Soft package lithium battery and battery module

Abstract

The invention provides a soft package lithium battery and a battery module, the soft package lithium battery comprises a packaging battery and a protective shell, the packaging battery comprises a battery cell and a packaging film, the packaging film wraps the outer side of the battery cell, and the packaging film is provided with a packaging edge; the protective shell comprises a first shell body and a second shell body which are oppositely arranged, the first shell body and the second shell body are connected, the first shell body and the second shell body are spliced to form a containing cavity, a pressure relief opening is formed in the connecting position of the first shell body and the second shell body, the pressure relief opening is communicated with the containing cavity and the outer side of the protective shell, and the packaged battery is arranged in the containing cavity. And at least part of the packaging edge is arranged at the pressure relief opening. According to the soft package lithium battery and the battery module, safe pressure relief can be realized when the internal pressure of the battery cell is abnormal, and the safety and reliability of a battery system are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a soft-pack lithium battery and a battery module. Background Art

[0002] Soft-pack lithium batteries are usually wrapped with multi-layer packaging films, such as aluminum-plastic composite films, to achieve good sealing and certain mechanical strength, and protect the internal structure of the battery from the external environment. However, the uniqueness of the packaging structure of soft-pack lithium batteries 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, which will not only increase the risk of thermal spread of the battery, but also increase the difficulty of accident handling and subsequent rescue. Summary of the invention

[0003] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

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

[0005] However, since the strength of the weak seal area is deliberately reduced, it is more susceptible to interference from external factors (such as mechanical stress, temperature changes, humidity, etc.), resulting in packaging failures such as leakage, gas leakage and other serious defects. These defects not only directly affect the performance and life of the battery, but may also cause safety problems such as battery short circuit and thermal runaway, further increasing the risk of the battery system.

[0006] To this end, an embodiment of the present invention provides a soft-pack lithium battery, which includes: a packaged battery and a protective shell, the packaged battery includes a battery cell and a packaging film, the packaging film is wrapped around the outside of the battery cell, and the packaging film has a packaging edge; the protective shell includes a first shell and a second shell that are relatively arranged, the first shell and the second shell are connected, the first shell and the second shell are assembled to form a accommodating cavity, a pressure relief port is provided at the connection between the first shell and the second shell, the pressure relief port communicates the accommodating cavity and the outside of the protective shell, the packaged battery is arranged in the accommodating cavity, and at least part of the packaging edge is arranged at the pressure relief port.

[0007] In summary, the soft-pack lithium battery provided in the embodiment of the present invention, by providing a protective shell on the outside of the packaged battery and providing a pressure relief port at the edge of the package, not only ensures the packaging strength of the battery and the stability of the overall structure, but also realizes safe pressure relief when the internal pressure of the battery cell is abnormal, thereby effectively improving the safety and reliability of the battery system.

[0008] In some embodiments, the first shell includes a first plate body and a first frame, the first plate body and the first frame are combined to form a first groove, the second shell covers the first groove to form the accommodating cavity, and the pressure relief port is provided on the first frame.

[0009] In some embodiments, the second shell also includes a second plate body and a second frame, the second plate body and the second frame are combined to form a second groove, the first groove and the second groove are combined to form the accommodating cavity, the first plate body and the second plate body are arranged opposite to each other, the first frame and the second frame are connected, the first frame and the second frame are both provided with grooves to be assembled to form the pressure relief port, and the packaging edge is clamped between the first frame and the second frame.

[0010] In some embodiments, the soft-pack lithium battery further includes an aerogel layer, the aerogel layer is arranged in contact with the first plate body and the second plate body, the aerogel layer has an extension portion, and the extension portion is arranged in the pressure relief port.

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

[0012] And y ≥ 1;

[0013] Where: y is the thickness of the aerogel layer; x is the thickness of the battery cell in a fully charged state; m is the thickness of the battery cell in a depleted state;

[0014] And / or, the distance from the edge of the extension portion to the battery core is set to 3 mm to 100 mm.

[0015] In some embodiments, the widths of the first border and the second border both satisfy the following formula:

[0016] A = 115% (X + 0.5y - 2Z) ± 2;

[0017] Wherein: A is the width of the first frame or the second frame; x is the thickness of the soft-pack battery cell in a fully charged 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 combinations of silicon dioxide, expanded perlite, calcium silicate, and rock wool.

[0019] In some embodiments, the first frame and the second frame both have a first side wall and a second side wall that are oppositely disposed, and a plurality of pressure relief openings are provided, and the plurality of pressure relief openings are respectively disposed on the first side wall and the second side wall;

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

[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] Where: e is the natural constant; V is the cell volume, in mm 3 ; W is the width of the battery cell package, in mm; L is the opening length, in mm; Q is the battery cell capacity, in Ah; P is the bursting pressure, which is set to 0.2Mpa to 0.9Mpa.

[0025] In addition, one embodiment of the present invention also provides a battery module, which includes the soft-pack lithium battery provided by any of the above embodiments, wherein a plurality of the soft-pack lithium batteries are provided, and the plurality of the soft-pack lithium batteries are arranged in a close fit, and the first shell of one of the two adjacent soft-pack lithium batteries is arranged back to back with the second shell of the other, and the first shell of one of the two adjacent soft-pack lithium batteries is arranged as a whole with the second shell of the other. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of an explosion of a soft-pack lithium battery provided in one embodiment of the present invention.

[0027] Figure 2 It is a cross-sectional schematic diagram of a soft-pack lithium battery provided in one embodiment of the present invention.

[0028] Figure 3 A schematic structural diagram of a first shell in a soft-pack lithium battery provided by an embodiment of the present invention.

[0029] Figure 4 It is a structural schematic diagram of a battery module provided by an embodiment of the present invention.

[0030] Reference numerals:

[0031] 10. Package battery; 11. Package film; 111. Package edge; 12. Battery cell; 13. Tab;

[0032] 20. Protective shell; 21. First shell; 211. First plate; 212. First frame; 2121. First side wall; 2122. Second side wall; 213. First groove; 22. Second shell; 221. Second plate; 222. Second frame; 223. Second groove; 23. Pressure relief port; 24. Aerogel layer; 241. Extension portion; 25. Placement slot. DETAILED DESCRIPTION

[0033] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood 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 battery cell 12 and a packaging film 11, the packaging film 11 is wrapped around the outside of the battery cell 12, and the packaging film 11 has a packaging edge 111; the protective shell 20 includes a first shell 21 and a second shell 22 arranged opposite to each other, the first shell 21 and the first shell 21 are connected, the first shell 21 and the second shell 22 are assembled to form an accommodating 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 outside of the accommodating cavity and the protective shell 20, the packaged battery 10 is arranged in the accommodating cavity, and at least part of the packaging edge 111 is arranged at the pressure relief port 23.

[0035] Specifically, the packaging film 11 fits and wraps the battery cell 12 to ensure the sealing and stability of the battery cell 12. The packaging films 11 on both sides of the battery cell 12 are bonded together by vacuum pumping or hot pressing under certain temperature, pressure and time conditions to form a packaging edge 111. The first shell 21 and the second shell 22 can be respectively located on both sides of the packaged battery 10, and the first shell 21 and the second shell 22 are connected by screws, buckles or adhesives to form a receiving cavity.

[0036] The pressure relief port 23 is provided at the connection between the first shell 21 and the second shell 22, and during the placement of the packaged battery 10, at least part of the package edge 111 is located at the pressure relief port 23, so that the battery cell 12 can be quickly depressurized. When the battery cell 12 generates abnormally high pressure due to overcharging, short circuit, high temperature, etc., so that the pressure inside the battery cell 12 reaches 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 in the embodiment of the present invention does not need to change the battery packaging process, and does not need to set a weak sealing area during the packaging process of the battery cell 12. Instead, by setting a protective shell 20 on the outside of the packaged battery 10 and setting a pressure relief port 23 at the position of the packaging edge 111, not only the packaging strength of the battery and the stability of the overall structure are ensured, but also safe pressure relief is achieved when the internal pressure of the battery cell 12 is abnormal, thereby effectively improving the safety and reliability of the battery system.

[0038] In this embodiment, the battery cell 12 further includes a tab 13, and a placement groove 25 is further provided on the first shell 21 and the second shell 22. The placement groove 25 is used to place the tab 13 to ensure that the tab 13 can be perfectly embedded therein, thereby avoiding the potential safety hazards caused by the tab 13 shaking freely inside the battery module. It should be noted that the drawings provided in this embodiment illustrate the packaged battery with tabs at both ends. It can be imagined that the solution provided in the embodiment of the present invention is also applicable to the packaged battery with tabs on the side, which will not be described one by one here.

[0039] like Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments, the first shell 21 includes a first plate body 211 and a first frame 212, the first plate body 211 and the first frame 212 enclose a first groove 213, the second shell 22 covers the first groove 213 to form a 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 is connected to the edge of the first plate 211, together forming a first groove 213 with a compact structure and complete functions. The second shell 22 can cover the first groove 213, and together with the first shell 21, form a receiving cavity to accommodate the packaged battery 10. The pressure relief port 23 is arranged on the first frame 212, which can facilitate the production of the pressure relief port 23 and reduce the production cost.

[0041] Furthermore, the second shell 22 also includes a second plate 221 and a second frame 222, and the second plate 221 and the second frame 222 enclose a second groove 223. In other words, the first shell 21 and the second shell 22 can have the same structure, which can simplify the manufacturing process and improve the convenience of assembly. It should be noted that the structures of the first shell 21 and the second shell 22 are similar, and their structures can refer to Figure 3 .

[0042] In addition, the first groove 213 and the second groove 223 are combined to form a accommodating cavity, the first plate body 211 and the second plate body 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 grooves to be assembled to form a pressure relief port 23, and the packaging edge 111 is clamped between the first frame 212 and the second frame 222.

[0043] In this embodiment, the packaging edge 111 includes a clamping area and a pressure relief area, the clamping area is located between the first frame 212 and the second frame 222, and the pressure relief area is located at the pressure relief port 23. In other words, the first frame 212 and the second frame 222 can strengthen the edge locking of the clamping area and enhance the edge locking force of the clamping area, so that the battery cell 12 can be exploded and relieved through the pressure relief area when the pressure reaches the safety threshold.

[0044] Furthermore, the width of the packaging edge 111 is greater than 3 mm, so that the effective locking 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 compression 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 strength, and the battery cell 12 and the internal structure cannot be effectively fixed, which may lead to safety hazards such as loosening, deformation or even damage during the use of the battery.

[0045] Furthermore, the first plate and the first frame can be integrated, and the second plate and the second frame can be integrated, which is convenient for manufacturing. And the first shell and the second shell can be made of one or more combinations of ceramic silicone rubber, vulcanized silicone rubber, silicone rubber, fluororubber, nitrile rubber, and fluorosilicone rubber.

[0046] In some embodiments, the soft-pack lithium battery further includes an aerogel layer 24, and the aerogel layer 24 is arranged in contact with the first plate 211 and the second plate 221. The aerogel layer 24 can effectively alleviate the expansion of the battery cell 12 caused by charging and discharging during operation. When the battery cell 12 is fully charged, the volume expansion caused by the internal chemical reaction may cause the connection strength of the first frame 212 and the second frame 222 to loosen, and the aerogel layer 24 can effectively absorb the stress generated by the expansion of the battery cell 12 and maintain a close fit between the battery cell 12 and the shell.

[0047] Secondly, since the volume of the battery cell 12 will shrink accordingly during the discharge process, if there is a lack of sufficient support, the fit between the battery cell 12 and the first plate 211 and the second plate 221 may not be tight enough. The aerogel layer 24 can provide necessary support when the battery cell 12 is low on power, maintain close contact between the battery cell 12 and the outer shell, thereby ensuring the stable operation of the battery and the long-term durability of the battery cell 12.

[0048] Furthermore, the aerogel layer 24 has an extension portion 241, which is disposed in the pressure relief port 23, and can guide the fluid that is sprayed during the pressure relief process of the battery cell 12, effectively alleviate the heat spread of the battery cell 12, and avoid causing thermal runaway of the adjacent battery cells 12. In other words, when the battery cell 12 is depressurized, the sprayed fluid will first contact the extension portion 241 of the aerogel layer 24, and the extension portion 241 can guide the fluid to spray out along a specific path, avoiding it from directly impacting the battery housing and surrounding components, and preventing the fluid from diffusing inside the battery pack, effectively curbing the heat spread between the battery cells 12.

[0049] Furthermore, the distance from the edge of the extension portion 241 to the battery cell 12 is set to 3 mm to 100 mm, which not only ensures that the extension portion 241 can effectively guide the fluid when the battery cell 12 is depressurized to prevent it from directly impacting the battery cell 12, but also can curb the spread of heat at a critical moment to avoid thermal 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] Wherein: y is the thickness of the aerogel layer 24; x is the thickness of the battery cell 12 in a fully charged state; and m is the thickness of the battery cell 12 in a depleted state.

[0053] That is to say, 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 a fully charged state and the thickness of the battery cell 12 in a depleted state, and is allowed to fluctuate by 2 mm on this basis, which can not only ensure that the aerogel layer 24 effectively relieves the expansion pressure when the battery cell 12 is fully charged and prevents the reduction of the fit between the battery cell 12 and the shell, but also provide sufficient support when the battery cell 12 is depleted to maintain close contact between the battery cell 12 and the shell. At the same time, the design that allows a 2 mm fluctuation on this basis also provides greater flexibility for tolerance control and material selection in the manufacturing process, ensuring the consistency and reliability of battery products.

[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 frame 212 and the second frame 222 is consistent with the width direction of the battery cell 12. The widths of the first frame 212 and the second frame 222 both satisfy the following formula:

[0055] A = 115% (X + 0.5y - 2Z) ± 2;

[0056] Wherein: A is the width of the first frame 212 or the second frame 222 ; x is the thickness of the battery cell 12 in a fully charged 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 a fully charged state, the thickness of the aerogel layer 24 , and the thickness of the packaging film 11 , these three key parameters jointly determine the width of the first frame 212 and the second frame 222 .

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

[0059] Secondly, the aerogel layer 24 can not only effectively relieve the pressure caused by the expansion of the battery cell 12, but also provide necessary support when the battery cell 12 is low on power. Therefore, when determining the width of the first frame 212 and the second frame 222, the thickness of the aerogel layer 24 must be considered to avoid excessive occupation of the width of the first frame 212 and the second frame 222.

[0060] Furthermore, the packaging film 11 is used to package the battery cell 12 in the battery housing. Therefore, when determining the width of the first frame 212 and the second frame 222, the thickness of the packaging film 11 must also be considered to ensure that it can fit the frame tightly to form an effective packaging structure.

[0061] like Figure 1 , Figure 2 As shown, in some embodiments, the length of the pressure relief port 23 is consistent with the length of the battery cell 12. The length of the pressure relief port 23 affects the bursting pressure during the pressure relief process, minimizes the risk of the battery cell 12 under abnormal pressure conditions, and avoids heat spread. The length of the pressure relief port 23 satisfies the following formula:

[0062]

[0063] Where: e is a natural constant; V is the volume of the battery cell 12, in mm 3 ; W is the package width of the battery cell 12, in mm; L is the opening length, in mm; Q is the capacity of the battery cell 12, in Ah; P is the bursting pressure, which is set to 0.2Mpa to 0.9Mpa.

[0064] like Figure 2 and Figure 3As shown, in some embodiments, the first frame 212 may include a first side wall 2121 and a second side wall 2122 that are arranged opposite to each other, and a plurality of pressure relief ports 23 are provided, and the plurality of pressure relief ports 23 are respectively arranged on the first side wall 2121 and the second side wall 2122, so as to ensure that when an abnormality occurs on any side of the battery cell 12, there is a corresponding pressure relief port 23 to release the internal pressure in time, thereby minimizing the safety risk. At the same time, this distribution method also makes the opening of the pressure relief port 23 more uniform, avoiding the degradation or damage of the battery performance caused by uneven pressure distribution.

[0065] Of course, in some other embodiments, multiple pressure relief ports 23 may be arranged at intervals along the length direction of the battery cell 12, so as to ensure that when an abnormality occurs at any position along the length direction of the battery cell 12, 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, thereby ensuring the independence and effectiveness of the pressure relief ports 23.

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

[0067] Furthermore, the thickness of the packaging 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 0.05W / (m·K). The aerogel layer 24 should have a suitable compression force characteristic curve. For example, when the stress is 0.5Mpa, the strain is 20%±5%; when the stress is 1Mpa, the strain is 35%±5%; when the stress is 1.5Mpa, the strain is 40%±5%.

[0069] like Figure 4 As shown, an embodiment of the present invention further provides a battery module, which includes the soft-pack lithium battery provided in the above embodiment, wherein a plurality of soft-pack lithium batteries are provided, and the plurality of soft-pack lithium batteries are arranged in a close relationship, and the first shell 21 of one of the two adjacent soft-pack lithium batteries is arranged opposite to the second shell 22 of the other, and the first shell 21 of one of the two adjacent soft-pack lithium batteries is arranged as a whole with the second shell 22 of the other. That is, a groove is further provided on the side of the first shell 21 and the second shell 22 away from the battery cell 12, and the groove can facilitate the placement of another battery cell 12, thereby making the overall structure more compact.

[0070] Among them, when these soft-pack lithium batteries are arranged, a clever complementary relationship is formed between the two adjacent batteries. Among them, the first shell 21 of one and the second shell 22 of the other are arranged back to back, which not only ensures the maximum utilization of the space between the batteries, but also avoids performance degradation or safety hazards caused by improper battery arrangement. At the same time, this back-to-back arrangement also makes the battery module perform well in heat dissipation, shock resistance and impact resistance, further improving the overall performance and reliability of the battery module.

[0071] Furthermore, the first shell 21 of one of the two adjacent soft-pack lithium batteries and the second shell 22 of the other are cleverly integrated in the design, which not only simplifies the production process of the battery module and reduces the manufacturing cost, but also makes 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 safer during transportation, installation and use.

[0072] During the assembly process of the battery module, the first shell 21 can be placed on the working surface, the aerogel layer 24 can be coated on the first shell 21, and then the packaged battery 10 can be placed in the first groove 213 of the first shell 21, and then the second shell 22 can be fastened to the first shell 21, so that the assembly of one battery cell 12 is completed. In the subsequent assembly process, the worker can repeat the above steps and assemble the battery cells 12 into the battery module one by one 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 in a suitable range. For example, when the state of charge of the battery cell 12 is 100% SOC (charge state), the strain of the protective shell 20 is 3% to 5%, and the strain of the aerogel layer 24 is 35% to 50%; when the state of charge is 50% SOC, the strain of the protective shell 20 is 5% to 15%, and the strain of the aerogel layer 24 is 25% to 40%; when the state of charge is 30% SOC, the strain of the protective shell 20 is 10% to 20%, and the strain of the aerogel layer 24 is 20% to 30%. SOC is

[0074] In addition, the battery module provided in the embodiment of the present application has the same implementation principle and technical effects as those of the aforementioned soft-pack lithium battery embodiment. For the sake of brief description, for parts not mentioned in this embodiment, reference can be made to the corresponding contents in the aforementioned soft-pack lithium battery embodiment.

[0075] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0076] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0077] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0078] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0079] In the present invention, the terms "one embodiment", "some embodiments", etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0080] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A soft-pack lithium battery, characterized in that: It includes a packaged battery and a protective shell, the packaged battery includes a battery cell and a packaging film, the packaging film is wrapped around the outside of the battery cell, and the packaging film has a packaging edge; the protective shell includes a first shell and a second shell that are relatively arranged, the first shell and the second shell are connected, the first shell and the second shell are assembled to form a accommodating cavity, a pressure relief port is provided at the connection between the first shell and the second shell, the pressure relief port communicates with the accommodating cavity and the outside of the protective shell, the packaged battery is arranged in the accommodating cavity, and at least part of the packaging edge is arranged at the pressure relief port.

2. The soft-pack lithium battery according to claim 1, characterized in that: The first shell includes a first plate and a first frame, the first plate and the first frame are enclosed to form a first groove, the second shell covers the first groove to form the accommodating cavity, and the pressure relief port is arranged on the first frame.

3. The soft-pack lithium battery according to claim 2, characterized in that: The second shell also includes a second plate body and a second frame, the second plate body and the second frame are combined to form a second groove, the first groove and the second groove are combined to form the accommodating cavity, the first plate body and the second plate body are arranged opposite to each other, the first frame and the second frame are connected, the first frame and the second frame are both provided with grooves to be assembled to form the pressure relief port, and the packaging edge is clamped between the first frame and the second frame.

4. The soft-pack lithium battery according to claim 3, characterized in that: The soft-pack lithium battery further includes an aerogel layer, the aerogel layer is arranged to fit the first plate body and the second plate body, the aerogel layer has an extension portion, and the extension portion is arranged in the pressure relief port.

5. The soft-pack lithium battery according to claim 4, characterized in that: The thickness of the aerogel layer satisfies the following formula: And y ≥ 1; Where: y is the thickness of the aerogel layer; x is the thickness of the battery cell in a fully charged state; m is the thickness of the battery cell in a depleted state; And / or, the distance from the edge of the extension portion to the battery core is set to 3 mm to 100 mm.

6. The soft-pack lithium battery according to claim 4, characterized in that: The widths of the first border and the second border both satisfy the following formula: A = 115% (X + 0.5y - 2Z) ± 2; Wherein: A is the width of the first frame or the second frame; x is the thickness of the soft-pack battery cell in a fully charged state; y is the thickness of the aerogel layer; and z is the thickness of the packaging film.

7. The soft-pack lithium battery according to claim 4, characterized in that: The aerogel layer is made of one or more combinations of silicon dioxide, expanded perlite, calcium silicate and rock wool.

8. The soft-pack lithium battery according to claim 3, characterized in that: The first frame and the second frame both have a first side wall and a second side wall that are arranged opposite to each other, and a plurality of pressure relief openings are provided, and the plurality of pressure relief openings are respectively arranged on the first side wall and the second side wall; And / or, the width of the packaging edge is greater than 3 mm; And / or, the packaging film is made of thermoplastic polyester material or polyethylene material, and the packaging film has a back adhesive layer.

9. The soft-pack lithium battery according to claim 1, characterized in that: The length of the pressure relief port satisfies the following formula: Where: e is the natural constant; V is the cell volume, in mm 3 ; W is the width of the battery cell package, in mm; L is the opening length, in mm; Q is the battery cell capacity, in Ah; P is the bursting pressure, which is set to 0.2Mpa to 0.9Mpa.

10. A battery module, characterized in that: A soft-pack lithium battery comprising any one of claims 1 to 9, wherein a plurality of the soft-pack lithium batteries are provided, the plurality of the soft-pack lithium batteries are arranged in a close fit, the first shell of one of two adjacent soft-pack lithium batteries is arranged back to back with the second shell of the other, and the first shell of one of the two adjacent soft-pack lithium batteries is arranged as a whole with the second shell of the other.

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