Pouch lithium battery and battery module

Abstract

The application provides a soft package lithium battery and a battery module, the soft package lithium battery comprises a packaged battery and a protective shell, the packaged battery comprises a battery core and a packaging film, the packaging film is wrapped on the outer side of the battery core, and the packaging film has a packaging edge; the protective shell comprises oppositely arranged first and second shell bodies, the first and second shell bodies are connected, the first and second shell bodies are spliced to form a containing cavity, a pressure relief port is arranged at the connecting position of the first and second shell bodies, the pressure relief port is communicated with the containing cavity and the outside of the protective shell, the packaged battery is arranged in the containing cavity, and at least part of the packaging edge is arranged at the pressure relief port; the soft package lithium battery and the battery module can realize safe pressure relief when the pressure in the battery core is abnormal, and the safety and reliability of the battery system are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium batteries, in particular to a soft package lithium battery and a battery module. BACKGROUND

[0002] The soft package lithium battery is usually wrapped with a multi-layer packaging film, such as an aluminum-plastic composite film, to achieve good sealing and certain mechanical strength, and to protect the internal structure of the battery from the external environment. However, the unique structure of the soft package lithium battery packaging structure makes it impossible to install a pressure relief device, so that the high-pressure gas and high-temperature substances inside the battery may be ejected in an uncontrolled manner, not only intensifying the risk of battery heat spread, but also increasing the difficulty of accident handling and subsequent rescue. SUMMARY

[0003] The present application is based on the inventors' discovery and understanding of the following facts and problems:

[0004] In the manufacturing process of the soft package lithium battery, the soft package lithium battery is usually wrapped with a packaging structure, and a weak sealing area is provided on the packaging structure, so that the strength of the weak sealing area is designed to be lower than that of the normal sealing edge area, so that directional explosion can be realized in this area when the internal pressure of the battery reaches the preset safety threshold, thereby releasing the internal pressure and avoiding more serious safety accidents.

[0005] However, since the strength of the weak sealing area is intentionally reduced, it is more susceptible to external factors such as mechanical stress, temperature changes, humidity effects, etc., leading to packaging failure such as liquid leakage, gas leakage, etc. These defects not only directly affect the performance and life of the battery, but also may cause battery short circuit, thermal runaway, etc. safety problems, further increasing the risk of the battery system.

[0006] Therefore, the present application provides a soft package lithium battery, which comprises a packaging battery and a protective shell, the packaging battery comprises a battery cell and a packaging film, the packaging film is wrapped outside the battery cell, and the packaging film has a packaging edge; the protective shell comprises a first shell and a second shell arranged oppositely, the first shell and the second shell are connected, the first shell and the second shell are combined to form a receiving cavity, a pressure relief port is provided at the connection of the first shell and the second shell, the pressure relief port communicates the receiving cavity and the outside of the protective shell, the packaging battery is arranged in the receiving cavity, and at least part of the packaging edge is arranged at the pressure relief port.

[0007] In summary, the soft package lithium battery provided by the present application has the advantages that by arranging the protective shell outside the packaging battery and arranging the pressure relief port at the position of the packaging edge, the sealing strength of the battery and the stability of the overall structure are ensured, and the safety pressure relief when the internal pressure of the battery cell is abnormal is realized, thereby effectively improving the safety and reliability of the battery system.

[0008] In some embodiments, the first shell comprises a first plate body and a first frame, the first plate body and the first frame enclosing a first recess, the second shell covering the first recess to form the accommodating cavity, and the pressure relief port being provided on the first frame.

[0009] In some embodiments, the second shell further comprises a second plate body and a second frame, the second plate body and the second frame enclosing a second recess, the first recess and the second recess combining to form the accommodating cavity, the first plate body and the second plate body being oppositely arranged, the first frame and the second frame being connected, the first frame and the second frame each being provided with a slot to be combined to form the pressure relief port, and the packaging edge being provided between the first frame and the second frame.

[0010] In some embodiments, the soft-pack lithium battery further comprises an aerogel layer, the aerogel layer being arranged in close contact with the first plate body and the second plate body, the aerogel layer having an extension, and the extension being provided in the pressure relief port.

[0011] In some embodiments, the thickness of the aerogel layer satisfies the following formula:

[0012] and y≥1;

[0013] In the formula, y is the thickness of the aerogel layer, x is the thickness of the battery cell in the full charge state, and m is the thickness of the battery cell in the discharge state.

[0014] In some embodiments, the distance from the edge of the extension to the battery cell is 3-100 mm.

[0015] In some embodiments, the width of the first frame and the second frame satisfies the following formula:

[0016] A=115%(X+0.5y-2Z)±2;

[0017] In the formula, A is the width of the first frame or the second frame, x is the thickness of the soft-pack battery cell in the full charge state, y is the thickness of the aerogel layer, and z is the thickness of the packaging film.

[0018] In some embodiments, the aerogel layer is made of one or more of silica, expanded perlite, calcium silicate, and rock wool.

[0019] In some embodiments, the first frame and the second frame each have oppositely arranged first and second side walls, and a plurality of pressure relief ports are provided on the first and second side walls, respectively.

[0020] And / or, the width of the packaging edge is greater than 3mm;

[0021] And / or, the packaging film is made of thermoplastic polyester material or polyethylene material, and the packaging film has a back adhesive layer.

[0022] In some embodiments, the length of the pressure relief port satisfies the following formula:

[0023]

[0024] In the formula, e is a natural constant; V is the volume of the battery cell, in mm 3 ; W is the packaging width of the battery cell, in mm; L is the length of the opening, in mm; Q is the capacity of the battery cell, in Ah; and P is the burst pressure, which is set to 0.2-0.9 MPa.

[0025] In addition, an embodiment of the present application also provides a battery module, which comprises a plurality of soft-pack lithium batteries provided by any of the above embodiments, the soft-pack lithium batteries are arranged in adhesion, the first shell of one of the two adjacent soft-pack lithium batteries is arranged opposite to the second shell of the other soft-pack lithium battery, and the first shell of one of the two adjacent soft-pack lithium batteries is integrated with the second shell of the other soft-pack lithium battery. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is an explosion schematic view of the soft-pack lithium battery provided by an embodiment of the present application.

[0027] Figure 2 is a sectional view of the soft-pack lithium battery provided by an embodiment of the present application.

[0028] Figure 3 is a structural schematic view of the first shell of the soft-pack lithium battery provided by an embodiment of the present application.

[0029] Figure 4 is a structural schematic view of the battery module provided by an embodiment of the present application.

[0030] REFERENCE SIGNS:

[0031] 10, packaged battery; 11, packaging film; 111, packaging edge; 12, battery cell; 13, tab;

[0032] 20, protective shell; 21, first shell; 211, first plate body; 212, first frame; 2121, first side wall; 2122, second side wall; 213, first groove; 22, second shell; 221, second plate body; 222, second frame; 223, second groove; 23, pressure relief port; 24, aerogel layer; 241, extension; 25, placement groove. DETAILED DESCRIPTION

[0033] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0034] like Figures 1 to 3 As shown, an embodiment of the present invention provides a soft-pack lithium battery, which includes a packaged battery 10 and a protective shell 20. The packaged battery 10 includes a cell 12 and a sealing film 11. The sealing film 11 wraps around the outside of the cell 12 and has a sealing edge 111. The protective shell 20 includes a first shell 21 and a second shell 22 disposed opposite to each other. The first shell 21 and the second shell 22 are connected to each other and are joined together to form a cavity. A pressure relief port 23 is provided at the connection between the first shell 21 and the second shell 22. The pressure relief port 23 communicates with the cavity and the outside of the protective shell 20. The packaged battery 10 is disposed in the cavity, and at least part of the sealing edge 111 is disposed at the pressure relief port 23.

[0035] Specifically, the encapsulation film 11 is bonded to and wraps around the battery cell 12 to ensure the sealing and stability of the battery cell 12. Under certain temperature, pressure and time conditions, the inner layers of the encapsulation film 11 located on both sides of the battery cell 12 are bonded together by vacuum pumping or hot pressing to form an encapsulation edge 111. The first housing 21 and the second housing 22 can be located on both sides of the encapsulated battery 10, respectively, and are connected by screws, clips or adhesives to form a receiving cavity.

[0036] The pressure relief port 23 is located at the connection between the first housing 21 and the second housing 22, and at least part of the encapsulation edge 111 is located at the pressure relief port 23 during the placement of the encapsulated battery 10, enabling rapid pressure relief of the cell 12. Specifically, when abnormally high pressure is generated inside the cell 12 due to overcharging, short circuit, high temperature, or other reasons, causing the internal pressure of the cell 12 to reach a preset safety threshold, the pressure can be quickly and directionally released through the pressure relief port 23, effectively avoiding the risk of battery rupture or explosion, and greatly protecting the safety of the battery system and its surrounding environment.

[0037] In summary, the soft-pack lithium battery provided by the present invention does not require changes to the battery packaging process or the setting of a weak sealing area during the cell 12 packaging process. Instead, by setting a protective shell 20 on the outside of the packaged battery 10 and setting a pressure relief port 23 at the packaging edge 111, it not only ensures the packaging strength and overall structural stability of the battery, but also achieves safe pressure relief when the internal pressure of the cell 12 is abnormal, effectively improving the safety and reliability of the battery system.

[0038] In this embodiment, the battery cell 12 also includes tabs 13. The first housing 21 and the second housing 22 are further provided with placement grooves 25 for placing the tabs 13, ensuring that the tabs 13 can be perfectly embedded within them. This avoids potential safety hazards caused by the tabs 13 moving freely inside the battery module. It should be noted that the accompanying drawings provided in this embodiment illustrate a packaged battery with tabs at both ends. It is conceivable that the solution provided in this embodiment is also applicable to packaged batteries with tabs on the sides, and will not be described in detail here.

[0039] like Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments, the first housing 21 includes a first plate 211 and a first frame 212, the first plate 211 and the first frame 212 surround to form a first groove 213, the second housing 22 covers the first groove 213 to form an accommodating cavity, and the pressure relief port 23 is provided on the first frame 212.

[0040] The first plate 211 is arranged parallel to the battery cell 12, and the first frame 212 tightly surrounds and connects to the edge of the first plate 211, together forming a compact and functional first groove 213. The second shell 22 can cover the first groove 213, forming a receiving cavity together with the first shell 21 to accommodate the encapsulated battery 10. The pressure relief port 23 is provided on the first frame 212, which facilitates the manufacturing of the pressure relief port 23 and reduces production costs.

[0041] Furthermore, the second housing 22 also includes a second plate 221 and a second frame 222, which together form a second groove 223. That is, the first housing 21 and the second housing 22 can have the same structure, which simplifies the manufacturing process and improves assembly convenience. It should be noted that the structures of the first housing 21 and the second housing 22 are similar, and their structures can be referenced. Figure 3 .

[0042] Furthermore, the first groove 213 and the second groove 223 are combined to form a receiving cavity, the first plate 211 and the second plate 221 are arranged opposite to each other, the first frame 212 and the second frame 222 are connected, and the first frame 212 and the second frame 222 are both provided with slots to be spliced ​​to form a pressure relief port 23, and the encapsulation edge 111 is sandwiched between the first frame 212 and the second frame 222.

[0043] In the embodiment, the packaging edge 111 includes a clamping region between the first frame 212 and the second frame 222, and a pressure relief region at the pressure relief port 23. That is, the first frame 212 and the second frame 222 can achieve edge locking reinforcement on the clamping region, improve the edge locking force of the clamping region, so that the battery cell 12 can be blown and relieved through the pressure relief region when the pressure reaches the safety threshold.

[0044] Further, the width of the packaging edge 111 is greater than 3 mm, so that the effective locking pressure width of the first frame 212 and the second frame 222 on the packaging edge 111 is greater than 3 mm, which can improve the pressure resistance and deformation resistance of the packaging edge 111. If the width of the packaging edge 111 is too narrow, it may lead to insufficient locking pressure strength, which cannot effectively fix the battery cell 12 and the internal structure, and further cause safety hazards such as loosening, deformation, and even damage during battery use.

[0045] Further, the first plate body and the first frame can be integrated, and the second plate body and the second frame can be integrated, which is convenient for manufacturing. The first shell and the second shell can be made of one or a combination of ceramic silicone rubber, vulcanized silicone rubber, silicone rubber, fluorine rubber, nitrile rubber, and fluorosilicone rubber.

[0046] In some embodiments, the soft-pack lithium battery further includes an aerogel layer 24 arranged in close contact with the first plate body 211 and the second plate body 221. The aerogel layer 24 can effectively alleviate the swelling phenomenon of the battery cell 12 caused by charging and discharging during operation. In the full charge state of the battery cell 12, the volume expansion caused by internal chemical reactions may cause loosening of the connection strength of the first frame 212 and the second frame 222, while the aerogel layer 24 can effectively absorb the stress generated by the swelling of the battery cell 12, and maintain the close contact between the battery cell 12 and the shell.

[0047] Secondly, the volume of the battery cell 12 will decrease during discharging, and if there is not enough support, it may cause the close contact between the battery cell 12 and the first plate body 211 and the second plate body 221 to be not tight enough, while the aerogel layer 24 can provide the necessary support when the battery cell 12 is discharged, and maintain the close contact between the battery cell 12 and the shell, thereby ensuring the stable operation of the battery and the long-term durability of the battery cell 12.

[0048] Further, the aerogel layer 24 has an extension 241 arranged in the pressure relief port 23, which can guide the fluid burst during the pressure relief of the battery cell 12, effectively alleviate the heat spread of the battery cell 12, and avoid causing the heat runaway of the adjacent battery cell 12. That is, when the battery cell 12 is relieved, the fluid burst will first contact the extension 241 of the aerogel layer 24, which can guide the fluid to burst along a specific path, avoid directly impacting the battery shell and the surrounding components, and prevent the fluid from spreading inside the battery pack, effectively suppressing the heat spread between the battery cells 12.

[0049] Further, the distance from the edge of the extension 241 to the battery cell 12 is 3-100 mm, which not only ensures that the extension 241 can effectively guide the fluid during the pressure relief of the battery cell 12, prevent it from directly impacting the battery cell 12, but also suppress the heat spread at the critical moment, and avoid the heat runaway of the adjacent battery cell 12.

[0050] In some embodiments, the thickness of the aerogel layer 24 satisfies the following formula:

[0051] And y≥1;

[0052] In the formula, y is the thickness of the aerogel layer 24, x is the thickness of the battery cell 12 in the full state, and m is the thickness of the battery cell 12 in the depleted state.

[0053] That is, the thickness of the aerogel layer 24 is set to be greater than 40% of the difference between the thickness of the battery cell 12 in the full state and the thickness of the battery cell 12 in the depleted state, and is allowed to float up and down by 2 mm, which not only can ensure that the aerogel layer 24 effectively alleviates the expansion pressure when the battery cell 12 is full, prevents the adhesion between the battery cell 12 and the shell from being reduced, but also can provide sufficient support when the battery cell 12 is depleted, and maintain the close contact between the battery cell 12 and the shell. At the same time, the design of allowing the thickness to float up and down by 2 mm provides greater flexibility for tolerance control and material selection in the manufacturing process, ensuring the consistency and reliability of the battery product.

[0054] In some embodiments, the battery cell 12 has a length direction, a width direction, and a thickness direction, and the width direction of the first and second side frames 212 and 222 is consistent with the width direction of the battery cell 12. The width of the first and second side frames 212 and 222 satisfies the following formula:

[0055] A=115%(X+0.5y-2Z)±2;

[0056] In the formula, A is the width of the first or second side frame 212 or 222, x is the thickness of the battery cell 12 in the full state, y is the thickness of the aerogel layer 24, and z is the thickness of the packaging film 11.

[0057] Specifically, the thickness of the battery cell 12 in the full state, the thickness of the aerogel layer 24, and the thickness of the encapsulation film 11, these three key parameters together determine the width of the first and second frames 212 and 222.

[0058] First, since the battery cell 12 will change in volume during charging and discharging, especially in the full state, its thickness will reach a maximum value. Therefore, when designing the width of the first and second frames 212 and 222, the thickness of the battery cell 12 in the full state must be fully considered to ensure that the battery can still maintain stable structure and performance when fully charged.

[0059] Second, the aerogel layer 24 not only effectively relieves the pressure caused by the expansion of the battery cell 12, but also provides the necessary support when the battery cell 12 is discharged. Therefore, when determining the width of the first and second frames 212 and 222, the thickness of the aerogel layer 24 must be considered to avoid excessive occupation of the width of the first and second frames 212 and 222.

[0060] Third, the encapsulation film 11 is used to encapsulate the battery cell 12 in the battery shell. Therefore, when determining the width of the first and second frames 212 and 222, the thickness of the encapsulation film 11 must also be considered to ensure that it can closely fit the frame and form an effective encapsulation structure.

[0061] As shown in Figure 1 , Figure 2 In some embodiments, the length of the pressure relief port 23 is consistent with the length of the battery cell 12, and the length of the pressure relief port 23 will affect the burst pressure during the pressure relief process, minimizing the risk of the battery cell 12 under abnormal pressure and avoiding the spread of heat. The length of the pressure relief port 23 satisfies the following formula:

[0062]

[0063] In the formula, e is the natural constant; V is the volume of the battery cell 12, in mm 3 ; W is the encapsulation width of the battery cell 12, in mm; L is the length of the opening, in mm; Q is the capacity of the battery cell 12, in Ah; and P is the burst pressure, which is set to 0.2-0.9 MPa.

[0064] As shown in Figure 2 and Figure 3As shown, in some embodiments, the first frame 212 may include a first sidewall 2121 and a second sidewall 2122 disposed opposite to each other. Multiple pressure relief ports 23 are provided, each located on the first sidewall 2121 and the second sidewall 2122. This ensures that if an abnormality occurs on either side of the battery cell 12, a corresponding pressure relief port 23 can promptly release the internal pressure, thereby minimizing safety risks. Simultaneously, this distribution method also makes the opening of the pressure relief ports 23 more uniform, avoiding battery performance degradation or damage caused by uneven pressure distribution.

[0065] Of course, in other embodiments, multiple pressure relief ports 23 can also be spaced apart along the length of the battery cell 12, which can ensure that when an abnormality occurs at any position of the battery cell 12 in the length direction, there is a corresponding pressure relief port 23 that can respond in time and release the internal pressure. At the same time, since there is a certain distance between the pressure relief ports 23, they will not interfere with each other, thus ensuring the independence and effectiveness of the pressure relief ports 23.

[0066] In some embodiments, the encapsulation film 11 is made of thermoplastic polyester or polyethylene material, which not only ensures the reliability and stability of the encapsulation film 11 during the battery encapsulation process, but also meets the comprehensive requirements of the battery for the encapsulation material in terms of strength, heat resistance, and cost. The encapsulation film 11 has an adhesive backing layer, which can be firmly bonded to the aerogel layer 24, thereby achieving a tight fit between the encapsulation film 11 and the aerogel layer 24.

[0067] Furthermore, the thickness of the encapsulation film 11 can be set to 0.05 mm to 0.2 mm.

[0068] It should be noted that the thermal conductivity of the aerogel layer 24 should be less than or equal to 0.05 W / (m·K). The aerogel layer 24 should have a suitable compressive stress characteristic curve. For example, when the stress is 0.5 MPa, the strain is 20% ± 5%; when the stress is 1 MPa, the strain is 35% ± 5%; and when the stress is 1.5 MPa, the strain is 40% ± 5%.

[0069] like Figure 4 As shown, one embodiment of the present invention also provides a battery module, which includes the pouch lithium battery provided in the above embodiment. Multiple pouch lithium batteries are arranged in a close-fitting manner. The first housing 21 of one of two adjacent pouch lithium batteries and the second housing 22 of the other are positioned opposite to each other, and the first housing 21 of one of two adjacent pouch lithium batteries and the second housing 22 of the other are integrally formed. That is, a groove is provided on the side of the first housing 21 and the second housing 22 opposite to the cell 12, which facilitates the placement of another cell 12, thereby making the overall structure more compact.

[0070] Wherein, the soft package lithium battery forms a clever complementary relationship between the two adjacent batteries. Wherein, the first shell 21 of one is arranged opposite to the second shell 22 of the other, not only to ensure the maximum use of space between the batteries, but also to avoid performance degradation or safety hazards caused by improper arrangement of the battery. At the same time, this opposite arrangement makes the battery module perform well in heat dissipation, shockproof and impact resistance, further improving the overall performance and reliability of the battery module.

[0071] And, the first shell 21 of one of the two adjacent soft package lithium batteries and the second shell 22 of the other are cleverly designed as a whole, not only simplifying the production process of the battery module and reducing the manufacturing cost, but also making the battery module more compact and stable in structure. This integrated design not only improves the structural strength of the battery module, but also makes the battery module more convenient and safe during transportation, installation and use.

[0072] In the assembly process of the battery module, the first shell 21 can be placed on the working surface, the aerogel layer 24 is applied on the first shell 21, and then the encapsulated battery 10 is placed in the first groove 213 of the first shell 21. Then, the second shell 22 is buckled on the first shell 21, thus completing the assembly of one battery cell 12. In the subsequent assembly process, the worker can repeat the above steps to assemble the battery cells 12 one by one into the battery module until the number of battery cells 12 fully meets the design requirements of the battery module.

[0073] It should be noted that according to the expansion characteristics of the battery cell 12, the strain of the protective shell 20 and the strain of the aerogel layer 24 are within a suitable range, for example: when the state of charge of the battery cell 12 is 100% SOC (state of charge), the strain of the protective shell 20 is 3%~5%, and the strain of the aerogel layer 24 is 35%~50%; when the state of charge is 50% SOC, the strain of the protective shell 20 is 5%~15%, and the strain of the aerogel layer 24 is 25%~40%; when the state of charge is 30% SOC, the strain of the protective shell 20 is 10%~20%, and the strain of the aerogel layer 24 is 20%~30%. SOC is

[0074] In addition, the battery module provided by the embodiment of the application has the same implementation principle and technical effects as the aforementioned soft package lithium battery, and for brevity of description, the parts not mentioned in this embodiment can be referred to the corresponding contents in the aforementioned soft package lithium battery.

[0075] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0076] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0077] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or communicate with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0078] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0079] In this disclosure, the terms "an embodiment", "some embodiments", or the like, mean that the particular feature, structure, material, or characteristic following the term is included in at least one embodiment or example of the present application. The illustrative examples of the application should not be construed as being limiting in any manner. In the description of the present application, the illustrative examples can have been presented for illustrative purposes only and are not intended to limit the scope of the application. Furthermore, the described features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Moreover, the terms "first", "second", and the like can be understood as having arbitrary numbers that do not necessarily indicate an order or a sequence. Moreover, the terms "comprises", "comprising", or the like, can be understood to encompass the cases where the stated feature or features are included but do not constitute an entire set of essential features of the application or a corresponding example or embodiment thereof.

[0080] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that variations, modifications, substitutions, and changes can be made by those skilled in the art without departing from the scope of the present application.

Claims

1. A pouch lithium battery, characterized by, The soft package lithium battery comprises a packaged battery and a protective shell, the packaged battery comprises a battery core and a packaging film, the packaging film is wrapped outside the battery core, and the packaging film has a packaging edge; the protective shell comprises oppositely arranged first and second shells, the first and second shells are connected, the first and second shells are combined to form a containing cavity, a pressure relief port is arranged at the connection of the first and second shells, the pressure relief port communicates the containing cavity and the outside of the protective shell, and the packaged battery is arranged in the containing cavity; at least part of the packaging edge is arranged at the pressure relief port. The length of the pressure relief port satisfies the following formula: In the formula, e is a natural constant; V is the volume of the battery cell, in mm 3 W is the width of the battery cell package, in mm; L is the length of the opening, in mm; Q is the capacity of the battery cell, in Ah; and P is the burst pressure, which is set to 0.2 Mpa to 0.9 Mpa.

2. The pouch lithium battery of claim 1, wherein, The first shell comprises a first plate body and a first frame, the first plate body and the first frame form a first groove, the second shell covers the first groove to form the containing cavity, and the pressure relief port is arranged on the first frame.

3. The pouch lithium battery of claim 2, wherein, The second shell further comprises a second plate body and a second frame, the second plate body and the second frame form a second groove, the first groove and the second groove combine to form the containing cavity, the first plate body and the second plate body are oppositely arranged, the first frame and the second frame are connected, and the first frame and the second frame are both provided with a slot to combine to form the pressure relief port, and the packaging edge is clamped between the first frame and the second frame.

4. The pouch lithium battery of claim 3, wherein, The soft package lithium battery further comprises an aerogel layer, the aerogel layer is arranged in close contact with the first plate body and the second plate body, the aerogel layer has an extension, and the extension is arranged in the pressure relief port.

5. The pouch lithium battery of claim 4, wherein, The thickness of the aerogel layer satisfies the following formula: In the formula, y is the thickness of the aerogel layer, x is the thickness of the battery core in the full charge state, and m is the thickness of the battery core in the discharge state. And / or, the distance from the edge of the extension to the battery core is 3-100 mm.

6. The pouch lithium battery of claim 4, wherein, The width of the first frame and the second frame satisfies the following formula: A = 115% (X + 0.5y - 2Z) ± 2; In the formula, A is the width of the first frame or the second frame, x is the thickness of the soft package battery core in the full charge state, y is the thickness of the aerogel layer, and z is the thickness of the packaging film.

7. The pouch lithium battery of claim 4, wherein, The aerogel layer is made of one or more of silica, expanded perlite, calcium silicate and rock wool.

8. The pouch lithium battery of claim 3, wherein, The first frame and the second frame both have oppositely arranged first and second side walls, and the pressure relief port is provided with a plurality of pressure relief ports, and the plurality of pressure relief ports are arranged on the first and second side walls, respectively. And / or, the width of the packaging edge is greater than 3 mm. And / or, the packaging film is made of a thermoplastic polyester material or a polyethylene material, and the packaging film has a back adhesive layer.

9. A battery module, characterized by The soft package lithium battery comprises a packaged battery and a protective shell, the packaged battery comprises a battery core and a packaging film, the packaging film is wrapped outside the battery core, and the packaging film has a packaging edge; the protective shell comprises oppositely arranged first and second shells, the first and second shells are connected, the first and second shells are combined to form a containing cavity, a pressure relief port is arranged at the connection of the first and second shells, the pressure relief port communicates the containing cavity and the outside of the protective shell, and the packaged battery is arranged in the containing cavity; at least part of the packaging edge is arranged at the pressure relief port.

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