Safe sodium ion battery pack

Abstract

The invention discloses a safe sodium ion battery pack, and relates to the technical field of battery packs. A battery cell shell is arranged outside a battery cell in a sleeving mode, an outer protective shell is arranged outside the battery cell shell, a locking cavity is formed in the middle of the battery cell, the battery cell sequentially penetrates through the battery cell shell and the outer protective shell along the locking cavity to be provided with a locking mechanism, an annular air chamber is arranged between the outer protective shell and the battery cell shell, and a sealing ring is arranged at the top of the annular air chamber. An exhaust assembly is arranged in the locking mechanism, a fire extinguishing mechanism is arranged on one side of the annular air chamber in the outer protective shell, and a heat conduction plate is installed on one side of the outer portion of the outer protective shell. By arranging the locking mechanism and the sealing ring, external high-temperature gas and flame are prevented from entering the battery to damage the battery, so that the safety of the battery in case of fire is improved, and by arranging the fire extinguishing mechanism and the exhaust assembly, all the surrounding environments inside and outside the battery are in a state of being filled with fire extinguishing gas, and the safety of the battery is improved. And the protection range of the battery pack is expanded.

Description

Technical Field

[0001] The present invention relates to the technical field of battery packs, and in particular to a safe sodium ion battery pack. Background Art

[0002] Sodium-ion batteries use sodium ions (Na + ) As a charge carrier, due to its much higher stock than lithium ions, it has the advantages of low cost, abundant resources and environmental friendliness. It is mainly suitable for scenarios with low requirements for energy density, such as micro electric vehicles, low-speed electric vehicles, energy storage systems, etc. With the advancement of technology, the application scope of sodium-ion batteries is expected to be further expanded. Since sodium-ion battery packs are now mostly used in electric vehicles and other means of transportation, it is necessary to ensure their safety during use.

[0003] The patent specification with publication number CN116903546B discloses a sodium ion battery pack and vehicle with fire extinguishing function. The exhaust valve of the sodium ion battery pack has the performance of one-way large-flow ventilation, which can prevent external oxygen from entering the battery pack and prevent external gaseous water and liquid water from entering the battery pack.

[0004] The shortcomings of this technical solution are: first, it monitors the external high temperature by installing a temperature-sensitive glass ball inside the battery. When the external temperature is too high, the glass ball breaks and the internal fire extinguishing agent evaporates to extinguish the fire. Since it is installed at the bottom of the pop-up exhaust valve, in order to ensure that the exhaust valve pops out in time in the event of a fire, the sealing performance of its installation is low, and the low sealing performance will lead to the risk of flames entering the battery while extinguishing the fire, that is, this solution cannot take into account both the fire extinguishing stability and the battery sealing performance, and there is a problem of insufficient structural sealing, which affects the safety of the battery in a high temperature environment; secondly, this solution only installs the fire extinguishing agent in the middle part of the battery, and when a fire occurs, the battery is in a flame environment all around, and the fire extinguishing agent concentrated in the middle cannot stably take into account the fire extinguishing ability of the entire battery, that is, the fire extinguishing agent of this solution cannot fully extinguish the fire all around the battery, and the protection range is limited. Summary of the invention

[0005] The purpose of the present invention is to provide a safe sodium ion battery pack, and the technical problems to be solved are as follows: the existing sodium ion batteries cannot maintain the sealing of the battery itself during fire extinguishing, and there is a problem of a small fire extinguishing range during the fire extinguishing process.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A safe sodium ion battery pack comprises a battery cell, wherein a battery cell shell is sleeved on the outside of the battery cell, an outer protective shell is arranged on the outside of the battery cell shell, a locking cavity is arranged in the middle of the battery cell, the battery cell passes through the battery cell shell and the outer protective shell in sequence along the locking cavity, and a locking mechanism is installed on the battery cell, an annular air chamber is arranged between the outer protective shell and the battery cell shell, a sealing ring is arranged on the top of the annular air chamber, and the locking mechanism is used to cooperate with the sealing ring to seal the battery pack; an exhaust assembly is arranged inside the locking mechanism, a fire extinguishing mechanism is arranged inside the outer protective shell on one side of the annular air chamber, a heat conducting plate is installed on one side of the outer protective shell, and the heat conducting plate is used to cooperate with the exhaust assembly and the fire extinguishing mechanism to extinguish the battery pack.

[0007] As a further solution of the present invention: the locking mechanism includes a base fixedly installed on the top of the battery cell, a locking rod is slidably connected to the middle of the base, a guide plate is rotatably connected to the top of the locking rod, a support arm is fixedly connected to one side of the base, a buckling plate is installed between the support arm and the guide plate, and the locking rod passes through the battery cell and extends into the locking cavity.

[0008] As a further solution of the present invention: a rotating handle is installed on the outer protective shell just below the locking rod, a locking buckle is installed on the top of the rotating handle, and the locking buckle is threadedly connected to the bottom of the locking rod.

[0009] As a further solution of the present invention: a sealing ring is fixedly connected to the bottom of the battery cell just above the sealing ring, the sealing ring includes a ring baffle fixedly connected to the inner side of the top of the outer protective shell, the battery cell shell is adapted to be provided with a ring baffle on the same horizontal plane as the ring baffle, and the bottom surface of the sealing ring is in contact with the ring baffle and the ring baffle.

[0010] As a further solution of the present invention: the fire extinguishing mechanism includes a fire extinguishing chamber arranged inside the outer protective shell, the fire extinguishing chamber is filled with fire extinguishing agent, winding springs are installed on both sides of the top of the fire extinguishing chamber, a rotating shaft is installed between the tops of the two winding springs, a packaging film is installed between the bottoms of the two winding springs, and a fuse strip is installed between the heat conduction plate and the packaging film.

[0011] As a further solution of the present invention: the exhaust assembly includes air outlets opened on both sides of the base, the locking rod is fixedly connected to a spring inside the same horizontal plane as the air outlet, the bottom of the spring is fixedly connected to an air baffle, an air duct is arranged in the middle of the locking rod, the air duct is located in the middle of the locking cavity, and air connecting strips are arranged on both sides.

[0012] As a further solution of the present invention: a handle is installed on the top of the battery cell, the locking cavity is arranged in the middle of the bottom of the battery cell, the two locking rods are both located in the locking cavity, and the lock buckle is located at the bottom of the locking cavity.

[0013] As a further solution of the present invention: the annular air chamber is communicated with the locking cavity, and air holes are provided on both sides of the battery cell housing to adapt to the locking cavity.

[0014] Beneficial effects of the present invention: 1. In the present invention, by providing a locking mechanism and a sealing ring, a locking mechanism is provided between the battery cell, the battery cell shell and the outer protective shell, and the battery pack is detachably locked as a whole. The ring baffle and the ring retaining ring provided between the battery cell shell and the top of the outer protective shell are used to seal the top of the ring gas chamber inside the battery, so that the battery pack can maintain an overall sealed state inside when in a fire state, and prevent external high-temperature gas and flame from entering the battery to cause damage to the battery, thereby improving the safety of the battery when in fire; 2. In the present invention, by arranging a fire extinguishing mechanism on one side of the inner part of the outer protective shell and arranging an exhaust assembly at the locking mechanism, when the external temperature rises, the fuse bar of the fire extinguishing mechanism is melted, and the fire extinguishing agent in the fire extinguishing chamber is released into the annular air chamber, and enters the interior of the locking rod through the air receiving bar port of the exhaust assembly until it is discharged from the air outlet at the top. When the internal air pressure is in a normal state, the air baffle of the exhaust assembly is still in a state of sealing the battery pack, which is intended to allow the battery pack to only exhaust air to the outside when encountering a fire, always maintaining the internal sealing performance, and ensuring the safety of the internal battery pack; Furthermore, since the internal annular air chamber and the locking cavity are located at all positions around the battery cell pack, after the fire extinguishing agent enters the annular air chamber, when the internal gas pushes open the air baffle and discharges to the outside, all the surrounding environments inside and outside the battery are filled with fire extinguishing gas, thereby further increasing the fire extinguishing range and improving environmental safety. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a bottom-up structural schematic diagram of the present invention; Figure 3 is an exploded view of the present invention; Figure 4 It is a schematic diagram of the structure of the battery cell of the present invention; Figure 5 It is a schematic diagram of a half-section structure of a battery cell shell and an outer protective shell of the present invention; Figure 6It is a partial cross-sectional view of the battery cell housing and the outer protective shell at the bottom of the sealing ring of the present invention; Figure 7 It is a schematic diagram of the overall structure of the locking mechanism of the present invention; Figure 8 The present invention Figure 1 A magnified detail of the center point A; Fig. 9 The present invention Figure 5 A magnified view of the details at C in the middle; Fig.10 The present invention Figure 7 A magnified view of the detail at E in the middle; Fig.11 The present invention Figure 3 A magnified view of the detail at B in the middle; Fig.12 The present invention Figure 5 A magnified view of the detail at D in the middle; Fig.13 The present invention Figure 7 Enlarged detail of point F in the middle.

[0017] In the figure: 1. battery cell; 2. battery cell shell; 3. outer protective shell; 4. locking cavity; 5. locking mechanism; 51. base; 52. locking rod; 53. guide plate; 54. support arm; 55. buckle plate; 56. rotating handle; 57. lock; 58. reset spring; 6. annular air chamber; 7. sealing ring; 8. exhaust assembly; 81. air outlet; 82. spring; 83. air baffle; 84. air duct; 85. air strip connection port; 9. fire extinguishing mechanism; 91. fire extinguishing chamber; 92. winding spring; 93. rotating shaft; 94. packaging film; 95. fuse strip; 10. heat conducting plate; 11. handle; 12. sealing ring; 13. annular baffle; 14. annular baffle ring; 15. air outlet. DETAILED DESCRIPTION

[0018] 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.

[0019] like Figures 1 to 13As shown, a safe sodium ion battery pack comprises a battery cell 1, a battery cell shell 2 is sleeved on the outside of the battery cell 1, an outer protective shell 3 is arranged on the outside of the battery cell shell 2, a locking cavity 4 is arranged in the middle of the battery cell 1, the battery cell 1 passes through the battery cell shell 2 and the outer protective shell 3 in sequence along the locking cavity 4, and a locking mechanism 5 is installed, an annular air chamber 6 is arranged between the inside of the outer protective shell 3 and the outside of the battery cell shell 2, the annular air chamber 6 is communicated with the locking cavity 4, a sealing ring 7 is arranged on the top of the annular air chamber 6, and the locking mechanism 5 is used to cooperate with the sealing ring 7 to seal the battery pack; an exhaust component 8 is arranged inside the locking mechanism 5, a fire extinguishing mechanism 9 is arranged on one side of the annular air chamber 6 inside the outer protective shell 3, a heat conducting plate 10 is installed on one side of the outer protective shell 3, and the heat conducting plate 10 is used to cooperate with the exhaust component 8 and the fire extinguishing mechanism 9 to extinguish the battery pack.

[0020] It should be noted that a rotatable handle 11 is installed on the top of the battery cell 1 for portable transfer of the battery pack. Since it is used in a micro electric vehicle, there is an actual need to transfer the battery pack during actual use. The handle 11 facilitates its carrying. The bottom is two battery packs, each of which is provided with ten battery cells to provide sufficient power capacity. The locking cavity 4 is arranged in the middle position between the two battery packs (see Figure 4 ), a sealing ring 12 is fixedly connected to the bottom of the battery cell 1 just above the sealing ring 7, which is used to cooperate with the sealing ring 7 to seal the inside of the battery.

[0021] like Figure 1 , Figure 2 , Figure 7 , Figure 8 and Fig.10 As shown, the locking mechanism 5 includes a base 51 fixedly mounted on the top of the battery cell 1, a locking rod 52 is slidably connected to the middle of the base 51, a guide piece 53 is rotatably connected to the top of the locking rod 52, a support arm 54 is fixedly connected to one side of the base 51, a buckling piece 55 is installed between the support arm 54 and the guide piece 53, the locking rod 52 passes through the battery cell 1 and extends into the locking cavity 4, a rotating handle 56 is installed on the outer shell 3 just below the locking rod 52, a lock buckle 57 is installed on the top of the rotating handle 56, and the lock buckle 57 is threadedly connected to the bottom of the locking rod 52; It should be noted that when the battery pack needs to be locked, the locking rod 52 is pressed down to the locking position by pressing the buckle plate 55, and then the rotating handle 56 at the bottom of the battery pack is rotated to connect the lock buckle 57 with the bottom of the locking rod 52 until it is locked. Since the rotating handle 56 is installed between the battery cell shell 2 and the outer protective shell 3, and the locking rod 52 extends downward from the battery cell 1, when the two are connected, the locking function of the entire battery pack can be completed. When the battery pack needs to be unlocked, the rotating handle 56 can be rotated in the opposite direction to disengage the locking rod 52 from the lock buckle 57, and the buckle plate 55 can be lifted up at the same time to complete the separation between the battery cell 1 and the two protective shells. In addition, a reset spring 58 is installed at the bottom of the rotating handle 56 to provide auxiliary effect for the rebound of the lock buckle 57 when unlocking.

[0022] like Figure 4 , Figure 5 and Fig. 9 As shown, the sealing ring 7 includes a ring baffle 13 fixedly connected to the inner side of the top of the outer protective shell 3, and the battery cell housing 2 is provided with a ring retaining ring 14 adapted to the ring baffle 13 on the same horizontal plane, and the bottom surface of the sealing ring 12 abuts between the ring baffle 13 and the ring retaining ring 14; It should be noted that after the locking mechanism 5 completes the locking of the battery cell 1, the battery cell shell 2 and the outer protective shell 3, the annular sealing ring 12 installed on the bottom surface of the battery cell 1 immediately presses against the annular baffle 13 and the annular retaining ring 14. Since the bottom surfaces of the annular baffle 13 and the annular retaining ring 14 are the annular gas chamber 6 arranged around the battery pack, when the fire extinguishing agent reacts to produce fire extinguishing gas, it can effectively prevent external high-temperature flames from invading the interior of the battery through the gap between the battery cell shell 2 and the outer protective shell 3. At the same time, the locking mechanism 5 effectively seals the battery pack installed at the bottom, so that the fire extinguishing gas takes into account the sealing of the battery pack while working, thereby improving the safety of fire extinguishing.

[0023] like Figure 3 , Figure 5 , Fig. 9 , Fig.11 and Fig.12 As shown, the fire extinguishing mechanism 9 includes a fire extinguishing chamber 91 arranged inside the outer protective shell 3, the fire extinguishing chamber 91 is filled with fire extinguishing agent, winding springs 92 are installed on both sides of the top of the fire extinguishing chamber 91, a rotating shaft 93 is installed between the two winding springs 92, a packaging film 94 is installed between the two winding springs 92, and a fuse strip 95 is installed between the heat conducting plate 10 and the packaging film 94; It should be noted that, preferably, the fire extinguishing agent is sodium bicarbonate, which slowly decomposes at 50 degrees and violently and completely decomposes at 270 degrees, and produces a large amount of carbon dioxide during the decomposition process, which can be used to isolate the oxygen inside the battery pack to achieve the purpose of fire extinguishing. It is sealed in the fire extinguishing compartment 91 in an unsealed state and does not decompose. When the ambient temperature rises, the external heat energy of the battery is transferred to the fuse bar 95 through the heat conducting plate 10, and the fuse bar 95 melts accordingly. Preferably, the fuse bar 95 is a tin bar with a melting point of 230 degrees. After melting, the two winding springs 92 drive the packaging film 94 that seals the fire extinguishing agent to be wound to the rotating shaft 93. After the fire extinguishing agent is unsealed, a decomposition reaction occurs to produce a large amount of carbon dioxide; like Figures 6 to 8 , Fig.13 As shown, air ports 15 are provided on both sides of the cell housing 2 to adapt to the locking cavity 4, the exhaust assembly 8 includes air outlets 81 provided on both sides of the base 51, the locking rod 52 is fixedly connected to a spring 82 inside the same horizontal plane as the air outlet 81, the bottom of the spring 82 is fixedly connected to an air baffle 83, an air channel 84 is provided in the middle of the locking rod 52, and an air receiving strip port 85 is provided in the middle of the locking cavity 4; It should be noted that the annular air chamber 6 is arranged at the bottom of the sealing ring 7 and is connected to the locking cavity 4. Since the annular air chamber 6 is arranged around the batteries along the two battery packs, when the fire extinguishing agent is unsealed to generate carbon dioxide, it can be filled in all positions of the internal battery pack through the annular air chamber 6, the air port 15 and the locking cavity 4, thereby ensuring its ability to protect the battery as a whole and improving the overall fire extinguishing ability. At the same time, as the internal air pressure increases, the carbon dioxide reaches the air baffle 83 along the air connection strip port 85, and the spring 82 is compressed by the force. Then the carbon dioxide gas is transmitted to the outside of the battery pack through the air outlet 81, so that both the inside and outside of the battery pack are in a carbon dioxide environment, further improving the safety of the battery pack. At the same time, when no fire occurs, the air baffle 83 is pushed by the elastic force of the spring 82 and is located below the air outlet 81, thereby maintaining the overall sealing performance of the battery pack.

[0024] Working principle of the present invention: By installing a locking mechanism 5 between the battery cell 1 and the battery cell shell 2 and the outer protective shell 3, and cooperating with the sealing effect of the sealing ring 12 on the sealing ring 7 inside the battery pack, the sealing performance inside the battery pack can be ensured in case of fire, and open flames can be prevented from entering the battery and directly damaging the battery pack body, thereby effectively preventing the battery pack from being damaged and further burning and detonating. At the same time, with the help of the fire extinguishing mechanism 9 installed inside the outer protective shell 3, the melting effect of the fuse bar 95 by the heat conducting plate 10 is cooperated to release the fire extinguishing agent into the annular air chamber 6. With the connection between the annular air chamber 6 and the locking cavity 4, the locking rod 52 located in the locking cavity 4 can be temporarily connected to the outside when the internal air pressure rises, so that the carbon dioxide filled inside can be discharged to the outside of the battery pack, so that when the battery pack encounters fire, both the inside and the outside are in an environment of high concentration of carbon dioxide, thereby isolating oxygen and achieving a safe environment for comprehensive fire extinguishing.

[0025] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A safe sodium ion battery pack, comprising a battery cell (1), wherein the battery cell (1) is provided with a battery cell shell (2) on the outside, and an outer protective shell (3) is provided on the outside of the battery cell shell (2). It is characterized in that A locking cavity (4) is provided in the middle of the battery cell (1); the battery cell (1) passes through the battery cell shell (2) and the outer protective shell (3) in sequence along the locking cavity (4); a locking mechanism (5) is installed; an annular air chamber (6) is provided between the outer protective shell (3) and the battery cell shell (2); a sealing ring (7) is provided at the top of the annular air chamber (6); the locking mechanism (5) is used to cooperate with the sealing ring (7) to seal the battery pack; an exhaust assembly (8) is provided inside the locking mechanism (5); a fire extinguishing mechanism (9) is provided inside the outer protective shell (3) on one side of the annular air chamber (6); a heat conducting plate (10) is installed on one side of the outer protective shell (3); the heat conducting plate (10) is used to cooperate with the exhaust assembly (8) and the fire extinguishing mechanism (9) to extinguish the fire of the battery pack.

2. A safe sodium ion battery pack according to claim 1, It is characterized in that The locking mechanism (5) comprises a base (51) fixedly mounted on the top of the battery cell (1); a locking rod (52) is slidably connected to the middle of the base (51); a guide piece (53) is rotatably connected to the top of the locking rod (52); a support arm (54) is fixedly connected to one side of the base (51); a buckling piece (55) is mounted between the support arm (54) and the guide piece (53); and the locking rod (52) penetrates the battery cell (1) and extends into the locking cavity (4).

3. A safe sodium ion battery pack according to claim 2, It is characterized in that The outer protective shell (3) is provided with a rotating handle (56) directly below the locking rod (52), a locking buckle (57) is provided at the top end of the rotating handle (56), and the locking buckle (57) is threadedly connected to the bottom of the locking rod (52).

4. A safe sodium ion battery pack according to claim 1, It is characterized in that A sealing ring (12) is fixedly connected to the bottom of the battery cell (1) just above the sealing ring (7); the sealing ring (7) includes a ring baffle (13) fixedly connected to the inner side of the top of the outer protective shell (3); the battery cell housing (2) is adapted to be provided with a ring baffle (14) on the same horizontal plane as the ring baffle (13); and the bottom surface of the sealing ring (12) abuts against the ring baffle (13) and the ring baffle (14).

5. A safe sodium ion battery pack according to claim 1, It is characterized in that The fire extinguishing mechanism (9) comprises a fire extinguishing chamber (91) arranged inside the outer protective shell (3), the fire extinguishing chamber (91) is filled with fire extinguishing agent, winding springs (92) are installed on both sides of the top of the fire extinguishing chamber (91), a rotating shaft (93) is installed between the tops of the two winding springs (92), a packaging film (94) is installed between the bottoms of the two winding springs (92), and a fuse strip (95) is installed between the heat conducting plate (10) and the packaging film (94).

6. A safe sodium ion battery pack according to claim 3, It is characterized in that The exhaust assembly (8) comprises air outlets (81) opened on both sides of the base (51); the locking rod (52) is fixedly connected to a spring (82) inside the same horizontal plane as the air outlet (81); the bottom of the spring (82) is fixedly connected to an air baffle (83); an air passage (84) is provided in the middle of the locking rod (52); the air passage (84) is located in the middle of the locking cavity (4), and air receiving strip openings (85) are provided on both sides.

7. A safe sodium ion battery pack according to claim 3, It is characterized in that A handle (11) is installed on the top of the battery cell (1), the locking cavity (4) is arranged in the middle of the bottom of the battery cell (1), the two locking rods (52) are both located in the locking cavity (4), and the lock buckle (57) is located at the bottom of the locking cavity (4).

8. A safe sodium ion battery pack according to claim 1, It is characterized in that The annular air chamber (6) is in communication with the locking cavity (4), and air holes (15) are provided on both sides of the battery cell housing (2) to match the locking cavity (4).

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