An in-situ monitoring device for pressure and temperature changes inside large cylindrical lithium batteries

Abstract

This utility model relates to the field of lithium battery monitoring technology, specifically an in-situ monitoring device for internal pressure and temperature changes in a large cylindrical lithium battery. It mainly includes a frame, a hydraulic drive mechanism mounted at the top of the frame, a lifting plate at the output end of the hydraulic drive mechanism, and a stainless steel cylinder housed in a groove on the end face of the frame. It also includes a sealing mechanism, comprising a cylinder cover. This utility model utilizes an annular sealing ring on the bottom side of the cylinder cover. When the cylinder cover is positioned by a positioning block and a positioning hole on the cylinder body, the annular sealing ring at the bottom of the cylinder cover is embedded in an annular sealing groove, creating a sealed environment within the cylinder. This reduces the influence of the external environment during monitoring of the large cylindrical battery. When the hydraulic drive mechanism descends, the extruder squeezes the gas storage bladder through an arc-shaped pressure plate, increasing the internal air pressure. This opens the one-way valve, allowing gas to be forced into the annular sealing ring, causing it to expand and improving the sealing performance.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery monitoring, and in particular to an in-situ monitoring device for internal pressure and temperature changes in large cylindrical lithium batteries. Background Technology

[0002] Due to the characteristics of wet-process lithium-ion battery electrode manufacturing, electrochemical expansion inevitably occurs during battery material formation. A series of side reactions also occur inside the battery during formation, generating gases and increasing pressure to varying degrees, leading to increased internal pressure. Changes in the total gas volume cause corresponding changes in internal pressure. During charging and discharging, the lithium intercalation / deintercalation reaction at the positive and negative electrodes causes reversible electrode volume changes, resulting in internal pressure variations. Therefore, the pressure change during a single charge / discharge cycle is strongly correlated with the state of charge (SOC). Furthermore, with cycle aging, the graphite SEI film on the lithium-ion battery continuously thickens, causing irreversible volume changes, which also lead to changes in internal pressure and temperature. Therefore, accurately describing the internal pressure and temperature changes of lithium-ion batteries is crucial for monitoring side reactions, health status, SOC, battery leakage, battery design, and quantitatively understanding the impact of electrode lithium intercalation / deintercalation reactions on battery performance and safety. Along with changes in internal pressure, the electrochemical reactions within the battery also cause changes in internal temperature, heat accumulation, and even thermal runaway. Therefore, the detection, management, and control of changes in internal pressure and temperature of batteries are fundamental requirements for battery manufacturing and important guarantees for battery performance and safety management.

[0003] The battery monitoring device mainly consists of a monitoring module, a signal transmission module, and an external receiving unit. The battery to be monitored is placed inside the cylinder to form a sealed environment, reducing external interference and thus ensuring the accuracy of monitoring. However, in the existing technology, rubber O-rings are used to seal the cylinder head assembly when monitoring large cylindrical batteries. Rubber O-rings are prone to aging and, after long-term pressure fluctuations, they are prone to creep and loosening, resulting in a decrease in sealing effect and leakage. Utility Model Content

[0004] The purpose of this invention is to provide an in-situ monitoring device for pressure and temperature changes inside a large cylindrical lithium battery, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an in-situ monitoring device for internal pressure and temperature changes in a large cylindrical lithium battery, comprising a frame, a hydraulic drive mechanism mounted on the top of the frame, a lifting plate at the output end of the hydraulic drive mechanism, and a stainless steel cylinder disposed in a groove on the end face of the frame, and further comprising:

[0006] A sealing mechanism is provided, comprising a cylinder head, on which air storage bladders are symmetrically arranged at the upper end. An annular sealing ring is fixedly connected to the bottom edge of the cylinder head, and an air supply pipe is provided at the bottom of each air storage bladder. The sealing mechanism is used for the normal sealing of the stainless steel cylinder body.

[0007] An inflation tensioning mechanism includes an extrusion member fixedly connected to the bottom side of a lifting plate. A rack plate is fixedly connected to one outer surface of the extrusion member. A non-circular fixing bracket is symmetrically arranged on the cylinder head at both ends of the rack plate. A pawl is movably connected to one side of each of the two non-circular fixing brackets facing each other. The pawl engages with the rack plate. The inflation tensioning mechanism is used for inflating and expanding the annular sealing ring.

[0008] Preferably, the cylinder head has symmetrical arc-shaped placement grooves on its upper end, and the air storage bags are all placed in the arc-shaped placement grooves. The inner wall of the arc-shaped placement groove is slidably connected to an arc-shaped pressure plate. The arc-shaped pressure plate is placed above the air storage bag, and the outer walls on both sides of the arc-shaped pressure plate slide and limit the movement with the inner wall of the arc-shaped placement groove.

[0009] Preferably, the upper side of the gas storage bladder has the same structure as the gas delivery pipe. A T-shaped rod is fixedly connected to the through hole at the lower part of the gas delivery pipe. A spring is sleeved on the outer side of the T-shaped rod. A sealing plate is slidably connected to the upper outer wall of the T-shaped rod. A connecting cylinder is fixedly connected to the upper inner wall of the gas delivery pipe. The bottom of the connecting cylinder abuts against the edge of the upper surface of the sealing plate.

[0010] Preferably, a wrench is fixedly connected to the outer surface of one side of the ratchet pawl, and the wrench faces away from the rack plate.

[0011] Preferably, an annular sealing groove is provided on the top side of the stainless steel cylinder body, and a rubber sealing ring is provided in the through hole on the bottom side of the stainless steel cylinder body.

[0012] Preferably, U-shaped sealing elements are provided on both the upper and lower sides of the outer surface of the annular sealing ring, and the U-shaped sealing elements are interference-fitted with the inner wall of the annular sealing groove.

[0013] Preferably, a pressure sensor is welded into a pre-drilled hole near the port of the stainless steel cylinder, and a temperature sensor is welded into a pre-drilled hole in the middle of the stainless steel cylinder.

[0014] Preferably, the pressure sensor is a MEMS piezoresistive pressure sensor, the temperature sensor is an NTC thermistor, the pressure sensor is electrically connected to an external pressure monitoring display, and the temperature sensor is electrically connected to an external temperature monitoring display.

[0015] Preferably, positioning blocks are fixedly connected to the bottom of the other two ends of the cylinder head, and the positioning blocks are engaged with the positioning holes on the top side edge of the stainless steel cylinder body.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] This invention features an annular sealing ring on the bottom side of the cylinder head. When the cylinder head is positioned by the positioning block and the positioning hole on the cylinder body, the annular sealing ring at the bottom of the cylinder head is embedded in the annular sealing groove, creating a sealed environment inside the cylinder. This reduces the impact of the external environment during the monitoring of the large cylindrical battery. When the hydraulic drive mechanism descends, the extruder squeezes the gas storage bag through the arc-shaped pressure plate, increasing the internal air pressure. The one-way valve opens, and the gas is forced into the annular sealing ring, causing it to expand and improving the interference fit between the annular sealing ring and the annular sealing groove, thereby further improving the sealing performance.

[0018] This invention features a rack plate on the extruder. When the extruder compresses the gas storage bladder, the rack plate engages with the pawl, delivering gas segment by segment. Each compression action corresponds to a fixed, minute gas delivery volume. Users can accurately and quantitatively control the total amount of gas injected into the annular sealing ring by counting the number of compressions, thereby improving operational safety and reliability. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings:

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0021] Figure 2 This is a cross-sectional view of the stainless steel cylinder body of this utility model;

[0022] Figure 3 This is a schematic diagram of the sealing mechanism of this utility model;

[0023] Figure 4 This is a cross-sectional view of the sealing mechanism of this utility model;

[0024] Figure 5 This is an enlarged view of Figure A of this utility model;

[0025] Figure 6 This is a schematic diagram of the disassembled structure of the air-storage bladder compression of this utility model;

[0026] Figure 7 This is a schematic diagram of the rack plate and ratchet pawl of this utility model separated.

[0027] Figure 8 This is a cross-sectional view of the gas transmission pipe of this utility model;

[0028] In the picture:

[0029] 1. Frame; 2. Hydraulic drive mechanism; 3. Lifting plate;

[0030] 4. Sealing mechanism; 41. Cylinder head; 411. Arc-shaped placement groove; 412. Positioning block; 42. Annular sealing ring; 421. U-shaped seal; 43. Air supply pipe; 431. T-shaped rod; 432. Spring; 433. Sealing plate; 434. Connecting cylinder; 44. Air storage bag; 45. Arc-shaped pressure plate; 46. Extrusion part; 47. Rack plate; 48. Irregularly shaped fixing bracket; 49. Pawl; 491. Wrench;

[0031] 5. Stainless steel cylinder body; 51. Annular sealing groove; 52. Air pressure sensor; 53. Temperature sensor; 54. Rubber sealing ring. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0034] Please see Figures 1 to 8 This utility model provides a technical solution: an in-situ monitoring device for internal pressure changes in a large cylindrical lithium battery, comprising a frame 1, a hydraulic drive mechanism 2 mounted on the top of the frame 1, a lifting plate 3 at the output end of the hydraulic drive mechanism 2, and a stainless steel cylinder 5 disposed in a groove on the end face of the frame 1, and further comprising:

[0035] A sealing mechanism 4 is provided at the upper end of the stainless steel cylinder body 5. The sealing mechanism 4 includes a cylinder cover 41. Air storage bags 44 are symmetrically arranged at the upper end of the cylinder cover 41. An annular sealing ring 42 is fixedly connected at the bottom edge of the cylinder cover 41. Air supply pipes 43 are provided at the bottom of each air storage bag 44. The sealing mechanism 4 is used to seal the stainless steel cylinder body 5 under normal conditions.

[0036] Specifically, such as Figure 3-5 As shown, U-shaped seals 421 are provided on both the upper and lower sides of the outer surface of the annular sealing ring 42, and the U-shaped seals 421 are interference-fitted with the inner wall of the annular sealing groove 51.

[0037] In this embodiment, multiple sets of U-shaped seals 421 are provided on the outer surface of the annular sealing ring 42, which can contact the inner wall of the annular sealing groove 51, further improving the sealing effect between the cylinder head 41 and the stainless steel cylinder body 5.

[0038] The bottom ends of the lifting plate 3 are provided with an inflation tensioning mechanism. The inflation tensioning mechanism includes an extrusion member 46 fixedly connected to the bottom side of the lifting plate 3. A rack plate 47 is fixedly connected to one outer surface of the extrusion member 46. On the cylinder head 41, irregularly shaped fixing brackets 48 are symmetrically arranged at both ends of the rack plate 47. A pawl 49 is movably connected to the opposite side of the two irregularly shaped fixing brackets 48. The pawl 49 engages with the rack plate 47. The inflation tensioning mechanism is used to inflate the annular sealing ring 42.

[0039] Specifically, such as Figure 5-7 As shown, a wrench 491 is fixedly connected to one side of the outer surface of the pawl 49, with the wrench 491 facing away from the rack plate 47.

[0040] In this embodiment, after the battery monitoring is completed, the operator manually pinches the wrench 491 and pulls it outward, so that the pawl 49 disengages from the rack plate 47, and the pressing part 46 is reset by the hydraulic drive mechanism 2.

[0041] Specifically, such as Figure 3-6 As shown, the cylinder head 41 has symmetrical arc-shaped placement grooves 411 on its upper end. All air storage bags 44 are placed in the arc-shaped placement grooves 411. Arc-shaped pressure plates 45 are slidably connected to the inner wall of the arc-shaped placement grooves 411. The arc-shaped pressure plates 45 are placed above the air storage bags 44. The outer walls on both sides of the arc-shaped pressure plates 45 slide and limit the movement of the inner wall of the arc-shaped placement grooves 411.

[0042] In this embodiment, by squeezing the air storage bag 44 with a rigid arc-shaped pressure plate 45, the gas inside the air storage bag 44 can be better forced into the annular sealing ring 42.

[0043] Specifically, such as Figure 4-8 As shown, the upper side of the air storage bag 44 has the same structure as the air supply pipe 43. T-shaped rods 431 are fixedly connected to the through holes at the lower part of the air supply pipe 43. Springs 432 are sleeved on the outer side of the T-shaped rods 431. A sealing plate 433 is slidably connected to the upper outer wall of the T-shaped rods 431. A connecting cylinder 434 is fixedly connected to the upper inner wall of the air supply pipe 43. The bottom of the connecting cylinder 434 abuts against the edge of the upper surface of the sealing plate 433.

[0044] In this embodiment, an air supply pipe 43 is provided at the air outlet of the air storage bag 44. When gas passes through, it squeezes the sealing plate 433 downward, causing the sealing plate 433 to separate from the connecting cylinder 434, thereby causing the gas to be pressed downward into the annular sealing ring 42. When the extruder 46 does not squeeze the air storage bag 44 downward, the sealing plate 433 contacts the connecting cylinder 434, which can prevent the annular sealing ring 42 from flowing back. An air supply pipe 43 is provided at the air inlet of the air storage bag 44, which can replenish the air storage bag 44 with gas, while the internal structure prevents the replenished gas from leaking.

[0045] Specifically, such as Figure 3-4 As shown, positioning blocks 412 are fixedly connected to the bottom of the other two ends of the cylinder head 41, and the positioning blocks 412 are engaged with the positioning holes at the top side edge of the stainless steel cylinder body 5.

[0046] In this embodiment, the positioning block 412 can engage with the positioning hole, so that the rack plate 47 on the lifting extruder 46 can engage with the pawl 49 on the cylinder head 41, and trigger the effect of continuously and controllably squeezing the gas downward, thus having a positioning function.

[0047] Specifically, such as Figure 1-2 As shown, an annular sealing groove 51 is provided on the top side of the stainless steel cylinder body 5, and a rubber sealing ring 54 is provided in the through hole on the bottom side of the stainless steel cylinder body 5.

[0048] In this embodiment, the rubber sealing ring 54 is able to make a sealed contact with the positive electrode of the battery, preventing external gas from entering the interior through the bottom of the stainless steel cylinder 5, and further maintaining the airtightness of the stainless steel cylinder 5.

[0049] Specifically, such as Figure 1-2 As shown, a pressure sensor 52 is welded into a pre-drilled hole near the port of the stainless steel cylinder 5, and a temperature sensor 53 is welded into a pre-drilled hole in the middle of the stainless steel cylinder 5.

[0050] In this embodiment, during monitoring, the gas pressure change inside the battery under test is rapidly transmitted to the cylinder head 41 and the stainless steel cylinder 5. Therefore, the gas pressure change inside the stainless steel cylinder 5 is very close to the pressure change inside the battery under test, and the temperature sensor 53 is placed close to the battery casing.

[0051] Specifically, such as Figure 1-2 As shown, the pressure sensor 52 is a MEMS piezoresistive pressure sensor, and the temperature sensor 53 is an NTC thermistor. The pressure sensor 52 is electrically connected to an external pressure monitoring display, and the temperature sensor 53 is electrically connected to an external temperature monitoring display.

[0052] In this embodiment, the battery pressure is monitored by a pressure sensor 52 connected to an external pressure monitoring display, and the temperature sensor 53 is connected to an external temperature monitoring display to monitor the temperature change of the battery, thereby realizing battery monitoring.

[0053] In use, the large cylindrical battery is placed inside the stainless steel cylinder 5, ensuring close contact between the battery's positive terminal and the rubber sealing ring 54. At this time, the pressure sensor 52 is positioned above the battery, and the temperature sensor 53 is attached to the outer surface of the battery. During monitoring, the cylinder cover 41 is placed over the stainless steel cylinder 5, embedding the annular sealing ring 42 into the annular sealing groove 51, thus creating a sealed environment for the stainless steel cylinder 5 and preventing external environmental influences on battery monitoring. The positioning block 412 on the bottom side of the cylinder cover 41 is aligned with the positioning hole on the top side of the stainless steel cylinder 5, causing them to engage. Then, the hydraulic drive mechanism 2 is activated, causing the bottom side of the lifting plate 3 to... The extruder 46 moves toward the cylinder head 41 and extrudes the arc-shaped pressure plate 45. The rigid arc-shaped pressure plate 45 extrudes the air storage bladder 44, increasing the internal air pressure. The one-way valve opens, and the gas is forced into the annular sealing ring 42, causing the annular sealing ring 42 to expand. This improves the interference fit between the annular sealing ring 42 and the annular sealing groove 51. When the extruder 46 extrudes the air storage bladder 44, the rack plate 47 engages with the pawl 49, and the gas is delivered section by section. Each pressing action corresponds to a fixed and small gas delivery volume. The user can accurately and quantitatively control the total amount of gas injected into the annular sealing ring 42 by counting the number of pressing actions.

[0054] At the same time, the positive and negative contacts are connected to the positive and negative terminals of the battery, and the positive and negative terminals of the battery are connected to external devices respectively, thereby realizing the closed-loop conduction of the battery circuit and is insulated from the stainless steel cylinder body 5 and cylinder head 41.

[0055] During monitoring, the gas pressure change inside the battery under test is rapidly transmitted to the cylinder head 41 and the stainless steel cylinder 5. Therefore, the gas pressure change inside the stainless steel cylinder 5 is very close to the pressure change inside the battery under test. The battery pressure is monitored by the pressure sensor 52 connected to an external pressure monitoring display. The temperature sensor 53 is placed close to the battery casing and the temperature change of the battery is monitored by the external temperature monitoring display.

[0056] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples; within the framework of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in the details for the sake of brevity.

[0057] This utility model is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An in-situ monitoring device for internal pressure changes and temperature changes of large cylindrical lithium batteries, comprising a frame (1), a hydraulic drive mechanism (2) is mounted at the top end of the frame (1), a lifting plate (3) is arranged at the output end of the hydraulic drive mechanism (2), a stainless steel cylinder body (5) is arranged in the groove of the end face of the frame (1), characterized in that, Also includes: The sealing mechanism (4) includes a cylinder head (41), and air storage bags (44) are symmetrically arranged on the upper end of the cylinder head (41). An annular sealing ring (42) is fixedly connected to the bottom edge of the cylinder head (41). Air supply pipes (43) are provided at the bottom of each air storage bag (44). The sealing mechanism (4) is used for the normal sealing of the stainless steel cylinder body (5). The inflation tensioning mechanism includes an extrusion member (46) fixedly connected to the bottom side of the lifting plate (3). A rack plate (47) is fixedly connected to one outer surface of the extrusion member (46). A special-shaped fixing frame (48) is symmetrically arranged on the cylinder head (41) and located at both ends of the rack plate (47). A pawl (49) is movably connected to one side of each of the two special-shaped fixing frames (48). The pawl (49) meshes with the rack plate (47). The inflation tensioning mechanism is used to inflate the annular sealing ring (42).

2. The in-situ monitoring device for pressure and temperature changes inside a large cylindrical lithium battery according to claim 1, characterized in that: The cylinder head (41) is symmetrically provided with arc-shaped placement grooves (411) at the upper end. The air storage bags (44) are all placed in the arc-shaped placement grooves (411). The inner wall of the arc-shaped placement grooves (411) is slidably connected with arc-shaped pressure plates (45). The arc-shaped pressure plates (45) are placed above the air storage bags (44). The outer walls on both sides of the arc-shaped pressure plates (45) are slidably limited to the inner wall of the arc-shaped placement grooves (411).

3. The in-situ monitoring device for internal pressure and temperature changes in a large cylindrical lithium battery according to claim 1, characterized in that: The gas storage bag (44) has a structure on one side above the gas delivery pipe (43). T-shaped rods (431) are fixedly connected to the through holes at the bottom of the gas delivery pipe (43). Springs (432) are sleeved on the outside of the T-shaped rods (431). A sealing plate (433) is slidably connected to the outer wall above the T-shaped rods (431). A connecting cylinder (434) is fixedly connected to the inner wall above the gas delivery pipe (43). The bottom of the connecting cylinder (434) abuts against the edge of the upper surface of the sealing plate (433).

4. The in-situ monitoring device for internal pressure and temperature changes in a large cylindrical lithium battery according to claim 1, characterized in that: A wrench (491) is fixedly connected to one side of the outer surface of the pawl (49), and the wrench (491) faces away from the rack plate (47).

5. The in-situ monitoring device for internal pressure and temperature changes in a large cylindrical lithium battery according to claim 1, characterized in that: The stainless steel cylinder body (5) has an annular sealing groove (51) on its top side and a rubber sealing ring (54) in the through hole on the bottom side of the stainless steel cylinder body (5).

6. The in-situ monitoring device for internal pressure and temperature changes in a large cylindrical lithium battery according to claim 1, characterized in that: The annular sealing ring (42) has U-shaped sealing elements (421) on both the upper and lower sides of its outer surface. The U-shaped sealing elements (421) are interference-fitted with the inner wall of the annular sealing groove (51).

7. The in-situ monitoring device for internal pressure and temperature changes in a large cylindrical lithium battery according to claim 1, characterized in that: A pressure sensor (52) is welded into a pre-drilled hole near the port of the stainless steel cylinder (5), and a temperature sensor (53) is welded into a pre-drilled hole in the middle of the stainless steel cylinder (5).

8. The in-situ monitoring device for internal pressure and temperature changes in a large cylindrical lithium battery according to claim 7, characterized in that: The pressure sensor (52) is a MEMS piezoresistive pressure sensor, and the temperature sensor (53) is an NTC thermistor. The pressure sensor (52) is electrically connected to an external pressure monitoring display, and the temperature sensor (53) is electrically connected to an external temperature monitoring display.

9. The in-situ monitoring device for internal pressure and temperature changes in a large cylindrical lithium battery according to claim 1, characterized in that: The bottom of the other two ends of the cylinder head (41) is fixedly connected with positioning blocks (412), and the positioning blocks (412) are engaged with the positioning holes on the top side edge of the stainless steel cylinder body (5).

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