A core structure, a lithium battery device and a manufacturing method thereof

Abstract

The present invention discloses a cell structure, a lithium battery device and a manufacturing method thereof, belonging to the technical field of power lithium batteries. The cell assembly of the present invention includes a first cell assembly and a second cell assembly. The first cell assembly includes a plurality of first wound cores, a positive electrode tab and a negative electrode tab located on one side of the first wound core. The second cell assembly includes a plurality of second wound cores, a positive electrode tab and a negative electrode tab located on one side of the second wound core. The positive electrode tabs of the first cell assembly and the second cell assembly face each other and are connected to a positive electrode connecting piece, and the negative electrode tabs of the first cell assembly and the second cell assembly face each other and are connected to a negative electrode connecting piece. The positive electrode tabs and the negative electrode tabs are bent at their roots so that the positions of the first cell assembly and the second cell assembly are staggered from each other in the height direction of the wound core. The main use of the present invention is to further improve the battery energy density by adopting the method of cross-stacking cells.

Description

Technical Field

[0001] The present invention relates to the technical field of power lithium batteries, and more specifically, to a battery cell structure, a lithium battery device and a manufacturing method thereof. Background Art

[0002] Lithium batteries, also known as lithium-ion batteries, are currently widely used as a new energy source in power vehicles and mobile devices, which is conducive to alleviating the pollution problems caused by traditional fossil energy. With the development of lithium battery technology, in order to meet the needs of the industry and improve the convenience of using new energy batteries, large-capacity lithium batteries have become the development trend of the industry. On this basis, major battery manufacturers have launched multi-core parallel solutions to increase the energy capacity of battery packs. In order to increase the storage capacity of lithium batteries and extend the discharge time of lithium batteries, manufacturers have proposed many technical solutions to increase the capacity of lithium batteries. At this stage, the market is still dominated by double-core assembly, and butterfly welding technology is used for connection.

[0003] For example, Chinese patent CN215146167U discloses a butterfly welding device for battery cells, which includes a workbench, a linear module fixed on the workbench, a positive electrode welding mechanism, a positive electrode station pressing mechanism, a negative electrode welding mechanism and a negative electrode station pressing mechanism, and a battery cell tooling mechanism connected to the linear module. However, the butterfly welding process generally has the following defects: First, in order to reserve space for the butterfly welding process, it is necessary to reserve longer positive and negative pole ears, which easily leads to undesirable phenomena such as folding and wrinkling of the pole ears during the forming process of the battery cell, thereby causing the battery cell to be short-circuited and scrapped; second, during butterfly welding, the process requires the operation of combining the two battery cells, during which the positive and negative pole ears will be bent into a "Z" shape, which easily causes the pole ears to be bent and inserted into the battery cell body, thereby causing the lithium battery to be short-circuited and scrapped; third, the battery cell structure made by this process is not compact, and the energy density of the lithium battery is difficult to be further improved, which cannot meet the market demand.

[0004] After searching Chinese patent CN113644357A, a battery based on multi-core parallel connection and its assembly method are disclosed. After laser welding, the first pair of core units and the second pair of core units are bent toward the side facing away from the cover plate mechanism in the middle of the first single core and the second single core, and the positive and negative pole ears of the first pair of core units and the positive and negative pole ears of the second pair of core units are bent so that the first single core, the second single core, the third single core and the fourth single core are stacked along their thickness direction. Although the butterfly welding process is avoided in this scheme, the positive and negative pole ears still need to be bent and connected to the stop frame member after being extended. The required pole ears are relatively long, which is not conducive to the compactness of the battery cell structure. Moreover, if the battery cell structure requires any structure, pole ears of different lengths need to be designed, which is not convenient for any combination of batteries. Summary of the invention

[0005] 1. Technical problem to be solved by the invention

[0006] In view of at least some problems in the prior art, the present invention provides a cell structure, a lithium battery device and a manufacturing method thereof. By adopting the way of cross-stacking cells, the problem of difficult to further improve the energy density of the battery is solved.

[0007] 2. Technical solution

[0008] To achieve the above object, the technical solution provided by the present invention is as follows:

[0009] A cell structure includes

[0010] a cell assembly, the cell assembly includes a first cell assembly and a second cell assembly, the first cell assembly includes a plurality of first wound cores and a positive tab and a negative tab located on one side of the first wound core;

[0011] the second cell assembly includes a plurality of second wound cores and a positive tab and a negative tab located on one side of the second wound core;

[0012] the positive tab of the first cell assembly and the positive tab of the second cell assembly are opposite and connected to a positive connection piece, and the negative tab of the first cell assembly and the negative tab of the second cell assembly are opposite and connected to a negative connection piece;

[0013] the positive tab and the negative tab are bent at their roots, so that the positions of the first cell assembly and the second cell assembly are staggered with each other in the height direction of the wound core.

[0014] Further, when there are multiple wound cores in the first cell assembly or the second cell assembly, a positive tab and a negative tab are commonly led out by the multiple wound cores.

[0015] Further, the positive connection piece and the negative connection piece are perpendicular to the surface of the wound core.

[0016] The present invention also provides a manufacturing method of a cell structure for manufacturing the cell structure described above, including the following steps:

[0017] Step 1: Align the positive tab of the first cell assembly and the positive tab of the second cell assembly, and connect them to the positive connection piece; align the negative tab of the first cell assembly and the negative tab of the second cell assembly, and connect them to the negative connection piece;

[0018] Step 2: Move the first cell assembly and the second cell assembly along the height direction of the wound core, bend the positive tab and the negative tab at their roots, so that the surfaces of the positive tab and the negative tab are attached to one of the wound cores, and at the same time, the positions of the first cell assembly and the second cell assembly are staggered with each other.

[0019] Further, after the first battery cell assembly and the second battery cell assembly in the first step are aligned and connected, before the positive electrode tab and the negative electrode tab are bent at their roots, the first battery cell assembly and the second battery cell assembly are axisymmetric or centrosymmetric along their connection center line; when the first battery cell assembly and the second battery cell assembly are displaced in the second step, their moving directions are opposite.

[0020] The present invention also provides a lithium battery device, including two sets of the above-mentioned battery cell structures, and the two sets of battery cell structures are cross-fitted and stacked together along the gap where the first battery cell assembly and the second battery cell assembly are displaced and connected.

[0021] Further, the positive electrode connecting piece and the negative electrode connecting piece extend and are located on the same side of the lithium battery device.

[0022] Further, the positive electrode connecting pieces of the two sets of battery cell structures are both connected to the positive electrode adapter piece, and the negative electrode connecting pieces of the two sets of battery cell structures are both connected to the negative electrode adapter piece. The end of the positive electrode adapter piece that is not connected to the positive electrode connecting piece extends out of the lithium battery device, and the end of the negative electrode adapter piece that is not connected to the negative electrode connecting piece extends out of the lithium battery device, and the positive electrode adapter piece and the negative electrode adapter piece are attached to the surface of the core.

[0023] Further, the end of the positive electrode adapter piece extending out of the lithium battery device is connected to the positive electrode cover plate, and the end of the negative electrode adapter piece extending out of the lithium battery device is connected to the negative electrode cover plate.

[0024] The present invention also provides a manufacturing method for a lithium battery device for manufacturing the above-mentioned lithium battery device. Step 1: Stack two sets of the battery cell structures cross-fitted together along the gap where the first battery cell assembly and the second battery cell assembly are displaced and connected to form a square multi-core parallel structure.

[0025] Step 2: After the two sets of battery cell structures are cross-stacked, the positive electrode connecting piece and the negative electrode connecting piece extend and are located on the same side of the lithium battery device. Connect the positive electrode connecting pieces of the two sets of battery cell structures to the positive electrode adapter piece, and bend the positive electrode adapter piece towards the core to make the positive electrode adapter piece fit the surface of the core.

[0026] Connect the negative electrode connecting pieces of the two sets of battery cell structures to the negative electrode adapter piece, and bend the negative electrode adapter piece towards the core to make the negative electrode adapter piece fit the surface of the core.

[0027] Step 3: Connect one end of the positive electrode adapter piece to the positive electrode cover plate, and fold the positive electrode cover plate to make it fit the end face of the core; connect one end of the negative electrode adapter piece to the negative electrode cover plate, and fold the negative electrode cover plate to make it fit the end face of the core.

[0028] 3. Beneficial effects

[0029] Adopting the technical solution provided by the present invention, compared with the existing well-known technologies, it has the following remarkable effects:

[0030] (1) For a core structure, a lithium battery device and a manufacturing method thereof according to the present invention, the core components in the core structure include a first core component and a second core component, and the first core component and the second core component are paired and connected in the way of positive electrode tab to positive electrode tab, and negative electrode tab to negative electrode tab; then the positive electrode tab and the negative electrode tab are bent at their roots, so that the positions of the first core component and the second core component are staggered with each other in the winding core height direction, and two groups of core structures are connected in parallel to double the battery energy.

[0031] (2) For a core structure, a lithium battery device and a manufacturing method thereof according to the present invention, after the positions of the first core component and the second core component are staggered with each other in the winding core height direction, the positive electrode tab and the negative electrode tab are only bent at their roots, and other parts of the positive electrode tab and the negative electrode tab are in a state of mutual tension, avoiding the risk of battery short circuit and scrapping caused by the pole ear being bent and inserted into the core body again.

[0032] (3) For a core structure, a lithium battery device and a manufacturing method thereof according to the present invention, the positive electrode tabs are all connected to the positive electrode connecting piece in a straight state, and the negative electrode tabs are all connected to the negative electrode connecting piece in a straight state. The positive and negative electrode tabs do not need to be bent again to be connected to the positive and negative connecting pieces, and the required positive and negative electrode tabs are shorter, reducing the risk of easy folding and wrinkling caused by the length of the pole ear during the front-end forming process of the core.

[0033] (4) For a core structure, a lithium battery device and a manufacturing method thereof according to the present invention, the lithium battery device includes two groups of the core structures described above. The two groups of core structures are cross-matched and stacked together along the gap where the first core component and the second core component are misaligned and connected, doubling the number of cores and doubling the battery energy in this way. Moreover, only one positive electrode adapter piece and one negative electrode adapter piece are provided in each lithium battery device, simplifying the components and component structures in the device, making the battery device more compact, and further improving the energy density of the lithium battery.

[0034] (5) For a core structure, a lithium battery device and a manufacturing method thereof according to the present invention, the two groups of core structures are cross-matched and stacked together. The core structure combination method is simple and easy to operate, the combination method is flexible and changeable, and different forms and different numbers of core structures can be derived. Moreover, once the core structure is successfully combined, the battery capacity is doubled, greatly improving the energy of the battery and having good applicability to large-capacity lithium batteries. Description of the Drawings

[0035] Figure 1 It is a three-dimensional structure schematic diagram of the first core component or the second core component in the first embodiment of the present invention;

[0036] Figure 2 Schematic diagram of the three-dimensional structure of the first battery cell assembly or the second battery cell assembly from another angle in Embodiment 1 of the present invention;

[0037] Figure 3 Schematic diagram after the first battery cell assembly and the second battery cell assembly in Embodiment 1 of the present invention are paired and connected;

[0038] Figure 4 is Figure 3 Enlarged top view of the connection part between the first battery cell assembly and the second battery cell assembly in

[0039] Figure 5 is Figure 4 Bottom view in

[0040] Figure 6 Schematic diagram of the structure after the first battery cell assembly and the second battery cell assembly in Embodiment 1 of the present invention are paired and connected with a protective tape attached;

[0041] Figure 7 Schematic diagram of the structure from another angle after the first battery cell assembly and the second battery cell assembly in Embodiment 1 of the present invention are paired and connected with a protective tape attached;

[0042] Figure 8 Schematic diagram of the structure after the first battery cell assembly and the second battery cell assembly in Embodiment 1 of the present invention are staggered in the winding core height direction;

[0043] Figure 9 Enlarged front view of the connection positions where the first battery cell assembly and the second battery cell assembly in Embodiment 1 of the present invention are staggered;

[0044] Figure 10 Schematic diagram of the crosswise cooperation of the two groups of battery cell structures in Embodiment 1 in Embodiment 5 of the present invention;

[0045] Figure 11 Schematic diagram of the completed superposition structure of the two groups of battery cell structures in Embodiment 1 in Embodiment 5 of the present invention;

[0046] Figure 12 Planar schematic diagram after the two groups of battery cell structures in Embodiment 1 in Embodiment 5 of the present invention are completed in superposition;

[0047] Figure 13 Schematic diagram after the negative connection piece and the negative transfer piece of the battery cell structure in Embodiment 5 of the present invention are connected;

[0048] Figure 14 Schematic diagram of the negative connection piece and the negative transfer piece being folded together onto the surface of the winding core in Embodiment 5 of the present invention;

[0049] Figure 15 Schematic diagram of the positive connection piece and the positive transfer piece being folded together onto the surface of the winding core in Embodiment 5 of the present invention;

[0050] Figure 16 Schematic diagram of the structure of the insulating film wrapped around the outside of the lithium battery device in the fifth embodiment of the present invention;

[0051] Figure 17 Schematic diagram after the positive electrode adapter is connected to the positive electrode cover plate and the negative electrode adapter is connected to the negative electrode cover plate in the fifth embodiment of the present invention;

[0052] Figure 18 Schematic diagram of the structure after the positive electrode cover plate and the negative electrode cover plate are folded and buckled with the aluminum shell in the fifth embodiment of the present invention;

[0053] Figure 19 Schematic diagram after the first battery cell assembly and the second battery cell assembly are paired and connected in the second embodiment of the present invention;

[0054] Figure 20 Main view enlarged drawing of the connection position of the first battery cell assembly and the second battery cell assembly after they are paired and connected in the second embodiment of the present invention;

[0055] Figure 21 Schematic diagram of the completed superposition structure of the battery cell structure of Embodiment 1 and the battery cell structure of Embodiment 2 in the sixth embodiment of the present invention;

[0056] Figure 22 Schematic diagram of another angle structure of the completed superposition of the battery cell structure of Embodiment 1 and the battery cell structure of Embodiment 2 in the sixth embodiment of the present invention;

[0057] Figure 23 Schematic diagram after the first battery cell assembly and the second battery cell assembly are paired and connected in the third embodiment of the present invention;

[0058] Figure 24 Planar schematic diagram after the superposition of two sets of battery cell structures of Embodiment 3 in the seventh embodiment of the present invention;

[0059] Figure 25 Planar schematic diagram after the superposition of two sets of battery cell structures when the first battery cell assembly in the two sets of battery cell structures in the eighth embodiment of the present invention includes one wound core and the second battery cell assembly includes two wound cores;

[0060] Figure 26 Planar schematic diagram after the superposition of two sets of battery cell structures when the first battery cell assembly in the two sets of battery cell structures in the ninth embodiment of the present invention includes two wound cores and the second battery cell assembly includes two wound cores.

[0061] Explanation of the reference numerals in the schematic diagram:

[0062] 10. Battery cell assembly; 101. Wound core; 101a. First wound core; 101b. Second wound core; 102. Positive tab; 103. Negative tab; 104. Protective tape; 105. Pre-welding mark; 106. Protective sheet; 107. Connecting piece; 1071. Positive connecting piece; 1072. Negative connecting piece; 108. Final welding mark; 109. Adapter piece; 1091. Positive adapter piece; 1092. Negative adapter piece; 1010. Insulating film; 1011. Laser welding mark; 20. Positive cover plate; 30. Negative cover plate; 40. Aluminum shell. Detailed implementation manners

[0063] Next, the present invention will be described in detail with reference to the accompanying drawings. What is described here is only the preferred implementation manner of the present invention. Those skilled in the art can think of other ways to implement the present invention based on the preferred implementation manner, and these other ways also fall within the scope of the present invention.

[0064] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0065] Embodiment 1

[0066] This embodiment provides a battery cell structure. Combining Figure 1 As shown, for the convenience of description, the directions of X, Y, and Z are defined as shown in Figure 1 . Among them, the length direction of the wound core 101 is the X direction, the width direction is the Y direction, and the height direction is the Z direction. The definition of the above directions is only for the convenience of explanation and does not represent a limitation to the present invention.

[0067] As Figure 1-7, a battery cell structure, including a battery cell assembly 10, and the battery cell assembly 10 includes a first battery cell assembly and a second battery cell assembly. The first battery cell assembly includes a first wound core 101a and a positive tab 102 and a negative tab 103 located on one side of the first wound core 101a. The second battery cell assembly includes a second wound core 101b and a positive tab 102 and a negative tab 103 located on one side of the second wound core 101b. Specifically, the positive tabs and negative tabs of the first battery cell assembly and the second battery cell assembly are both located on the XZ side surface of the wound core. When the first battery cell assembly and the second battery cell assembly are connected, the tabs are connected to each other through a connecting piece 107, and the connecting piece 107 is divided into a positive connecting piece 1071 and a negative connecting piece 1072. Specifically, when connecting, the positive tab of the first battery cell assembly and the positive tab of the second battery cell assembly face each other and are connected to the positive connecting piece 1071, and the negative tab of the first battery cell assembly and the negative tab of the second battery cell assembly face each other and are connected to the negative connecting piece 1072.

[0068] As Figure 3 In this case, in this embodiment, after the first battery cell assembly and the second battery cell assembly are connected through the connecting piece 107, the two pairs of XY surfaces of the first battery cell assembly and the second battery cell assembly are aligned, and the first battery cell assembly and the second battery cell assembly are axisymmetric with respect to the middle position where they are connected. At the same time, the positive connecting piece 1071 fits with the surfaces of the two positive tabs 102 and the XY surface of the first wound core 101a, and the negative connecting piece 1072 fits with the surfaces of the two negative tabs 103 and the XY surface of the first wound core 101a, and the positive tab and the negative tab are both in a straight state.

[0069] As Figure 8 and Figure 9 In this case, the first wound core 101a in the first battery cell assembly is moved in the negative direction of the Z axis, and the second wound core 101b in the second battery cell assembly is moved in the positive direction of the Z axis, so that the positive tab and the negative tab are bent at their roots, and the positions of the first battery cell assembly and the second battery cell assembly are staggered from each other in the height direction of the wound core, forming the battery cell structure in this embodiment, where the connection part between the tab and the wound core is the root of the tab. After their positions are staggered, the positive connecting piece 1071 and the negative connecting piece 1072 are perpendicular to the surface, and the positive tab and the negative tab are in contact with the XZ end face of the wound core. Moreover, the distance by which the first battery cell assembly and the second battery cell assembly are staggered from each other is the thickness of one wound core 101.

[0070] In this embodiment, the roots of the positive tabs 102 and the negative tabs 103 of the first battery cell assembly and the second battery cell assembly are both located on the side close to the XY plane, and the negative tab 103 is closer to one end of the wound core than the positive tab 102, that is, the positive tab 102 is located inside the negative tab 103.

[0071] Before the first battery cell assembly and the second battery cell assembly are connected, the positive electrode tab 102 and the negative electrode tab 103 are respectively pre-welded together to obtain a pre-weld mark 105, and protective tapes 104 are respectively attached to the roots of the electrode tabs. In this embodiment, the specific welding method is not limited, but ultrasonic welding is preferably used.

[0072] In this embodiment, when the first battery cell assembly and the second battery cell assembly are paired and connected, the protective sheet 106 and the connecting sheet 107 are respectively placed above and below the corresponding electrode tabs, and then the three are welded together to obtain a final weld mark 108, and protective tapes 104 are respectively attached to the final weld mark 108. The materials of the positive electrode tab 102, its corresponding protective sheet 106, and connecting sheet 1071 are all aluminum, and the materials of the negative electrode tab 103, its corresponding protective sheet 106, and connecting sheet 1072 are all copper. Similarly, the specific welding method is not limited during welding, but ultrasonic welding is preferably used.

[0073] In some cases, in this embodiment, there are multiple wound cores in the first battery cell assembly or the second battery cell assembly. When there are multiple wound cores in the first battery cell assembly or the second battery cell assembly, a positive electrode tab and a negative electrode tab are jointly led out by the multiple wound cores.

[0074] Embodiment Two

[0075] Combined with Figure 19 and Figure 20 , this embodiment provides another battery cell structure. In this embodiment, compared with Embodiment One, the difference is that in this embodiment, the positive electrode tabs 102 and the negative electrode tabs 103 of the first battery cell assembly and the second battery cell assembly are both located on the side close to the XY plane, but the positive electrode tab 102 is closer to one end of the wound core than the negative electrode tab 103, that is, the positive electrode tab 102 is located outside the negative electrode tab 103.

[0076] In this embodiment, after the first battery cell assembly and the second battery cell assembly are paired and connected, the positive electrode connecting sheet 1071 is attached to the surfaces of the two positive electrode tabs 102 and the XY surface of the second wound core 101b, and the negative electrode connecting sheet 1072 is attached to the surfaces of the two negative electrode tabs 103 and the XY surface of the second wound core 101b. When there is a dislocation, the first wound core 101a in the first battery cell assembly is moved in the positive direction of the Z axis, and the second wound core 101b in the second battery cell assembly is moved in the negative direction of the Z axis. The positive electrode tab 102 and the negative electrode tab 103 are bent at their roots, so that the positions of the first battery cell assembly and the second battery cell assembly are staggered in the height direction of the wound core, forming the battery cell structure in this embodiment.

[0077] The other structures of the battery cell structure in this embodiment are the same as those in Embodiment One, and will not be elaborated here.

[0078] Embodiment Three

[0079] Combined with Figure 23In this embodiment, another cell structure is provided. In this embodiment, compared with the first embodiment, the difference is that in this embodiment, the positive tab 102 is located inside the negative tab 103, or the positive tab 102 is located outside the negative tab 103, and both are acceptable.

[0080] In this embodiment, after the first cell component and the second cell component are paired and connected, the fitting position of the connecting piece 107 is not limited either. The connecting piece 107 can be fitted to the XY surface of the first wound core 101a, or can be fitted to the XY surface of the second wound core 101b. As Figure 23 shown, after the first cell component and the second cell component are paired and connected, the connecting piece 107 is fitted to the XY surface of the first wound core 101a. When misaligned, the first wound core 101a in the first cell component is moved in the positive direction of the Z axis, and the second wound core 101b in the second cell component is moved in the negative direction of the Z axis, so that the positive tab and the negative tab are bent at their roots, and the positions of the first cell component and the second cell component are staggered from each other in the height direction of the wound core, forming the cell structure in this embodiment. In this embodiment, the distance by which the first cell component and the second cell component are staggered from each other is the thickness of one wound core 101.

[0081] It should be emphasized that in this embodiment, when the first cell component and the second cell component are paired and connected, before the positive tab and the negative tab are bent at their roots, the first cell component and the second cell component are already staggered in the thickness direction of the wound core. Only one pair of the two pairs of XY surfaces of the first cell component and the second cell component is aligned, and the first cell component and the second cell component are centrosymmetric with respect to the intermediate position where they are connected.

[0082] The other structures of the cell structure in this embodiment are the same as those in the first embodiment and will not be elaborated here.

[0083] Embodiment Four

[0084] In this embodiment, a manufacturing method for the cell structure in Embodiment One, Embodiment Two, or Embodiment Three is provided, including the following steps:

[0085] Step One: Align the positive tabs of the first cell component and the second cell component and connect them to the positive connecting piece 1071; align the negative tabs of the first cell component and the second cell component and connect them to the negative connecting piece 1072;

[0086] Step Two: Move the first cell component and the second cell component in the height direction of the wound core, that is, move along the Z axis, and the positive tab and the negative tab are bent at their roots so that the positive tab and the negative tab are fitted to one end face of the wound core, and at the same time, the positions of the first cell component and the second cell component are staggered from each other.

[0087] In this embodiment, after the first battery cell assembly and the second battery cell assembly are aligned and connected in step one, before the positive electrode tab 102 and the negative electrode tab 103 are bent at their roots, the first battery cell assembly and the second battery cell assembly are axisymmetric or centrosymmetric along their connection center line. When the first battery cell assembly and the second battery cell assembly are misaligned and moved in step two, their moving directions are opposite.

[0088] Before performing step one, the positive electrode tab 102 and the negative electrode tab 103 are respectively pre-welded together to obtain a pre-weld mark 105, and protective tapes 104 are respectively attached to the roots of the electrode tabs. In step one, when the first battery cell assembly and the second battery cell assembly are paired and connected, the protection sheet 106 and the connection sheet 107 are respectively placed above and below the corresponding electrode tabs, and then the three are welded together to obtain a final weld mark 108, and protective tapes 104 are also respectively attached to the final weld mark 108.

[0089] Embodiment Five

[0090] This embodiment provides a lithium battery device, including two sets of battery cell structures in Embodiment One, and the two sets of battery cell structures are mutually cross-matched and stacked together along the gap where the first battery cell assembly and the second battery cell assembly are misaligned and connected. Specifically, as Figure 10 shown, after one set of battery cell structures is rotated 180° in the XY plane, the two sets of battery cell structures are mutually cross-matched and stacked together along the gap where the first battery cell assembly and the second battery cell assembly are misaligned and connected, forming the lithium battery device in this embodiment, as Figure 11 shown. As Figure 12 shown, in the lithium battery device in this embodiment, the orientations of the electrode tabs in each battery cell assembly are the same, and are all located at the negative orientation in the Z-axis direction.

[0091] Combined with Figure 13-18, in this embodiment, after two groups of battery cell structures are cross - stacked together, the positive connection pieces 1071 and the negative connection pieces 1072 extend and are located on the same side of the lithium - battery device, and the positive connection pieces 1071 of the two groups of battery cell structures are close to each other. Both the positive connection pieces 1071 and the negative connection pieces 1072 are connected to the adapter piece 109. The adapter piece 109 is divided into a positive - pole adapter piece 1091 and a negative - pole adapter piece 1092. Among them, the material of the positive - pole adapter piece 1091 is aluminum, and the material of the negative - pole adapter piece 1092 is copper. Specifically, the positive connection pieces 1071 of the two groups of battery cell structures are both connected to the positive - pole adapter piece 1091, and the negative connection pieces 1072 of the two groups of battery cell structures are both connected to the negative - pole adapter piece 1092. The end of the positive - pole adapter piece 1091 that is not connected to the positive connection piece 1071 extends out of the lithium - battery device, and the end of the negative - pole adapter piece 1092 that is not connected to the negative connection piece 1072 extends out of the lithium - battery device. The extending directions of the positive - pole adapter piece 1091 and the negative - pole adapter piece 1092 out of the lithium - battery device are opposite, and the positive - pole adapter piece 1091 and the negative - pole adapter piece 1092 are attached to the surface of the core. The end of the positive - pole adapter piece 1091 extending out of the lithium - battery device is connected to the positive - pole cover plate 20, and the end of the negative - pole adapter piece 1092 extending out of the lithium - battery device is connected to the negative - pole cover plate 30.

[0092] It should be noted that in this embodiment, after the positive connection piece 1071 is welded to the positive - pole adapter piece 1091 and the negative connection piece 1072 is welded to the negative - pole adapter piece 1092, laser welding marks 1011 will be formed at the welded joints, and a protective tape 104 needs to be attached to the laser welding marks 1011. Then, the positive connection piece 1071 and the positive - pole adapter piece 1091 are folded together onto the core 101, so that the adapter piece 109 is attached to the surface of the core 101; similarly, the negative connection piece 1072 and the negative - pole adapter piece 1092 are folded together onto the core 101 in the other direction and attached to the surface of the core 101. The specific welding method is not limited in this embodiment, but laser welding is preferably used.

[0093] In this embodiment, after the positive - pole adapter piece 1091 and the negative - pole adapter piece 1092 are folded onto the surface of the core, the outside of the lithium - battery device is coated with an insulating film 1010, and then it is placed into the aluminum shell 40. The function of the insulating film 1010 is to fix the two groups of battery cell structures and prevent the battery cells from being scratched during the subsequent process of being placed into the aluminum shell 40.

[0094] The positive - pole adapter piece 1091 is connected to the positive - pole cover plate 20 by laser welding, and the negative - pole adapter piece 1092 is connected to the negative - pole cover plate 30 by laser welding. The welded positive - pole cover plate 20 and negative - pole cover plate 30 are respectively folded 90 degrees and buckled with the aluminum shell 40, and finally welded by laser to finally form the lithium - battery device in this embodiment, as Figure 18 shown.

[0095] In some cases, the two sets of battery cell structures in Embodiment 2 can also be cross-over stacked together. In this case, after the two sets of battery cell structures are cross-over stacked together, the positive connection piece 1071 and the negative connection piece 1072 extend out and are located on the same side of the lithium battery device, and the negative connection pieces 1072 of the two sets of battery cell structures are close to each other.

[0096] Embodiment 6

[0097] Combined with Figure 21 and Figure 22 , different from Embodiment 5, in this embodiment, another lithium battery device is provided, which includes a set of battery cell structures in Embodiment 1 and a set of battery cell structures in Embodiment 2. The two sets of battery cell structures are cross-overly cooperatively stacked together along the gap where the first battery cell assembly and the second battery cell assembly are misaligned and connected. After one set of battery cell structures is rotated 180° in the XY plane, the two sets of battery cell structures are cross-overly cooperatively stacked together along the gap where the first battery cell assembly and the second battery cell assembly are misaligned and connected, forming the lithium battery device in this embodiment. In this embodiment, after the two sets of battery cell structures are cross-over stacked together, the positive connection piece 1071 and the negative connection piece 1072 extend out and are located on the same side of the lithium battery device, and the positions of the positive connection piece 1071 and the negative connection piece 1072 cross each other.

[0098] The other structures and formation methods of the lithium battery device in this embodiment are the same as those in Embodiment 5, and will not be elaborated here.

[0099] Embodiment 7

[0100] Combined with Figure 24 , in this embodiment, another lithium battery device is provided, which includes two sets of battery cell structures in Embodiment 3. The two sets of battery cell structures are cross-overly cooperatively stacked together along the gap where the first battery cell assembly and the second battery cell assembly are misaligned and connected. For the lithium battery device in this embodiment, the orientation of the tab root of the battery cell assembly located in the upper layer is different from that of the tab root of the battery cell assembly located in the lower layer. The orientation of the tab root of the battery cell assembly located in the upper layer is close to the positive orientation in the Z-axis direction, and the orientation of the tab root of the battery cell assembly located in the lower layer is close to the negative orientation in the Z-axis direction.

[0101] The other structures and formation methods of the lithium battery device in this embodiment are the same as those in Embodiment 5, and will not be elaborated here.

[0102] Embodiment 8

[0103] Combined with Figure 25As shown in the figure, in this embodiment, another lithium battery device is provided. In some cases, in Embodiment 1, there are multiple wound cores in the first core assembly or the second core assembly. In this embodiment, the first core assembly includes one wound core, and the second core assembly includes two wound cores. The positive tabs of the two wound cores in the second core assembly are pre-welded into one positive tab, and the negative tabs of the two wound cores are pre-welded into one negative tab. Then, the first core assembly and the second core assembly are paired and connected, and their connection structure and connection method are the same as those in Embodiment 1 and Embodiment 4, forming the core structure in this embodiment.

[0104] Two sets of the core structures in this embodiment are overlapped with each other in a crosswise manner along the gap where the first core assembly and the second core assembly are misaligned and connected to form a lithium battery device, and other structures and formation methods are the same as those in Embodiment 5.

[0105] Embodiment 9

[0106] Combined with Figure 26 As shown in the figure, in this embodiment, another lithium battery device is provided. In some cases, in Embodiment 1, there are multiple wound cores in the first core assembly or the second core assembly. In this embodiment, the first core assembly includes two wound cores, and the second core assembly includes two wound cores. The positive tabs of the two wound cores in the first core assembly are pre-welded into one positive tab, and the negative tabs of the two wound cores are pre-welded into one negative tab; the positive tabs of the two wound cores in the second core assembly are pre-welded into one positive tab, and the negative tabs of the two wound cores are pre-welded into one negative tab. Then, the first core assembly and the second core assembly are paired and connected, and their connection structure and connection method are the same as those in Embodiment 1 and Embodiment 4, forming the core structure in this embodiment.

[0107] Two sets of the core structures in this embodiment are overlapped with each other in a crosswise manner along the gap where the first core assembly and the second core assembly are misaligned and connected to form a lithium battery device, and other structures and formation methods are the same as those in Embodiment 5.

[0108] Embodiment 10

[0109] In this embodiment, a manufacturing method for the lithium battery device in Embodiment 6, Embodiment 7, Embodiment 8 or Embodiment 9 is provided, including the following steps:

[0110] Step 1: Two sets of core structures are overlapped with each other in a crosswise manner along the gap where the first core assembly and the second core assembly are misaligned and connected to form a square multi-wound core parallel structure;

[0111] Step 2: After the two groups of cell structures are stacked in a cross pattern, the positive connection piece 1071 and the negative connection piece 1072 extend and are located on the same side of the lithium battery device. Connect the positive connection pieces 1071 of the two groups of cell structures to the positive adapter piece 1091, and bend the positive adapter piece 1091 in the direction close to the core so that the positive adapter piece 1091 fits against the surface of the core.

[0112] Connect the negative connection pieces 1072 of the two groups of cell structures to the negative adapter piece 1092, and bend the negative adapter piece 1092 in the direction close to the core so that the negative adapter piece 1092 fits against the surface of the core.

[0113] Step 3: Connect one end of the positive adapter piece 1091 to the positive cover plate 20, and fold the positive cover plate 20 so that it fits against the end face of the core; connect one end of the negative adapter piece 1092 to the negative cover plate 30, and fold the negative cover plate 30 so that it fits against the end face of the core.

[0114] Specifically, in this embodiment, in Step 1, before the two groups of cell structures are stacked in a cross pattern, one of the groups of cell structures needs to be rotated 180° in the XY plane, and then the two groups of cell structures are mutually cross-fitted and stacked along the gap where the first cell assembly and the second cell assembly are misaligned to form a square multi-core parallel structure. In Step 2, after the positive connection piece 1071 is welded to the positive adapter piece 1091 and the negative connection piece 1072 is welded to the negative adapter piece 1092, laser welding marks 1011 will be formed at the welded joints, and a protective tape 104 needs to be attached to the laser welding marks 1011. Between Step 2 and Step 3, the outside of the lithium battery device needs to be coated with an insulating film 1010, and then it is placed in an aluminum shell 40. In Step 3, the welded positive cover plate 20 and negative cover plate 30 are respectively folded 90 degrees and buckled with the aluminum shell 40, and finally welded by laser.

[0115] It should be noted that although only some specific forms of cell structures and lithium battery devices are listed in the above embodiments, the cell structures and lithium battery devices in the present invention are not limited to the forms in the above embodiments. By referring to the embodiments listed in the present invention for combination, other different forms and different numbers of cell structures can be derived to form different lithium battery devices.

[0116] The above schematically describes the present invention and its embodiments. This description is not restrictive, and only one of the embodiments of the present invention is shown in the drawings. The actual structure is not limited to this. Therefore, if those of ordinary skill in the art are inspired by it and design similar structural methods and embodiments without creative efforts without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A battery cell structure, characterized in that: Comprising, a battery cell assembly (10), the battery cell assembly (10) comprising a first battery cell assembly and a second battery cell assembly, the first battery cell assembly comprising a plurality of first wound cores (101a) and a positive electrode tab (102) and a negative electrode tab (103) located on one side of the first wound core (101a); the second battery cell assembly comprising a plurality of second wound cores (101b) and a positive electrode tab (102) and a negative electrode tab (103) located on one side of the second wound core (101b); the positive electrode tabs (102) of the first battery cell assembly and the positive electrode tabs (102) of the second battery cell assembly are opposite to each other and connected to a positive electrode connecting piece (1071), and the negative electrode tabs (103) of the first battery cell assembly and the negative electrode tabs (103) of the second battery cell assembly are opposite to each other and connected to a negative electrode connecting piece (1072); move the first wound cores (101a) in the first battery cell assembly in the negative direction of the Z-axis, and move the second wound cores (101b) in the second battery cell assembly in the positive direction of the Z-axis, so that the positive electrode tabs (102) and the negative electrode tabs (103) are bent at their roots, and the positions of the first battery cell assembly and the second battery cell assembly are staggered from each other in the height direction of the wound core.

2. The cell structure according to claim 1, wherein: When there are multiple wound cores in the first battery cell assembly or the second battery cell assembly, a positive electrode tab (102) and a negative electrode tab (103) are jointly led out by the multiple wound cores.

3. A core cell structure according to claim 1 or 2, characterized in that: The positive electrode connecting piece (1071) and the negative electrode connecting piece (1072) are perpendicular to the surface of the wound core.

4. A method for manufacturing a battery cell structure, which is used to manufacture a battery cell structure according to any one of claims 1-3, characterized in that, Including the following steps: Step 1: Align the positive electrode tabs (102) of the first battery cell assembly and the positive electrode tabs (102) of the second battery cell assembly, and connect them to the positive electrode connecting piece (1071); align the negative electrode tabs (103) of the first battery cell assembly and the negative electrode tabs (103) of the second battery cell assembly, and connect them to the negative electrode connecting piece (1072); Step 2: Move the first battery cell assembly and the second battery cell assembly in the height direction of the wound core, and the positive electrode tabs (102) and the negative electrode tabs (103) are bent at their roots, so that the surfaces of the positive electrode tabs (102) and the negative electrode tabs (103) are attached to one of the wound cores, and at the same time, the positions of the first battery cell assembly and the second battery cell assembly are staggered from each other.

5. The method for manufacturing a battery cell structure according to claim 4, characterized in that: After the first battery cell assembly and the second battery cell assembly in Step 1 are aligned and connected, before the positive electrode tabs (102) and the negative electrode tabs (103) are bent at their roots, the first battery cell assembly and the second battery cell assembly are axisymmetric or centrosymmetric about their connection center line; when the first battery cell assembly and the second battery cell assembly are displaced in Step 2, their moving directions are opposite.

6. A lithium battery device, characterized in that, Including two sets of battery cell structures manufactured by the battery cell structure according to any one of claims 1-3 or the manufacturing method of the battery cell structure according to any one of claims 4-5, and the two sets of battery cell structures are overlapped with each other in a cross-matching manner along the gap where the first battery cell assembly and the second battery cell assembly are connected in a staggered manner.

7. A lithium battery device according to claim 6, characterized in that: The positive electrode connecting piece (1071) and the negative electrode connecting piece (1072) extend and are located on the same side of the lithium battery device.

8. A lithium battery device according to claim 7, characterized in that: The positive connection tabs (1071) of the two groups of the cell structures are both connected to the positive transfer tab (1091), and the negative connection tabs (1072) of the two groups of the cell structures are both connected to the negative transfer tab (1092). The end of the positive transfer tab (1091) that is not connected to the positive connection tab (1071) extends out of the lithium battery device, and the end of the negative transfer tab (1092) that is not connected to the negative connection tab (1072) extends out of the lithium battery device. Moreover, the positive transfer tab (1091) and the negative transfer tab (1092) are attached to the surface of the wound core together.

9. The lithium battery device according to claim 8, wherein: The end of the positive transfer tab (1091) that extends out of the lithium battery device is connected to the positive cover plate (20), and the end of the negative transfer tab (1092) that extends out of the lithium battery device is connected to the negative cover plate (30).

10. A method for manufacturing a lithium battery device, which is used to manufacture a lithium battery device as described in claim 9, and is characterized in that: Step 1: Stack the two groups of the cell structures in a cross - type fit along the gap where the first cell assembly and the second cell assembly are misaligned with each other to form a square multi - wound - core parallel structure. Step 2: After the two groups of the cell structures are stacked in a cross - type manner, the positive connection tabs (1071) and the negative connection tabs (1072) extend out and are located on the same side of the lithium battery device. Connect the positive connection tabs (1071) of the two groups of the cell structures to the positive transfer tab (1091), and bend the positive transfer tab (1091) towards the direction close to the wound core to make the positive transfer tab (1091) attached to the surface of the wound core. Connect the negative connection tabs (1072) of the two groups of the cell structures to the negative transfer tab (1092), and bend the negative transfer tab (1092) towards the direction close to the wound core to make the negative transfer tab (1092) attached to the surface of the wound core. Step 3: Connect one end of the positive transfer tab (1091) to the positive cover plate (20), and fold the positive cover plate (20) to make it attached to the end face of the wound core; connect one end of the negative transfer tab (1092) to the negative cover plate (30), and fold the negative cover plate (30) to make it attached to the end face of the wound core.

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