Method for measuring charge and discharge energy of lithium-ion batteries

Abstract

The present invention provides a method for measuring the charge and discharge energy of a lithium-ion battery. The above-mentioned method for measuring the charge and discharge energy of a lithium-ion battery includes: placing an insulation detection conductive component in a detection container; injecting a predetermined height of conductive liquid into the detection container; electrically connecting the positive detection wire and the negative detection wire of the insulation detection conductive component to a charge and discharge device, and simultaneously detecting the temperature and liquid level of the conductive liquid in the detection container to obtain the temperature difference and liquid level change value of the conductive liquid; calculating the heat loss energy of the charge and discharge process of the lithium-ion battery based on the temperature difference; calculating the volume expansion work of the charge and discharge process of the lithium-ion battery based on the liquid level change value; and calculating the actual charge and discharge energy of the lithium-ion battery based on the heat loss energy, volume expansion work, and the charge and discharge energy displayed and output by the charge and discharge device. The above-mentioned method for measuring the charge and discharge energy of a lithium-ion battery has high measurement accuracy for the actual charge and discharge energy of the lithium-ion battery.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion batteries, and in particular to a method for measuring the charge and discharge energy of a lithium-ion battery. Background Art

[0002] Lithium-ion batteries are batteries that can be charged and discharged multiple times. During the charging and discharging process, energy is also transferred. Traditional direct charging infers the energy of a lithium-ion battery based on the charge usage. However, lithium-ion batteries generate heat during the charging process, and some of this heat is dissipated through heat transfer to the air. Furthermore, during charging, the lithium-ion battery may expand, which means that during this expansion process, the internal energy within the lithium-ion battery changes. Similarly, lithium-ion batteries also experience energy losses. This results in low accuracy when simply inferring the energy of a lithium-ion battery based on the charge usage. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for measuring the charge and discharge energy of a lithium ion battery with high measurement accuracy.

[0004] The object of the present invention is achieved through the following technical solutions:

[0005] A method for measuring charge and discharge energy of a lithium-ion battery, comprising:

[0006] Conduct wiring treatment on the positive and negative electrodes of the lithium-ion battery to be measured, respectively, so that the positive electrode of the lithium-ion battery is electrically connected to the positive detection wire, and the negative electrode of the lithium-ion battery is electrically connected to the negative detection wire;

[0007] Performing insulation and sealing treatment on the connection points of the positive and negative electrodes of the lithium-ion battery respectively to form an insulation detection conductive component;

[0008] Placing the insulation detection conductive component in a detection container;

[0009] injecting a conductive liquid to a predetermined height into the detection container;

[0010] The positive detection wire and the negative detection wire of the insulation detection conductive component are electrically connected to a charging and discharging device, and the temperature and liquid level of the conductive liquid in the detection container are detected to obtain the temperature difference of the conductive liquid and the change in the liquid level;

[0011] Calculating heat loss energy during the charging and discharging process of the lithium-ion battery according to the temperature difference of the conductive liquid;

[0012] Calculating the volume expansion work during the charge and discharge process of the lithium-ion battery according to the change in the liquid level height;

[0013] The actual charge and discharge energy of the lithium-ion battery is calculated according to the heat loss energy, the volume expansion work, and the charge and discharge energy displayed and output by the charge and discharge device.

[0014] In one embodiment, the step of wiring the positive and negative electrodes of the lithium-ion battery to be measured includes:

[0015] Adhere the positive electrode of the lithium-ion battery and the positive detection wire with insulating tape to fix them so that the positive electrode of the lithium-ion battery is electrically connected to the positive detection wire;

[0016] The negative electrode of the lithium ion battery and the negative detection wire are glued and fixed by the insulating tape, so that the negative electrode of the lithium ion battery and the negative detection wire are electrically connected.

[0017] In one embodiment, the insulating tape is made of polyvinyl chloride insulating tape or polyolefin insulating tape.

[0018] In one embodiment, the steps of fixing the insulating tape include:

[0019] Pre-winding and bending the exposed section of the positive detection wire to form a positive spiral contact end;

[0020] Pre-fixing the positive electrode spiral contact end to the positive electrode contact portion of the lithium-ion battery by gluing the insulating tape to form a positive electrode pre-fixed terminal;

[0021] Wrap the positive electrode pre-fixed terminal with insulating tape for several turns to form the positive electrode connection point of the lithium-ion battery;

[0022] Pre-winding and bending the exposed section of the negative detection wire to form a negative electrode spiral contact end;

[0023] Pre-fixing the negative electrode spiral contact end to the negative electrode contact portion of the lithium-ion battery by gluing the insulating tape to form a negative electrode pre-fixed terminal;

[0024] The negative electrode pre-fixed terminal is wrapped with insulating tape for several turns to form the negative electrode connection point of the lithium ion battery.

[0025] In one embodiment, the step of performing insulation and sealing treatment on the connection points of the positive and negative electrodes of the lithium-ion battery respectively includes:

[0026] Wrapping the positive electrode connection of the lithium-ion battery with a sealing film;

[0027] The negative electrode connection point of the lithium-ion battery is wound with the sealing film.

[0028] In one embodiment, before the insulation detection conductive component is placed in the detection container, one end of an auxiliary fixing belt is fixed to the insulation detection conductive component, and the other end of the auxiliary fixing belt is fixed to the fixing column of the detection container.

[0029] In one embodiment, the step of injecting a predetermined height of conductive liquid into the detection container comprises:

[0030] The lithium-ion battery to be measured is completely immersed in the conductive liquid.

[0031] In one embodiment, before the step of electrically connecting the positive detection wire and the negative detection wire of the insulation detection conductive component to the charging and discharging device and simultaneously detecting the temperature and the liquid level of the conductive liquid in the detection container, the method further includes:

[0032] A thermometer is placed in the detection container.

[0033] In one embodiment, before the step of electrically connecting the positive detection wire and the negative detection wire of the insulation detection conductive component to the charging and discharging device and simultaneously detecting the temperature and the liquid level of the conductive liquid in the detection container, the method further includes:

[0034] A liquid level measuring instrument is arranged in the detection container.

[0035] Compared with the prior art, the present invention has at least the following advantages:

[0036] First, a conductive liquid is injected into a detection container to a predetermined height, and the initial temperature and initial liquid level of the conductive liquid in the detection container are recorded. Second, the positive detection lead and the negative detection lead of the insulation detection conductive assembly are electrically connected to the charging and discharging device, so that the insulation detection conductive assembly forms a closed circuit during charging and discharging, allowing the insulation detection conductive assembly to operate normally. Simultaneously, the temperature and liquid level of the conductive liquid in the detection container are detected, and a second temperature and a second liquid level of the conductive liquid in the detection container are recorded. The initial temperature is subtracted from the second temperature to obtain a temperature difference of the conductive liquid, and the initial liquid level is subtracted from the second liquid level to obtain a liquid level change. Furthermore, heat loss energy during the charge and discharge process of the lithium-ion battery is calculated based on the temperature difference of the conductive liquid, and the volume expansion work during the charge and discharge process of the lithium-ion battery is calculated based on the liquid level change. Finally, the actual charge and discharge energy of the lithium-ion battery is calculated based on the heat loss energy, the volume expansion work, and the charge and discharge energy displayed and output by the charging and discharging device. In this way, based on the heat loss energy, volume expansion work and the charge and discharge energy displayed by the charge and discharge equipment, the actual charge and discharge energy of the lithium-ion battery can be accurately calculated, so that the charge and discharge energy measurement method of the lithium-ion battery has a high measurement accuracy for the actual charge and discharge energy of the lithium-ion battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 A flow chart of a method for measuring charge and discharge energy of a lithium-ion battery according to one embodiment;

[0039] Figure 2 A cross-sectional view of a detection container according to an embodiment from one viewing angle;

[0040] Figure 3 A schematic structural diagram of a detection container according to an embodiment from another perspective;

[0041] Figure 4 for Figure 2 A cross-sectional view of the first fixing bracket of the detection container is shown. DETAILED DESCRIPTION

[0042] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0043] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] The present invention provides a method for measuring the charge and discharge energy of a lithium ion battery, comprising: performing wiring processing on the positive and negative electrodes of a lithium ion battery to be measured, respectively, so that the positive electrode of the lithium ion battery is electrically connected to a positive detection wire, and the negative electrode of the lithium ion battery is electrically connected to a negative detection wire; performing insulation and sealing processing on the connection points of the positive and negative electrodes of the lithium ion battery, respectively, to form an insulation detection conductive assembly; placing the insulation detection conductive assembly in a detection container; injecting a conductive liquid to a predetermined height into the detection container; electrically connecting the positive detection wire and the negative detection wire of the insulation detection conductive assembly to a charge and discharge device, and simultaneously detecting the temperature and liquid level of the conductive liquid in the detection container to obtain a temperature difference and a liquid level change value of the conductive liquid; calculating heat loss energy during the charge and discharge process of the lithium ion battery based on the temperature difference of the conductive liquid; calculating volume expansion work during the charge and discharge process of the lithium ion battery based on the liquid level change value; and calculating the actual charge and discharge energy of the lithium ion battery based on the heat loss energy, the volume expansion work, and the charge and discharge energy displayed and output by the charge and discharge device.

[0046] The above-mentioned method for measuring the charge and discharge energy of a lithium-ion battery includes the following steps: first, a conductive liquid is injected into a detection container to a predetermined height, and the initial temperature and initial liquid level of the conductive liquid in the detection container are recorded. Second, the positive and negative detection leads of the insulation detection conductive assembly are electrically connected to a charge and discharge device so that the insulation detection conductive assembly forms a closed circuit during charge and discharge, enabling normal operation of the insulation detection conductive assembly. Simultaneously, the temperature and liquid level of the conductive liquid in the detection container are detected, and a second temperature and a second liquid level of the conductive liquid in the detection container are recorded. The initial temperature is subtracted from the second temperature to obtain a temperature difference of the conductive liquid, and the initial liquid level is subtracted from the second liquid level to obtain a liquid level change. Furthermore, heat loss energy during the charge and discharge process of the lithium-ion battery is calculated based on the temperature difference of the conductive liquid, and the volume expansion work during the charge and discharge process of the lithium-ion battery is calculated based on the liquid level change. Finally, the actual charge and discharge energy of the lithium-ion battery is calculated based on the heat loss energy, the volume expansion work, and the charge and discharge energy displayed by the charge and discharge device. In this way, based on the heat loss energy, volume expansion work and the charge and discharge energy displayed by the charge and discharge equipment, the actual charge and discharge energy of the lithium-ion battery can be accurately calculated, so that the charge and discharge energy measurement method of the lithium-ion battery has a high measurement accuracy for the actual charge and discharge energy of the lithium-ion battery.

[0047] To better understand the technical solutions and beneficial effects of the present application, the present application is further described in detail below with reference to specific embodiments:

[0048] like Figures 1 to 2 As shown, a method for measuring the charge and discharge energy of a lithium-ion battery 10 according to an embodiment is used to measure the actual charge and discharge energy of the lithium-ion battery 10. In one embodiment, the method for measuring the charge and discharge energy of the lithium-ion battery 10 includes some or all of the following steps:

[0049] S100 , performing wiring processing on the positive and negative electrodes of the lithium-ion battery 10 to be measured, so that the positive electrode of the lithium-ion battery 10 is electrically connected to the positive detection wire 110 , and the negative electrode of the lithium-ion battery 10 is electrically connected to the negative detection wire 120 .

[0050] In this embodiment, the positive and negative electrodes of the lithium-ion battery 10 to be measured are connected separately, so that the positive detection wire 110 is fixedly connected to the positive electrode of the lithium-ion battery 10, and the negative detection wire 120 is fixedly connected to the negative electrode of the lithium-ion battery 10.

[0051] S200 , performing insulation and sealing treatment on the connection points of the positive and negative electrodes of the lithium-ion battery 10 to form an insulation detection conductive assembly.

[0052] In this embodiment, the positive and negative electrode connection points of the lithium-ion battery 10 are respectively subjected to insulation and sealing treatment, that is, the positive electrode connection point of the lithium-ion battery 10 is subjected to insulation and sealing treatment, and the negative electrode connection point of the lithium-ion battery 10 is also subjected to insulation and sealing treatment to form an insulation detection conductive component.

[0053] S300 , placing the insulation detection conductive component in the detection container 20 .

[0054] In this embodiment, the vertical distance between the center of the lithium-ion battery 10 and the bottom of the detection container 20 is recorded.

[0055] S400 , injecting a conductive liquid 210 to a predetermined height into the detection container 20 .

[0056] In this embodiment, when the conductive liquid 210 is injected into the detection container 20 to a predetermined height, the initial temperature and the initial liquid level of the conductive liquid 210 in the detection container 20 are recorded.

[0057] S500: Electrically connect the positive detection wire 110 and the negative detection wire 120 of the insulation detection conductive component to a charging and discharging device, and simultaneously detect the temperature and liquid level of the conductive liquid 210 in the detection container 20 to obtain the temperature difference of the conductive liquid 210 and the change in the liquid level.

[0058] In this embodiment, the positive detection wire 110 and the negative detection wire 120 of the insulation detection conductive assembly are electrically connected to a charging and discharging device, so that the insulation detection conductive assembly forms a closed circuit during charging and discharging, allowing the insulation detection conductive assembly to function normally. Simultaneously, the temperature and liquid level of the conductive liquid 210 in the detection container 20 are detected, and the second temperature and second liquid level of the conductive liquid 210 in the detection container 20 are recorded for calculating the required temperature difference and liquid level change.

[0059] S600 , calculating heat loss energy during the charge and discharge process of the lithium-ion battery 10 according to the temperature difference of the conductive liquid 210 .

[0060] In this embodiment, the formula for calculating heat release and heat absorption by an object is: QHeatLoss = CConductiveLiquid210×mConductiveLiquid210×Tdifference; wherein QHeatLoss is the heat loss energy; CConductiveLiquid210 is the specific heat capacity of the conductive liquid 210, which is a constant; mConductiveLiquid210 is the mass of the conductive liquid 210; and Tdifference is the temperature change, i.e., the temperature difference, which is equal to the second temperature minus the initial temperature. The heat loss energy during the charge and discharge process of the lithium-ion battery 10 is calculated according to the steps of the above formula.

[0061] S700 , calculating the volume expansion work during the charge and discharge process of the lithium-ion battery 10 according to the change in the liquid level height.

[0062] In this embodiment, the formula for calculating energy is as follows: W expansion work = ρ conductive liquid 210 × g × h × V difference; where W expansion work is the volume expansion work; ρ conductive liquid 210 is the density of the conductive liquid 210, which is a constant; g is the acceleration due to gravity, which is a constant; h is the vertical height from the center of the lithium-ion battery 10 to be measured to the liquid surface of the conductive liquid 210 at a predetermined height within the detection container 20, the specific value of which is determined based on actual measurements; V difference is the volume change of the conductive liquid 210 within the detection container 20. The initial volume of the conductive liquid 210 within the detection container 20 is calculated based on the initial liquid level and the length and width of the detection container 20. The second volume of the conductive liquid 210 within the detection container 20 after charge and discharge is calculated based on the second liquid level and the length and width of the detection container 20. V difference is equal to the second volume minus the initial volume. The volume expansion work of the lithium-ion battery 10 during the charge and discharge process is calculated using the above formula.

[0063] S800 , calculating the actual charge and discharge energy of the lithium-ion battery 10 according to the heat loss energy, the volume expansion work, and the charge and discharge energy displayed and output by the charge and discharge device.

[0064] In this embodiment, based on the calculated heat loss energy and volume expansion work, combined with the charge and discharge energy displayed and output by the charge and discharge device, the actual charge and discharge energy of the lithium-ion battery 10 is calculated according to the formula: Eactual Charge and Discharge Energy = WCharge and Discharge Energy - QHeat Loss - WExpansion Work, where Wcharge / discharge energy is the charge and discharge energy displayed and output by the charge and discharge device; Eactual Charge and Discharge Energy is the actual charge and discharge energy of the lithium-ion battery 10. The actual charge and discharge energy of the lithium-ion battery 10 is calculated according to the steps of the above formula.

[0065] The above-mentioned method for measuring the charge and discharge energy of the lithium-ion battery 10 first injects a conductive liquid 210 to a predetermined height into the detection container 20, and records the initial temperature and initial liquid level of the conductive liquid 210 in the detection container 20 at this time. Then, the positive detection wire 110 and the negative detection wire 120 of the insulation detection conductive component are electrically connected to the charging and discharging equipment so that the insulation detection conductive component forms a closed circuit during the charging and discharging, allowing the insulation detection conductive component to operate normally. At the same time, the temperature and liquid level of the conductive liquid 210 in the detection container 20 are detected, and the initial temperature and liquid level of the detection container 20 at this time are recorded. The second temperature and second liquid level of the conductive liquid 210 in the conductive liquid 20 are calculated. The initial temperature is subtracted from the second temperature to obtain the temperature difference of the conductive liquid 210. The initial liquid level is then subtracted from the second liquid level to obtain the liquid level change. Furthermore, the heat loss energy during the charge and discharge process of the lithium-ion battery 10 is calculated based on the temperature difference of the conductive liquid 210. The volume expansion work during the charge and discharge process of the lithium-ion battery 10 is then calculated based on the liquid level change. Finally, the actual charge and discharge energy of the lithium-ion battery 10 is calculated based on the heat loss energy, volume expansion work, and the charge and discharge energy displayed by the charge and discharge device. In this way, the actual charge and discharge energy of the lithium-ion battery 10 can be accurately calculated based on the heat loss energy, volume expansion work, and the charge and discharge energy displayed by the charge and discharge device, thereby ensuring that the charge and discharge energy measurement method of the lithium-ion battery 10 has a high accuracy in measuring the actual charge and discharge energy of the lithium-ion battery 10.

[0066] In one embodiment, the step of separately wiring the positive and negative electrodes of the lithium-ion battery 10 to be measured includes: gluing and fixing the positive electrode of the lithium-ion battery 10 to the positive detection wire 110 with insulating tape, so that the positive electrode of the lithium-ion battery 10 is electrically connected to the positive detection wire 110; and gluing and fixing the negative electrode of the lithium-ion battery 10 to the negative detection wire 120 with the insulating tape, so that the negative electrode of the lithium-ion battery 10 is electrically connected to the negative detection wire 120. In this embodiment, the positive electrode of the lithium-ion battery 10 and the positive detection wire 110 are bonded and fixed by insulating tape, and the negative electrode of the lithium-ion battery 10 and the negative detection wire 120 are bonded and fixed by insulating tape, so that the positive detection wire 110 can be quickly removed from the positive electrode, and the negative detection wire 120 can be quickly removed from the negative electrode, so that the lithium-ion battery 10 can be quickly used after the measurement is completed, thereby improving the convenience of using the lithium-ion battery 10 and improving the convenience of the charge and discharge energy measurement method of the lithium-ion battery 10.

[0067] In one embodiment, the insulating tape is made of polyvinyl chloride (PVC) or polyolefin-based insulating tape. In this embodiment, PVC or polyolefin-based insulating tapes are common types of insulating tapes and can be easily found in hardware stores, thereby reducing operator tool search time and improving the efficiency of the method for measuring the charge and discharge energy of the lithium-ion battery 10.

[0068] In one embodiment, the steps of fixing the insulating tape include: pre-winding and bending the exposed section of the positive detection wire 110 to form a positive spiral contact terminal; gluing the positive spiral contact terminal to the positive contact portion of the lithium-ion battery 10 by gluing the insulating tape to form a positive pre-fixed terminal; wrapping the positive pre-fixed terminal with several turns of insulating tape to form a positive terminal of the lithium-ion battery 10; pre-winding and bending the exposed section of the negative detection wire 120 to form a negative spiral contact terminal; gluing the negative spiral contact terminal to the negative contact portion of the lithium-ion battery 10 by gluing the insulating tape to form a negative pre-fixed terminal; and wrapping the negative pre-fixed terminal with several turns of insulating tape to form a negative terminal of the lithium-ion battery 10.

[0069] In this embodiment, the exposed section of the positive detection wire 110 is pre-wound and bent to form a positive electrode spiral contact end, so that the contact area between the positive detection wire 110 and the positive electrode of the lithium-ion battery 10 is larger, thereby improving the contact effect between the positive detection wire 110 and the positive electrode of the lithium-ion battery 10, and thus improving the measurement accuracy of the charge and discharge energy measurement method of the lithium-ion battery 10; the exposed section of the negative detection wire 120 is pre-wound and bent to form a negative electrode spiral contact end, so that the contact area between the negative detection wire 120 and the negative electrode of the lithium-ion battery 10 is larger, thereby improving the contact effect between the negative detection wire 120 and the negative electrode of the lithium-ion battery 10, and thus improving the measurement accuracy of the charge and discharge energy measurement method of the lithium-ion battery 10.

[0070] In one embodiment, the step of insulating and sealing the positive and negative electrode connections of the lithium-ion battery 10 includes: wrapping the positive electrode connection of the lithium-ion battery 10 with a sealing film; and wrapping the negative electrode connection of the lithium-ion battery 10 with the sealing film. In this embodiment, wrapping the positive electrode connection of the lithium-ion battery 10 with the sealing film improves the waterproof performance of the positive electrode connection of the lithium-ion battery 10; wrapping the negative electrode connection of the lithium-ion battery 10 with the sealing film improves the waterproof performance of the negative electrode connection of the lithium-ion battery 10, making the connection structure of the positive electrode connection of the lithium-ion battery 10 and the negative electrode connection of the lithium-ion battery 10 more secure, thereby improving the measurement accuracy of the charge and discharge energy measurement method of the lithium-ion battery 10.

[0071] In one embodiment, the positive and negative electrode connections of the lithium-ion battery 10, which have been wrapped with a sealing film, are each wrapped with a sealing insulating member. This provides secondary sealing protection, improving the waterproof performance of the positive and negative electrode connections of the lithium-ion battery 10 and thereby enhancing the structural strength of the insulation detection conductive assembly. In this embodiment, the sealing insulating member can be an insulating joint or other existing sealing insulating member.

[0072] like Figures 2 to 3 As shown, in one embodiment, before the insulation detection conductive assembly is placed in the detection container 20, one end of the auxiliary fixing strap 220 is fixed to the insulation detection conductive assembly, and the other end of the auxiliary fixing strap 220 is fixed to the fixing post 230 of the detection container 20. In this embodiment, by fixing one end of the auxiliary fixing strap 220 to the insulation detection conductive assembly and the other end of the auxiliary fixing strap 220 to the fixing post 230 of the detection container 20, the position of the insulation detection conductive assembly is fixed, thereby reducing shaking of the insulation detection conductive assembly and preventing breakage at the connection points of the positive and negative electrodes of the lithium-ion battery 10 caused by shaking. This further improves the measurement accuracy of the charge and discharge energy measurement method of the lithium-ion battery 10.

[0073] like Figure 2As shown, in one embodiment, the step of injecting a predetermined height of conductive liquid 210 into the detection container 20 includes completely immersing the lithium-ion battery 10 to be measured in the conductive liquid 210. In this embodiment, completely immersing the lithium-ion battery 10 to be measured in the conductive liquid 210 allows all heat loss energy during the charge and discharge process of the lithium-ion battery 10 to be transferred into the conductive liquid 210, thereby increasing the accuracy of the measured temperature difference. This increases the accuracy of the heat loss energy during the charge and discharge process of the lithium-ion battery 10 calculated based on the temperature difference of the conductive liquid 210, thereby increasing the accuracy of the charge and discharge energy measurement method of the lithium-ion battery 10. Furthermore, completely immersing the lithium-ion battery 10 to be measured in the conductive liquid 210 increases the accuracy of the measured liquid level change value, thereby increasing the accuracy of the volume expansion work during the charge and discharge process of the lithium-ion battery 10 calculated based on the liquid level change value, thereby increasing the accuracy of the charge and discharge energy measurement method of the lithium-ion battery 10.

[0074] In one embodiment, a heat-insulating film layer (not shown) is formed on the outer wall of the detection container 20 to prevent the heat in the detection container 20 from being conducted to the outside, so that the measured temperature difference is more accurate, thereby making the measurement accuracy of the charge and discharge energy measurement method of the lithium-ion battery 10 higher.

[0075] Furthermore, a heat-insulating film layer is formed on the inner wall of the detection container 20 to prevent the heat in the detection container 20 from being conducted to the outside, so that the measured temperature difference is more accurate, thereby making the measurement accuracy of the charge and discharge energy measurement method of the lithium-ion battery 10 higher.

[0076] In one embodiment, a liquid level scale is provided on the peripheral wall of the detection container 20. In this embodiment, the material of the detection container 20 can be glass or other existing transparent containers.

[0077] In one embodiment, before electrically connecting the positive detection wire 110 and the negative detection wire 120 of the insulation detection conductive assembly to the charging and discharging device and simultaneously detecting the temperature and liquid level of the conductive liquid 210 in the detection container 20, the method further includes: disposing a thermometer 30 in the detection container 20. In this embodiment, the thermometer 30 is disposed in the detection container 20 and is used to measure the initial temperature of the conductive liquid 210 in the detection container 20 and a second temperature during the charging and discharging process. This allows the temperature difference of the conductive liquid 210 to be quickly determined. Based on the temperature difference, the heat loss energy during the charging and discharging process of the lithium-ion battery 10 can be accurately calculated, thereby accurately determining the actual charge and discharge energy of the lithium-ion battery 10. This facilitates thermal simulation of the lithium-ion battery 10 and reduces the research and development costs of the lithium-ion battery 10. In this embodiment, the thermometer 30 can be a thermometer, a temperature measuring instrument, or other existing temperature measuring instruments.

[0078] In one embodiment, before electrically connecting the positive detection wire 110 and the negative detection wire 120 of the insulation detection conductive assembly to the charging and discharging device and simultaneously detecting the temperature and liquid level of the conductive liquid 210 in the detection container 20, the method further includes: disposing a liquid level measuring instrument 40 in the detection container 20. In this embodiment, the liquid level measuring instrument 40 is disposed in the detection container 20 and is used to measure the initial liquid level of the conductive liquid 210 in the detection container 20 and the second liquid level during the charge and discharge process. This allows for rapid determination of the liquid level change of the conductive liquid 210. Based on this liquid level change, the volume expansion work during the charge and discharge process of the lithium-ion battery 10 can be accurately calculated, thereby accurately determining the actual charge and discharge energy of the lithium-ion battery 10. This facilitates thermal simulation of the lithium-ion battery 10 and reduces the research and development costs of the lithium-ion battery 10. In this embodiment, the liquid level measuring instrument 40 can be a graduated cylinder or other existing liquid level measuring instrument.

[0079] In one embodiment, the detection container 20 is provided with an insulating cover plate 240, which is covered on the detection container 20 and connected to the peripheral wall of the detection container 20. The insulating cover plate 240 is provided with a first avoidance hole 241 and a second avoidance hole 242. The thermometer 30 is passed through the first avoidance hole 241 and connected to the insulating cover plate 240, and the liquid level measuring instrument 40 is passed through the second avoidance hole 242 and connected to the insulating cover plate 240. In this embodiment, the insulating cover plate 240 is used to prevent heat from dissipating within the detection container 20, thereby preventing the second temperature from being lowered due to heat dissipation, thereby increasing the accuracy of the temperature difference, and further increasing the measurement accuracy of the charge and discharge energy measurement method of the lithium-ion battery 10. In this embodiment, a first sealing ring 243 and a second sealing ring 244 are provided on the insulating cover plate 240, so that the heat in the detection container 20 is difficult to dissipate to the outside through the first avoidance hole 241 and the second avoidance hole 242, thereby ensuring the accuracy of the temperature difference of the conductive liquid 210, so that the measurement accuracy of the charge and discharge energy measurement method of the lithium-ion battery 10 is higher.

[0080] like Figure 2 and Figure 4 As shown, in one embodiment, the detection container 20 is formed with a first fixing frame 250 and a second fixing frame 260. The first fixing frame is used to fix the thermometer 30, and the second fixing frame 260 is used to fix the liquid level meter 40. In this embodiment, the position of the thermometer 30 is fixed by the first fixing frame 250, preventing the thermometer 30 from shaking, thereby ensuring more uniform contact between the thermometer 30 and the conductive liquid 210, and improving the accuracy of the temperature measured by the thermometer 30. The position of the liquid level meter 40 is fixed by the second fixing frame 260, reducing the shaking of the liquid level meter 40, allowing the operator to quickly record the liquid level height based on the liquid level meter 40, thereby improving the working efficiency of the method for measuring the charge and discharge energy of the lithium-ion battery 10. In this embodiment, the first fixing frame 250 and the second fixing frame 260 are both made of silicone.

[0081] In this embodiment, the first fixing frame 250 is formed with a conical fixing hole 251, and the thermometer 30 is inserted into the conical fixing hole 251 and is connected to the first fixing frame 250. This makes the thermometer 30 more stable as it moves closer to the bottom of the detection container 20, thereby preventing the thermometer 30 from shaking. In addition, the contact between the thermometer 30 and the conductive liquid 210 is more uniform, making the temperature measured by the thermometer 30 more accurate, and thus improving the measurement accuracy of the charge and discharge energy measurement method of the lithium-ion battery 10.

[0082] In one embodiment, it is understood that the conductive liquid 210 can be water or another existing conductive liquid 210 with excellent thermal conductivity. In this embodiment, the conductive liquid 210 uses a conductive liquid 210 with excellent thermal conductivity, thereby increasing the rate at which the temperature is transferred to the thermometer 30, improving the measurement accuracy of the thermometer 30, and shortening the measurement time of the thermometer 30, thereby increasing the efficiency of the method for measuring the charge and discharge energy of the lithium-ion battery 10.

[0083] In one embodiment, the detection container 20 includes a container body and a vibration component (not shown) disposed at the bottom of the container body. The vibration component is used to vibrate the container body so that the heat in the detection container 20 can be transferred to the thermometer 30 more quickly, thereby shortening the measurement time of the thermometer 30 and making the working efficiency of the charge and discharge energy measurement method of the lithium-ion battery 10 higher.

[0084] like Figure 2 As shown, in one embodiment, the thermal insulation cover 240 is further formed with a first wire through hole 245 and a second wire through hole 246, the positive detection wire 110 is passed through the first wire through hole 245 and connected to the thermal insulation cover 240, and the negative detection wire 120 is passed through the second wire through hole 246 and connected to the thermal insulation cover 240.

[0085] Compared with the prior art, the present invention has at least the following advantages:

[0086] First, a conductive liquid 210 is injected into the detection container 20 to a predetermined height, and the initial temperature and initial liquid level of the conductive liquid 210 in the detection container 20 are recorded. Second, the positive detection wire 110 and the negative detection wire 120 of the insulation detection conductive component are electrically connected to the charging and discharging device so that the insulation detection conductive component forms a closed circuit during charging and discharging, allowing the insulation detection conductive component to operate normally. At the same time, the temperature and liquid level of the conductive liquid 210 in the detection container 20 are detected, and the initial liquid level of the conductive liquid 210 in the detection container 20 is recorded. The second temperature and second liquid level are calculated, the initial temperature is subtracted from the second temperature to obtain the temperature difference of the conductive liquid 210, and the initial liquid level is subtracted from the second liquid level to obtain the liquid level change. Furthermore, the heat loss energy during the charge and discharge process of the lithium-ion battery 10 is calculated based on the temperature difference of the conductive liquid 210, and the volume expansion work during the charge and discharge process of the lithium-ion battery 10 is calculated based on the liquid level change. Finally, the actual charge and discharge energy of the lithium-ion battery 10 is calculated based on the heat loss energy, volume expansion work, and the charge and discharge energy displayed by the charge and discharge device. In this way, the actual charge and discharge energy of the lithium-ion battery 10 can be accurately calculated based on the heat loss energy, volume expansion work, and the charge and discharge energy displayed by the charge and discharge device, resulting in a method for measuring the charge and discharge energy of the lithium-ion battery 10 with high accuracy.

[0087] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for measuring the charge and discharge energy of a lithium-ion battery, characterized in that: include: Conduct wiring treatment on the positive and negative electrodes of the lithium-ion battery to be measured, respectively, so that the positive electrode of the lithium-ion battery is electrically connected to the positive detection wire, and the negative electrode of the lithium-ion battery is electrically connected to the negative detection wire; Performing insulation and sealing treatment on the connection points of the positive and negative electrodes of the lithium-ion battery respectively to form an insulation detection conductive component; Placing the insulation detection conductive component in a detection container; injecting a conductive liquid to a predetermined height into the detection container; The positive detection wire and the negative detection wire of the insulation detection conductive component are electrically connected to a charging and discharging device, and the temperature and liquid level of the conductive liquid in the detection container are detected to obtain the temperature difference of the conductive liquid and the change in the liquid level; Calculating heat loss energy during the charging and discharging process of the lithium-ion battery according to the temperature difference of the conductive liquid; Calculating the volume expansion work during the charge and discharge process of the lithium-ion battery according to the change in the liquid level height; Calculating the actual charge and discharge energy of the lithium-ion battery according to the heat loss energy, the volume expansion work, and the charge and discharge energy displayed and output by the charge and discharge device; The step of wiring the positive and negative electrodes of the lithium-ion battery to be measured comprises: Adhere the positive electrode of the lithium-ion battery and the positive detection wire with insulating tape to fix them so that the positive electrode of the lithium-ion battery is electrically connected to the positive detection wire; Adhere the negative electrode of the lithium-ion battery and the negative detection wire with the insulating tape to fix them so that the negative electrode of the lithium-ion battery is electrically connected to the negative detection wire; The steps of fixing the insulating tape include: Pre-winding and bending the exposed section of the positive detection wire to form a positive spiral contact end; Pre-fixing the positive electrode spiral contact end to the positive electrode contact portion of the lithium-ion battery by gluing the insulating tape to form a positive electrode pre-fixed terminal; Wrap the positive electrode pre-fixed terminal with insulating tape for several turns to form the positive electrode connection point of the lithium-ion battery; Pre-winding and bending the exposed section of the negative detection wire to form a negative electrode spiral contact end; Pre-fixing the negative electrode spiral contact end to the negative electrode contact portion of the lithium-ion battery by gluing the insulating tape to form a negative electrode pre-fixed terminal; The negative electrode pre-fixed terminal is wrapped with insulating tape for several turns to form the negative electrode connection point of the lithium ion battery.

2. The method for measuring the charge and discharge energy of a lithium-ion battery according to claim 1, wherein: The insulating tape is made of polyvinyl chloride insulating tape or polyolefin insulating tape.

3. The method for measuring the charge and discharge energy of a lithium-ion battery according to claim 1, wherein: The step of performing insulation and sealing treatment on the connection points of the positive and negative electrodes of the lithium-ion battery respectively comprises: Wrapping the positive electrode connection of the lithium-ion battery with a sealing film; The negative electrode connection point of the lithium-ion battery is wound with the sealing film.

4. The method for measuring charge and discharge energy of a lithium-ion battery according to claim 1, wherein: Before placing the insulation detection conductive component in the detection container, one end of the auxiliary fixing belt is fixed to the insulation detection conductive component, and the other end of the auxiliary fixing belt is fixed to the fixing column of the detection container.

5. The method for measuring charge and discharge energy of a lithium-ion battery according to claim 1, wherein: The step of injecting a predetermined height of conductive liquid into the detection container comprises: The lithium-ion battery to be measured is completely immersed in the conductive liquid.

6. The method for measuring charge and discharge energy of a lithium-ion battery according to claim 1, wherein: Before the step of electrically connecting the positive detection wire and the negative detection wire of the insulation detection conductive component to the charging and discharging device and simultaneously detecting the temperature and the liquid level of the conductive liquid in the detection container, the method further includes: A thermometer is placed in the detection container.

7. The method for measuring charge and discharge energy of a lithium-ion battery according to claim 1, wherein: Before the step of electrically connecting the positive detection wire and the negative detection wire of the insulation detection conductive component to the charging and discharging device and simultaneously detecting the temperature and the liquid level of the conductive liquid in the detection container, the method further includes: A liquid level measuring instrument is arranged in the detection container.

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