Explosion-proof charging box for lithium ion battery

Abstract

The application provides an explosion-proof charging box for lithium ion batteries, which comprises a box body with an accommodating space inside, an opening communicating with the accommodating space, an upper cover connected to the box body, at least one battery seat arranged in the accommodating space, at least one pressure relief hole communicating between the outside of the box body and the accommodating space, a fireproof body arranged in the pressure relief hole, and the fireproof body shielding the pressure relief hole and having a porous structure when in action. When the fireproof body is in action, it can block open fire, reduce the passage of heat and smoke, and has the ability to resist impact, thereby providing an explosion-proof charging box for lithium ion batteries with excellent open fire, heat and smoke blocking or reducing effect, impact resistance and passive fire resistance function.

Description

Technical Field

[0001] This application belongs to the technical field of battery charging boxes, and in particular to an explosion-proof charging box for lithium-ion batteries. Background Technology

[0002] Rechargeable batteries originated with lead-acid batteries produced in 1859. They have accompanied human civilization for over a century, undergoing countless technological improvements, and remain the most technologically mature type of rechargeable battery. However, driven by environmental goals and the rapid development of new energy technologies, lithium-ion batteries have become the mainstream rechargeable battery. Lithium-ion polymer batteries (also commonly referred to as "lithium polymer batteries") are essentially lithium-ion batteries, but are improvements on ordinary lithium-ion batteries. They utilize gel or solid polymers instead of liquid organic solvents to create rechargeable lithium-ion batteries. They offer better safety, do not explode, and can be molded into various cell shapes, making them the current mainstream form of rechargeable lithium-ion battery. The term "lithium-ion battery" in this specification also includes lithium-ion polymer batteries.

[0003] Lithium-ion batteries are widely used in various electronic products and electric vehicles due to their advantages such as fast charging, high energy density, small size, and mature technology. However, due to the highly reactive nature of lithium, there are also considerable risks involved, and news of lithium-ion battery fires is frequently reported. In particular, the recent spate of electric vehicle fires and their difficulty in extinguishing them have raised serious concerns about the safety of lithium-ion batteries. Thermal runaway is known to be one of the main causes of lithium-ion battery fires. Thermal runaway occurs when the rate of heat generation from an internal short circuit in the battery far exceeds the rate of heat dissipation, leading to a large accumulation of heat that is not dissipated in time. Furthermore, the temperature increases further, creating a vicious cycle and spreading the heat. Thermal runaway in a lithium-ion battery triggers a series of irreversible chain reactions, causing the internal temperature to rise rapidly within milliseconds. The energy stored in the lithium-ion battery is suddenly released, generating internal temperatures of approximately 500°C to 1000°C. Simultaneously, the high temperature causes some materials in the lithium-ion battery to release flammable high-temperature gas, resulting in a fire that is almost impossible to extinguish using conventional methods.

[0004] Known methods for preventing thermal runaway in lithium-ion batteries include: using high-temperature resistant plastic materials for insulation to increase the spacing between battery cells; encasing lithium-ion batteries in carbon steel to form battery packs, as a means of preventing thermal runaway and its propagation; and using heat-insulating two-dimensional planar materials, such as mica, ceramic plates, silica sheets, carbon fiber fabrics, and steel plates, as heat insulation and heat-blocking materials to prevent heat transfer. Regarding the application of heat-insulating two-dimensional planar materials, their effect cannot prevent the generation of impact gas in lithium-ion battery cells under thermal runaway. For high-temperature resistant and melt-preventing two-dimensional planar materials only attached to the inner side of the outer casing, once subjected to an internal explosion impact from the lithium-ion battery cell, the casing is easily punctured / broken, leading to the entry of external air, such as oxygen, into the lithium-ion battery, causing reignition or deflagration. Furthermore, this type of material lacks the ability to prevent the propagation and diffusion of high-temperature gases within the lithium-ion battery (pile).

[0005] A published Chinese invention patent application (publication number CN 101894930 A) proposes a battery box with good ventilation and heat dissipation, which includes a box body and a battery pack placed inside the box body. The battery pack is fixed to the box body by clamps on both sides. There is a gap between each battery in the battery pack. The two side plates of the box body, which are perpendicular to the plane of the gap, are an air inlet plate and an air outlet plate, respectively. The air inlet plate is provided with an air inlet, and the air outlet plate is provided with an exhaust fan. A diversion plate is provided on the side of the battery pack facing the air inlet plate, and the gap between each diversion plate corresponds to the gap between each battery.

[0006] An improved battery box is proposed in a Chinese invention patent that has been granted and announced (authorization announcement number CN 101894926 B). The battery box includes a box body and two battery modules disposed on opposite sides of the box body. The box body consists of four side plates, a box cover and a box bottom. Two parallel side plates serve as air inlets of the battery box, and the other side plate, which is perpendicular to the air inlets and farther away from the battery modules, serves as the air outlet of the battery box. The battery module includes a battery pack, a baffle and a guide plate. A fan is mounted on the baffle. An air inlet is provided on the air inlet plate, and an air outlet is provided on the air outlet plate. An outlet fan and a guide plate are installed at the air outlet, and the guide plates are symmetrically arranged on both sides of the fan.

[0007] The aforementioned patented technology is an active heat dissipation technology for secondary batteries. Its function is to quickly remove heat from the battery, thereby improving safety during use and extending the lifespan of the battery module. Utility Model Content

[0008] The technical problem to be solved by this application is to provide an explosion-proof charging box for lithium-ion batteries that can block open flames, reduce the passage of heat and smoke, and has impact resistance and passive flame-retardant function.

[0009] To achieve the above objectives, a preferred embodiment of the explosion-proof charging box for lithium-ion batteries of this application comprises: a box body having an internal accommodating space, the box body having an opening communicating with the accommodating space, a top cover connected to the box body, the top cover being able to open or close the opening, and at least one battery holder disposed in the accommodating space; wherein the box body has at least one pressure relief hole communicating with the outside of the box body and the accommodating space, a fireproof body is disposed at the pressure relief hole, the fireproof body shielding the pressure relief hole, the fireproof body having a porous structure when in action, and the fireproof body being able to block open flames while allowing smoke to pass through.

[0010] In a preferred embodiment of the explosion-proof charging box for the lithium-ion battery of this application, the pressure relief hole is a single hole or multiple holes.

[0011] In a preferred embodiment of the explosion-proof charging box for the lithium-ion battery of this application, a fireproof body is disposed on the inner side of the box and covers the pressure relief hole.

[0012] In a preferred embodiment of the explosion-proof charging box for the lithium-ion battery of this application, a fireproof body is disposed on the outside of the box and covers the pressure relief hole.

[0013] As a preferred embodiment of the explosion-proof charging box for lithium-ion batteries of this application, the box body is equipped with a frame and a perforated plate. The frame is fixedly disposed in the box body and surrounds the pressure relief hole. The perforated plate and the fireproof body are assembled on the frame to shield the pressure relief hole, and the fireproof body is located between the perforated plate and the pressure relief hole.

[0014] As a preferred embodiment of the explosion-proof charging box for the lithium-ion battery of this application, the material of the fireproof body is selected from the group consisting of: worm graphite sheets, coatings containing worm graphite material, worm graphite that has expanded into a porous structure, and foam metal, wherein the material of the foam metal includes any one of: steel, silver, iron, copper, aluminum, and nickel.

[0015] As a preferred embodiment of the explosion-proof charging box for the lithium-ion battery of this application, worm graphite sheets and a coating containing worm graphite material are applied to the mesh surface of a metal mesh plate.

[0016] In a preferred embodiment of the explosion-proof charging box for the lithium-ion battery of this application, worm-like graphite that has expanded into a porous structure is sandwiched between two metal meshes.

[0017] In a preferred embodiment of the explosion-proof charging box for the lithium-ion battery of this application, the surface of the pores of the foam metal is coated with worm graphite sheets or a coating containing worm graphite material.

[0018] The advantages and effects of this application are as follows: the explosion-proof charging box for lithium-ion batteries is equipped with a pressure relief hole and a fireproof body. When the fireproof body is activated, it can block open flames, reduce the passage of heat and smoke, and has impact resistance. Thus, it provides an explosion-proof charging box for lithium-ion batteries with excellent blocking or reduction effects of open flames, heat and smoke, impact resistance and passive flame retardancy.

[0019] The other effects and embodiments of this application are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is an exploded structural diagram of one embodiment of the explosion-proof charging box for lithium-ion batteries of this application;

[0022] Figure 2A , Figure 2B This is a cross-sectional view of a partial structure of the explosion-proof charging box for the lithium-ion battery of this application;

[0023] Figure 3A This is a cross-sectional view of a preferred embodiment of the fireproof body of the explosion-proof charging box for lithium-ion batteries in this application;

[0024] Figure 3B yes Figure 3A Enlarged view of the fireproof body 50 and the metal mesh panel 60;

[0025] Figure 4A , Figure 4B This is a cross-sectional view of another preferred embodiment of the fireproof body of the explosion-proof charging box for lithium-ion batteries in this application.

[0026] Symbol Explanation

[0027] B: Lithium-ion battery; S: Storage space

[0028] 10: Box body 101: Opening

[0029] 11: Annular side plate 111: First side plate

[0030] 112: Second side panel 113: Third side panel

[0031] 114: Fourth side plate; 12: Base plate

[0032] 13: Pressure relief hole 14: Frame

[0033] 15: Perforated plate 20: Top cover

[0034] 21: Connecting component 22: Press-fit fastener

[0035] 30: Battery holder; 40: Charging system

[0036] 41: Power converter 42: Charging management circuit

[0037] 43: Power connector; 50: Fireproof body

[0038] 60: Metal mesh plate; 601: Mesh size

[0039] 61, 62: Metal mesh Detailed Implementation

[0040] In the embodiments described below, the positional relationships include: up, down, left, and right. Unless otherwise specified, they are all based on the direction shown by the components in the diagram.

[0041] Please refer to the following first. Figure 1 This is an exploded structural diagram of one embodiment of the explosion-proof charging box for lithium-ion batteries according to this application. The explosion-proof charging box for lithium-ion batteries proposed in this application is basically used to house lithium-ion batteries B and to charge them. Preferably, the explosion-proof charging box for lithium-ion batteries proposed in this application is used to house and charge multiple lithium-ion batteries B.

[0042] like Figure 1 As shown, a preferred embodiment of the explosion-proof charging box for lithium-ion batteries proposed in this application includes: a box body 10, a top cover 20, and at least one battery holder 30; in a preferred embodiment, the box body 10 has a rectangular structure, but is not limited thereto, and the shape of the box body 10 can be changed according to actual needs without affecting the effectiveness of this application; in a preferred embodiment, the structure of the box body 10 includes: an annular side plate 11 and a bottom plate 12, the bottom plate 12 being tightly connected to the bottom edge of the annular side plate 11 (see... Figure 2A The bottom plate 12 and the annular side plate 11 together form a box 10 having an opening 101, and have an accommodating space S inside the box 10. The annular side plate 11 is composed of a plurality of side plates connected end to end to each other. In a preferred embodiment, the annular side plate is constructed to include: a first side plate 111, a second side plate 112, a third side plate 113 and a fourth side plate 114, which are connected end to end to each other and surround each other to form a rectangle.

[0043] The battery holder 30 is disposed in the accommodating space S. The lithium-ion battery B can be placed into the battery holder 30 in the accommodating space S through the opening 101. The battery holder 30 is electrically connected to a charging power source for the lithium-ion battery B to be electrically coupled and charged.

[0044] The top cover 20 is movably connected to the housing 10 via a connecting component 21. In a preferred embodiment, the connecting component 21 may be a hinge. The top cover 20 can be moved to an open position via the connecting component 21 to expose the opening 101, and the top cover 20 can be moved to a closed position via the connecting component 21 to close the opening 101. Preferably, the top cover 20 is also provided with a clamping buckle 22 to fix the top cover 20 in the closed position to close the opening 101.

[0045] The charging power is supplied by a charging system 40. In a preferred embodiment, the charging system 40 is directly disposed within the accommodating space S of the housing 10 (see [link to original text]). Figure 1 In another embodiment, the charging system 40 is separate from the housing 10. The charging system 40 is electrically connected to the battery holder 30 by wires, and can supply the charging power required by the battery holder 30 and the lithium-ion battery B.

[0046] Generally, the charging system 40 includes: a power converter 41, a charging management circuit 42, and a power connector 43. The power connector 43 is used to electrically connect the power converter 41 to an external power source; the power converter 41 converts the external power source into a charging power source (generally a DC charging power source) for charging the lithium-ion battery B; the charging management circuit 42 is electrically connected to the power converter 41 and the battery holder 30, and is responsible for controlling the charging current and voltage to prevent overcharging, over-discharging, overheating, and other potentially dangerous situations, thereby extending battery life and improving safety.

[0047] To achieve the objectives of this application, the housing 10 has at least one pressure relief hole 13, which connects the accommodating space S and the outside of the housing 10. A fireproof body 50 is disposed on the pressure relief hole 13. The fireproof body 50 has a porous structure when in action, and it can block open flames and reduce the passage of heat and smoke. The pressure relief hole 13 can be disposed on any side of the housing 10. In one embodiment shown in the figure, the pressure relief hole 13 is provided on one side of the housing 10. In other preferred embodiments, the pressure relief hole 13 can also be provided on one or more other sides of the housing 10. The preferred location is close to the battery holder 30 or the lithium-ion battery B. The pressure relief hole 13 can be in the form of a single hole or multiple holes. In a preferred embodiment, the pressure relief hole 13 is in the form of multiple holes (see...). Figure 1Multiple pressure relief holes 13 are arranged in a matrix. The function of the pressure relief holes 13 is to provide a path for open flame, smoke and heat to be discharged from the box after the lithium-ion battery B experiences thermal runaway. When the fireproof body 50 is activated, it can block open flame and reduce the passage of heat and smoke, thereby reducing the internal pressure of the box 10 and reducing damage.

[0048] In a preferred embodiment of this application, the fireproof body 50 is disposed inside the housing 10 and covers the pressure relief hole 13 (see...). Figure 2A In another preferred embodiment, the fireproof body 50 is disposed on the outside of the housing 10 and covers the pressure relief hole 13 (see...). Figure 2B ).

[0049] In a preferred embodiment of this application, the housing 10 is provided with a frame 14 and a perforated plate 15. The frame 14 is fixedly disposed on the housing 10 and surrounds the pressure relief hole 13. The perforated plate 15 and a fireproof body 50 are assembled on the frame 14 to shield the pressure relief hole 13, wherein the fireproof body 50 is located between the perforated plate 15 and the pressure relief hole 13. Preferably, the housing 10, the top cover 20, the frame 14, and the perforated plate 15 are all made of metal materials, preferably stainless steel or iron.

[0050] In a preferred embodiment of this application, the material of the fireproof body 50 is selected from the group consisting of: worm graphite sheets, coatings containing worm graphite material, worm graphite that has expanded into a porous structure, and foam metal, wherein the material of the foam metal includes any one of: steel, silver, iron, copper, aluminum, and nickel.

[0051] The expanded worm-shaped graphite, through a pre-treatment process involving heating, becomes a porous fire-resistant body 50. When exposed to high temperatures or open flames, this expanded porous worm-shaped graphite exhibits excellent flame, heat, and smoke blocking properties, as well as impact resistance. On the other hand, foamed metal possesses excellent physical, chemical, and mechanical properties, is impact-resistant, has excellent anti-aging properties, and reduces the passage of open flames and smoke.

[0052] Please see Figure 3A and Figure 3B In a preferred embodiment, either worm graphite flakes or a coating containing worm graphite material is applied to the surface of the mesh 601 of a metal mesh plate 60 (see [link to embodiment]). Figure 3A The worm-shaped graphite sheets and materials, acting as the fire-resistant body 50, begin to function upon exposure to heat or open flame, subsequently expanding into a porous structure (see...). Figure 3B Therefore, it can block open flames and reduce the passage of heat and smoke. The outer layer of worm graphite has a velvety carbide structure, which can reduce the kinetic energy of impact and reduce the damage caused by fire.

[0053] Please see Figure 4A and Figure 4B In a preferred embodiment of this application, worm-shaped graphite that has expanded into a porous structure is used as the fireproof body 50; a preferred embodiment is to fill the space between two metal meshes 61 and 62 with worm-shaped graphite sheets, and through a heating pretreatment process, the worm-shaped graphite sheets expand into a porous structure to form the fireproof body 50 (see...). Figure 4A When exposed to high temperatures or open flames, this worm-like graphite, which has already expanded into a porous structure, can expand further and produce even more tiny pores (see...). Figure 4B It can block open flames, reduce the passage of heat and smoke, and its porous structure has excellent structural strength, thereby reducing the impact kinetic energy of deflagration and reducing the damage caused by fire.

[0054] In a preferred embodiment of this application, foamed metal is used as the fireproof body 50. The foamed metal has many pores with a porosity that is typically high, reaching over 90%. By selecting different metal materials and manufacturing methods, the size of the pores can be controlled. Worm graphite flakes or coatings containing worm graphite materials are coated on the surface of these pores. When heated or exposed to open flame, the coating begins to function and expands into a porous structure, thereby achieving the purpose of this application.

[0055] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of this application, and are not intended to limit the implementation methods of the technology of this application in any way. Any person skilled in the art may make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in this application, but these should still be regarded as the technology or embodiments that are substantially the same as those of this application.

Claims

1. An explosion-proof charging box for lithium-ion batteries, comprising: A housing having an internal accommodating space, the housing having an opening communicating with the accommodating space, a top cover connected to the housing, the top cover being able to open or close the opening, and at least one battery holder disposed in the accommodating space; characterized in that: The enclosure has at least one pressure relief hole connecting the exterior of the enclosure to the accommodating space. A fireproof body is disposed in the pressure relief hole and the fireproof body covers the pressure relief hole. When in action, the fireproof body has a porous structure and can block open flames while allowing smoke to pass through.

2. The explosion-proof charging box for lithium-ion batteries according to claim 1, characterized in that, The pressure relief hole can be single-hole or multi-hole.

3. The explosion-proof charging box for lithium-ion batteries according to claim 1, characterized in that, The fireproof body is located inside the enclosure and covers the pressure relief hole.

4. The explosion-proof charging box for lithium-ion batteries according to claim 1, characterized in that, The fireproof body is located on the outside of the enclosure and covers the pressure relief hole.

5. The explosion-proof charging box for lithium-ion batteries according to claim 3 or 4, characterized in that, The enclosure is equipped with a frame and a perforated plate. The frame is fixedly disposed in the enclosure and surrounds the pressure relief hole. The perforated plate and the fireproof body are assembled in the frame to cover the pressure relief hole, and the fireproof body is located between the perforated plate and the pressure relief hole.

6. The explosion-proof charging box for lithium-ion batteries according to claim 1, characterized in that, The fireproof structure is made by filling the space between two metal meshes with worm-like graphite that has expanded into a porous structure.

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