Battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery pack, which comprises two battery monomers arranged side by side along a second direction, each battery monomer comprises a battery cell, and a tab is formed on at least one side along a first direction; the packaging bag wraps the outer side of the battery cell, a top sealing edge is formed on the side, corresponding to the tab, of the packaging bag, a bottom sealing edge is formed on the side, opposite to the tab, of the packaging bag in the first direction, a side sealing edge and a mold closing surface which are opposite to each other are formed on the packaging bag in the second direction, and the two ends of the side sealing edge and the two ends of the mold closing surface are connected with the top sealing edge and the bottom sealing edge respectively; the mold closing surface is attached to the side wall of the battery cell; and the top sealing edge, the side sealing edges and the bottom sealing edge are all formed by attaching packaging bags located on the two sides of the battery cell in the third direction. According to the battery pack provided by the utility model, the mold closing surface is formed, so that no sealing edge exists on one side, positioned on the mold closing surface, of the battery cell, and the inapplicability of the conventional protection plate design caused by interference between the folded edge and the protection plate is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, concretely relates to a battery pack. BACKGROUND

[0002] To meet the application scene of high capacity, high voltage, fast charging of consumer electronics, some batteries will select double cell battery pack design, that is, two finished battery monomers are arranged side by side and connected in the mode of welding protection plate, as shown in Figure 1

[0003] Since the cell needs to be packaged with the packaging bag to form the battery monomer, in the packaging process, the cell side edge and the second edge will be folded. When two battery monomers are assembled into a battery pack side by side, the two battery monomers respectively have a first middle fold edge 901 and a second middle fold edge 902 close to each other, and the fold edge will interfere with the protection plate. The conventional protection plate design cannot meet the assembly requirements, and the protection plate needs to be crossed by a soft plate "U" type to bypass the fold edge protrusion between the two battery monomers, which leads to complex protection plate structure and increased production cost.

[0004] In addition, in addition to the interference between the fold edge and the protection plate, there are at least four layers of aluminum plastic film and an insulating adhesive layer 903 wrapping the exposed aluminum layer between the two battery monomers, which increases the width of the battery, resulting in reduced battery energy density. SUMMARY

[0005] Therefore, the utility model provides a battery pack to solve the problem of interference between the fold edge and the protection plate when two battery monomers are assembled into a battery pack side by side, and the fold edge and the insulating adhesive layer reduce the volume energy density.

[0006] The utility model provides a battery pack, comprising: two battery monomers arranged side by side along a second direction, the two battery monomers being a first battery monomer and a second battery monomer respectively;

[0007] The battery monomer comprises:

[0008] The cell has a tab formed on at least one side thereof along a first direction;

[0009] The packaging bag covers the outside of the cell, and a top edge of the packaging bag is formed on a side corresponding to the tab. A bottom edge of the packaging bag is formed on a side opposite to the tab along the first direction. The packaging bag forms opposite side edges and a mold closing surface along the second direction. The two ends of the side edge are connected to the top edge and the bottom edge respectively. The two ends of the mold closing surface are connected to the top edge and the bottom edge respectively.

[0010] The mold closing surface is attached to the side wall of the cell;

[0011] ​The top seal edge, the side seal edge and the bottom seal edge are formed by the packaging bag located on both sides of the battery cell along the third direction, and the third direction is perpendicular to the first direction and the second direction;

[0012] The first battery monomer comprises a first joint surface and a first tab, and the second battery monomer comprises a second joint surface and a second tab, and the first joint surface is arranged in abutment with the second joint surface;

[0013] The battery pack further comprises a protection plate connected with the first tab and the second tab respectively, and the distance between the first joint surface and the protection plate in the first direction is greater than the distance between the top surface of the packaging bag close to the top seal edge and the protection plate.

[0014] The battery pack provided by the embodiment of the utility model has the following beneficial effects: the side of the packaging bag corresponding to the tab forms a top seal edge, the side of the packaging bag located on the opposite side of the tab along the first direction forms a bottom seal edge, the packaging bag forms opposite side seal edges and joint surfaces along the second direction, the two ends of the side seal edge are connected with the top seal edge and the bottom seal edge respectively, the two ends of the joint surface are connected with the top seal edge and the bottom seal edge respectively, and the joint surface is in abutment with the side wall of the battery cell; the joint surface is formed, so that there is no seal edge on the side of the battery cell located on the joint surface, thereby facilitating the abutment of the two battery cells arranged side by side through the joint surface, realizing the design of the double-battery-cell battery pack, and the double-battery-cell battery pack formed will not interfere with the protection plate, avoiding the problem that the conventional protection plate design is not applicable due to the interference between the folded edge and the protection plate, and the production cost of the soft package battery can be reduced. In addition, there is no seal edge on the side of the battery cell located on the joint surface, avoiding the increase in width caused by the folded edge and the adhesive, and preventing the volume energy density from being reduced. The first battery monomer and the second battery monomer are arranged side by side along the second direction, and the first joint surface of the first battery monomer and the second joint surface of the second battery monomer are arranged in abutment. The design of the double-battery-cell battery pack is realized, and the double-battery-cell battery pack formed will not interfere with the protection plate because the first joint surface and the second joint surface are in abutment, so that the interference between the folded edge and the protection plate does not cause the problem that the conventional protection plate design is not applicable, and the production cost of the soft package battery can be reduced. In addition, because the first joint surface and the second joint surface are in abutment, neither of them has a seal edge, avoiding the increase in width caused by the folded edge and the adhesive, and preventing the volume energy density from being reduced.

[0015] In an optional embodiment, the side seal edge is formed with a side seal edge seal stamp;

[0016] Along the first direction, the length of the overlapping area of the side seal edge seal stamp and the top seal edge is J1, and W1 is greater than or equal to 2*J1, wherein W1 is the width of the top seal edge along the first direction;

[0017] In the first direction, the length of the overlap area between the side sealing edge seal and the bottom sealing edge is J2, and W2≥2*J2 is satisfied, where W2 is the width of the bottom sealing edge in the first direction.

[0018] Beneficial effect: By limiting W1≥2*J1 and limiting W2≥2*J2, the situation of excessive PP overflow caused by excessive seal interface can be reduced, and the situation of poor head extrusion of the battery cell can be avoided.

[0019] In an optional embodiment, the bottom sealing edge is formed with a bottom sealing edge seal;

[0020] In the second direction, the length of the overlap area between the bottom sealing edge seal and the side sealing edge is J3, and W3≥2*J3 is satisfied, where W3 is the width of the side sealing edge in the second direction.

[0021] The second direction is perpendicular to the first direction and the third direction.

[0022] Beneficial effect: By limiting W3≥2*J3, the situation of excessive PP overflow caused by excessive seal interface can be reduced, and the situation of poor head extrusion of the battery cell can be avoided.

[0023] In an optional embodiment, the width W1 of the top sealing edge in the first direction is in the range of 0.8mm≤W1≤2mm.

[0024] The width W2 of the bottom sealing edge in the first direction is in the range of 1mm≤W2≤5mm.

[0025] The width W3 of the side sealing edge in the second direction is in the range of 1mm≤W3≤5mm.

[0026] In an optional embodiment, the side sealing edge and the bottom sealing edge are folded on the same side of the battery cell in the third direction, and side sealing edge folding parts and bottom sealing edge folding parts are formed respectively.

[0027] In an optional embodiment, the overlap area between the side sealing edge folding part and the bottom sealing edge folding part forms a folding edge interference area, and the folding edge interference area is adapted to be folded towards the side sealing edge folding part or the bottom sealing edge folding part to form a folding angle.

[0028] Beneficial effect: By folding the folding edge interference area towards the side sealing edge folding part or the bottom sealing edge folding part to form a folding angle, the interference between the side sealing edge and the bottom sealing edge caused by the folding edge can be solved, and the increase in the length of the battery cell can be avoided.

[0029] In an optional embodiment, the tab includes a first positive tab and a first negative tab formed on the same side of the first battery cell in the first direction; and the tab further includes a second positive tab and a second negative tab formed on the same side of the second battery cell in the first direction.

[0030] The polarity of the tab of the first battery monomer close to the first die face along the second direction is opposite to the polarity of the tab of the second battery monomer close to the second die face along the second direction.

[0031] Beneficial effect: when the battery cell and the packaging bag are assembled into the first battery monomer and the second battery monomer respectively, the first battery cell and the second battery cell are opposite in the way of entering the shell, that is, the polarity of the tab close to the die face of the first battery monomer and the second battery monomer is opposite. The purpose is to ensure that the polarity of the corresponding position is the same when the battery pack structure composed of the first battery monomer and the second battery monomer is connected with the protection plate, avoiding the redesign of the protection plate and reducing the production cost.

[0032] In an optional embodiment, the distance of the first negative tab to the first die face along the second direction is L1; the distance of the first positive tab to the first die face along the second direction is L2;

[0033] The distance of the second negative tab to the second die face along the second direction is L1'; the distance of the second positive tab to the second die face along the second direction is L2';

[0034] L1+L1'=L2+L2'=L is met, wherein L is the width of the first battery monomer or the second battery monomer along the second direction.

[0035] Beneficial effect: by limiting L1+L1'=L2+L2'=L, it can be ensured that the connection position is corresponding and the polarity is the same when the battery pack formed by the first battery monomer and the second battery monomer is connected with the protection plate. At the same time, this design does not need to produce additional types of battery cells, reducing the production cost.

[0036] In an optional embodiment, the first battery monomer includes a first battery cell, and the second battery monomer includes a second battery cell;

[0037] One side of the first battery cell along the third direction is a first reference surface, and the part of the tab of the first battery monomer connected with the first battery cell is bent towards the first reference surface and forms a first tab bending part; the tab of the first battery monomer further forms a first tab main area;

[0038] One side of the second battery cell along the third direction is a second reference surface, and the part of the tab of the second battery monomer connected with the second battery cell is bent towards the second reference surface and forms a second tab bending part; the tab of the second battery monomer further forms a second tab main area.

[0039] In an optional embodiment, the first tab main area is parallel to the first reference surface, the second tab main area is parallel to the second reference surface, and the distance between the first tab main area and the first reference surface along the third direction is D1, and the distance between the second tab main area and the second reference surface along the third direction is D2, satisfying D1=D2.

[0040] Beneficial effects: By limiting D1 to D2, it can be ensured that all tabs of the battery pack formed by the first and second battery cells remain flush in the same plane when connected to the protection board, eliminating the need to bend the protection board. Furthermore, the tabs at corresponding positions have the same polarity, avoiding the need to redesign the protection board. Attached Figure Description

[0041] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the battery pack before the improvement.

[0043] Figure 2 This is a front view of the battery pack of this utility model before folding.

[0044] Figure 3 This is a bottom view of the battery pack of this utility model after the edges have been folded.

[0045] Figure 4 This is a schematic diagram of the first battery cell and the first packaging bag assembled to form the first battery cell of this utility model;

[0046] Figure 5 This is a schematic diagram of the second battery cell and the second packaging bag assembled to form the second battery cell of this utility model;

[0047] Figure 6 This is a front view of the first battery cell of this utility model before folding.

[0048] Figure 7 for Figure 6 Schematic diagram of AA section;

[0049] Figure 8 This is a front view of the second battery cell of this utility model before folding.

[0050] Figure 9 for Figure 6 Schematic diagram of the BB cross section;

[0051] Figure 10 This is a schematic diagram showing the battery cell of this utility model being sealed from the top and bottom before being sealed from the side.

[0052] Figure 11The utility model discloses a schematic diagram of top sealing and side sealing of battery monomer first and then bottom sealing;

[0053] Figure 12 The utility model discloses a schematic diagram of the interference area of the edge folding of battery monomer;

[0054] Figure 13 The utility model discloses a schematic diagram of the edge folding of battery monomer and the formation of the corner;

[0055] Figure 14 The utility model discloses a schematic diagram of the assembly state of the edge folding of battery monomer and the protection plate.

[0056] Mark explanation:

[0057] 1, first battery monomer;2, second battery monomer;4, protection plate;

[0058] 10, electric core;101, bottom edge;1011, bottom edge seal;102, side edge;1021, side edge seal;103, top edge;14, tab;104, positive tab;105, negative tab;106, die face;107, edge interference area;1071, corner;1012, bottom edge folding part;1022, side edge folding part;

[0059] 11, first electric core;111, first bottom edge;112, first side edge;113, first top edge;114, first positive tab;115, first negative tab;116, first die face;1111, first bottom edge folding part;1121, first side edge folding part;117, first tab insulating glue;118, first tab bending part;119, first reference surface;1141, first tab main area;

[0060] 12, second electric core;121, second bottom edge;122, second side edge;123, second top edge;124, second positive tab;125, second negative tab;126, second die face;1211, second bottom edge folding part;1221, second side edge folding part;127, second tab insulating glue;128, second tab bending part;129, second reference surface;1241, second tab main area;

[0061] 30, packing bag;31, first packing bag;32, second packing bag;

[0062] 901, first middle edge;902, second middle edge;903, insulating glue layer. Specific implementation

[0063] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments but not all of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0064] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description and cannot be understood as indicating or implying relative importance.

[0065] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. Those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0066] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0067] The embodiments of the present application will be described below in combination with Figures 1 to 14 .

[0068] In the present embodiment, the first direction is the width direction of the battery cell, the second direction is the length direction of the battery cell, and the third direction is the thickness direction of the battery cell.

[0069] According to the embodiments of the present application, a battery pack is provided, comprising: two battery monomers arranged side by side along a second direction, the two battery monomers being a first battery monomer 1 and a second battery monomer 2 respectively;

[0070] The battery monomer comprises:

[0071] The battery cell 10 is formed with a tab 14 on at least one side thereof along the first direction;

[0072] The packaging bag 30 is wrapped on the outer side of the battery cell 10, a top sealing edge 103 is formed on the side of the packaging bag 30 corresponding to the tab 14, a bottom sealing edge 101 is formed on the side of the packaging bag 30 opposite to the tab 14 along the first direction, opposite side sealing edges 102 and a mold closing surface 106 are formed on the packaging bag 30 along the second direction, the two ends of the side sealing edge 102 are connected with the top sealing edge 103 and the bottom sealing edge 101 respectively, and the two ends of the mold closing surface 106 are connected with the top sealing edge 103 and the bottom sealing edge 101 respectively;

[0073] The mold closing surface 106 is attached to the side wall of the battery cell 10;

[0074] The top sealing edge 103, the side sealing edge 102 and the bottom sealing edge 101 are all formed by the packaging bag 30 located on both sides of the battery cell 10 along the third direction; the third direction is perpendicular to the first direction and the second direction;

[0075] The first battery monomer 1 comprises a first mold closing surface 116 and a first tab, the second battery monomer 2 comprises a second mold closing surface 126 and a second tab, and the first mold closing surface 116 is attached to the second mold closing surface 126;

[0076] The battery pack further comprises a protection plate 4 connected with the first tab and the second tab respectively, and the distance between the first mold closing surface 116 and the protection plate 4 is greater than the distance between the top surface of the packaging bag 30 close to the top sealing edge 103 and the protection plate 4 in the first direction.

[0077] The battery pack provided by the embodiment of the utility model, by first battery monomer 1 and second battery monomer 2 are arranged side by side along the second direction, and the first mold closing surface 116 of first battery monomer 1 and the second mold closing surface 126 of second battery monomer 2 are attached, the design of double battery cell battery pack is realized, and the double battery cell battery pack formed due to the attachment of the first mold closing surface 116 and the second mold closing surface 126. The edge does not exist in the attachment position, so as not to cause interference to the protection plate, avoid the problem that the conventional protection plate design is not applicable due to the interference of the folded edge and the protection plate, and the production cost of the soft package battery can be reduced. And due to the attachment of the first mold closing surface 116 and the second mold closing surface 126, there is no edge in both, the width increase caused by the folded edge and the attached glue is avoided, and the volume energy density is prevented from being reduced.

[0078] In the embodiment, the first battery monomer 1 is packaged by the first packaging bag 31, and the second battery monomer 2 is packaged by the second packaging bag 32.

[0079] The electrode 10 is provided with the tab 14 on at least one side in the first direction. Specifically, the electrode 10 can be provided with the tab 14 on one side in the first direction, or the electrode 10 can be provided with the tab 14 on both sides in the first direction. In this embodiment, the electrode 10 is provided with the tab 14 on one side in the first direction, and the electrode 10 is provided with the positive tab 104 and the negative tab 105 on the same side in the first direction. The positive tab 104 and the negative tab 105 are arranged side by side in the second direction.

[0080] The packaging bag 30 covers the outside of the electrode 10, and the packaging bag 30 is provided with the sealing surface 106 on one side of the electrode 10 in the second direction. In actual production, the packaging bag 30 can be flattened, the packaging bag 30 is divided into a first area and a second area in the second direction, the electrode 10 is placed in the first area of the packaging bag 30, and one side of the electrode 10 in the second direction is placed in the middle area of the packaging bag 30 between the first area and the second area. The second area of the packaging bag 30 covers the electrode 10. At this time, the packaging bag 30 is provided with the sealing surface 106 on one side of the electrode 10 in the second direction, and the other three sides of the packaging bag 30 are provided with the top sealing edge 103, the side sealing edge 102, and the bottom sealing edge 101, respectively.

[0081] In this embodiment, the first electrode 11 and the second electrode 12 can be the same model of electrode, and the electrochemical system and the size design of the first electrode 11 and the second electrode 12 are the same.

[0082] In some embodiments, the first battery monomer 1 and the second battery monomer 2 are provided with the tab 14 on the same side in the first direction.

[0083] In some embodiments, the protection plate 4 is connected to the first tab main area 1141 and the second tab main area 1241. When the battery group formed by the first battery monomer 1 and the second battery monomer 2 is connected to the protection plate 4, all the tabs 14 are kept flush in the same plane without bending the protection plate 4. Moreover, the polarity of the tabs at the corresponding positions is the same, which avoids the redesign of the protection plate 4.

[0084] The battery monomer provided by the embodiment of the utility model, the side corresponding to the tab 14 of the packaging bag 30 forms the top sealing edge 103, the side opposite to the tab 14 of the packaging bag 30 along the first direction forms the bottom sealing edge 101, the side opposite of the packaging bag 30 along the second direction forms the side sealing edge 102 and the mold closing surface 106; and the mold closing surface 106 is attached to the side wall of the battery cell 10; by forming the mold closing surface 106, the side of the battery cell 10 on the mold closing surface 106 does not exist the sealing edge, so that the two side-by-side arranged battery cells 10 are attached through the mold closing surface 106, the design of the double battery cell group is realized, and the double battery cell group formed does not exist the sealing edge on the side of the mold closing surface 106, so that the interference to the protection plate 4 is avoided, the problem that the conventional protection plate design is not applicable due to the interference between the folded edge and the protection plate 4 is avoided, and the production cost of the soft package battery can be reduced. And the side of the battery cell 10 on the mold closing surface 106 does not exist the sealing edge, the increase of the width caused by the folded edge and the attached glue is avoided, and the volume energy density is prevented from being reduced.

[0085] The battery cell 10 of the embodiment can be a winding type battery cell and can also be a laminated type battery cell.

[0086] After the battery cell 10 is packaged, the battery cell 10 is prepared into a battery monomer through the processes of liquid injection, formation, vacuum extraction and side sealing. In order to reduce the excessive PP glue overflow caused by the sealing stamping interface and the poor extrusion glue of the head of the battery cell, the packaging of the battery cell 10 can be performed in steps.

[0087] In some embodiments, in combination with Figure 10 As shown in the figure, the top sealing edge 103 and the bottom sealing edge 101 are packaged before the side sealing edge 102.

[0088] The side sealing edge 102 is formed with a side sealing edge sealing stamp 1021;

[0089] Along the first direction, the length of the overlapping area of the side sealing edge sealing stamp 1021 and the top sealing edge 103 is J1, and W1 is greater than or equal to 2*J1, where W1 is the width of the top sealing edge 103 along the first direction.

[0090] Along the first direction, the length of the overlapping area of the side sealing edge sealing stamp 1021 and the bottom sealing edge 101 is J2, and W2 is greater than or equal to 2*J2, where W2 is the width of the bottom sealing edge 101 along the first direction.

[0091] By limiting W1 to be greater than or equal to 2*J1 and limiting W2 to be greater than or equal to 2*J2, the excessive PP glue overflow caused by the sealing stamping interface can be reduced, and the poor extrusion glue of the head of the battery cell can be avoided.

[0092] In some other embodiments, in combination with Figure 11 As shown in the figure, the top sealing edge 103 and the side sealing edge 102 can be packaged before the bottom sealing edge 101.

[0093] The bottom seal edge 101 is formed with a bottom seal edge seal 1011;

[0094] In the second direction, the length of the overlapping area of the bottom seal edge seal 1011 and the side seal edge 102 is J3, which satisfies: W3≥2*J3, wherein W3 is the width of the side seal edge 102 in the second direction;

[0095] The second direction is perpendicular to both the first direction and the third direction.

[0096] By limiting W3≥2*J3, the situation of excessive PP overflow caused by excessive seal transfer can be reduced, and the situation of poor glue extrusion at the head of the battery cell can be avoided.

[0097] In some embodiments, the width W1 of the top seal edge 103 in the first direction is in the range of 0.8mm≤W1≤2mm;

[0098] The width W2 of the bottom seal edge 101 in the first direction is in the range of 1mm≤W2≤5mm;

[0099] The width W3 of the side seal edge 102 in the second direction is in the range of 1mm≤W3≤5mm.

[0100] In some embodiments, as shown in Figure 12 , Figure 13 The side seal edge 102 and the bottom seal edge 101 are folded on the same side of the battery cell 10 in the third direction and form a side seal edge folded edge portion 1022 and a bottom seal edge folded edge portion 1012, respectively.

[0101] The overlapping area of the side seal edge folded edge portion 1022 and the bottom seal edge folded edge portion 1012 forms a folded edge interference area 107, which is adapted to be folded towards the side seal edge folded edge portion 1022 or the bottom seal edge folded edge portion 1012 to form a folded corner 1071.

[0102] To reduce the width and height of the battery monomer, i.e. the size of the battery monomer in the second direction and the size of the battery monomer in the first direction, the side seal edge 102 and the bottom seal edge 101 need to be folded. The folding can be done in different ways such as single folding, double folding, etc. In this embodiment, no particular limitation is made.

[0103] After folding, the schematic diagram of the battery monomer is shown in Figure 12 The side seal edge 102 and the bottom seal edge 101 will interfere to form a sharp corner, i.e. a folded edge interference area 107. To avoid the sharp corner affecting the height of the battery, the sharp corner can be bent towards the side seal edge 102 or the bottom seal edge 101. As shown in Figure 13 It is preferred that the folded edge interference area 107 is bent towards the bottom seal edge 101 to form a folded corner 1071, and the angle of the bent sharp corner is smaller, which can reduce the stress applied to the aluminum plastic film during the bending process.

[0104] The embodiment can solve the interference between the side seal 102 and the bottom seal 101 caused by the folding edge by folding the folding edge interference area 107 towards the side seal folding edge portion 1022 or the bottom seal folding edge portion 1012 to form a folding corner 1071, thereby avoiding the length of the battery monomer from increasing.

[0105] In the embodiment, the side seal 102 and the bottom seal 101 are folded towards the same side of the battery cell 10 along the third direction. Since the top seal 103, the side seal 102 and the bottom seal 101 are all formed by the packaging bag 30 located on both sides of the battery cell 10 along the third direction. As one implementation form, both packaging bags 30 are folded towards the middle region of the battery cell 10 along the third direction. As another implementation form, the surfaces on both sides of the battery cell 10 along the third direction are defined as a first surface and a second surface respectively; one packaging bag 30 is kept flush with the first surface of the battery cell 10, and the other packaging bag 30 is folded along the third direction from the second surface towards the first surface. As still another implementation form, the surfaces on both sides of the battery cell 10 along the third direction are defined as a first surface and a second surface respectively; one packaging bag 30 is folded along the third direction from the first surface towards the second surface, and the other packaging bag 30 is folded along the third direction from the second surface towards the first surface. In this embodiment, the folding lengths of the packaging bags 30 along the third direction on both sides are not equal, that is, one side has a longer folding length and the other side has a shorter folding length.

[0106] Further, after the side seal 102 and the bottom seal 101 are folded towards the same side of the battery cell 10 along the third direction, the side seal folding edge portion 1022 and the bottom seal folding edge portion 1012 are preferably not beyond the surface of the battery cell 10 along the third direction, so as to avoid interference.

[0107] In some embodiments, the tab 14 includes a first positive tab 114 and a first negative tab 115 formed on the same side of the first battery monomer 1 along the first direction; the tab 14 also includes a second positive tab 124 and a second negative tab 125 formed on the same side of the second battery monomer 2 along the first direction.

[0108] The polarity of the tab 14 of the first battery monomer 1 close to the first mold joint surface 116 along the second direction is opposite to that of the tab 14 of the second battery monomer 2 close to the second mold joint surface 126 along the second direction.

[0109] After the first battery cell 11 is packaged by the first packaging bag 31, a first top seal 113 is formed on the side of the first packaging bag 31 corresponding to the tab 14 of the first battery cell 11; the first packaging bag 31 forms a first bottom seal 111 on the side opposite to the tab 14 along the first direction; the first packaging bag 31 forms a first side seal 112 on one of the sides adjacent to the first top seal 113 and the first bottom seal 111, and forms a first mold joint surface 116 on the other side.

[0110] Similarly, after the second packaging bag 32 encapsulates the second battery cell 12, a second top sealing edge 123 is formed on the side of the second packaging bag 32 corresponding to the tab 14 of the second battery cell 12, a second bottom sealing edge 121 is formed on the side of the second packaging bag 32 opposite to the tab 14 along the first direction, and a second side sealing edge 122 is formed on one of the sides of the second packaging bag 32 adjacent to the second top sealing edge 123 and the second bottom sealing edge 121, and a second mold closing surface 126 is formed on the other side.

[0111] When the battery cell 10 and the packaging bag 30 are assembled into the first battery monomer 1 and the second battery monomer 2 respectively, the first battery cell 11 and the second battery cell 12 are opposite in the way of entering the shell, that is, the polarity of the tabs on the side close to the mold closing surface 106 of the first battery monomer 1 and the second battery monomer 2 is opposite. The purpose is to ensure that the polarity of the corresponding positions is the same when the battery pack structure composed of the first battery monomer 1 and the second battery monomer 2 is connected with the protection plate 4, so as to avoid redesigning the protection plate 4 and reducing the production cost.

[0112] In some embodiments, the distance from the first negative tab 115 to the first mold closing surface 116 along the second direction is L1; the distance from the first positive tab 114 to the first mold closing surface 116 along the second direction is L2;

[0113] The distance from the second negative tab 125 to the second mold closing surface 126 along the second direction is L1'; the distance from the second positive tab 124 to the second mold closing surface 126 along the second direction is L2';

[0114] L1+L1'=L2+L2'=L is satisfied, where L is the width of the first battery monomer 1 or the second battery monomer 2 along the second direction.

[0115] By limiting L1+L1'=L2+L2'=L, it can be ensured that the connection positions correspond to each other and have the same polarity when the battery pack formed by the first battery monomer 1 and the second battery monomer 2 is connected with the protection plate 4. At the same time, this design does not require the production of additional types of battery cells, thereby reducing the production cost.

[0116] In some embodiments, in combination with Figures 6 to 9 As shown in the drawings, the first battery monomer 1 includes the first battery cell 11, and the second battery monomer 2 includes the second battery cell 12.

[0117] One side of the first battery cell 11 along the third direction is a first reference surface 119, and the part of the tab 14 of the first battery monomer 1 connected to the first battery cell 11 is bent towards the first reference surface 119 and forms a first tab bending part 118; the tab 14 of the first battery monomer 1 also forms a first tab main body area 1141;

[0118] The second electrode 12 has a second reference surface 129 on one side of the third direction. The tab 14 of the second battery cell 2 is bent towards the second reference surface 129 and forms a second tab bending part 128.

[0119] The first tab body area 1141 is parallel to the first reference surface 119, and the second tab body area 1241 is parallel to the second reference surface 129. The distance between the first tab body area 1141 and the first reference surface 119 along the third direction is D1, and the distance between the second tab body area 1241 and the second reference surface 129 along the third direction is D2. D1 = D2 is satisfied.

[0120] By limiting D1 = D2, when the battery pack formed by the first battery cell 1 and the second battery cell 2 is connected to the protection plate 4, all the tabs 14 can be kept flush in the same plane without bending the protection plate 4.

[0121] It should be noted that when the first electrode 11 and the second electrode 12 are placed in the same posture, the first reference surface 119 and the second reference surface 129 are two opposite surfaces of the two electrodes. At this time, in order to ensure that the battery pack has the same height, the tabs of the first battery cell 1 and the second battery cell 2 are bent in opposite directions.

[0122] The first tab bending part 118 is bonded to the first packaging bag 31 via the first tab insulating glue 117, and the second tab bending part 128 is bonded to the second packaging bag 32 via the second tab insulating glue 127.

[0123] In combination Figure 14 As shown, after the first battery cell 1 and the second battery cell 2 are placed side by side and form a battery pack, the first side sealing edge 112 of the first battery cell 1 is bent to form a first side sealing edge folding part 1121, and the first bottom sealing edge 111 of the first battery cell 1 is bent to form a first bottom sealing edge folding part 1111. The second side sealing edge 122 of the second battery cell 2 is bent to form a second side sealing edge folding part 1221, and the second bottom sealing edge 121 of the second battery cell 2 is bent to form a second bottom sealing edge folding part 1211. The first side sealing edge folding part 1121 and the second side sealing edge folding part 1221 are parallel to the first direction and are arranged opposite to each other along the second direction. The first bottom sealing edge folding part 1111 and the second bottom sealing edge folding part 1211 are parallel to the second direction.

[0124] Obviously, the above embodiments are only examples for clearly illustrating, and are not limitation to the embodiments. Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope of the present application.

Claims

1. A battery pack, characterized in that, The battery pack comprises: two battery cells arranged side by side along a second direction, the two battery cells being a first battery cell (1) and a second battery cell (2) respectively; the battery cell comprises: an electrode core (10) having a tab (14) formed on at least one side thereof along a first direction; a packaging bag (30) covering the outer side of the electrode core (10), the packaging bag (30) having a top sealing edge (103) formed on the side corresponding to the tab (14), a bottom sealing edge (101) formed on the side opposite to the tab (14) along the first direction, and opposite side sealing edges (102) and a mold closing surface (106) formed along a second direction, the two ends of the side sealing edge (102) being connected to the top sealing edge (103) and the bottom sealing edge (101) respectively, and the two ends of the mold closing surface (106) being connected to the top sealing edge (103) and the bottom sealing edge (101) respectively; the mold closing surface (106) is in contact with the side wall of the electrode core (10); the top sealing edge (103), the side sealing edge (102) and the bottom sealing edge (101) are all formed by the packaging bag (30) on both sides of the electrode core (10) along a third direction, the third direction being perpendicular to the first direction and the second direction; the first battery cell (1) comprises a first mold closing surface (116) and a first tab, and the second battery cell (2) comprises a second mold closing surface (126) and a second tab, the first mold closing surface (116) being arranged in contact with the second mold closing surface (126); the battery pack further comprises a protection plate (4) connected to the first tab and the second tab respectively, and the distance between the first mold closing surface (116) and the protection plate (4) along the first direction is greater than the distance between the top surface of the packaging bag (30) close to the top sealing edge (103) and the protection plate (4).

2. The battery pack of claim 1, wherein, the side sealing edge (102) is formed with a side sealing edge seal (1021); along the first direction, the length of the overlapping area of the side sealing edge seal (1021) and the top sealing edge (103) is J1, and W1≥2*J1 is satisfied, wherein W1 is the width of the top sealing edge (103) along the first direction; along the first direction, the length of the overlapping area of the side sealing edge seal (1021) and the bottom sealing edge (101) is J2, and W2≥2*J2 is satisfied, wherein W2 is the width of the bottom sealing edge (101) along the first direction.

3. The battery pack of claim 1, wherein, the bottom sealing edge (101) is formed with a bottom sealing edge seal (1011); along the second direction, the length of the overlapping area of the bottom sealing edge seal (1011) and the side sealing edge (102) is J3, and W3≥2*J3 is satisfied, wherein W3 is the width of the side sealing edge (102) along the second direction; the second direction is perpendicular to the first direction and the third direction.

4. The battery pack of claim 1, wherein, the width W1 of the top sealing edge (103) along the first direction is in the range of 0.8mm≤W1≤2mm. The width W2 of the bottom sealing edge (101) along the first direction ranges from 1mm to 5mm. The width W3 of the side sealing edge (102) along the second direction ranges from 1mm to 5mm.

5. The battery pack according to any one of claims 1 to 4, characterized by The side sealing edge (102) and the bottom sealing edge (101) are folded towards the same side of the battery cell (10) along the third direction, and form a side sealing edge folded edge portion (1022) and a bottom sealing edge folded edge portion (1012), respectively.

6. The battery pack of claim 5, wherein, The overlapping area of the side sealing edge folded edge portion (1022) and the bottom sealing edge folded edge portion (1012) forms a folded edge interference area (107), which is adapted to be folded towards the side sealing edge folded edge portion (1022) or the bottom sealing edge folded edge portion (1012) to form a folded corner (1071).

7. The battery pack of claim 1, wherein, The tab (14) includes a first positive tab (114) and a first negative tab (115) formed on the same side of the first battery monomer (1) along the first direction; the tab (14) also includes a second positive tab (124) and a second negative tab (125) formed on the same side of the second battery monomer (2) along the first direction. The polarity of the tab (14) of the first battery monomer (1) close to the first mold closing surface (116) along the second direction is opposite to that of the tab (14) of the second battery monomer (2) close to the second mold closing surface (126) along the second direction.

8. The battery pack of claim 7, wherein, The distance of the first negative tab (115) to the first mold closing surface (116) along the second direction is L1; the distance of the first positive tab (114) to the first mold closing surface (116) along the second direction is L2. The distance of the second negative tab (125) to the second mold closing surface (126) along the second direction is L1'; the distance of the second positive tab (124) to the second mold closing surface (126) along the second direction is L2'; L1+L1'=L2+L2'=L is satisfied, wherein L is the width of the first battery monomer (1) or the second battery monomer (2) along the second direction.

9. The battery pack of claim 7, wherein, The first battery monomer (1) includes a first battery cell (11), and the second battery monomer (2) includes a second battery cell (12). One side of the first battery cell (11) along the third direction is a first reference surface (119), and the part of the tab (14) of the first battery monomer (1) connected to the first battery cell (11) is folded towards the first reference surface (119) to form a first tab folding portion (118); the tab (14) of the first battery monomer (1) also forms a first tab main area (1141). One side of the second battery cell (12) along the third direction is a second reference surface (129), and the part of the tab (14) of the second battery monomer (2) connected to the second battery cell (12) is folded towards the second reference surface (129) to form a second tab folding portion (128); the tab (14) of the second battery monomer (2) also forms a second tab main area (1241).

10. The battery pack of claim 9, wherein, The first tab body area (1141) is parallel to the first reference surface (119), the second tab body area (1241) is parallel to the second reference surface (129), and the distance between the first tab body area (1141) and the first reference surface (119) along the third direction is D1, and the distance between the second tab body area (1241) and the second reference surface (129) along the third direction is D2, satisfying: D1=D2.

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