Lithium battery positive electrode slurry leakage-proof structure and leakage-proof method thereof

Abstract

The invention relates to the technical field of lithium battery manufacturing, in particular to a lithium battery positive electrode slurry leakage-proof structure which is used in cooperation with a shell and a battery cell set and comprises a sliding channel, isolation pieces, a gel storage pipe, a water vapor conveying pipe, a guide plate, a reaction box, a lifting plate and a one-way air outlet hole, and the isolation pieces and the guide plate are located at the four corners of an inner cavity of the shell. The lifting plate is driven by the pressure of a large amount of gas generated by the thermal runaway behavior to move upwards, so that the gas is directionally guided into the reaction box, and meanwhile, the lifting plate moves upwards to drive the material guide gear to stir a reaction substance to fall and carry out a neutralization reaction with the gas, so that the gas is reduced, the pressure in the lithium battery is reduced, and the reaction efficiency is improved. Therefore, the leakage of the anode slurry caused by the damage of the lithium battery shell due to overlarge pressure is prevented, the overflow of inflammable gas is avoided, and the possibility of explosion of the lithium battery pack caused by the overflow of the inflammable gas is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of lithium battery manufacturing, and in particular to a lithium battery positive electrode slurry leakage prevention structure and a leakage prevention method thereof. Background Art

[0002] With the development of society, lithium batteries have been distributed in various fields of life due to their advantages such as high energy density, long cycle life, fast charging speed and wide operating temperature range, such as mobile phones, computers, mobile power supplies, emergency power supplies, electric bicycles, electric vehicles, sightseeing vehicles, drones and other types of power tools.

[0003] With the promotion of new energy, new energy vehicles are being designed, manufactured and sold like mushrooms after rain. Their environmental protection, economy, good power performance and comfort make them the choice of most people. The power source of new energy vehicles is lithium battery pack.

[0004] As lithium batteries are continuously used, certain potential safety hazards have become an urgent problem to be solved. Lithium batteries are composed of positive active materials, negative active materials, isolation membranes and electrolytes. Due to their structure, they may explode due to overcharging or short circuit during use. In addition, the leakage of positive electrode slurry of lithium batteries is also difficult to prevent during use. For the leakage of positive electrode slurry of lithium batteries, the existing solutions are generally to improve welding technology to ensure that there is no leakage or cold welding when welding the battery shell and battery cover; improve detection technology to detect whether the battery is qualified in all directions; set up explosion-proof valves. However, the above series of measures are based on lithium battery manufacturing technology. There are many reasons for lithium battery leakage, especially during use, excessive internal pressure, hitting, puncturing or collision and other improper operations may cause battery leakage. The above series of behaviors that may cause leakage will cause the lithium battery to have thermal runaway behavior, and thermal runaway behavior will cause a large amount of gas to be filled inside the lithium battery, resulting in excessive internal air pressure in the lithium battery, thereby causing the lithium battery to be damaged and leaking. If the leaked slurry flows through other intact lithium batteries, it may cause the intact lithium batteries to be corroded and damaged, and even more seriously, it may explode. For this reason, a lithium battery positive electrode slurry leakage prevention structure and a leakage prevention method thereof are proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a lithium battery positive electrode slurry leakage prevention structure and a leakage prevention method thereof, which solves the problem that after the existing lithium battery pack is subjected to mechanical extrusion and thermal runaway behavior, the gas pressure is enhanced, causing the shell to be damaged and the slurry to leak. By utilizing the gas pressure generated by the thermal runaway behavior, the gas pressure is reduced and the lithium battery is cooled at the same time.

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

[0007] A lithium battery positive electrode slurry leakage prevention structure and a leakage prevention method thereof, used in conjunction with an outer shell and a battery cell group, comprising a sliding channel, an isolating sheet, a gel storage tube, a water vapor delivery tube, a guide plate, a reaction box, a lifting plate and a one-way air outlet, wherein the isolating sheet and the guide plate are both located at the four corners of the inner cavity of the outer shell, the one-way air outlet is opened at the bottom of the outer wall of the isolating sheet, the inner cavity of the one-way air outlet is provided with a one-way valve, the lifting plate is slidably connected to the outer wall of the isolating sheet, the reaction box is slidably connected to the outer wall of the guide plate, the outer end of the lifting plate is located in the inner cavity of the reaction box, the sliding channel is opened at the four corners of the outer wall of the outer shell, one end of the water vapor delivery tube is located in the inner cavity of the sliding channel and is fixedly connected to the reaction box, the gel storage tube is located on the outer wall of the outer shell and is connected to the water vapor delivery tube, and the water vapor delivery tube surrounds the outer wall of the outer shell after being connected to the gel storage tube.

[0008] Existing methods for preventing leakage of positive electrode slurry of lithium batteries are generally improved during manufacturing, such as: 1. Improving welding technology to ensure that there is no leakage or cold welding when welding the battery shell and the battery cover; 2. Improving detection technology to detect whether the battery is qualified in multiple directions; 3. Setting an explosion-proof valve; However, the above series of measures are based on the improvement of lithium battery manufacturing technology, and there are many reasons for lithium battery leakage. In particular, during use, improper operations such as excessive internal pressure, hitting, puncturing or collision may cause battery leakage. The above series of behaviors that may cause leakage will cause the lithium battery to produce thermal runaway behavior, and thermal runaway behavior will cause a large amount of gas to be filled inside the lithium battery, thereby causing excessive internal gas pressure in the lithium battery, thereby causing damage to the lithium battery and causing leakage. This solution neutralizes the gas generated by thermal runaway to reduce the pressure, and absorbs the runaway heat to reduce the battery temperature, so as to avoid continuous temperature increase and aggravation of thermal runaway reaction, thereby achieving the purpose of preventing leakage of positive electrode slurry of lithium batteries. Compared with the single improvement from the manufacturing technology aspect, it can provide an additional guarantee during the use of the battery.

[0009] Preferably, a glue outlet is provided on the outer wall of the gel storage tube, and baffles are rotatably connected at both ends of the gel storage tube, the two baffles are fixedly connected to the water vapor delivery tube on opposite sides, and connecting holes and fixed grooves are provided on the surfaces of the two baffles, and the inner cavities of the two fixed grooves are provided with glue outlet closing plates matching the glue outlet, and a left-right symmetrical fan-shaped matching piece is fixedly connected to the inner cavity of the gel storage tube, and the fan-shaped matching piece matches the connecting hole, and a left-right symmetrical rotating mechanism is provided on the outer wall of the gel storage tube.

[0010] In the above scheme, when thermal runaway does not occur, the fan-shaped matching piece blocks the surface of the connecting hole, so that the connection port between the gel storage tube and the water vapor delivery tube can be sealed, which can prevent the gel powder in the gel storage tube from entering the water vapor delivery tube, thereby affecting the delivery of water vapor.

[0011] Preferably, the rotating mechanism comprises meshing racks and steering gears, the steering gear is fixedly connected to the outer wall of the gel storage tube, the rack is fixedly connected to the outer wall of the shell, and the steering gear is a 1 / 4 arc.

[0012] In the above scheme, after thermal runaway occurs, the gel storage tube can be turned as it rises to ensure that its gel outlet is opposite to the outer wall of the shell, thereby completing the gel coating and staggering the fan-shaped matching piece and the connecting hole to ensure that water vapor can enter the gel storage tube and mix with the gel powder inside it.

[0013] Preferably, a sliding groove is provided on the inner side of the reaction box, the height of the sliding groove is 1.5-2 times of the height of the lifting plate, and the lifting plate is provided with an air inlet in the middle of the inner cavity of the reaction box.

[0014] In the above scheme, by limiting the height of the sliding groove, when thermal runaway occurs, the gas can enter the reaction box after the lifting plate rises to the top of the sliding groove and complete the neutralization reaction. When thermal runaway does not occur, the lifting plate is at the bottom of the sliding groove, ensuring the sealing of the lithium battery.

[0015] Preferably, a multi-stage telescopic plate is fixedly connected to the bottom of the reaction box, the multi-stage telescopic plate is set in a "U" shape, the outer wall of the guide plate is provided with a sliding groove matching the multi-stage telescopic plate, the outer wall of the guide plate is provided with a penetrating guide groove, and the middle part of the lifting plate is located in the inner cavity of the guide groove.

[0016] In the above scheme, a multi-stage telescopic plate is provided which can be extended synchronously with the rise of the reaction box, thereby sealing the guide groove leaking from the bottom of the reaction box, which can ensure the ascending movement and prevent the gas generated by thermal runaway from overflowing.

[0017] Preferably, a delivery channel is fixedly connected to the top of the reaction box, a reactant storage box is fixedly connected to the top of the delivery channel, the delivery channel is made of a telescopic hose, and an automatic feeding mechanism is provided on the inner wall of the guide plate.

[0018] In the above scheme, the reaction box and the reactants are arranged separately, so as to avoid the reaction box carrying a sufficient amount of reactants from being too heavy and affecting its upward movement, thereby ensuring that the gel storage tube can move upward with the reaction box to complete the gel coating.

[0019] Preferably, the automatic feeding mechanism includes a transmission wheel, a transmission belt and a guide gear. The transmission wheel is rotatably connected to the inner wall of the guide plate and is symmetrically arranged up and down. The transmission belt is sleeved on the outer walls of the two transmission wheels. The guide gear is fixedly connected to the top of the transmission wheel, and the right side of the transmission belt is fixedly connected to the lifting plate.

[0020] In the above scheme, an automatic feeding mechanism is provided to ensure continuous delivery of reactants, thereby ensuring sufficient reaction between the gas and the reactants and avoiding incomplete reaction caused by accumulation of reactants, thereby causing waste of reactants.

[0021] Preferably, a discharge port matching the material guide gear is provided at the bottom of the reactant storage box, and the teeth of the material guide gear are arranged obliquely, with an inclination angle of 20°-30°.

[0022] In the above scheme, the material guide gear is limited so that it can complete the action of material discharging and unloading, and can prevent the gas of the thermal runaway reaction from directly entering the reactant storage box to react with the reactants, thereby ensuring that the neutralization reaction occurs in the reaction box. The limited inclination angle can limit the amount of material discharging at one time, avoiding excessive material discharging causing excessive reactants in the reaction box and affecting movement.

[0023] Preferably, a protective strip is provided at the top of the outer wall of the shell, the inner wall of the protective strip is hollow, and the outer wall of the protective strip is provided with ventilation holes that penetrate and are evenly distributed.

[0024] In the above scheme, the narrow tube effect is utilized to concentrate the wind force through the ventilation holes and make it flow through the outer wall of the housing, so as to dissipate the heat when the lithium battery is working normally.

[0025] The method for preventing leakage of the positive electrode slurry leakage-proof structure of a lithium battery comprises the following steps:

[0026] S1: Gas neutralization: After the lithium battery in the outer ring is squeezed, thermal runaway occurs, and a large amount of gas is generated into the closed space composed of the isolation plate and the guide plate through the one-way valve. The continuously entering gas pushes the lifting plate to the top. When it moves to the top of the sliding groove, the bottom of the sliding groove is connected to the space filled with gas, and the gas enters the reaction box. When the lifting plate rises, the right side of the transmission belt connected to it also rises, thereby causing the transmission wheel to rotate, and the guide gear connected to the top transmission wheel also rotates, thereby causing the reactant in the reactant storage box to enter the reaction box through the conveying channel and react chemically with the gas in the reaction box, thereby neutralizing the gas;

[0027] S2: Gel heat dissipation: Based on the above step S1, when the lifting plate moves up, the reaction box, the water vapor delivery tube and the gel storage tube are also driven to move up. Since the steering gear on the outer wall of the gel storage tube is meshed with the rack on the outer shell surface, the steering gear can drive the gel storage tube to rotate 90 degrees, so that the gel outlet rotates to face the outer wall of the outer shell, and the fan-shaped matching piece is also staggered with the connecting hole as it rotates; a large amount of water vapor released after the gas is neutralized will enter the gel storage tube through the water vapor delivery tube, mix with the gel powder in the gel storage tube and overflow, and thus, as the gel storage tube rises, it is coated on the surface of the outer shell to absorb heat from the thermal runaway lithium battery.

[0028] In the above scheme, the gas generated by the thermal runaway behavior is neutralized to reduce the air pressure inside the lithium battery, thereby avoiding excessive air pressure causing bulging and damage of the lithium battery, which in turn causes leakage of the positive electrode slurry. When the gas is neutralized, the water vapor generated by the neutralization is used to mix the gel powder, and the mixed semi-solid viscous gel is coated on the surface of the lithium battery shell to absorb its heat, thereby achieving the purpose of heat dissipation of the lithium battery and avoiding continuous heat increase and aggravation of thermal runaway behavior. Therefore, not only the air pressure generated by the thermal runaway behavior is relieved, but also the heat generated by the thermal runaway behavior is absorbed. The combination of these two aspects can effectively avoid the leakage of the positive electrode slurry caused by damage to the lithium battery shell due to excessive air pressure or excessive heat.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention utilizes the pressure of a large amount of gas generated by thermal runaway behavior to drive the lifting plate to move upward, thereby directing the gas into the reaction box, and at the same time utilizes the upward movement of the lifting plate to drive the guide gear to move the reactant to fall, and react with the gas to neutralize, thereby reducing the gas. This not only reduces the pressure inside the lithium battery, thereby preventing the lithium battery shell from being damaged due to excessive pressure, thereby causing leakage of the positive electrode slurry, but also avoids the overflow of flammable gas, reducing the possibility of explosion of the lithium battery pack caused by the overflow of flammable gas.

[0031] 2. The present invention utilizes a large amount of gas generated by thermal runaway behavior and a large amount of water vapor generated by reactants, mixes them with gel powder in the gel storage tube, and synchronously coats them on the lithium battery casing as the reaction box rises, thereby cooling the lithium battery and preventing the thermal runaway behavior from being aggravated by excessive temperature. The semi-solid gel coated on the lithium battery casing can also block the positive electrode slurry that overflows from the small damage of the lithium battery casing to prevent it from overflowing.

[0032] 3. The present invention neutralizes the gas generated in the early stage of thermal runaway behavior and absorbs its heat, thereby effectively preventing the positive electrode slurry from leaking through the intact lithium batteries in the lithium battery pack, thereby corroding the intact lithium battery pack, effectively reducing the loss of the lithium battery pack when subjected to external mechanical extrusion, and making certain optimizations for the protection of lithium batteries in electric vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] The above and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0035] Figure 1 It is a structural schematic diagram of the positional relationship between the baffle plate and the fan-shaped matching plate in the original state of the present invention;

[0036] Figure 2 It is a structural schematic diagram of the lifting plate of the present invention rising to the top of the sliding groove;

[0037] Figure 3 This is a schematic diagram of the structure in which the sliding groove of the present invention drives the reaction box to move to 1 / 3 of the housing;

[0038] Figure 4 It is a structural schematic diagram of the automatic feeding mechanism of the present invention;

[0039] Figure 5 It is a structural schematic diagram of the glue outlet position after the rotating mechanism of the present invention is rotated;

[0040] Figure 6 It is a structural schematic diagram of the material guide gear of the present invention;

[0041] Figure 7 It is a schematic diagram of the structure of the protection strip of the present invention;

[0042] Figure 8 It is a schematic diagram of the structure of the present invention.

[0043] In the figure: 100, shell; 101, sliding channel; 102, protection strip; 103, ventilation hole; 104, battery cell group; 105, isolation sheet; 106, rack; 107, steering gear; 108, gel storage tube; 109, glue outlet; 110, water vapor conveying pipe; 111, baffle; 112, fan-shaped matching sheet; 113, connecting hole; 114, fixing groove; 115, glue outlet closing plate; 116, guide plate; 117, reaction box; 118, sliding groove; 119, lifting plate; 120, conveying channel; 121, reactant storage box; 122, transmission wheel; 123, transmission belt; 124, multi-stage telescopic plate; 125, guide groove; 126, material guide gear; 127, material outlet; 128, air inlet; 129, one-way air outlet. DETAILED DESCRIPTION

[0044] The following is a more clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention, and the described embodiments are only a part of all the embodiments of the present invention. Based on the embodiments of the present invention, all embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0045] See also Figures 1 to 8 The present invention provides a lithium battery positive electrode slurry leakage prevention structure, and the technical solution is as follows:

[0046] A lithium battery positive electrode slurry leakage prevention structure, used in conjunction with a housing 100 and a battery cell group 104, includes a sliding channel 101, a spacer 105, a gel storage tube 108, a water vapor delivery tube 110, a guide plate 116, a reaction box 117, a lifting plate 119 and a one-way vent 129, wherein the spacer 105 and the guide plate 116 are located at the four corners of the inner cavity of the housing 100, the one-way vent 129 is provided at the bottom of the outer wall of the spacer 105, and a one-way valve is fixedly connected to the inner cavity of the one-way vent 129, and the one-way valve is closed when the lithium battery is thermally runaway. When a large amount of gas is generated rapidly, the gas can be discharged in one direction. The lifting plate 119 is slidably connected to the outer wall of the isolation plate 105. As the gas is continuously discharged, the lifting plate 119 can move upward under the action of gas pressure. The gas here is H2, CO2, C3H6, CO, CH4, C2H4, C2H6 and HF generated by the lithium battery after mechanical extrusion. According to the data, H2 and CO2 account for about 70%-75% of the gas, so the subsequent neutralization reaction is mainly for these two gases. The reaction box 117 is slidably connected to the outer wall of the guide plate 116, and the outer end of the lifting plate 119 is slidably connected to the inner cavity of the reaction box 117. As the lifting plate 119 moves upward, it can drive the reaction box 117 to move upward synchronously. The sliding channel 101 is opened at the four corners of the outer wall of the shell 100. One end of the water vapor delivery pipe 110 is slidably connected to the inner cavity of the sliding channel 101 and is fixedly connected to the reaction box 117. The reaction box 117 and the water vapor delivery pipe 110 are connected. The water vapor generated by the neutralization reaction is carried out in the reaction box 117. It will be transported through the water vapor delivery tube 110, and at the same time, as the reaction box 117 rises, the water vapor delivery tube 110 can also be driven to rise synchronously. The gel storage tube 108 is located on the outer wall of the outer shell 100 and is fixedly connected to the water vapor delivery tube 110. After the water vapor delivery tube 110 and the gel storage tube 108 are connected, they surround the outer wall of the outer shell 100. The water vapor transported by the water vapor delivery tube 110 can be combined with the gel powder stored in the gel storage tube 108. The gel powder here uses heat dissipation hydrogel, specifically a mixed material of PVA and AR.

[0047] As an embodiment of the present invention, refer to Figure 1The outer wall of the gel storage tube 108 is provided with a glue outlet 109, and both ends of the gel storage tube 108 are rotatably connected with baffles 111, and the two baffles 111 are fixedly connected to the water vapor delivery pipe 110 on the opposite sides, and the surfaces of the two baffles 111 are provided with connecting holes 113 and fixing grooves 114, and the inner cavities of the two fixing grooves 114 are plugged with glue outlet sealing plates 115 matching the glue outlet 109, and the glue outlet sealing plates 115 ensure that the gel storage tube 108 is closed when no thermal runaway behavior occurs. 8 has good sealing performance to prevent powder from overflowing, and the gel outlet 109 is set at the top to prevent gel powder from overflowing when the lithium battery encounters external pressure. The inner cavity of the gel storage tube 108 is fixedly connected with a left-right symmetrical fan-shaped matching piece 112, and the fan-shaped matching piece 112 and the connecting hole 113 match. When thermal runaway does not occur, the fan-shaped matching piece 112 blocks the surface of the connecting hole 113, so that the connection port of the gel storage tube 108 and the water vapor delivery pipe 110 can be sealed. The gel powder in the gel storage tube 108 can be prevented from entering the water vapor delivery tube 110, thereby blocking the water vapor delivery tube 110 and affecting the delivery of water vapor after thermal runaway occurs. The outer wall of the gel storage tube 108 is provided with a left-right symmetrical rotating mechanism; the rotating mechanism includes a meshing rack 106 and a steering gear 107, the steering gear 107 is fixedly connected to the outer wall of the gel storage tube 108, the rack 106 is fixedly connected to the outer wall of the shell 100, and the steering gear 107 is a 1 / 4 arc. After the water vapor delivery tube 110 rises with the reaction box 117, the gel storage tube 108 will also rise accordingly. During its rising process, it rotates 90° under the action of the rack 106 and the steering gear 107, so that the glue outlet 109 can be opposite to the outer wall of the shell 100, and the fan-shaped matching piece 112 and the connecting hole 113 are staggered, so that water vapor can enter the gel storage tube 108 and mix with the gel powder inside it to achieve gel coating.

[0048] As an embodiment of the present invention, refer to Figures 2 to 4A sliding groove 118 is provided inside the reaction box 117, and the height of the sliding groove 118 is 1.5-2 times of the lifting plate 119. The lifting plate 119 is located in the middle of the inner cavity of the reaction box 117 and has an air inlet 128. When thermal runaway occurs, the gas can enter the reaction box 117 through the air inlet 128 after the lifting plate 119 rises to the top of the sliding groove 118 and complete the neutralization reaction. When thermal runaway does not occur, the lifting plate 119 is at the bottom of the sliding groove 118 to ensure The sealing of the lithium battery is improved; a multi-stage telescopic plate 124 is fixedly connected to the bottom of the reaction box 117, the multi-stage telescopic plate 124 is set in a "U" shape, the outer wall of the guide plate 116 is provided with a slide groove matching the multi-stage telescopic plate 124, the outer wall of the guide plate 116 is provided with a penetrating guide groove 125, and the middle of the lifting plate 119 is located in the inner cavity of the guide groove 125; the multi-stage telescopic plate 124 is used to seal the guide groove 125 that leaks out after the reaction box 117 rises, so as to avoid the gas overflow caused by thermal runaway behavior.

[0049] As an embodiment of the present invention, refer to Figures 3 to 6 The top of the reaction box 117 is fixedly connected with a conveying channel 120, and the top of the conveying channel 120 is fixedly connected with a reactant storage box 121. The conveying channel 120 is made of a telescopic hose material, specifically an aluminum foil telescopic hose, and the reaction box 117 and the reactant are set separately, so as to avoid the reaction box 117 carrying a sufficient amount of reactants from being too heavy and affecting its upward movement. An automatic feeding mechanism is set on the inner wall of the guide plate 116; the automatic feeding mechanism includes a transmission wheel 122, a transmission belt 123 and a guide gear 126, the transmission wheel 122 is rotatably connected to the inner wall of the guide plate 116 and is symmetrically arranged up and down, the transmission belt 123 is sleeved on the outer walls of the two transmission wheels 122, the guide gear 126 is fixedly connected to the top transmission wheel 122, and the right side of the transmission belt 123 is fixedly connected to the lifting plate 119. As the lifting plate 119 rises, the transmission belt 123 connected thereto is The right side of the belt 123 also rises, thereby driving the transmission wheel 122 to rotate, and the guide gear 126 connected to the top transmission wheel 122 also rotates, and the reaction material in the reactant storage box 121 is pushed into the reaction box 117 through the conveying channel 120. The reactant here specifically uses CaO and CuO powder. CaO can react with CO2 to generate CaCO3 and H2O, and CuO can react with H2 to generate Cu and H2O. Therefore, a large amount of water vapor can be mixed with the gel powder in the gel storage tube 108; a discharge port 127 matching the guide gear 126 is provided at the bottom of the reactant storage box 121. The teeth of the guide gear 126 are obliquely set with an inclination angle of 20°-30°; this setting can control the amount of reaction material pushed each time, to avoid excessive material pushing resulting in excessive reactants in the reaction box 117, affecting movement.

[0050] As an embodiment of the present invention, refer to Figure 7 , 8 A protective strip 102 is fixedly connected to the top of the outer wall of the shell 100. There is a certain gap between the protective strip 102 and the outer wall of the shell 100. The inner wall of the protective strip 102 is hollow, and the outer wall of the protective strip 102 is provided with ventilation holes 103 that penetrate and are evenly distributed. By utilizing the narrow tube effect, the wind force is concentrated through the ventilation holes 103 and flows through the outer wall of the shell 100, thereby dissipating the heat when the lithium battery is working normally.

[0051] Working principle: This solution prevents lithium battery bulging and damage by neutralizing the gas generated by thermal runaway to reduce the pressure and absorb the runaway heat, thereby preventing the leakage of lithium battery positive electrode slurry. The specific method is as follows:

[0052] The lithium battery equipped with the leakproof structure is used in electric vehicles, and its placement position is the four corners of the lithium battery pack and the weak stress point. When the lithium battery is not squeezed and used normally, the ventilation holes 103 opened on the outer wall of the protection strip 102 will concentrate the wind force entering the lithium battery pack, and use the narrow tube effect to guide the concentrated wind force to the outer wall of the shell 100, thereby improving the heat dissipation efficiency of the lithium battery pack;

[0053] After the lithium battery is squeezed, thermal runaway occurs inside it, thereby generating a large amount of H2, CO2 and a small amount of C3H6, CO, CH4, C2H4, C2H6 and HF gases. These gases will enter the closed space composed of the isolation plate 105 and the guide plate 116 through the one-way valve of the one-way outlet 129. As the gas continues to enter, the gas pressure increases, pushing up the lifting plate 119. When it moves to the uppermost end of the sliding groove 118, the lowermost end of the sliding groove 118 is connected to the space filled with gas, so that the gas enters the reaction box 117, and When the lifting plate 119 rises, the right side of the transmission belt 123 connected thereto also rises, thereby driving the transmission wheel 122 to rotate, and the guide gear 126 connected to the top transmission wheel 122 also rotates accordingly, so that the reaction substances CaO and CuO powder in the reactant storage box 121 enter the reaction box 117 through the conveying channel 120, CaO can react with CO2 to generate CaCO3 and H2O, CuO can react with H2 to generate Cu and H2O, and a large amount of water vapor enters the water vapor conveying pipe 110 connected to the reaction box 117;

[0054] As the lifting plate 119 rises, the reaction box 117, the water vapor delivery tube 110 and the gel storage tube 108 are pushed upward, and the gel storage tube 108 rotates 90 degrees under the action of the steering gear 107 and the rack 106. At this time, the glue outlet 109 rotates to face the outer wall of the shell 100 and disengages the glue outlet sealing plate 115 limited by the blocking piece 111. At the same time, the fan-shaped matching piece 112 is also staggered with the connecting hole 113 as it rotates, and the water vapor entering the water vapor delivery tube 110 enters the gel storage tube 108 along the connecting hole 113 and mixes with the gel powder inside. As the mixing, the gel powder becomes a semi-solid gel, and the volume continues to increase, and then overflows from the glue outlet 109, and is coated on the shell 100 as the gel storage tube 108 rises, thereby absorbing the heat of the lithium battery, completing its heat dissipation, and avoiding continuous heat increase, which causes the thermal runaway behavior to intensify.

[0055] See also Figures 1 to 8 The present invention provides a method for preventing leakage of a positive electrode slurry leakage-proof structure of a lithium battery, comprising the following steps:

[0056] S1: Gas neutralization: After the lithium battery in the outer ring is squeezed, thermal runaway occurs, thereby generating a large amount of gas. These gases enter the closed space composed of the isolation plate 105 and the guide plate 116 through the one-way valve of the one-way air outlet 129. As the gas continues to enter, the air pressure increases, pushing the lifting plate 119 up. When it moves to the uppermost end of the sliding groove 118, the lowermost end of the sliding groove 118 is connected to the space filled with gas, so that the gas enters the reaction box 117. While the lifting plate 119 rises, the right side of the transmission belt 123 connected to it also rises, thereby driving the transmission wheel 122 to rotate, and the guide gear 126 connected to the top transmission wheel 122 also rotates, thereby allowing the reactants in the reactant storage box 121 to enter the reaction box 117 through the conveying channel 120. At this time, the gas entering the reaction box 117 will react chemically with these reactants, thereby neutralizing the gas;

[0057] S2: Gel heat dissipation: Based on the above step S1, when the lifting plate 119 moves up, the reaction box 117 is pushed up, and the water vapor delivery pipe 110 and the gel storage tube 108 connected to the reaction box 117 are also moved up. When the gel storage tube 108 moves up, the steering gear 107 on its outer wall is engaged with the rack 106 on the surface of the shell 100, so that the steering gear 107 can drive the gel storage tube 108 to rotate 90 degrees. At this time, the glue outlet closing plate 115 is blocked by the baffles 111 on both sides. The limiter remains stationary, and the glue outlet 109 rotates to face the outer wall of the shell 100, and the fan-shaped matching piece 112 is also staggered with the connecting hole 113 as it rotates; therefore, a large amount of water vapor released after the gas is neutralized will enter the gel storage tube 108 through the water vapor delivery pipe 110, and mix with the gel powder in the gel storage tube 108, so that the gel powder becomes a semi-solid gel, and the gel will overflow as it mixes, and thus as the gel storage tube 108 rises, it is coated on the surface of the shell 100 to absorb heat from the lithium battery in thermal runaway.

[0058] The main advantages and working principles of the embodiments of the present invention have been explained above. Then, as a person skilled in the art, it should be understood that the above embodiments are not intended to be limiting conditions of the present invention. Various changes, modifications, substitutions and variations may be made without departing from the principles, spirit and scope of the invention. These changes, modifications, substitutions and variations should all fall within the scope of protection of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A lithium battery positive electrode slurry leakage prevention structure, used in conjunction with a housing (100) and a battery cell group (104), characterized in that: The invention comprises a sliding channel (101), an isolation sheet (105), a gel storage tube (108), a water vapor transport tube (110), a guide plate (116), a reaction box (117), a lifting plate (119) and a one-way air outlet (129), wherein the isolation sheet (105) and the guide plate (116) are located at the four corners of the inner cavity of the housing (100), the one-way air outlet (129) is opened at the bottom of the outer wall of the isolation sheet (105), a one-way valve is arranged in the inner cavity of the one-way air outlet (129), the lifting plate (119) is slidably connected to the outer wall of the isolation sheet (105), and the reaction box (117) is slidably connected to the outer wall of the reaction box (117). The outer end of the lifting plate (119) is located in the inner cavity of the reaction box (117); the sliding channel (101) is opened at the four corners of the outer wall of the shell (100); one end of the water vapor transport pipe (110) is located in the inner cavity of the sliding channel (101) and is fixedly connected to the reaction box (117); the gel storage tube (108) is located on the outer wall of the shell (100) and is connected to the water vapor transport pipe (110); and the water vapor transport pipe (110) and the gel storage tube (108) are connected and surround the outer wall of the shell (100).

2. The lithium battery positive electrode slurry leakage prevention structure according to claim 1, characterized in that: The outer wall of the gel storage tube (108) is provided with a glue outlet (109), and baffles (111) are rotatably connected at both ends of the gel storage tube (108). The two baffles (111) are fixedly connected to the water vapor transport tube (110) at opposite sides, and the surfaces of the two baffles (111) are provided with communication holes (113) and fixed grooves (114). The inner cavities of the two fixed grooves (114) are provided with glue outlet sealing plates (115) matching the glue outlet (109). The inner cavity of the gel storage tube (108) is fixedly connected with a left-right symmetrical fan-shaped matching piece (112), and the fan-shaped matching piece (112) matches the communication hole (113). The outer wall of the gel storage tube (108) is provided with a left-right symmetrical rotation mechanism.

3. A lithium battery positive electrode slurry leakage prevention structure according to claim 2, characterized in that: The rotating mechanism comprises a meshing rack (106) and a steering gear (107), wherein the steering gear (107) is fixedly connected to the outer wall of the gel storage tube (108), the rack (106) is fixedly connected to the outer wall of the housing (100), and the steering gear (107) is a 1 / 4 arc.

4. The lithium battery positive electrode slurry leakage prevention structure according to claim 1, characterized in that: A sliding groove (118) is provided inside the reaction box (117), and the height of the sliding groove (118) is 1.5-2 times that of the lifting plate (119). The lifting plate (119) is provided with an air inlet (128) in the middle of the inner cavity of the reaction box (117).

5. A lithium battery positive electrode slurry leakage prevention structure according to claim 4, characterized in that: The bottom of the reaction box (117) is fixedly connected to a multi-stage telescopic plate (124), the multi-stage telescopic plate (124) is set in a "U" shape, the outer wall of the guide plate (116) is provided with a sliding groove matching the multi-stage telescopic plate (124), the outer wall of the guide plate (116) is provided with a penetrating guide groove (125), and the middle part of the lifting plate (119) is located in the inner cavity of the guide groove (125).

6. A lithium battery positive electrode slurry leakage prevention structure according to claim 5, characterized in that: The top of the reaction box (117) is fixedly connected to a delivery channel (120), the top of the delivery channel (120) is fixedly connected to a reactant storage box (121), the delivery channel (120) is made of a telescopic hose, and the inner wall of the guide plate (116) is provided with an automatic feeding mechanism.

7. A lithium battery positive electrode slurry leakage prevention structure according to claim 6, characterized in that: The automatic feeding mechanism comprises a transmission wheel (122), a transmission belt (123) and a guide gear (126); the transmission wheel (122) is rotatably connected to the inner wall of the guide plate (116) and is symmetrically arranged in an upper and lower manner; the transmission belt (123) is sleeved on the outer walls of the two transmission wheels (122); the guide gear (126) is fixedly connected to the top of the transmission wheel (122); and the right side of the transmission belt (123) is fixedly connected to the lifting plate (119).

8. The lithium battery positive electrode slurry leakage prevention structure according to claim 7, characterized in that: The bottom of the reactant storage box (121) is provided with a discharge port (127) matching the guide gear (126), and the gears of the guide gear (126) are arranged obliquely, with an inclination angle of 20°-30°.

9. The lithium battery positive electrode slurry leakage prevention structure according to claim 1, characterized in that: A protective strip (102) is arranged at the top of the outer wall of the shell (100), the inner wall of the protective strip (102) is hollow, and the outer wall of the protective strip (102) is provided with ventilation holes (103) that penetrate and are evenly distributed.

10. A leakage prevention method applicable to the lithium battery positive electrode slurry leakage prevention structure according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1: Gas neutralization: After the lithium battery in the outer ring is squeezed, thermal runaway occurs, and a large amount of gas generated enters the closed space composed of the isolation plate (105) and the guide plate (116) through the one-way valve. The continuously entering gas pushes up the lifting plate (119). When it moves to the uppermost end of the sliding groove (118), the lowermost end of the sliding groove (118) is connected to the space filled with gas, and the gas enters the reaction box (117). When the lifting plate (119) rises, the right side of the transmission belt (123) connected to it also rises, thereby causing the transmission wheel (122) to rotate, and the guide gear (126) connected to the top transmission wheel (122) also rotates, thereby causing the reaction material in the reactant storage box (121) to enter the reaction box (117) through the conveying channel (120) and react chemically with the gas in the reaction box (117), thereby neutralizing the gas; S2: Gel heat dissipation: Based on the above step S1, when the lifting plate (119) moves upward, the reaction box (117), the water vapor delivery pipe (110) and the gel storage tube (108) are also driven to move upward. Since the steering gear (107) on the outer wall of the gel storage tube (108) and the rack (106) on the surface of the shell (100) are meshed, the steering gear (107) can drive the gel storage tube (108) to rotate 90 degrees, so that the gel outlet (109) rotates to face the outer wall of the shell (100), and the fan-shaped matching piece (112) is also staggered with the connecting hole (113) as it rotates; a large amount of water vapor released after the gas is neutralized will enter the gel storage tube (108) through the water vapor delivery pipe (110), mix with the gel powder in the gel storage tube (108) and overflow, and thus, as the gel storage tube (108) rises, it is coated on the surface of the shell (100) to absorb heat from the thermal runaway lithium battery.

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