor 53 and a controller, the liquid level sensor 53 is used to detect the liquid level height of the base liquid in the liquid storage tank 2, the controller is communicated with the liquid level sensor 53 and the pumping device 52 respectively, and the controller is configured to pump the base liquid between the liquid reservoir 51 and the liquid storage tank 2 by controlling the pumping device 52 to make the liquid level height of the base liquid in the liquid storage tank 2 constant.

[0048] Among them, the liquid level sensor 53 can be at least partially arranged in the liquid storage tank 2. The liquid level sensor 53 can adopt a contact float liquid level sensor or a magnetic liquid level sensor, or a non-contact ultrasonic liquid level sensor. When the gas production detection of the battery cell begins, the liquid level sensor 53 can collect the liquid level height signal of the base liquid in the liquid storage tank 2 in real time and send it to the controller. When the liquid level height signal changes, the controller can control the pumping device 52 to pump the base liquid between the liquid reservoir 51 and the liquid storage tank 2 to make the liquid level of the base liquid in the liquid storage tank 2 constant.

[0049] It is understandable that when the battery cell gas production detection system 10 detects the gas production of the battery cell, the battery cell needs to undergo multiple charge and discharge cycles, and the detection time is relatively long. There may be a situation where the base liquid level in the liquid storage tank 2 drops due to the volatilization of the base liquid. When the base liquid level drops, the volume of the base liquid displaced by the pole ears partially immersed in the base liquid will decrease, and the buoyancy of the base liquid on the battery cell as a whole will decrease. The tension sensor 3 detects that the tension value of the charge and discharge wire 41 has increased, resulting in errors in the detection of the gas production of the battery cell.

[0050] At the same time, the base liquid pressure P outside the battery cell body satisfies the relationship: P=ρgh, ρ is the base liquid density, g is the ratio of gravity to mass (g can be 9.8N / kg), and h is the immersion depth of the battery cell body. When the base liquid level in the liquid storage tank 2 drops due to volatilization of the base liquid, the immersion depth h of the battery cell body decreases, and the base liquid pressure P outside the battery cell body decreases, which will cause the gas in the battery cell body to expand, the volume of the battery cell body to increase, and the buoyancy of the base liquid on the battery cell body to increase. The tension sensor detects that the tension value of the charge and discharge wire is reduced, resulting in errors in the detection of the gas production of the battery cell.

[0051] In addition, when the volume of the battery cell increases after gas production, the volume of the base liquid displaced by the battery cell body becomes larger, which will cause the liquid level of the base liquid in the liquid storage tank 2 to rise, thereby causing the volume of the pole ear partially immersed in the base liquid to displace the base liquid to increase, and the buoyancy of the base liquid on the battery cell as a whole increases. At the same time, the immersion depth h of the battery cell body increases, and the base liquid pressure P outside the battery cell body increases, which will cause the volume of the gas in the battery cell body to be compressed and the volume to decrease, and the buoyancy of the base liquid on the battery cell body decreases, ultimately causing the tension sensor 53 to detect fluctuations in the tension value of the charge and discharge cable 41, and errors in the detection of gas production in the battery cell.

[0052] In the above embodiment, the controller can control the pumping device 52 according to the base liquid level height signal in the liquid storage tank 2 collected by the liquid level sensor 53 to maintain the base liquid level in the liquid storage tank 2 constant, so as to avoid measurement errors caused by changes in the base liquid level in the liquid storage tank 2, thereby improving the accuracy of the detection results.

[0053] According to other embodiments of the present invention, the fluid replenishing device 5 also includes: a depth sensor and a controller, the depth sensor is used to detect the immersion depth of the battery cell body in the base liquid, the controller is communicated with the depth sensor and the pumping device 52 respectively, and the controller is configured to control the pumping device 52 to pump the base liquid between the liquid reservoir 51 and the liquid storage tank 2 so that the immersion depth of the battery cell body in the base liquid is constant.

[0054] Among them, the depth sensor can be at least partially arranged in the liquid reservoir 2. The depth sensor can measure the immersion depth of the battery cell body in the base liquid in the liquid reservoir 2 by time difference ranging. The depth sensor can also use the structured light principle to measure the immersion depth of the battery cell body in the base liquid in the liquid reservoir 2. The depth sensor can collect the immersion depth signal of the battery cell body in the base liquid in the liquid reservoir 2 in real time and send it to the controller. When the immersion depth signal changes, the controller can control the pumping device 52 to pump the base liquid between the liquid reservoir 51 and the liquid reservoir 2 to make the immersion depth of the battery cell body in the base liquid in the liquid reservoir 2 constant.

[0055] It is understandable that when the battery cell gas production detection system 10 detects the gas production of the battery cell, the battery cell needs to undergo multiple charge and discharge cycles, and the detection time is relatively long. There may be a situation where the base liquid level in the liquid storage tank 2 drops due to the volatilization of the base liquid. When the base liquid level drops, the immersion depth of the battery cell body in the base liquid in the liquid storage tank 2 decreases synchronously, which will cause the volume of the base liquid displaced by the pole ears partially immersed in the base liquid to decrease, and the buoyancy of the base liquid on the battery cell as a whole will decrease. The tension sensor 3 detects that the tension value of the charge and discharge cable 41 has increased, resulting in errors in the detection of the gas production of the battery cell.

[0056] At the same time, the base liquid pressure P outside the battery cell body satisfies the relationship: P=ρgh, ρ is the base liquid density, g is the ratio of gravity to mass (g can be 9.8N / kg), and h is the immersion depth of the battery cell body. When the base liquid level in the liquid storage tank 2 drops due to volatilization of the base liquid, the immersion depth h of the battery cell body decreases, and the base liquid pressure P outside the battery cell body decreases, which will cause the gas in the battery cell body to expand, the volume of the battery cell body to increase, and the buoyancy of the base liquid on the battery cell body to increase. The tension sensor 3 detects that the tension value of the charge and discharge cable 41 is reduced, resulting in an error in the detection of the gas production of the battery cell.

[0057] In addition, when the volume of the battery cell increases after gas production, the volume of the base liquid displaced by the battery cell body becomes larger, which will cause the liquid level of the base liquid in the liquid storage tank 2 to rise, and the immersion depth of the battery cell body in the base liquid in the liquid storage tank 2 to rise synchronously, thereby causing the volume of the pole ears partially immersed in the base liquid to displace the base liquid to increase, and the buoyancy of the base liquid on the battery cell as a whole to increase, thereby increasing the immersion depth h of the battery cell body, and increasing the base liquid pressure P outside the battery cell body, which will cause the gas volume in the battery cell body to be compressed and the volume to decrease, and the buoyancy of the base liquid on the battery cell body to decrease, ultimately causing the tension sensor 53 to detect fluctuations in the tension value of the charge and discharge cable 41, and errors in the detection of the gas production of the battery cell.

[0058] Furthermore, when the battery cell gas production detection system 10 detects the gas production of the battery cell, the strain gauge of the tension sensor 3 will bend downward due to the tension of the charging and discharging wires. When the volume of the battery cell body increases due to gas production, the buoyancy of the battery cell body increases, and the tension sensor 3 detects that the tension value of the charging and discharging wires 41 decreases. The strain gauge of the tension sensor 3 will rebound due to the decrease in the tension value of the charging and discharging wires. In other words, the strain gauge of the tension sensor 3 produces an upward displacement, causing the battery cell body to produce an upward displacement, the immersion depth of the battery cell body is reduced, and the base fluid pressure outside the battery cell body is reduced, which will cause the gas in the battery cell body to expand, the volume of the battery cell body to increase, and errors in the detection of the gas production of the battery cell.

[0059] In the above-mentioned embodiment of the present application, the controller can control the pumping device 52 according to the immersion depth signal of the battery cell body in the base liquid in the liquid storage tank 2 collected by the depth sensor, so as to maintain the immersion depth of the battery cell body in the base liquid in the liquid storage tank 2 constant, so as to avoid measurement errors caused by changes in the immersion depth of the battery cell body in the base liquid in the liquid storage tank 2, thereby improving the accuracy of the detection results.

[0060] According to some embodiments of the present invention, referring to Figure 1 As shown, the battery cell gas production detection system 10 also includes a mounting frame 1, and the liquid storage tank 2 and the tension sensor 3 are both fixedly connected to the mounting frame 1.

[0061] Among them, the mounting frame 1 may include a test table 11, a bracket 12 and a fixed plate 13, the liquid storage tank 2 can be fixedly placed on the desktop of the test table 11, the bracket 12 can be a "c" type structure, the lower end surface of the bracket 12 is fixedly connected to the test table 11, the fixed plate 13 can be fixed to the upper end surface of the bracket 12, and the tension sensor 3 is fixedly connected to the fixed plate 13.

[0062] In the above embodiment, the liquid storage tank 2 and the tension sensor 3 are both fixedly connected to the mounting frame 1, and the mounting frame 1 ensures that the various experimental components are stably connected, which is conducive to the smooth progress of the battery cell gas production detection experiment.

[0063] According to some embodiments of the present invention, referring to Figure 1 As shown, the battery cell gas production detection system 10 also includes a heater, which is installed in the liquid storage tank 2 and is used to heat the base liquid in the liquid storage tank 2.

[0064] Among them, the heater can be installed inside the liquid storage tank 2, and the heater can directly heat the base liquid in the liquid storage tank 2. The heater can also be installed outside the liquid storage tank 2, and the heater can indirectly heat the base liquid in the liquid storage tank by heating the liquid storage tank 2. The heater can be a resistance wire heater or an electric heating tube heater.

[0065] In the above embodiment, the heater can heat the base liquid in the liquid storage tank 2 to simulate the ambient temperature of the battery cell in actual application and verify the gas production of the battery cell in different temperature environments.

[0066] According to the battery cell gas production detection system 10 of the embodiment of the utility model, the battery cell gas production detection system 10 also includes a constant temperature and humidity controller, which has a constant temperature and humidity chamber, and the liquid storage tank 2, the tension sensor 3 and the charging and discharging equipment 4 are all arranged in the constant temperature and humidity chamber. The constant temperature and humidity controller ensures the relative stability of the battery cell gas production detection environment. The constant temperature and humidity controller reduces the detection error caused by changes in environmental factors and improves the accuracy of the detection result.

[0067] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0068] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A battery cell gas production detection system, It is characterized in that The battery cell includes a battery cell body and a tab that are fixedly connected, and the battery cell gas production detection system includes: A liquid storage tank (2), wherein a base liquid is stored in the liquid storage tank (2); A tension sensor (3), the tension sensor (3) being arranged above the liquid storage tank (2); A charging and discharging device (4), the charging and discharging device (4) comprising a charging and discharging wire (41), the upper end of the charging and discharging wire (41) being fixedly connected to the tension sensor (3), and the lower end of the charging and discharging wire (41) being fixedly connected to the pole lug; The battery cell body is immersed in the base liquid in the liquid storage tank (2), and the tension sensor (3) is used to measure the tension value applied to the charge and discharge cable (41).

2. The battery cell gas production detection system according to claim 1, It is characterized in that The charging and discharging equipment (4) further comprises a charging and discharging cabinet (42) and an electrical connection line (43), wherein the electrical connection line (43) is electrically connected between the charging and discharging line (41) and the charging and discharging cabinet (42).

3. The battery cell gas production detection system according to claim 2, It is characterized in that The electrical connection line (43) is in a relaxed state.

4. The battery cell gas production detection system according to claim 1, It is characterized in that The charging and discharging device (4) further comprises a charging and discharging cabinet (42), the charging and discharging cabinet (42) having a first coil, the charging and discharging line (41) having a second coil, the first coil and the second coil being opposite to and spaced apart from each other, and the first coil and the second coil being suitable for wireless transmission of electric energy.

5. The battery cell gas production detection system according to any one of claims 1 to 4, It is characterized in that The battery cell gas production detection system further comprises: a liquid replenishing device (5), wherein the liquid replenishing device (5) is used to adjust the liquid level of the base liquid in the liquid storage tank (2).

6. The battery cell gas production detection system according to claim 5, It is characterized in that The fluid replenishment device (5) comprises: a liquid reservoir (51), wherein the base liquid is stored in the liquid reservoir (51); A pumping device (52), the pumping device (52) is connected to the liquid reservoir (51) and the liquid storage tank (2) respectively, and the pumping device (52) is used to pump the base liquid between the liquid reservoir (51) and the liquid storage tank (2).

7. The battery cell gas production detection system according to claim 6, It is characterized in that The fluid replenishment device (5) further comprises: A liquid level sensor (53), the liquid level sensor (53) being used to detect the liquid level of the base liquid in the liquid storage tank (2); A controller is communicatively connected to the liquid level sensor (53) and the pumping device (52) respectively, and the controller is configured to control the pumping device (52) to pump the base liquid between the liquid reservoir (51) and the liquid storage tank (2) so that the liquid level of the base liquid in the liquid storage tank (2) is constant.

8. The battery cell gas production detection system according to claim 6, It is characterized in that The fluid replenishment device (5) further comprises: A depth sensor, the depth sensor is used to detect the immersion depth of the battery cell body in the base liquid; A controller is communicatively connected to the depth sensor and the pumping device (52) respectively, and the controller is configured to control the pumping device (52) to pump the base liquid between the liquid reservoir (51) and the liquid storage tank (2) so that the immersion depth of the battery cell body in the base liquid is constant.

9. The battery cell gas production detection system according to claim 1, It is characterized in that The battery cell gas production detection system further comprises: a mounting frame (1), and the liquid storage tank (2) and the tension sensor (3) are both fixedly connected to the mounting frame (1).

10. The battery cell gas production detection system according to claim 1, It is characterized in that The battery cell gas production detection system further comprises: a heater, which is installed in the liquid storage tank (2) and is used to heat the base liquid in the liquid storage tank (2).

Images