A temperature control test device for lithium-ion battery cells with fan cooling

Abstract

A temperature control test device for a lithium-ion battery cell with fan heat dissipation comprises a temperature controller and a temperature control chamber; the temperature controller comprises a temperature-averaging power supply, a temperature sensing module, a cooling plate control module and a heat dissipation monitoring module; the temperature-averaging power supply provides power for a temperature-averaging fan, the cooling plate control module is connected to a cooling plate of the temperature control chamber, and controls the cooling plate to work in a cooling mode or a heating mode by changing the direction of current; the temperature sensing module is connected to the temperature probe pin in the temperature control chamber, and communicates with the cooling plate control module, and compares whether the monitored surface temperature of the battery cell is the same as the set value, and then controls the module to start or stop the cooling plate; the heat dissipation monitoring module is connected to the pin of the heat dissipation fan of the temperature control chamber to supply power to it, and monitors the current on the heat dissipation fan; the cooling plate control module communicates with the heat dissipation monitoring module, and when the heat dissipation monitoring module detects that the fan current is abnormal, the cooling plate control module stops supplying power to the cooling plate; the invention has the characteristics of small size, low cost, fast and stable temperature control, accurate temperature measurement, wide temperature range, easy electrical testing and high working stability.

Description

Technical Field

[0001] The present invention relates to the technical field of battery testing, and in particular to a temperature control testing device for a lithium-ion battery cell with fan heat dissipation. Background Art

[0002] In the rapidly developing new energy field, lithium-ion batteries stand out from many types of secondary batteries due to their high specific energy characteristics and become a popular energy storage device. They are widely used in electric vehicles, power tools, and grid energy storage. The only drawback is that the electrode materials, electrolytes, and diaphragms that make up lithium-ion batteries can usually only work in a narrow temperature window, and exceeding their temperature window will cause serious damage. For example, when working at a lower temperature, the negative electrode will undergo severe lithium precipitation, and the resulting lithium dendrites may pierce the diaphragm, causing an internal short circuit; under high temperature conditions, the electrode material may undergo a phase change, the electrolyte may volatilize or oxidize, and the diaphragm may fail. However, lithium-ion batteries need to be applicable to a wider temperature range in their applications. For example, in electric vehicles in extremely cold areas, the battery needs to be able to maintain sufficient power at -20°C; while in tropical areas, or when the battery itself heats up during operation, the battery is required to maintain normal operation at a temperature of +50°C. Therefore, the study of the temperature characteristics of lithium-ion batteries is of great practical significance for their practical applications.

[0003] At present, the most widely used in commercialization are 18650 lithium-ion batteries and soft-pack batteries. 18650 refers to a cylindrical lithium-ion battery with a diameter of 18 mm and a length of 65 mm. Soft-pack batteries are usually square or rectangular, usually used in 3C electronic products such as mobile phones, and have a higher volume density. Different from batteries with protection circuits and shells that can be used directly, unpackaged batteries can also be called batteries. They are generally used for experimental testing and can be divided into aluminum shell batteries, soft-pack batteries (also known as "polymer batteries"), cylindrical batteries, etc. In the laboratory, the most commonly used temperature test method is to put the battery to be tested into a large constant temperature chamber for electrical testing. Constant temperature chambers usually use compressors and cold air to cool down. Constant temperature chambers are large in size, high in price, slow in temperature adjustment, and have high requirements for use, resulting in low test efficiency and inconvenience in actual use. In addition, the measured temperature is usually the temperature inside the chamber, which is different from the actual electrode temperature of the button battery, so it is impossible to accurately determine the actual working temperature of the lithium-ion battery. A comparative study was conducted on the temperature test problem of lithium-ion battery cells. Through keyword search, the patent listed in patent number CN105700587A belongs to the constant temperature chamber test type and cannot solve the existing problem; the lithium-ion temperature control device shown in patent CN103487761 is actually just a lithium-ion battery temperature sensing chamber and cannot achieve real-time temperature control; the content contained in CN107887672 and CN206180060 is a control strategy for battery thermal management, not a temperature control device for lithium-ion battery cells. Therefore, there is an urgent need for a device that can provide an efficient and stable temperature environment for lithium-ion battery cell testing. Summary of the invention

[0004] In order to overcome the defects of the above-mentioned prior art and improve the temperature testing efficiency of lithium-ion battery cells, the purpose of the present invention is to provide a lithium-ion battery cell temperature control testing device based on fan heat dissipation, which has the characteristics of small size, low cost, fast and stable temperature control, accurate temperature measurement, wide temperature range, easy electrical testing, and high working stability. By using fan heat dissipation, the outer surface of the lithium-ion battery cell can be maintained at a temperature of 0°C to 60°C or even wider without the need for other auxiliary equipment.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A fan-cooled lithium-ion battery cell temperature control test device comprises a temperature controller 1 and a temperature control chamber 2;

[0007] The cavity wall of the temperature control cavity 2 is a double-layer structure, the outer layer 2-5 is a shell material, and the inner layer 2-6 is a heat-insulating material; a battery test rack 2-1 is arranged inside the temperature control cavity 2 for placing the lithium-ion battery cell 2-2 to be tested, and the test line connected to the electrode test point 2-3 of the battery test rack 2-1 passes through the temperature control cavity 2 and is connected to the battery test equipment outside the temperature control cavity 2; the temperature probe 2-4 is closely attached to the surface of the lithium-ion battery cell 2-2; a temperature-averaging fan 2-7 is installed on the inner wall of the cavity; a hole is arranged on the cavity wall for installing a refrigeration plate 2-8, the cold surface of the refrigeration plate 2-8 is bonded to the cold storage block 2-9 by thermal conductive silicone grease, and the cold storage block 2-9 is located in the cavity, and the hot surface of the refrigeration plate 2-8 is bonded to the fan heat sink 2-10 by thermal conductive silicone grease, and the heat sink 2-10 is located outside the cavity, and a heat dissipation fan 2-11 is installed on the heat sink 2-10 to take away the heat of the heat sink 2-10;

[0008] The temperature controller 1 includes a temperature-averaging power supply 1-1, a temperature sensing module 1-2, a cooling plate control module 1-3 and a heat dissipation monitoring module 1-4; the temperature-averaging power supply 1-1 provides power for the temperature-averaging fan 2-7, which needs to be started first after the temperature controller 1 is powered on, so as to ensure a uniform temperature in the temperature control chamber 2;

[0009] The acquisition line of the temperature sensing module 1-2 is connected to the pin of the temperature probe 2-4 in the temperature control chamber 2, and communicates with the cooling plate control module 1-3 to compare whether the monitored surface temperature of the battery cell is the same as the set value, and then the control module 1-3 starts or stops the cooling plate 2-8;

[0010] The cooling plate control module 1-3 is connected to the cooling plate 2-8 pin of the temperature control chamber 2 through a control line, and controls the cooling plate 2-8 to work in the cooling mode or the heating mode by changing the current direction;

[0011] The heat dissipation monitoring module 1-4 is connected to the pin of the heat dissipation fan 2-11 of the temperature control chamber 2 to power it and monitor the current on the heat dissipation fan; the refrigeration plate control module 1-3 communicates with the heat dissipation monitoring module 1-4. When the heat dissipation monitoring module 1-4 detects that the fan current is abnormal, the refrigeration plate control module 1-3 stops supplying power to the refrigeration plate 2-8.

[0012] The side length of the refrigeration sheet 2-8 is 4 cm and the thickness is 5 mm.

[0013] The advantages of the present invention are as follows: the side length of the cooling plate is only in the order of centimeters, the required chamber is very small, and it has the ability to heat and cool at the same time. Compared with the traditional lithium-ion battery cell test device, the fan heat dissipation test device designed with the cooling plate of the present invention is compact, efficient, and has more accurate and easy-to-implement temperature control. The heat dissipation monitoring function can effectively protect the cooling plate and prevent overheating damage. The device is safer and the test is more stable. The use of the heat dissipation fan does not require other refrigeration accessories, such as circulating cooling water, compressors, etc., to achieve a better temperature control effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the present invention.

[0015] Figure 2 It is a cross-sectional schematic diagram of the temperature control chamber of the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings.

[0017] Reference Figure 1 , a fan-cooled lithium-ion battery cell temperature control test device, comprising a temperature controller 1 and a temperature control chamber 2;

[0018] Reference Figure 2 The wall of the temperature control chamber 2 is a double-layer structure, the outer layer 2-5 is a shell material, and the inner layer 2-6 is a heat-insulating material; a battery test rack 2-1 is arranged inside the temperature control chamber 2 for placing the lithium-ion battery cell 2-2 to be tested, and the test line connected to the electrode test point 2-3 of the battery test rack 2-1 passes through the temperature control chamber 2 and is connected to the battery test equipment outside the temperature control chamber 2; the temperature probe 2-4 is closely attached to the surface of the lithium-ion battery cell 2-2 to measure the surface temperature of the battery cell; in the chamber A temperature-averaging fan 2-7 is installed on the wall to balance the temperature in the chamber; a hole is set on the chamber wall to install a refrigeration plate 2-8, the cold surface of the refrigeration plate 2-8 is bonded to a cold storage block 2-9 through thermal conductive silicone grease, and the cold storage block 2-9 is located in the chamber, and the hot surface of the refrigeration plate 2-8 is bonded to a fan heat sink 2-10 through thermal conductive silicone grease, and the heat sink 2-10 is located outside the chamber, and a heat dissipation fan 2-11 is installed on the heat sink 2-10 to take away the heat of the heat sink 2-10;

[0019] Reference Figure 1 The temperature controller 1 includes a temperature-averaging power supply 1-1, a temperature sensing module 1-2, a refrigeration plate control module 1-3 and a heat dissipation monitoring module 1-4;

[0020] The temperature-averaging power supply 1 - 1 provides power for the temperature-averaging fan 2 - 7 , and needs to be started first after the temperature controller 1 is powered on to ensure that the temperature in the temperature control chamber 2 is uniform.

[0021] The cooling plate control module 1-3 is connected to the cooling plate 2-8 pin of the temperature control chamber 2 through a control line, and controls the cooling plate 2-8 to work in the cooling mode or the heating mode by changing the current direction;

[0022] The acquisition line of the temperature sensing module 1-2 is connected to the pin of the temperature probe 2-4 in the temperature control chamber 2, and communicates with the cooling plate control module 1-3 to compare whether the monitored surface temperature of the battery cell is the same as the set value, and then the control module 1-3 starts or stops the cooling plate 2-8;

[0023] The heat dissipation monitoring module 1-4 is connected to the pin of the heat dissipation fan 2-11 of the temperature control chamber 2 to supply power to it and monitor the current on the heat dissipation fan;

[0024] The cooling plate control module 1-3 communicates with the heat dissipation monitoring module 1-4. When the heat dissipation monitoring module 1-4 detects that the fan current is abnormal, the cooling plate control module 1-3 stops supplying power to the cooling plate 2-8;

[0025] The working principle of the present invention is as follows: when in use, first open the temperature control chamber 2, install the lithium-ion battery cell 2-2 on the battery test frame 2-1, attach the temperature probe 2-4 to the surface of the lithium-ion battery cell 2-2, and connect the electrode test point 2-3 to the positive and negative electrodes of the lithium-ion battery cell 2-2 respectively, and then close the temperature control chamber 2. Turn on the thermostat 1, start the temperature-averaging fan 2-7 to make the temperature inside the temperature control chamber 2 more uniform, and return the temperature value measured by the temperature probe 2-4 to the thermostat 1. At the same time, the heat dissipation monitoring 1-4 drives and monitors the heat dissipation fan 2-11 to work. When the heat dissipation fan 2-11 works normally, set the temperature value to be measured, and the cooling plate control module 1-3 compares the set value with the actual value, and drives the cooling plate 2-8 to the cooling mode or the heat dissipation mode. When the temperature in the temperature control chamber 2 is stable near the set value, the battery testing equipment can be used to measure the electrical properties of the lithium-ion battery cell 2-2 at the set temperature. It has been proved through actual use that when the external environment temperature is 20°C, the device can stably achieve a low-temperature test environment of 0°C to a high-temperature test environment of 50°C in the temperature control chamber 2.

Claims

1. A fan-cooled lithium-ion battery cell temperature control test device, characterized in that: It comprises two parts: a temperature controller (1) and a temperature control chamber (2); The wall of the temperature control chamber (2) is a double-layer structure, wherein the outer layer (2-5) is a shell material, and the inner layer (2-6) is a heat-insulating material; a battery test rack (2-1) is arranged inside the temperature control chamber (2) for placing the lithium-ion battery cell (2-2) to be tested; a test line connected to an electrode test point (2-3) of the battery test rack (2-1) passes through the temperature control chamber (2) and is connected to a battery test device outside the temperature control chamber (2); a temperature probe (2-4) is closely attached to the surface of the lithium-ion battery cell (2-2); A temperature-averaging fan (2-7) is installed on the inner wall; a hole is provided on the chamber wall to install a refrigeration plate (2-8); a cold surface of the refrigeration plate (2-8) is bonded to a cold storage block (2-9) through thermally conductive silicone grease, and the cold storage block (2-9) is located in the chamber; a hot surface of the refrigeration plate (2-8) is bonded to a fan heat sink (2-10) through thermally conductive silicone grease, and the heat sink (2-10) is located outside the chamber; a heat sink fan (2-11) is installed on the heat sink (2-10) to remove heat from the heat sink (2-10); The temperature controller (1) comprises a temperature-averaging power supply (1-1), a temperature sensing module (1-2), a refrigeration plate control module (1-3) and a heat dissipation monitoring module (1-4); the temperature-averaging power supply (1-1) provides power for a temperature-averaging fan (2-7), which needs to be started in advance after the temperature controller (1) is powered on to ensure that the temperature in the temperature control chamber (2) is uniform; The collection line of the temperature sensing module (1-2) is connected to the pin of the temperature probe (2-4) in the temperature control cavity (2), and communicates with the cooling plate control module (1-3), and compares whether the monitored surface temperature of the battery cell is the same as the set value, and then the control module (1-3) starts or stops the cooling plate (2-8) from working; The cooling plate control module (1-3) is connected to the cooling plate (2-8) pin of the temperature control chamber (2) via a control line, and controls the cooling plate (2-8) to work in a cooling mode or a heating mode by changing the direction of the current; The heat dissipation monitoring module (1-4) is connected to the pin of the heat dissipation fan (2-11) of the temperature control chamber (2) to supply power to it and monitor the current on the heat dissipation fan; the refrigeration plate control module (1-3) communicates with the heat dissipation monitoring module (1-4); when the heat dissipation monitoring module (1-4) detects that the fan current is abnormal, the refrigeration plate control module (1-3) stops supplying power to the refrigeration plate (2-8).

2. A fan-cooled lithium-ion battery cell temperature control test device according to claim 1, characterized in that: The side length of the refrigeration plate (2-8) is 4 cm and the thickness is 5 mm.

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