Battery module and electronic device

Abstract

A battery module and an electronic device, relating to the technical field of batteries. A first bonding member and a second bonding member are respectively provided in two battery cells, so that the stress on electrode sheets in the battery cells is effectively reduced, thereby reducing the risk of drop-induced failure of batteries. In addition, the first bonding member in the first battery cell, the second bonding member in the second battery cell, and a third bonding member used for connecting the two battery cells are arranged on adjacent sides of the two battery cells, so that a good cushioning effect can be achieved, further reducing the risk of drop-induced failure of batteries.

Description

Battery module and electronic device TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery module and an electronic device. BACKGROUND

[0002] Lithium ion batteries as power sources for mobile devices are critical to ensure the normal use of mobile devices. At the same time, mobile devices such as mobile phones, notebooks, and other devices are becoming more and more popular, and their use conditions are becoming more and more complex, so the safety requirements for batteries are also becoming higher and higher.

[0003] During use, the battery will inevitably encounter mechanical drop caused by improper use, which will cause problems such as internal electrode rupture or packaging damage of the battery, resulting in the battery being unable to be used normally, liquid leakage, short circuit, and even fire and explosion. At the same time, mobile devices can connect multiple battery monomers in a certain way to obtain greater battery capacity and improve the user experience. The force received by each single battery monomer during the drop process is more complex, and the safety risk brought by the battery under failure conditions is also higher.

[0004] SUMMARY

[0005] In view of the above problems, the present application provides a battery module and an electronic device to improve the poor safety of the battery formed by the mutual connection of multiple battery monomers.

[0006] In a first aspect, the present application provides a battery module, which comprises: a first battery monomer, a second battery monomer, and a third adhesive; the first battery monomer comprises a first electrode assembly, a first shell, and a first adhesive; the first electrode assembly is arranged in the first shell, the first shell has a first adhesive side, and the first adhesive is adhered between the first electrode assembly and the first adhesive side; the second battery monomer comprises a second electrode assembly, a second shell, and a second adhesive; the second electrode assembly is arranged in the second shell, the second shell has a second adhesive side, and the second adhesive is adhered between the second electrode assembly and the second adhesive side; the first battery monomer and the second battery monomer are arranged in a stacked manner along a first direction X, and the first adhesive side and the second adhesive side are arranged oppositely, and the first direction X is perpendicular to the first adhesive side; and the third adhesive is adhered between the first adhesive side and the second adhesive side.

[0007] In the implementation process, by arranging the first adhesive member and the second adhesive member in the two battery monomers respectively, the stress on the pole piece in the battery monomer is effectively reduced, and the risk of failure of the battery caused by falling is reduced. At the same time, the first adhesive member in the first battery monomer, the second adhesive member in the second battery monomer, and the third adhesive member for connecting the two battery monomers are arranged at the adjacent side of the two battery monomers, which can have a good buffering effect and further reduce the risk of failure of the battery caused by falling.

[0008] In one or more optional embodiments above, the projection area S1 of the first adhesive member is 20% to 80% of the projection area S2 of the first pasted side portion in the projection along the first direction X; and / or

[0009] The projection area S3 of the second adhesive member is 20% to 80% of the projection area S4 of the second pasted side portion in the projection along the first direction X; and / or

[0010] The projection area S5 of the third adhesive member is 25% to 80% of the projection area S2 of the first pasted side portion or the projection area S4 of the second pasted side portion in the projection along the first direction X.

[0011] In the implementation process, the larger the area of the first adhesive member, the second adhesive member, and the third adhesive member, the more conducive to reducing the stress on the pole piece in the battery monomer or the stress on the two battery monomers, and thus the safety of the battery. The smaller the area of the first adhesive member, the second adhesive member, and the third adhesive member, the more conducive to the energy density of the battery, and also can reduce the tearing of the shell, which is also conducive to the safety of the battery to a certain extent. By controlling the area of the first adhesive member, the second adhesive member, and the third adhesive member within a certain range, the safety and energy density of the battery can be considered.

[0012] In one or more optional embodiments above, the projection of the first adhesive member, the second adhesive member, and the third adhesive member has a first overlapping area in the projection along the first direction X.

[0013] In the implementation process, by making the first adhesive member, the second adhesive member, and the third adhesive member have a common overlapping area, the buffering effect on the pole piece in the battery monomer and the two battery monomers can be fully exerted, which is conducive to improving the safety of the battery.

[0014] In one or more optional embodiments above, the area S6 of the first overlapping area is 30% to 75% of the projection area S2 of the first pasted side portion or the projection area S4 of the second pasted side portion in the projection along the first direction X.

[0015] In the implementation process, by controlling the area of the common overlapping area of the first adhesive, the second adhesive and the third adhesive to be 30% to 75%, the risk of failure of the battery caused by falling can be controlled in a lower range, and at the same time, the battery has a higher energy density.

[0016] In one or more optional embodiments above, in the projection along the first direction X, the projection of the third adhesive is a rectangle, and along the length direction Y of the battery module, the length L3 of the third adhesive is 50% to 120% of the length L1 of the first adhesive or the length L2 of the second adhesive; and / or

[0017] In the projection along the first direction X, the projection of the third adhesive is a rectangle, and along the width direction Z of the battery module, the width W3 of the third adhesive is 50% to 90% of the width W1 of the first adhesive or the width W2 of the second adhesive.

[0018] In the implementation process, by using the rectangular third adhesive, the difficulty of pasting the third adhesive can be reduced, and the third adhesive can be applied to most battery monomers, and by controlling the length and width of the third adhesive within a certain range, the safety and energy density of the battery can be considered.

[0019] In one or more optional embodiments above, in the projection along the first direction X, the projections of the first adhesive and the second adhesive are separately arranged, and the projection of the third adhesive has a second overlapping area with at least one of the projections of the first adhesive and the second adhesive.

[0020] In the implementation process, by making two of the first adhesive, the second adhesive and the third adhesive have a common overlapping area, the pole in the battery monomer and the two battery monomers can be better buffered, which is beneficial to improve the safety of the battery, and at the same time, it is beneficial to control the thickness of the whole battery, and further beneficial to the energy density of the battery.

[0021] In one or more optional embodiments above, in the projection along the first direction X, the area S7 of the second overlapping area is 20% to 60% of the projection area S2 of the first pasting side or the projection area S4 of the second pasting side.

[0022] In the implementation process, by controlling the area of the common overlapping area of the third adhesive and at least one of the first adhesive and the second adhesive to be 20% to 60%, the risk of failure of the battery caused by falling can be controlled in a lower range, and at the same time, the battery has a higher energy density.

[0023] In one or more optional embodiments above, in the projection along the first direction X, the projections of the first adhesive and the second adhesive have a third overlapping area, and the projection of the third adhesive is separately arranged from the projections of the first adhesive and the second adhesive.

[0024] In the above implementation process, by making two of the first adhesive, the second adhesive and the third adhesive have a common overlapping area, the pole in the battery monomer and the two battery monomers can be better buffered, which is beneficial to improve the safety of the battery, and at the same time can be beneficial to control the thickness of the whole battery, and then is beneficial to the energy density of the battery.

[0025] In one or more optional embodiments above, the projections of the first adhesive, the second adhesive and the third adhesive are arranged separately along the first direction X.

[0026] In the above implementation process, by making the first adhesive, the second adhesive and the third adhesive arranged separately, the pole in the battery monomer and the two battery monomers can be buffered to a certain extent, which is beneficial to the safety of the battery, and at the same time can control the thickness of the whole battery in a smaller range, and then is beneficial to the energy density of the battery.

[0027] In one or more optional embodiments above, the thickness D1 of the first adhesive is 0.021mm-0.054mm; and / or

[0028] The thickness D2 of the second adhesive is 0.021mm-0.054mm; and / or

[0029] The thickness D3 of the third adhesive is 0.04mm-0.06mm.

[0030] In the above implementation process, the thicker the thickness of the first adhesive, the second adhesive and the third adhesive, the more beneficial to the buffering between the pole in the battery monomer or the two battery monomers, and then the safety of the battery, the thinner the thickness of the first adhesive, the second adhesive and the third adhesive, the more beneficial to the energy density of the battery, by controlling the thickness of the first adhesive, the second adhesive and the third adhesive within a certain range, the safety and energy density of the battery can be considered.

[0031] In one or more optional embodiments above, the shell is a packaging bag.

[0032] In a second aspect, the application provides an electronic device, which comprises the battery module provided in the first aspect.

[0033] In one or more optional embodiments above, the electronic device further comprises a device shell and a fourth adhesive, the device shell has a battery compartment, and the battery module is installed in the battery compartment through the fourth adhesive, and along the first direction X, the fourth adhesive is arranged on the opposite side of the third adhesive.

[0034] In the implementation process, the fourth adhesive is arranged on the opposite side of the third adhesive, which can more effectively buffer the battery and improve the safety of the battery.

[0035] In one or more optional embodiments above, the projection of the fourth adhesive in the first direction X is a rectangle, and the length L4 of the fourth adhesive in the length direction Y of the battery module is 30% to 60% of the first adhesive side length L5 or the second adhesive side length L6; and / or

[0036] The projection of the fourth adhesive in the first direction X is a rectangle, and the width W4 of the fourth adhesive in the width direction Z of the battery module is 30% to 60% of the first adhesive side width W5 or the second adhesive side width W6.

[0037] In the implementation process, by controlling the length and width of the fourth adhesive within a certain range, the safety of the battery can be maintained while pursuing lightweight. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0039] Fig. 1 is a structural schematic diagram of a battery module provided by an embodiment of the present application;

[0040] Fig. 2 is a first cross-sectional schematic diagram of A-A in Fig. 1;

[0041] Fig. 3 is a second cross-sectional schematic diagram of A-A in Fig. 1;

[0042] Fig. 4 is a third cross-sectional schematic diagram of A-A in Fig. 1;

[0043] Fig. 5 is a fourth cross-sectional schematic diagram of A-A in Fig. 1;

[0044] Fig. 6 is a fifth cross-sectional schematic diagram of A-A in Fig. 1.

[0045] Reference signs: 1000 - battery module, 1100 - first battery monomer, 1110 - first electrode assembly, 1120 - first shell, 1121 - first adhesive side, 1130 - first adhesive, 1200 - second battery monomer, 1210 - second electrode assembly, 1220 - second shell, 1221 - second adhesive side, 1230 - second adhesive, 1300 - third adhesive. DETAILED DESCRIPTION

[0046] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0048] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0049] In this paper, the reference to "embodiments" means that the specific features, structures or properties described in conjunction with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. The skilled person in the art explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.

[0050] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0051] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0052] In the description of the embodiments of the present application, the orientations or positional relationships indicated by the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements 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 embodiments of the present application.

[0053] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0054] The embodiments of the present application provide an electronic device, which can be any electronic device, such as a mobile phone, a notebook computer, a video camera, a digital camera, an electric toy, an electric car, etc., and the electronic device is provided with a battery module for providing electric energy.

[0055] Lithium ion batteries as power sources for mobile devices are critical to ensure the normal use of mobile devices. At the same time, mobile devices such as mobile phones, notebook computers, etc. are becoming more and more popular, and their use conditions are becoming more and more complex, so the safety requirements for batteries are also becoming higher and higher.

[0056] During use, the battery will inevitably encounter mechanical drop caused by improper use, which will cause problems such as internal tab rupture or packaging damage of the battery, resulting in problems such as normal use of the battery, liquid leakage, short circuit, and even fire and explosion. At the same time, mobile devices can connect multiple battery monomers in a certain way to obtain greater battery capacity and improve the user experience. The force received by each single battery monomer during the drop process is more complex, and the safety risk brought by the battery under failure conditions is also higher.

[0057] Therefore, the inventors intend to provide a battery with good drop resistance to improve the problem of easy failure risk caused by drop.

[0058] Figures 1 to 6 are schematic diagrams of the battery structure provided in the embodiments of this application. As shown in Figures 1 to 6, the embodiments of this application provide a battery module, which includes: a first battery cell, a second battery cell, and a third adhesive component. The first battery cell includes a first electrode assembly, a first housing, and a first adhesive component. The first electrode assembly is disposed within the first housing, and the first housing has a first adhesive side. The first adhesive component is bonded between the first electrode assembly and the first adhesive side. The second battery cell includes a second electrode assembly, a second housing, and a second adhesive component. The second electrode assembly is disposed within the second housing, and the second housing has a second adhesive side. The second adhesive component is bonded between the second electrode assembly and the second adhesive side. The first battery cell and the second battery cell are stacked along a first direction X, and the first adhesive side and the second adhesive side are disposed opposite to each other. The first direction X is perpendicular to the first adhesive side. The third adhesive component is bonded between the first adhesive side and the second adhesive side.

[0059] The first, second, and third adhesive components are all adhesive components. The structure of the first and second adhesive components can include a substrate layer and two adhesive layers, which are respectively disposed on the two surfaces of the substrate layer. One of the two adhesive layers is a pressure-sensitive adhesive, which is bonded to the electrolytic component, and the other layer is a hot melt adhesive, which is bonded to the shell. The substrate layer can be made of one or more of the following materials: PET, polyimide, polyester film, polyethylene film, nonwoven fabric, foam, and acrylic. The hot melt adhesive can be made of one or more of the following materials: hydrogenated styrene block copolymer, modified hydrogenated styrene block copolymer, hydrogenated petroleum resin II, antioxidant, styrene, isoprene, polymethyl methacrylate, polyacrylic acid, polyacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, ethylene-vinyl acetate copolymer, and polyimide. The pressure-sensitive adhesive can be made of one or more of the following materials: hydrogenated styrene block copolymer, hot melt pressure-sensitive adhesive layer, modified hydrogenated styrene block copolymer, hydrogenated petroleum resin I, plasticizer, antioxidant, polyethylene oxide, acrylonitrile-styrene-butadiene copolymer, polyvinyl alcohol, polyvinyl ether, polytetrafluoroethylene, polyhexafluoropropylene, styrene-butadiene copolymer, or polyvinylidene fluoride. The third adhesive layer can be a double-sided adhesive layer that is adhesive at room temperature.

[0060] The first adhesive side and the second adhesive side refer to the two sides that are set opposite to each other when the first shell and the second shell are glued together. Usually, the battery shell is cubic in shape, and the side refers to the area between two adjacent bends of the shell.

[0061] Typically, the first and second battery cells are stacked in the thickness direction, meaning that the first direction X can be the thickness direction of the first and second battery cells.

[0062] The electrode assembly comprises an electrode sheet, a separator and an electrode tab. The separator is arranged between two electrode sheets, and the separator is also arranged between two electrode assemblies. The electrode tab is connected to the electrode sheet.

[0063] In the battery module, the first adhesive and the second adhesive are arranged in the first battery cell and the second battery cell respectively, so as to effectively reduce the stress of the electrode sheet in the battery cell, and further reduce the risk of failure of the battery due to falling. The first adhesive in the first battery cell, the second adhesive in the second battery cell and the third adhesive for connecting the two battery cells are arranged on the adjacent side of the two battery cells, which can achieve a good buffering effect and further reduce the risk of failure of the battery due to falling.

[0064] It can be understood that when the battery module is composed of three or more battery cells, the adhesive is arranged on the opposite sides in the housing of the middle battery cell, and the adhesive is arranged on the outside of the corresponding position to realize the adhesion of the plurality of battery cells.

[0065] According to some embodiments of the present application, the projection area S1 of the first adhesive is 20% to 80% of the projection area S2 of the first adhesive side in the first direction X; the projection area S3 of the second adhesive is 20% to 80% of the projection area S4 of the second adhesive side; and the projection area S5 of the third adhesive is 25% to 80% of the projection area S2 of the first adhesive side or the projection area S4 of the second adhesive side.

[0066] The larger the area of the first adhesive, the second adhesive and the third adhesive, the more conducive to reducing the stress of the electrode sheet in the battery cell or the stress of the two battery cells, and further conducive to the safety of the battery. The smaller the area of the first adhesive, the second adhesive and the third adhesive, the more conducive to the energy density of the battery. By controlling the area of the first adhesive, the second adhesive and the third adhesive within a certain range, the safety and energy density of the battery can be considered.

[0067] For example, the projected area S1 of the first adhesive member in the first direction X can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%, etc. of the projected area S2 of the first adhesive side, or can be any value within the range of 20% to 80%. The projected area S3 of the second adhesive member in the first direction X can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%, etc. of the projected area S4 of the second adhesive side, or can be any value within the range of 20% to 80%. The projected area S5 of the third adhesive member in the first direction X can be 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%, etc. of the projected area S2 of the first adhesive side or the projected area S4 of the second adhesive side, or can be any value within the range of 25% to 80%.

[0068] According to some embodiments of the present application, the projections of the first adhesive member, the second adhesive member, and the third adhesive member have a first overlapping area in the first direction X.

[0069] The first overlapping area refers to the common overlapping area of the projections of the first adhesive member, the second adhesive member, and the third adhesive member. Referring to FIG. 2, the sizes of the first adhesive member and the second adhesive member are the same, and they are arranged opposite to each other. It can be understood that in other embodiments, the sizes of the first adhesive member and the second adhesive member can be different, and their positions can be arranged arbitrarily, as long as there is an overlapping area.

[0070] By having the first adhesive member, the second adhesive member, and the third adhesive member have a common overlapping area, the buffering effect on the pole pieces in the battery monomer and the two battery monomers can be fully exerted, which is beneficial to improve the safety of the battery.

[0071] According to some embodiments of the present application, the area S5 of the first overlapping area in the first direction X is 30% to 75% of the projected area S2 of the first adhesive side or the projected area S4 of the second adhesive side.

[0072] By controlling the area of the common overlapping area of the first adhesive member, the second adhesive member, and the third adhesive member to be 30% to 75%, the risk of failure of the battery due to falling can be controlled in a lower range, and at the same time, the battery has a higher energy density.

[0073] For example, the area S5 of the first overlap region projected along the first direction X can be 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or 75% of the projected area S2 of the first adhesive side or the projected area S4 of the second adhesive side, or any value within the range of 30% to 75%.

[0074] According to some embodiments of the present application, the third adhesive has a rectangular projection along the first direction X, the length L3 of the third adhesive is 50% to 120% of the length L1 of the first adhesive or the length L2 of the second adhesive, and the width W3 of the third adhesive is 50% to 90% of the width W1 of the first adhesive or the width W2 of the second adhesive.

[0075] By using the rectangular third adhesive, the difficulty of the third adhesive can be reduced, and the third adhesive can be applied to most battery monomers. By controlling the length and width of the third adhesive within a certain range, the safety and energy density of the battery can be considered.

[0076] For example, the length L3 of the third adhesive projected along the first direction X can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 105%, 110%, 115% or 120% of the length L1 of the first adhesive or the length L2 of the second adhesive, or any value within the range of 50% to 120%. The width W3 of the third adhesive projected along the first direction X can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% or 90% of the width W1 of the first adhesive or the width W2 of the second adhesive, or any value within the range of 50% to 90%.

[0077] According to some embodiments of the present application, the projections of the first adhesive and the second adhesive are arranged separately along the first direction X, and the projection of the third adhesive has a second overlap region with at least one of the projections of the first adhesive and the second adhesive.

[0078] The projection of the third adhesive has a second overlap region with at least one of the projections of the first adhesive and the second adhesive, which means that the third adhesive can only have an overlap region with the projection of the first adhesive or the second adhesive, and the overlap region is the second overlap region. The third adhesive can also have overlap regions with the projections of the first adhesive and the second adhesive, and the sum of the overlap regions of the third adhesive and the two is the second overlap region. Please refer to FIG. 3, the projection of the third adhesive has overlap regions with the projections of the first adhesive and the second adhesive. It can be understood that in other embodiments, the third adhesive can only have an overlap region with one of the first adhesive and the second adhesive.

[0079] By making two of the first adhesive, the second adhesive and the third adhesive have a common overlapping area, a better buffering effect can be achieved on the pole piece in the battery monomer and the two battery monomers, which is conducive to improving the safety of the battery, and at the same time, the thickness of the whole battery can be controlled, thereby the energy density of the battery is conducive.

[0080] According to some embodiments of the present application, the area S7 of the second overlapping area is 20% to 60% of the projected area S2 of the first pasted side or the projected area S4 of the second pasted side, projected along the first direction X.

[0081] By controlling the area of the common overlapping area of the third adhesive and at least one of the first adhesive and the second adhesive to be 20% to 60%, the risk of failure of the battery due to falling can be controlled in a lower range, while the battery has a higher energy density.

[0082] For example, the area S7 of the second overlapping area can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55% or 60% of the projected area S2 of the first pasted side or the projected area S4 of the second pasted side, projected along the first direction X, and it can also be any value within the range of 20% to 60%.

[0083] According to some embodiments of the present application, the projections of the first adhesive and the second adhesive have a third overlapping area projected along the first direction X, and the third adhesive is arranged separately from the projections of the first adhesive and the second adhesive. Please refer to FIG. 4, in which the first adhesive and the second adhesive are the same size and are arranged opposite to each other. It can be understood that in other embodiments, the first adhesive and the second adhesive can not be the same size and can be arranged at any position (please refer to FIG. 6), as long as there is an overlapping area.

[0084] By making two of the first adhesive, the second adhesive and the third adhesive have a common overlapping area, a better buffering effect can be achieved on the pole piece in the battery monomer and the two battery monomers, which is conducive to improving the safety of the battery, and at the same time, the thickness of the whole battery can be controlled, thereby the energy density of the battery is conducive.

[0085] In other embodiments, the distribution relationship of the first adhesive, the second adhesive and the third adhesive can also be that the projections of the first adhesive and the third adhesive have an overlapping area, the projections of the second adhesive and the third adhesive also have an overlapping area, and the projections of the first adhesive and the second adhesive also have an overlapping area, but the three overlapping areas do not overlap.

[0086] According to some embodiments of the present application, please refer to FIG. 5, the projections of the first adhesive, the second adhesive and the third adhesive are arranged separately along the first direction X.

[0087] By arranging the first adhesive, the second adhesive and the third adhesive separately, the pole piece in the battery monomer and the two battery monomers can be buffered, which is beneficial to the safety of the battery, and the thickness of the whole battery can be controlled in a small range, which is further beneficial to the energy density of the battery.

[0088] According to some embodiments of the present application, the thickness D1 of the first adhesive is 0.021mm-0.054mm; the thickness D2 of the second adhesive is 0.021mm-0.054mm; and the thickness D3 of the third adhesive is 0.04mm-0.06mm.

[0089] The thicker the thickness of the first adhesive, the second adhesive and the third adhesive, the more beneficial to the buffering of the pole piece in the battery monomer or between the two battery monomers, which is further beneficial to the safety of the battery. The thinner the thickness of the first adhesive, the second adhesive and the third adhesive, the more beneficial to the energy density of the battery. By controlling the thickness of the first adhesive, the second adhesive and the third adhesive within a certain range, the safety and energy density of the battery can be considered.

[0090] For example, the thickness D1 of the first adhesive can be 0.021mm, 0.023mm, 0.025mm, 0.027mm, 0.029mm, 0.031mm, 0.033mm, 0.035mm, 0.037mm, 0.039mm, 0.041mm, 0.043mm, 0.045mm, 0.047mm, 0.049mm, 0.051mm or 0.054mm, etc., which can also be any value within the range of 0.021mm-0.054mm. The thickness D2 of the second adhesive can be 0.021mm, 0.023mm, 0.025mm, 0.027mm, 0.029mm, 0.031mm, 0.033mm, 0.035mm, 0.037mm, 0.039mm, 0.041mm, 0.043mm, 0.045mm, 0.047mm, 0.049mm, 0.051mm or 0.054mm, etc., which can also be any value within the range of 0.021mm-0.054mm. The thickness D3 of the third adhesive can be 0.04mm, 0.042mm, 0.044mm, 0.046mm, 0.048mm, 0.050mm, 0.052mm, 0.054mm, 0.056mm, 0.058mm or 0.06mm, etc., which can also be any value within the range of 0.04mm-0.06mm.

[0091] According to some embodiments of the present application, the shell is a packaging bag, and specifically, the packaging bag can be selected from an aluminum plastic film.

[0092] When the battery is applied to an electronic device, the battery module is installed in a battery compartment of the electronic device by the fourth adhesive, and the fourth adhesive is arranged on the opposite side of the third adhesive along the first direction X.

[0093] The fourth adhesive can be a double-sided adhesive layer having adhesion at room temperature.

[0094] By arranging the fourth adhesive on the opposite side of the third adhesive, the buffering effect on the battery can be more favorable, thereby facilitating the safety of the battery.

[0095] According to some embodiments of the present application, the projection of the fourth adhesive along the first direction X is a rectangle, the length L4 of the fourth adhesive is 30% to 60% of the first adhesive side length L5 or the second adhesive side length L6, and the width W4 of the fourth adhesive is 30% to 60% of the first adhesive side width W5 or the second adhesive side width W6.

[0096] By controlling the length L4 and the width W4 of the fourth adhesive within a certain range, the safety of the battery can be maintained under the premise of pursuing lightweight.

[0097] For example, the length L4 of the fourth adhesive along the first direction X can be 30%, 35%, 40%, 45%, 50%, 55%, or 60% of the first adhesive side length L5 or the second adhesive side length L6, and it can also be any value within the range of 30% to 60%. The width W4 of the fourth adhesive can be 30%, 35%, 40%, 45%, 50%, 55%, or 60% of the first adhesive side width W5 or the second adhesive side width W6, and it can also be any value within the range of 30% to 60%.

[0098] The present application will be specifically described below through examples and comparative examples.

[0099] Examples and Comparative Examples

[0100] A battery module is assembled as follows:

[0101] Preparation of anode sheet:

[0102] Anode active material particles graphite, dispersant carboxymethyl cellulose sodium, and binder styrene-butadiene rubber are mixed, and an appropriate amount of deionized water is added for sufficient stirring and mixing to obtain anode active slurry. After the anode active slurry is coated on both surfaces of a copper foil with a thickness of 5 μm, drying and cold pressing are performed to form an anode active material layer, and then cutting is performed to obtain an anode sheet.

[0103] Preparation of cathode sheet:

[0104] 96wt% of lithium cobalt oxide, 2wt% of superconducting carbon black, and 2wt% of a binder polyvinylidene fluoride were mixed to obtain a positive active paste by using N-methyl pyrrolidone as a solvent and by thoroughly stirring the mixture. The positive active paste was coated on both surfaces of a cathode current collector aluminum foil having a thickness of 8μm at a coating amount of 0.1917g / 1540.25mm 2 After drying, a positive active paste layer was obtained; then, cold pressing and cutting were performed to obtain a cathode sheet.

[0105] An electrode assembly was prepared.

[0106] A separator film was made of polypropylene (PP) and had a thickness of 20μm. An anode sheet, a first separator film, a cathode sheet, and a second separator film were repeatedly stacked in sequence to form an electrode assembly.

[0107] A battery monomer was prepared.

[0108] The electrode assembly was installed in a housing through an adhesive member, and an electrolyte was injected, and then formation was performed to obtain a battery module. In the electrolyte, the solute was 1mol / L lithium hexafluorophosphate, and the solvent was ethylene carbonate and dimethyl carbonate at a volume ratio of 1:1.

[0109] The battery monomer had a weight of 15g and a size of 6.5mm*20mm*58mm.

[0110] A battery module was prepared.

[0111] Two battery monomers were bonded through an adhesive member to obtain a battery module.

[0112] In Comparative Example 1, the first adhesive member and the second adhesive member of the two battery monomers were bonded to the same bonding side with the third adhesive member.

[0113] In Comparative Example 2, the first adhesive member and the second adhesive member of the two battery monomers were not bonded to the same bonding side with the third adhesive member.

[0114] In Examples 1 to 13, the projections of the first adhesive member and the second adhesive member of the two battery monomers along the first direction X had a first overlapping area with the projection of the third adhesive member, as shown in FIG. 2.

[0115] In Examples 14 to 18, the projections of the first adhesive member and the second adhesive member of the two battery monomers along the first direction X were separately arranged, and the projection of the third adhesive member had a second overlapping area with at least one of the projections of the first adhesive member and the second adhesive member, as shown in FIG. 3.

[0116] In Example 19, the projections of the first bonding member and the second bonding member in the two battery cells have a third overlapping region in the projection along the first direction X, and the third bonding member is disposed apart from the projections of the first bonding member and the second bonding member, see Fig. 4.

[0117] In Example 20, the projections of the first bonding member and the second bonding member in the two battery cells are disposed apart from the projection of the third bonding member in the projection along the first direction X, see Fig. 5.

[0118] The main parameters of the examples and comparative examples are shown in the following table:

[0119] In the table, S1 / S2 refers to the ratio of the projected area of the first bonding member to the projected area of the first pasted side in the projection along the first direction X.

[0120] D1 refers to the thickness of the first bonding member.

[0121] S3 / S4 refers to the ratio of the projected area of the second bonding member to the projected area of the second pasted side in the projection along the first direction X.

[0122] D2 refers to the thickness of the second bonding member.

[0123] S5 / S2 refers to the ratio of the projected area of the third bonding member to the projected area of the first pasted side in the projection along the first direction X. It should be noted that since the two battery cells are identical, the ratio of the projected area of the third bonding member to the projected area of the first pasted side is the same as the ratio of the projected area of the third bonding member to the projected area of the second pasted side, i.e. S5 / S2 = S5 / S4.

[0124] D3 refers to the thickness of the third bonding member.

[0125] S6 / S2 refers to the ratio of the area of the first overlapping region to the projected area of the first pasted side in the projection along the first direction X. It should be noted that since the two battery cells are identical, the ratio of the area of the first overlapping region to the projected area of the first pasted side is the same as the ratio of the projected area of the first overlapping region to the projected area of the second pasted side, i.e. S6 / S2 = S6 / S4.

[0126] S7 / S2 refers to the ratio of the area of the second overlapping region to the projected area of the first pasted side in the projection along the first direction X. It should be noted that since the two battery cells are identical, the ratio of the area of the second overlapping region to the projected area of the first pasted side is the same as the ratio of the projected area of the second overlapping region to the projected area of the second pasted side, i.e. S7 / S2 = S7 / S4.

[0127] S8 / S2 refers to: the ratio of the area of the third overlapping region to the projected area of the first pasting side in the first direction X. Meanwhile, it should be noted that since the two battery monomers are the same, the ratio of the area of the third overlapping region to the projected area of the first pasting side is the same as the ratio of the projected area of the third overlapping region to the projected area of the second pasting side, i.e. S8 / S2 = S8 / S4.

[0128] Drop test was performed on each of the examples and the comparative examples, and the test included:

[0129] Drop test: the battery module was assembled into a fixture, and was dropped freely from a position 1.5 m away from the ground in the following order: head-tail-head right corner-tail right corner-head left corner-tail left corner (angle: 45±15°) by using a drop device, and the process was repeated for 2 rounds. After the drop, the battery module was disassembled, and whether the battery module was damaged was observed. 100 battery modules were tested for each example or comparative example, and if the battery module was damaged, the test was failed, and if the battery module was not damaged, the test was passed. The pass rate = (the number of passes / 100) x 100%.

[0130] Volume energy density test: at 25°C, the lithium ion battery was charged to 4.35V under 1C constant current / constant voltage, and was left for 10 min, and was discharged to a cut-off voltage of 3.0V at 1C constant current (5 battery modules per group), the energy of each battery module was detected, and then the energy density of the battery module was calculated according to the following formula: energy density (Wh / L) = energy / volume (wherein, W represents watt, h represents hour, and the volume represents the volume of the battery module, i.e. the thickness of the battery module * the width of the battery module * the length of the battery module)

[0131] The test results are shown in the following table:

[0132] As shown in the above table, the battery module provided by the embodiments of the present application has excellent drop resistance, and the pass rate of the drop test is more than 50%.

[0133] As shown in the data comparison of examples 1 to 5, with the gradual increase of the ratio of the projected area of the first adhesive to the projected area of the first pasting side, the drop pass rate shows a trend of first increasing and then decreasing, and controlling the ratio of the projected area of the first adhesive to the projected area of the first pasting side to be 20% to 80% can make the drop test pass rate of the battery module to be more than 89%.

[0134] By comparing the data of example 3 and example 6 to 9, it can be found that as the ratio of the projected area of the second adhesive to the projected area of the second adhesive side gradually increases, the drop pass rate presents a trend of first increasing and then decreasing, and controlling the ratio of the projected area of the second adhesive to the projected area of the second adhesive side in 20% to 80% can make the drop test pass rate of the battery module more than 90%.

[0135] By comparing the data of example 3 and example 10 to 13, it can be found that as the ratio of the projected area of the third adhesive to the projected area of the first adhesive side gradually increases, the drop pass rate presents a trend of first increasing and then decreasing, and controlling the ratio of the projected area of the third adhesive to the projected area of the first adhesive side in 25% to 80% can make the drop test pass rate of the battery module more than 88%.

[0136] By comparing the data of example 14 to 18, it can be found that as the ratio of the projected area of the second overlap area to the projected area of the first adhesive side gradually increases, the drop pass rate presents a trend of first increasing and then decreasing, and controlling the ratio of the projected area of the second overlap area to the projected area of the first adhesive side in 20% to 60% can make the drop test pass rate of the battery module more than 88%.

[0137] By comparing the data of example 1 to 13, example 14 to 18, example 19 and example 20, it can be found that the less the number of overlaps of the first adhesive, the second adhesive and the third adhesive, the more beneficial to the volume energy density of the battery module, and vice versa, the more the number of overlaps, the more beneficial to the drop resistance performance of the battery module.

[0138] The above is only a specific embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery module, characterized in that, The battery module includes: The first battery cell includes a first electrode assembly, a first housing, and a first adhesive component; the first electrode assembly is disposed within the first housing, the first housing has a first adhesive side, and the first adhesive component is bonded between the first electrode assembly and the first adhesive side. The second battery cell includes a second electrode assembly, a second housing, and a second adhesive component; the second electrode assembly is disposed within the second housing, the second housing has a second adhesive side, and the second adhesive component is bonded between the second electrode assembly and the second adhesive side. The first battery cell and the second battery cell are stacked along a first direction X, and the first adhesive side and the second adhesive side are arranged opposite to each other, with the first direction X being perpendicular to the first adhesive side; the third adhesive is bonded between the first adhesive side and the second adhesive side.

2. The battery module according to claim 1, characterized in that, Projecting along the first direction X, the projected area S1 of the first adhesive component is 20% to 80% of the projected area S2 of the first adhesive side; and / or Projecting along the first direction X, the projected area S3 of the second adhesive component is 20% to 80% of the projected area S4 of the second adhesive side; and / or Projecting along the first direction X, the projected area S5 of the third adhesive is 25% to 80% of the projected area S2 of the first adhesive side or the projected area S4 of the second adhesive side.

3. The battery module according to any one of claims 1 to 2, characterized in that, Projecting along the first direction X, the projections of the first adhesive, the second adhesive, and the third adhesive have a first overlapping area.

4. The battery module according to claim 3, characterized in that, Projecting along the first direction X, the area S6 of the first overlapping region is 30% to 75% of the projected area S2 of the first adhesive side or the projected area S4 of the second adhesive side.

5. The battery module according to any one of claims 3 to 4, characterized in that, Projecting along the first direction X, the projection of the third adhesive component is rectangular. Along the length direction Y of the battery module, the length L3 of the third adhesive component is 50% to 120% of the length L1 of the first adhesive component or the length L2 of the second adhesive component; and / or Projecting along the first direction X, the projection of the third adhesive is rectangular. Along the width direction Z of the battery module, the width W3 of the third adhesive is 50% to 90% of the width W1 of the first adhesive or the width W2 of the second adhesive.

6. The battery module according to any one of claims 1 to 2, characterized in that, Projecting along the first direction X, the projections of the first adhesive and the second adhesive are separated, and the projection of the third adhesive has a second overlapping area with the projection of at least one of the first adhesive and the second adhesive.

7. The battery module according to claim 6, characterized in that, Projecting along the first direction X, the area S7 of the second overlapping region is 20% to 60% of the projected area S2 of the first adhesive side or the projected area S4 of the second adhesive side.

8. The battery module according to any one of claims 1 to 2, characterized in that, Projecting along the first direction X, the projections of the first adhesive and the second adhesive have a third overlapping area, and the third adhesive is disposed separately from the projections of both the first adhesive and the second adhesive.

9. The battery module according to any one of claims 1 to 2, characterized in that, Projecting along the first direction X, the projections of the first adhesive, the second adhesive, and the third adhesive are all positioned separately.

10. The battery module according to any one of claims 1 to 9, characterized in that, The thickness D1 of the first adhesive component is 0.021 mm to 0.054 mm; and / or The thickness D2 of the second adhesive component is 0.021 mm to 0.054 mm; and / or The thickness D3 of the third adhesive component is 0.04 mm to 0.06 mm.

11. The battery module according to any one of claims 1 to 10, characterized in that, The casing is a packaging bag.

12. An electronic device, characterized in that, The electronic device includes a battery module as claimed in any one of claims 1 to 11.

13. The electronic device according to claim 12, characterized in that, The electronic device further includes a device housing and a fourth adhesive member. The device housing has a battery compartment, and the battery module is installed in the battery compartment via the fourth adhesive member along the first direction X. The fourth adhesive member is located on the opposite side of the third adhesive member.

14. The electronic device according to claim 13, characterized in that, Projecting along the first direction X, the projection of the fourth adhesive component is rectangular. Along the length direction Y of the battery module, the length L4 of the fourth adhesive component is 30% to 60% of the length L5 of the first adhesive side or the length L6 of the second adhesive side; and / or Projecting along the first direction X, the projection of the fourth adhesive is rectangular. Along the width direction Z of the battery module, the width W4 of the fourth adhesive is 30% to 60% of the width W5 of the first adhesive side or the width W6 of the second adhesive side.

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