A lithium battery forced discharge test device with explosion-proof function

Abstract

The present invention discloses a lithium battery forced discharge test device with explosion-proof function, which specifically belongs to the field of battery test technology, including a shell and a lithium battery to buffer the explosion impact of the lithium battery; the explosion buffer mechanism includes a sliding partition plate, a connecting rod, a fixed seat, a sliding block, a sliding rod and a buffer spring; the sliding partition plate can be slidably arranged inside the shell; one end of the sliding rod is fixed to the fixed seat, and the other end is slidably arranged on the sliding block, and correspondingly, the sliding block is correspondingly provided with a sliding groove; the buffer spring is sleeved on the sliding rod, one end of the buffer spring is fixed to the fixed seat, and the other end is fixed to the sliding block; the connecting rod is fixed to the end of the sliding block facing away from the fixed seat, and the free end of the connecting rod is fixed to the sliding partition plate. The lithium battery forced discharge test device can provide a buffer space for the gas generated instantly after the explosion of unqualified batteries, and the entire test environment is located in the shell to avoid battery fragments or electrolyte from affecting the safety of workers.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium ion battery forced discharge test, and in particular relates to a lithium battery forced discharge test device with an explosion-proof function. Background Art

[0002] Safety is the most important issue in the design and use of lithium-ion batteries, and forced discharge is one of the most common items in lithium battery safety testing. When lithium-ion batteries are subjected to forced discharge tests, battery fires and explosions are common, with instantaneous currents reaching nearly 1,000 amperes or more, temperatures reaching over 850°C, and various gas releases reaching over 0.27 mol, and the electrolyte released by the battery is corrosive and toxic.

[0003] There is no uniform specification for the lithium battery forced discharge test device currently used. It is generally assembled in a box made of wire mesh on all sides, with a DC power supply and a small electronic load, and the above equipment is placed in a room for testing. For the above discharge test, there are the following standards: GB31241 forced discharge, the discharged battery is reversely charged with a current of 1ItA to the negative upper charging voltage limit (-Uup), and the reverse charging time is 90 minutes. GB38031 forced discharge, the fully charged battery is discharged with a current of 1ItA for a total of 90 minutes. UN 38.3 forced discharge, each battery should be connected in series with a 12V DC power supply at ambient temperature and forced to discharge under the condition that the starting current is equal to the maximum discharge current given by the manufacturer.

[0004] According to the above test standards, when the staff conducts the test, if they use traditional test equipment, the advantage is that the gas generated during the explosion process can be easily dispersed in time. However, the disadvantage is that the mesh side of the box can only block larger battery fragments, and cannot effectively block small battery fragments or electrolytes, which can easily affect the safety of the testers. And if the battery to be tested is placed in a confined space for testing, the gas generated at the moment of its explosion can easily expand from the inside, causing a larger explosion, which still has an impact on the safety of the testers. Summary of the invention

[0005] The purpose of the present invention is to provide a lithium battery forced discharge test device with explosion-proof function. The lithium battery forced discharge test device can provide a buffer space for the gas generated instantly after the explosion of unqualified batteries, and the entire test environment is located in the shell to prevent battery fragments or electrolyte from affecting the safety of workers.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A lithium battery forced discharge test device with explosion-proof function, comprising a shell and a lithium battery explosion buffer mechanism for buffering the explosion impact of the lithium battery; the explosion buffer mechanism comprises a sliding partition plate, a connecting rod, a fixed seat, a sliding block, a sliding rod and a buffer spring; the sliding partition plate can be slidably arranged inside the shell; one end of the sliding rod is fixed to the fixed seat, and the other end is slidably penetrated on the sliding block, and correspondingly, the sliding block is correspondingly provided with a sliding groove; the buffer spring is sleeved on the sliding rod, one end of the buffer spring is fixed to the fixed seat, and the other end is fixed to the sliding block; the connecting rod is fixed to the end of the sliding block facing away from the fixed seat, and the free end of the connecting rod is fixed to the sliding partition plate.

[0008] Among them, the explosion buffer mechanism can provide a buffer area for the gas generated at the moment of explosion, avoiding the gas from being squeezed inside the shell and causing serious explosion accidents.

[0009] Preferably, the explosion buffer mechanism further comprises a limit block, which is fixed to the end of the slide bar facing away from the fixed seat. The purpose of the limit block is to prevent the end of the slide block from slipping out during the sliding process along the slide bar. Since a large amount of gas is generated at the moment of battery explosion, the instantaneous pressure on the slide block is increased through the connecting rod, and after the buffer spring absorbs the buffer, the slide block returns to its original position.

[0010] Preferably, an isolation net is provided inside the housing, and a space between the isolation net and the opening and closing door is used to place the battery sample to be tested. The isolation net can prevent large pieces of battery fragments from impacting the sliding partition plate and causing damage to the sliding partition plate.

[0011] Preferably, the lithium battery forced discharge test device also includes a fire extinguishing mechanism, which includes a containing assembly for containing fire extinguishing materials and an adaptive opening and closing assembly for controlling the discharge port of the containing assembly to open when the battery explodes; the containing assembly includes a containing box and a feeding pipe; a feeding through hole is provided above the shell, and the two ends of the feeding pipe are connected to the containing box and the feeding through hole respectively. The containing assembly can contain fire extinguishing materials, and when the battery explodes, it can be extinguished synchronously.

[0012] Preferably, the adaptive opening and closing assembly comprises a rotating transmission column, a rotating connecting rod, a main transmission conical wheel, a vertical transmission conical wheel, a transmission belt, a guide wheel, a driven wheel and an opening and closing plate;

[0013] A threaded groove is provided on the rotating transmission column, one end of the rotating connecting rod is fixed to the rotating transmission column, and the other end is fixed to the main transmission conical wheel; the main transmission conical wheel and the vertical transmission conical wheel are meshingly connected for transmission, and the vertical transmission conical wheel is coaxially connected with a transmission disk, and the transmission disk and the guide wheel are connected for transmission through a transmission belt; the opening and closing plate is slidably arranged on the upper end of the shell, and a transmission tooth segment is provided on the opening and closing plate, the bottom end of the driven wheel is meshingly connected to the transmission tooth segment for transmission, and the side end of the driven wheel is meshingly connected to the guide wheel for transmission; the upper end of the shell is provided with a groove adapted to expose the transmission tooth segment.

[0014] Among them, the setting of the adaptive opening and closing component solves the problem of achieving high air pressure buffer at the moment of battery explosion, while allowing the opening and closing plate to move to one side so that the discharge pipe containing the fire extinguishing material can be opened, allowing the fire extinguishing material to come into contact with the unqualified battery that is burning and exploding.

[0015] Preferably, a vertical connecting groove is further provided on the rotating transmission column, and two ends of the threaded groove are respectively connected to two ends of the vertical connecting groove.

[0016] Preferably, a guide slider is provided on the sliding block, and the lower end of the guide slider can slide on the thread groove and the vertical connecting groove.

[0017] Preferably, the number of the driven wheels is two, and the two driven wheels are fixed to each other via a synchronous connecting rod. Accordingly, the number of the transmission tooth segments is also two, and the two driven wheels are meshed and transmission-connected with the two transmission tooth segments.

[0018] Preferably, an exhaust valve is provided on the shell.

[0019] Preferably, an observation window is provided at the side end of the shell.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. When an unqualified battery explodes during the test, the high-pressure gas generated can be buffered by the explosion buffer mechanism to expand the gas holding volume and avoid high-pressure explosion accidents.

[0022] 2. The battery to be tested is tested in a closed space to prevent battery fragments or electrolyte from affecting the safety of testers in the event of explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the overall appearance structure diagram of a lithium battery forced discharge test device with explosion-proof function;

[0024] Figure 2 This is a structural diagram of a lithium battery forced discharge test device with explosion-proof function (without opening and closing door);

[0025] Figure 3 This is the internal structure diagram of a lithium battery forced discharge test device with explosion-proof function;

[0026] Figure 4 This is a side view of the internal structure of a lithium battery forced discharge test device with explosion-proof function;

[0027] Figure 5 It is a structural schematic diagram of the explosion buffer mechanism;

[0028] Figure 6 It is a schematic diagram of the side structure of the explosion buffer mechanism.

[0029] In the figure: 1, feed inlet, 2, containing box, 4, transmission gear segment, 5, driven wheel, 6, guide wheel, 7, opening and closing plate, 8, transmission belt, 9, synchronous connecting rod, 10, transmission plate, 11, sliding block, 12, vertical transmission conical wheel, 13, main transmission conical wheel, 14, fixed seat, 15, rotating transmission column, 16, sliding rod, 17, buffer spring, 19, limiting protrusion, 20, shell, 21, observation window, 22, rotating connecting rod, 23, threaded groove, 24, sliding partition plate, 25, isolation net, 26, discharge hopper, 27, battery sample to be tested, 28, opening and closing door, 29, guide slider, 30, limiting block, 31, connecting rod, 32, vertical connecting groove, 33, discharge pipe. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0031] like Figure 1-Figure 6 As shown, a lithium battery forced discharge test device with explosion-proof function includes a housing 20 and a lithium battery explosion buffering mechanism for buffering lithium battery explosion impact;

[0032] The explosion buffer mechanism includes a sliding partition plate 24, a connecting rod 31, a fixed seat 14, a sliding block 11, a sliding rod 16 and a buffer spring 17; the sliding partition plate 24 is slidably arranged inside the shell 20; one end of the sliding rod 16 is fixed to the fixed seat 14, and the other end is slidably penetrated on the sliding block 11, and accordingly, the sliding block 11 is correspondingly provided with a sliding groove; the buffer spring 17 is sleeved on the sliding rod 16, one end of the buffer spring 17 is fixed to the fixed seat 14, and the other end is fixed to the sliding block 11; the connecting rod 31 is fixed to the end of the sliding block 11 facing away from the fixed seat 14, and the free end of the connecting rod 31 is fixed to the sliding partition plate 24.

[0033] Working principle of explosion buffer mechanism:

[0034] When the battery to be tested in the housing 20 explodes, a large amount of gas is instantly generated, which will squeeze the four walls of the housing 22. Since the sliding partition plate 24 is slidably connected to the inner side of the housing 20, the sliding partition plate 24 will move to the left (by Figure 4 As an example). When the sliding partition plate 24 moves to the left, it will drive the fixed member 31 to move to the left, thereby causing the sliding block 11 to move to the left. Since the sliding block 11 is fixed to the buffer spring 17 sleeved on the slide rod 16, the buffer spring 17 can be squeezed, thereby achieving a shock-absorbing effect.

[0035] In the above process, since the sliding partition plate 24 moves to the left under the gas pressure, the area inside the shell 20 is also enlarged, so that the probability of gas explosion in the shell 20 is greatly reduced. The combustion and explosion buffer mechanism is only used to deal with the high-pressure gas generated instantaneously. After buffering, it can be discharged synchronously through the exhaust valve on the shell 20, so that the pressure difference between the shell 20 and the outside is gradually reduced.

[0036] like Figure 5 As shown, the explosion buffer mechanism also includes a limit block 30, which is fixed to the end of the slide bar 16 facing away from the fixed seat 14. The function of the limit block 30 is to prevent the slide block 11 from falling out during the process of sliding under pressure up and down.

[0037] like Figure 4 As shown, an isolation net 25 is provided inside the housing 20, and a space for placing a battery sample to be tested is provided between the isolation net 25 and the opening and closing door 28.

[0038] The function of the isolation net 25 is to block the battery fragments and to guide the gas. When the electrolyte or gas passes through the first layer of the isolation net 25, its impact force can be weakened. As for the gas, the holes on the isolation net 25 can guide the gas to avoid the gas from impacting the sliding partition plate 24 in one direction, thereby causing it to be punctured.

[0039] like Figure 1-Figure 4 As shown, the lithium battery forced discharge test device also includes a fire extinguishing mechanism, which includes a containing component for containing the fire extinguishing material and an adaptive opening and closing component for controlling the discharge port of the containing component to open when the battery explodes;

[0040] The containing assembly includes a containing box 2 and a feeding pipe 33. A feeding through hole is provided above the shell 20, and two ends of the feeding through hole are respectively connected to the containing box 2 and the feeding through hole.

[0041] Working principle of fire extinguishing mechanism:

[0042] The containment component contains fire extinguishing materials, such as sand or dry powder. Through the intervention and cooperation of the adaptive opening and closing components, the fire extinguishing materials in the containment box 2 are controlled to fall onto the battery to be tested through the feed through hole above the subject 20 after the battery explodes, thereby playing a role in extinguishing the fire. At the same time, the staff should cut off the circuit as soon as possible under safe conditions.

[0043] like Figure 3 As shown, the adaptive opening and closing assembly includes a rotating transmission column 15, a rotating connecting rod 22, a main transmission cone wheel 13, a vertical transmission cone wheel 12, a transmission belt 8, a guide wheel 6, a driven wheel 5 and an opening and closing plate 7;

[0044] A threaded groove 23 is provided on the rotating transmission column 15, one end of the rotating connecting rod 22 is fixed to the rotating transmission column 15, and the other end is fixed to the main transmission conical wheel 13; the main transmission conical wheel 13 and the vertical transmission conical wheel 12 are meshed and transmitted, and the vertical transmission conical wheel 12 is coaxially connected with a transmission plate 10, and the transmission plate 10 and the guide wheel 6 are connected through a transmission belt 8; the opening and closing plate 7 is slidably arranged on the upper end of the shell 20, and the opening and closing plate 7 is provided with a transmission tooth segment 4, the bottom end of the driven wheel 5 is meshed and transmitted with the transmission tooth segment 4, and the side end of the driven wheel 5 is meshed and transmitted with the guide wheel 6; the upper end of the shell 20 is provided with a groove adapted to expose the transmission tooth segment 4.

[0045] Regarding the rotation of the rotating transmission column 15: the rotating transmission column 15 is also provided with a vertical connection groove 32, and the two ends of the thread groove 23 are respectively connected to the two ends of the vertical connection groove 32. The sliding block 11 is provided with a guide slider 29, and the lower end of the guide slider 29 can slide on the thread groove 23 and the vertical connection groove 32.

[0046] Working principle of adaptive opening and closing components:

[0047] When the rotating connecting rod 22 is impacted by gas or liquid, it moves to the left, driving the sliding block that transmits the rotation to move, and can simultaneously drive the guide slider 29 to slide in the thread groove 23 and the vertical connecting groove 32, corresponding to two different states:

[0048] (1) When the guide slider 29 moves on the thread groove 23, it drives the rotating transmission column 15 to rotate.

[0049] (2) When the guide slider 29 moves to the vertical connection groove 32, it is acted upon by the elastic force of the buffer spring 17 and moves upward along the vertical connection groove 32. At this time, the rotating transmission column 15 does not rotate, and the sliding partition plate 24 also returns to its original position.

[0050] When the rotating transmission column 15 rotates, that is, in state (1), the main transmission conical wheel 13 is driven to rotate through the rotating connecting rod 22 fixed thereto, so the vertical transmission conical wheel 12 meshing with the main transmission conical wheel 13 also rotates. The transmission plate 10 and the vertical transmission conical wheel 12 are coaxially connected, so the guide wheel 6 can be driven to rotate synchronously through the action of the transmission belt 8. Therefore, the driven wheel 5 meshing with the guide wheel 6 can be driven to rotate in the end. Since the driven wheel 5 and the opening and closing plate 7 are driven by meshing teeth. Therefore, the driven wheel 5 can drive the opening and closing plate 7 to slide in the slide groove at the upper end of the shell 20. When the opening and closing plate 7 is pulled out of the feed pipe 33 and the feed port set on the shell 20, the fire extinguishing material can fall from the discharge hopper 26 and directly cover the battery to be tested, thereby realizing the function of rapid fire extinguishing.

[0051] In this embodiment, there are two driven wheels 5 , which are fixed to each other via a synchronous connecting rod 9 . Accordingly, there are also two transmission tooth segments 4 , and the two driven wheels 5 are meshed and transmission-connected with the two transmission tooth segments 4 .

[0052] In this embodiment, the housing 20 is provided with an exhaust valve.

[0053] In this embodiment, an observation window 21 is provided at the side end of the housing 20. The observation window 21 can facilitate the staff to observe the discharge condition of the battery to be tested. If an explosion condition is observed, the staff can move in time to avoid safety accidents.

[0054] In this embodiment, a temperature sensor, a voltage sensor, a deformation sensor and an air pressure sensor can be installed inside the housing. A pressure detector and a smoke alarm are installed on the sliding partition plate 24, so as to observe and collect signals such as voltage, temperature, sample deformation, and air pressure, and perform data analysis. Finally, after the battery returns to room temperature and data collection is completed, the cavity is opened to observe the sample after the test.

Claims

1. A lithium battery forced discharge test device with explosion-proof function, comprising a housing (20), characterized in that: It also includes a lithium battery explosion buffer mechanism for buffering the lithium battery explosion impact; The explosion buffer mechanism comprises a sliding partition plate (24), a connecting rod (31), a fixing seat (14), a sliding block (11), a sliding rod (16) and a buffer spring (17); The sliding partition plate (24) is slidably disposed inside the housing (20); One end of the sliding rod (16) is fixed to the fixed seat (14), and the other end is slidably inserted into the sliding block (11). Accordingly, the sliding block (11) is provided with a sliding groove. The buffer spring (17) is sleeved on the slide rod (16); one end of the buffer spring (17) is fixed to the fixed seat (14), and the other end is fixed to the slide block (11); The connecting rod (31) is fixed to one end of the sliding block (11) facing away from the fixing seat (14), and the free end of the connecting rod (31) is fixed to the sliding partition plate (24); It also includes a fire extinguishing mechanism, which includes a containing component for containing fire extinguishing materials and an adaptive opening and closing component for controlling the discharge port of the containing component to open when the battery explodes; The containing assembly comprises a containing box (2) and a feeding pipe (33); A feed through hole is provided above the shell (20), and two ends of the feed pipe (33) are respectively connected to the containing box (2) and the feed through hole; The adaptive opening and closing assembly comprises a rotating transmission column (15), a rotating connecting rod (22), a main transmission conical wheel (13), a vertical transmission conical wheel (12), a transmission belt (8), a guide wheel (6), a driven wheel (5) and an opening and closing plate (7); The rotating transmission column (15) is provided with a threaded groove (23); one end of the rotating connecting rod (22) is fixed to the rotating transmission column (15), and the other end is fixed to the main transmission conical wheel (13); The main transmission conical wheel (13) and the vertical transmission conical wheel (12) are meshed and transmission-connected, the vertical transmission conical wheel (12) is coaxially connected with a transmission disc (10), and the transmission disc (10) and the guide wheel (6) are transmission-connected via a transmission belt (8); The opening and closing plate (7) is slidably arranged on the upper end of the housing (20), and a transmission tooth segment (4) is provided on the opening and closing plate (7). The bottom end of the driven wheel (5) is meshed with the transmission tooth segment (4) for transmission, and the side end of the driven wheel (5) is meshed with the guide wheel (6) for transmission connection; The upper end of the housing (20) is provided with a groove adapted to expose the transmission tooth segment (4).

2. The lithium battery forced discharge test device with explosion-proof function according to claim 1, characterized in that: The explosion buffer mechanism further comprises a limit block (30), wherein the limit block (30) is fixed to an end of the slide rod (16) facing away from the fixed seat (14).

3. The lithium battery forced discharge test device with explosion-proof function according to claim 1, characterized in that: An isolation net (25) is provided inside the housing (20), and a space for placing a battery sample to be tested is provided between the isolation net (25) and the opening and closing door (28).

4. The lithium battery forced discharge test device with explosion-proof function according to claim 1, characterized in that: A vertical connection groove (32) is also provided on the rotating transmission column (15), and two ends of the thread groove (23) are respectively connected to two ends of the vertical connection groove (32).

5. The lithium battery forced discharge test device with explosion-proof function according to claim 4, characterized in that: The sliding block (11) is provided with a guide sliding block (29), and the lower end of the guide sliding block (29) can slide on the thread groove (23) and the vertical connection groove (32).

6. The lithium battery forced discharge test device with explosion-proof function according to claim 1, characterized in that: There are two driven wheels (5), which are fixed to each other via a synchronous connecting rod (9). Accordingly, there are also two transmission tooth segments (4), and the two driven wheels (5) are meshed and transmission-connected with the two transmission tooth segments (4).

7. The lithium battery forced discharge test device with explosion-proof function according to claim 1, characterized in that: The housing (20) is provided with an exhaust valve.

8. The lithium battery forced discharge test device with explosion-proof function according to claim 1, characterized in that: An observation window (21) is provided at a side end of the housing (20).

Images