Marine thermal runaway battery test pack

Abstract

A marine thermal runaway battery test pack disclosed by the present invention comprises a box body, a battery module and a cover plate assembly, sealing is realized through a butyronitrile sealing ring embedded in a sealing groove, the box body is provided with a power aviation plug, and the box body is also internally provided with a safety protection liquid for immersing the battery module. Each battery module is composed of a plurality of simulation battery cells and real battery cells which are connected in series in a module end plate and a module side plate, an aluminum extrusion harmonica-shaped tube is inserted between every two adjacent battery cells, each battery cell is sequentially connected with a copper bar and an overcharge power line through a connecting aluminum bar, then is connected with a power aviation plug and then is connected with a charging and discharging machine, and a water inlet and outlet valve is arranged on the box body. The cover plate assembly comprises thickened transparent acrylic, and an aerosol fire-fighting device or / and a perfluorohexanone capsule sheet is arranged in a cover plate; according to the invention, a fire-fighting measure-free thermal runaway test, a water inhibition overcharge thermal runaway test and a silicone oil inhibition overcharge thermal runaway test can be realized by opening and closing water inlet and outlet valves, and the overcharge thermal runaway test can be realized through an aerosol fire-fighting device or a perfluorohexanone capsule sheet.

Description

Technical Field

[0001] The invention belongs to the technical field of battery manufacturing, and in particular relates to a marine thermal runaway battery test package. Background Art

[0002] Lithium-ion batteries have excellent characteristics such as high specific energy, high specific power and long life. However, frequent safety accidents have caused widespread concern and doubts about the safety of lithium-ion batteries. In essence, the safety problem of lithium-ion batteries is a thermal problem. Improper use or production defects can cause the internal temperature of lithium-ion batteries to rise during use and storage. High temperature will induce a series of exothermic reactions in battery materials. The heat generated by the reaction will cause the internal temperature of the battery to further increase, thereby increasing the rate of exothermic reactions.

[0003] Ultimately, the exothermic reaction and high temperature interact with each other, presenting an out-of-control state, namely thermal runaway, which causes safety accidents such as combustion and explosion of lithium-ion batteries.

[0004] According to the actual use conditions of marine lithium battery systems, the effects of different thermal management methods on battery safety and service life are studied to improve the safety of battery systems. Taking the immersed battery pack as an example, the battery module of this pack is completely immersed in the safety protection liquid. The liquid cooling plate at the bottom absorbs and transfers the heat generated during battery operation, and can also prevent the thermal runaway of the battery cell from spreading. Once the battery cell has thermal runaway and the safety valve is opened, the coolant immediately penetrates into the battery cell, curbs its chemical reaction and instantly cools it down, greatly reducing the potential risk of thermal runaway spreading.

[0005] In addition, by using this marine thermal runaway battery test package, drawing on the test plans and test requirements of the national standard combustion laboratory for various abuse tests on marine lithium batteries, and based on the relevant experience of marine lithium battery fire tolerance test verification, a variety of marine lithium battery immersion precision fire protection technology demonstration experimental platforms can be built, and relevant thermal runaway fire protection demonstration tests can be carried out by formulating test outlines and configuring relevant accompanying test equipment, measurement and detection equipment, data acquisition and analysis equipment. Summary of the invention

[0006] The purpose of the present invention is to provide a marine thermal runaway fire demonstration battery test pack based on the deficiencies of the prior art, which is used to evaluate the effectiveness of various safety protection measures in the battery pack after the battery cell thermal runaway occurs.

[0007] The technical solution adopted by the present invention to solve its technical problems is: a marine thermal runaway battery test package, comprising a box body, a battery module arranged in the box body and a cover assembly arranged at the top opening of the box body, the joint surface of the box body and the cover assembly is sealed by a nitrile sealing ring embedded in a sealing groove, a power aviation plug is arranged on the box body, and a safety protective liquid for immersing the battery module is also arranged in the box body, the battery module is composed of a plurality of simulated battery cells and real battery cells connected in series in the module end plate and the module side plate, an aluminum extruded harmonica tube is inserted between two adjacent battery cells, each battery cell is connected to a copper bus and an overcharging power line in turn by connecting an aluminum bus bar, and then connected to a power aviation plug and then to a charging and discharging motor, the box body is provided with a water inlet and outlet valve, the cover assembly comprises thickened transparent acrylic, and an aerosol fire fighting device or / and perfluorohexanone capsule tablets are arranged in the cover plate.

[0008] The battery module of the marine thermal runaway battery test pack is composed of a battery module A including 3 real battery cells and 6 simulated battery cells and a battery module B including 1 real battery cell and 8 simulated battery cells.

[0009] The marine thermal runaway battery test pack has four real cells including an overcharged cell, on which a group of voltage sensors and two groups of temperature sensors are attached, and are connected to a sampling device through holes in a thickened transparent acrylic cover plate.

[0010] The safety protection liquid level of the marine thermal runaway battery test pack is 7.5 mm higher than the battery cell pole.

[0011] The beneficial effects of the present invention are as follows: the present invention adopts a battery module immersion fire protection scheme, the liquid level of the safety protection liquid is higher than the battery cell welding aluminum row, which effectively absorbs the heat of the battery cell, and at the same time quickly flows into the interior of the battery cell when the battery cell thermal runaways, inhibiting chemical reactions and reducing the risk of heat diffusion; the aluminum harmonica tubes between the battery cells are conducive to the uniform distribution of silicone oil in all directions in the package, thereby enhancing the heat dissipation effect between the battery cells.

[0012] The present invention can realize a thermal runaway test without firefighting measures, a water-suppressed overcharge thermal runaway test, and a silicone oil-suppressed overcharge thermal runaway test by opening and closing the inlet and outlet water valves; realize an aerosol-suppressed overcharge thermal runaway test by installing an aerosol firefighting device inside the cover plate assembly; or realize a perfluorohexanone capsule-suppressed overcharge thermal runaway test by sticking two perfluorohexanone capsule sheets inside the cover plate assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a structural schematic diagram of a battery module A of the present invention; Figure 3 It is a structural schematic diagram of the battery module B of the present invention; Figure 4 This is a schematic diagram of the structure of a test package of the present invention; Figure 5 It is a schematic structural diagram of the aerosol test package of the present invention; Figure 6 It is a structural schematic diagram of another test package of the present invention; Figure 7 It is a schematic structural diagram of the perfluorohexanone test package of the present invention; Figure 8 This is a schematic diagram of the structure of the silicone oil fire test package of the present invention; Fig. 9 It is a schematic diagram of the structure of the water fire test kit of the present invention; Fig.10 This is a schematic diagram of collecting the voltage and temperature of the battery cell of the present invention; Fig.11 This is a circuit diagram for collecting the cell voltage and temperature of the present invention; Fig.12 This is a schematic diagram of the test wiring of the present invention.

[0014] The figures are marked as follows: 1—box, 2—power aviation plug, 3—copper busbar, 4—battery module A, 41—module side plate, 42—module end plate, 43—aluminum extruded harmonica tube, 44—connecting aluminum busbar, 45—real battery cell, 46—simulated battery cell, 5—nitrile sealing ring, 6—cover assembly, 7—battery module B, 8—inlet and outlet valves, 9—aerosol fire fighting device, 10—perfluorohexanone capsule tablets, 11—power line for overcharging. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0016] like Figure 1 As shown, an embodiment of the present invention provides a marine immersion liquid-cooled thermal runaway test battery pack, which includes: a transparent acrylic cover assembly 6, a nitrile sealing ring 5, a battery module A4, a battery module B7, a safety protective liquid, a power aviation plug 2, and an aluminum alloy liquid cooling box 1 and other parts.

[0017] The acrylic cover assembly 6 at the top opening of the box body 1 formed by the box body end plate and the box body side plate is used to observe the thermal runaway of the battery cell and prevent the large-scale diffusion of thermal runaway smoke. At the same time, the temperature and voltage sensors of the battery cell can be connected to the sampling equipment through its holes; the joint surface of the box body 1 and the cover assembly 6 is sealed by the nitrile sealing ring 5 embedded in the sealing groove.

[0018] The battery module is composed of a plurality of simulated cells 46 and real cells 45 connected in series in the module end plate 42 and the module side plate 41. The battery module of 1P9S is divided into Figure 2 The battery module 4A shown and Figure 3The battery module B7 shown, wherein the battery module 4A includes 3 real battery cells 45 and 6 simulated battery cells 46, the battery module B7 includes 1 real battery cell 45 and 8 simulated battery cells 46, a total of 4 real battery cells 45 and 14 simulated battery cells 46, an aluminum extruded harmonica tube 43 is sandwiched between two adjacent battery cells.

[0019] The four real cells 45 include at least one overcharged cell. The overcharged cell pole welded aluminum bar is connected to the main electrical connector socket of the battery pack via a cable. The overcharged cell and the three adjacent cells can be attached with a set of voltage sensors and three sets of temperature sensors. These sensors are connected to the sampling device through the cover plate holes. The real cell 45 uses a K-type thermocouple to collect the temperature of the cell pole, pressure relief valve and side wall center, and collects the cell voltage at the same time. The thermocouples can be bundled together and passed through the cover plate hole to connect to the sampling device. The connection method is shown in Figure 1 .

[0020] The battery module can be immersed in the safety protection liquid in the box 1 to achieve good heat dissipation and temperature control effects. The liquid level is 7.5mm above the battery cell pole (welded aluminum bar). This layout can not only achieve efficient cooling and heat absorption, but also trigger the pressure relief valve when the real battery cell 45 thermal runaways to allow the safety protection liquid to quickly penetrate the inside of the battery cell, inhibit chemical reactions, reduce temperature, and thus reduce the risk of thermal runaway. By completely immersing the battery module to form an immersion fire test device, it effectively promotes heat exchange between battery cells and inhibits thermal runaway. The protection level of the battery pack can reach IP67; the safety protection liquid plays a role in inhibiting the thermal runaway of the real battery cell 45 and promoting heat exchange.

[0021] The box body 1 is provided with a water inlet and outlet valve 8, and the cover plate assembly 6 includes a cover plate, and the cover plate can be provided with Figure 4 and Figure 5 The aerosol fire fighting device 9 shown may also be provided as follows Figure 6 and Figure 7 The perfluorohexanone capsule tablet 10 shown. The above device is attached to the overcharged cell, and automatically releases the fire extinguishing agent when thermal runaway occurs, thereby reducing the cell temperature and preventing the spread of thermal runaway, and serves as a safety protection liquid for verifying non-immersion fire fighting solutions. It can be replaced through the inlet and outlet valves 8 to verify a variety of immersion fire fighting solutions. The test package is arranged as follows Figure 8 and Fig. 9 shown.

[0022] The technical route of the test comparison method for the test battery pack based on the present invention is as follows.

[0023] Firstly, a marine thermal runaway test battery sample pack with 18 real and fake battery cells is made. The test battery sample pack can be connected to a charger and discharger. In the sample pack, the copper bus 3 can be connected to the aluminum bus 44 for connecting the overcharged battery cells by connecting the overcharge power line 11 to the battery pack, and the temperature and voltage sensors are extended from the cover hole to the sampling equipment to realize the monitoring of the overcharge process of the single battery cell; then, the power aviation plug 2 of the battery pack is connected to the charger and discharger to realize overcharge-triggered thermal runaway.

[0024] The aluminum extruded harmonica tube 43 between the cells is connected to the copper bus 3 and the aluminum bus 44 for connecting the overcharged cells through the overcharge power line 11, and the temperature and voltage sensors are extended from the holes of the cover assembly 6 to the sampling device, realizing the monitoring of the overcharge process of the single cell; the power plug 2 is connected to the external charging and discharging motor, and the trigger object is charged with a constant current with a minimum of 1 / 3Crcn and a maximum current not greater than the maximum current that the product can continuously work, so as to realize the overcharge of the single cell until the thermal runaway is triggered. The aluminum extruded harmonica tube 43 is placed between the battery modules to enhance the convection of the safety protection liquid, improve the heat exchange efficiency, and effectively block the lateral transfer of heat, avoiding the spread of thermal runaway to adjacent cells.

[0025] By opening and closing the water inlet and outlet valves 8, the safety protection liquid can be replaced with water as a water firefighting verification tool, and the liquid level can be observed through the transparent cover assembly 6. In addition, by adding an aerosol 9 to the cover, it can be used as an aerosol firefighting verification tool, or by adding perfluorohexanone capsules 10 to the cover as a perfluorohexanone firefighting verification tool. Fig.10 and Fig.11 The temperature collection points are shown in the following table. The test site wiring is as follows: Fig.12 shown.

[0026] .

[0027] The sampling points in the table above indicate that each cell in the real cell 45 in the battery pack is connected to a pair of voltage acquisition wires and three pairs of temperature acquisition thermocouples, and the acquisition wires are led out from the two pressure relief valve installation holes on the battery pack cover. The sampling wires are fixed to various parts of the cell with high-temperature resistant Teflon tape, and ensure that the pressure relief valve of the real cell 45 is not blocked.

[0028] In addition, the test battery pack of the present invention can be used as a variety of test devices such as a thermal runaway test pack without firefighting measures, a water-suppressed overcharge thermal runaway test pack, a silicone oil-suppressed overcharge thermal runaway test pack, a perfluorohexanone capsule-suppressed overcharge thermal runaway test pack, and an aerosol-suppressed overcharge thermal runaway test pack through reasonable modification: the thermal runaway test without firefighting measures, the water-suppressed overcharge thermal runaway test, and the silicone oil-suppressed overcharge thermal runaway test are realized by opening and closing the inlet and outlet water valves 8, the aerosol-suppressed overcharge thermal runaway test is realized by the aerosol firefighting device 9 installed inside the cover assembly 6, or the perfluorohexanone capsule-suppressed overcharge thermal runaway test is realized by two perfluorohexanone capsule sheets 10 attached to the inside of the cover assembly 6. By opening and closing the inlet and outlet water valves, adding perfluorohexanone capsule sheets, and adding aerosol firefighting devices, the verification of various thermal runaway firefighting means can be realized.

[0029] Through experimental comparison, it can be concluded that water firefighting has the strongest ability to suppress thermal runaway, but the products produced are toxic gases, which pose a safety risk; while silicone oil firefighting has better temperature control effect and ability to extend the time from overcharging to complete thermal runaway than perfluorohexanone and aerosol firefighting schemes, and the reaction products pose no safety risks. In summary, the silicone oil firefighting scheme should be adopted.

[0030] This design can efficiently cool down and absorb heat while allowing the safety protection liquid to enter the battery cell when the thermal runaway pressure relief valve of the battery cell is opened, thereby inhibiting the spread of thermal runaway. Water or silicone oil can be used as the protection liquid, and the inlet and outlet valves on the box body can be set to replace the protection liquid. It can also realize the setting of thermal runaway sample packs without fire protection measures. The sealing of the battery pack shell of the present invention meets the requirements of IP67, ensuring the feasibility of immersion fire protection.

[0031] The above contents are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any reasonable changes or alternatives that can be thought of by any technician in the technical field on the premise of understanding the present invention should be deemed to be included in the protection scope of the present invention.

Claims

1. A marine thermal runaway battery test kit, comprising a box (1), a battery module arranged in the box (1), and a cover assembly (6) arranged at the top opening of the box (1), characterized in that: The joint surface between the box body (1) and the cover plate assembly (6) is sealed by a nitrile sealing ring (5) embedded in the sealing groove. The box body (1) is provided with a power aviation plug (2). The box body (1) is also provided with a safety protection liquid for immersing the battery module. The battery module is composed of a plurality of simulated battery cells (46) and real battery cells (45) connected in series in the module end plate (42) and the module side plate (41). An aluminum extruded harmonica tube (43) is inserted between two adjacent battery cells. Each battery cell is connected to the copper bus bar (3) and the overcharging power line (11) in sequence through the connecting aluminum bus bar (44) and then connected to the power aviation plug (2). The box body (1) is provided with an inlet and outlet valve (8). The cover plate assembly (6) includes a transparent acrylic cover plate. An aerosol fire fighting device (9) or / and perfluorohexanone capsule tablets (10) are provided in the cover plate.

2. A marine thermal runaway battery test package according to claim 1, characterized in that: The battery module is composed of a battery module A (4) including three real battery cells (45) and six simulated battery cells (46) and a battery module B (7) including one real battery cell (45) and eight simulated battery cells (46).

3. A marine thermal runaway battery test package according to claim 2, characterized in that: One of the four real battery cells (45) is an overcharge cell, and a voltage sensor and a temperature sensor are attached to the overcharge cell.

4. A marine thermal runaway battery test package according to claim 1, 2 or 3, characterized in that: The safety protection liquid level is 7.5mm higher than the battery cell pole.

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