Solid-state battery cell, battery module and battery pack

Abstract

The utility model discloses a solid-state battery cell, a battery module and a battery pack, and belongs to the technical field of solid-state batteries. The solid-state battery cell comprises a plurality of battery cell units, the battery cell units are connected in series, and each battery cell unit comprises a double-sided positive plate, a double-sided negative plate and a solid-state electrolyte; the double-sided negative plate and the double-sided positive plate are connected in parallel; a solid electrolyte is arranged between the adjacent double-sided positive plate and the double-sided negative plate to form a battery cell unit; wherein the double-sided positive plate and the double-sided negative plate respectively comprise a composite current collector. According to the solid-state battery cell, the formation mode of combining two connection modes of parallel connection and series connection is adopted, and the voltage and the capacity of the single battery cell can be adjusted according to the series-parallel connection number, so that the designability of the voltage and the capacity of the single battery cell is realized; moreover, the composite current collector is simple in structure, light in weight, simple and rapid to process, cost-saving, and good in structural stability, and can improve the safety performance and ensure the working reliability of the solid-state battery cell, the battery module and the battery pack.

Description

Technical Field

[0001] The utility model relates to the technical field of solid-state batteries, and in particular to a solid-state battery cell, a battery module and a battery pack. Background Art

[0002] At present, in the preparation process of lithium-ion solid-state batteries, lithium-ion solid-state batteries are usually formed by series connection or parallel connection. Among them, the series connection method can increase the voltage of the lithium-ion solid-state battery cell, but the disadvantage is that the capacity of the lithium-ion solid-state battery cell will be limited; and the parallel connection method can increase the capacity of the lithium-ion solid-state battery cell, but the disadvantage is that the voltage of the lithium-ion solid-state battery cell will be limited, and it is difficult to simultaneously meet the high voltage and high capacity requirements of the lithium-ion solid-state battery cell.

[0003] In response to the above problems, solid-state battery cells, battery modules and battery packs are urgently needed to solve the above problems. Utility Model Content

[0004] The purpose of the present invention is to provide a solid-state battery cell, a battery module and a battery pack, which can ensure that the voltage and capacity of the solid-state battery cell are relatively high, so as to simultaneously meet the requirements of high voltage and high capacity of the solid-state battery cell.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A solid-state battery cell comprises a plurality of battery cells, each of which is connected in series, and each of the battery cells comprises:

[0007] Double-sided positive electrode;

[0008] a double-sided negative electrode sheet connected in parallel with the double-sided positive electrode sheet;

[0009] A solid electrolyte is provided between the adjacent double-sided positive electrode sheet and the double-sided negative electrode sheet to form the battery cell unit;

[0010] Wherein, the double-sided positive electrode sheet and the double-sided negative electrode sheet respectively include composite current collectors.

[0011] As an optional solution, the composite current collector includes a composite layer, a conductive connector, a first metal layer and a second metal layer, the conductive connector is arranged in the composite layer, the first metal layer and the second metal layer are respectively arranged on two opposite surfaces of the composite layer, and the first metal layer and the second metal layer are respectively in contact with the conductive connector.

[0012] As an optional solution, a plurality of the double-sided positive electrode sheets and the double-sided negative electrode sheets are respectively provided, and one double-sided positive electrode sheet is connected in parallel with one double-sided negative electrode sheet.

[0013] As an alternative, the voltage between a pair of positive and negative electrodes is A, the capacitance is B, the number of the double-sided positive electrode sheets and the double-sided negative electrode sheets connected in parallel is M, the voltage of the battery cell unit is A, and the capacitance is M*B; the number of the battery cell units connected in series is N, the voltage of the solid-state battery is N*A, and the capacitance is M*B.

[0014] As an alternative, the double-sided positive electrode sheet further includes:

[0015] A first active material layer, disposed on the first metal layer, and a first portion of the first metal layer for welding the tab extends outside the first active material layer;

[0016] A second active material layer, disposed on one side of the second metal layer, and a second portion of the second metal layer for welding the tab extends outside the second active material layer, and both the first active material layer and the second active material layer are positive electrode materials.

[0017] As an alternative, the double-sided negative electrode sheet further includes:

[0018] A third active material layer, disposed on the first metal layer, and a first portion of the first metal layer for welding the tab extends outside the third active material layer;

[0019] A fourth active material layer, disposed on one side of the second metal layer, and a second portion of the second metal layer for welding the tab extends outside the fourth active material layer, and both the third active material layer and the fourth active material layer are negative electrode materials;

[0020] Wherein, the portions of the conductive connection members provided in the composite layer of the double-sided positive electrode sheet and the portions of the conductive connection members provided in the composite layer of the adjacent double-sided negative electrode sheet are respectively located on opposite sides.

[0021] As an alternative, the solid-state battery further includes:

[0022] Positive and negative series electrode sheets, connected in series between two adjacent battery cell units, and a solid-state electrolyte is provided between the adjacent positive and negative series electrode sheets and the double-sided positive electrode sheet, and between the adjacent positive and negative series electrode sheets and the double-sided negative electrode sheet.

[0023] As an alternative, the positive and negative series electrode sheets include:

[0024] The composite current collector;

[0025] A fifth active material layer, disposed on the first metal layer;

[0026] The sixth active material layer is disposed on one side of the second metal layer, and one of the fifth active material layer and the sixth active material layer is a positive electrode material, and the other is a negative electrode material.

[0027] The battery module includes a plurality of solid-state battery cells as described above.

[0028] The battery pack includes a plurality of battery modules as described above.

[0029] The beneficial effects of the present utility model are as follows:

[0030] By connecting the double-sided negative electrode sheet and the double-sided positive electrode sheet in parallel, and then arranging a solid electrolyte between adjacent double-sided positive electrode sheets and double-sided negative electrode sheets to form a battery cell unit; then connecting the formed battery cell units in series with each other to form a solid-state battery cell; that is, first forming a battery cell unit by parallel connection, and then connecting the formed battery cell units in series, so as to form a solid-state battery cell, combining the two connection methods of parallel connection and series connection, so as to ensure that the formed solid-state battery cell has a large voltage and a high capacitance, and further can simultaneously meet the requirements of large voltage and high capacitance of the solid-state battery cell.

[0031] Moreover, by making the double-sided positive electrode sheet and the double-sided negative electrode sheet respectively include a composite current collector, arranging the conductive connecting member in the composite layer, and then respectively disposing the first metal layer and the second metal layer on the opposite two surfaces of the composite layer, and making the first metal layer and the second metal layer respectively contact the conductive connecting member, so that the formed entire composite current collector is conductive, ensuring that the composite current collector can provide an electron conduction path; the composite current collector formed in the above manner, on the one hand, makes the structure of the composite current collector simple, light in weight, simple and fast to process, and cost-saving; on the other hand, it can make the structural stability of the composite current collector better, can be better applied to the solid-state battery cell, and ensure that the working reliability of the solid-state battery cell, the battery module and the battery pack is relatively high. Description of the Drawings

[0032] Figure 1 is a schematic structural diagram of the solid-state battery cell provided by the present utility model;

[0033] Figure 2 is a schematic structural diagram of the positive and negative series-connected electrode sheets provided by the present utility model.

[0034] Description of the Reference Numerals:

[0035] 10 - Solid-state battery cell;

[0036] 1 - Composite current collector; 11 - Composite layer; 111 - First surface; 112 - Second surface; 113 - Through hole; 12 - Conductive connecting member; 13 - First metal layer; 131 - First part; 14 - Second metal layer; 141 - Second part;

[0037] 2 - cell unit; 21 - double - sided positive electrode sheet; 211 - first active material layer; 212 - second active material layer; 22 - double - sided negative electrode sheet; 221 - third active material layer; 222 - fourth active material layer; 23 - solid - state electrolyte;

[0038] 3 - positive and negative series electrode sheets; 31 - fifth active material layer; 32 - sixth active material layer. Detailed implementation manners

[0039] All features disclosed in this specification, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any way.

[0040] Any feature disclosed in this specification, unless specifically stated, can be replaced by other equivalent or similar - purpose alternative features. That is, unless specifically stated, each feature is only an example in a series of equivalent or similar features. Throughout the specification, the same reference numerals indicate the same elements.

[0041] To make the technical problems solved, the technical solutions adopted, and the technical effects achieved by the present utility model clearer, the technical solutions of the present utility model will be further described below with reference to the drawings and through specific implementation manners.

[0042] Currently, in the preparation process of lithium - ion solid - state cells, the lithium - ion solid - state cells are usually formed by series connection or parallel connection; among them, the series - connection method can increase the voltage of the lithium - ion solid - state cell, but the disadvantage is that the capacitance of the lithium - ion solid - state cell will be limited; while the parallel - connection method can increase the capacitance of the lithium - ion solid - state cell, but the disadvantage is that the voltage of the lithium - ion solid - state cell will be limited, and it is difficult to simultaneously meet the requirements of large voltage and high capacitance of the lithium - ion solid - state cell.

[0043] Therefore, in this embodiment, a solid - state cell, a battery module, and a battery pack are proposed. The battery module includes a plurality of solid - state cells, the battery pack includes a plurality of battery modules, and the solid - state cell can simultaneously have a large voltage and a high capacitance to simultaneously meet the requirements of large voltage and high capacitance of the solid - state cell. In this embodiment, the battery pack can specifically be a lithium - ion battery pack.

[0044] Specifically, as Figure 1As shown, the solid - state battery cell 10 includes a plurality of battery cell units 2, and the battery cell units 2 are connected in series with each other; the battery cell unit 2 includes a double - sided positive electrode sheet 21, a double - sided negative electrode sheet 22, and a solid - state electrolyte 23; among them, the double - sided negative electrode sheet 22 is connected in parallel with the double - sided positive electrode sheet 21; a solid - state electrolyte 23 is arranged between the adjacent double - sided positive electrode sheet 21 and double - sided negative electrode sheet 22 to form a battery cell unit 2. Among them, the above - mentioned double - sided positive electrode sheet 21 and double - sided negative electrode sheet 22 respectively include a composite current collector 1.

[0045] In this embodiment, compared with the prior art, the connection formation method of the solid - state battery cell 10 is changed; by connecting the double - sided negative electrode sheet 22 in parallel with the double - sided positive electrode sheet 21, and then arranging a solid - state electrolyte 23 between the adjacent double - sided positive electrode sheet 21 and double - sided negative electrode sheet 22 to form a battery cell unit 2; then connecting the formed battery cell units 2 in series with each other to form the solid - state battery cell 10; that is, first forming the battery cell unit 2 through parallel connection, and then connecting the formed battery cell units 2 in series, so as to form the solid - state battery cell 10. By combining the two connection methods of parallel connection and series connection, it can ensure that the formed solid - state battery cell 10 has a relatively large voltage and a relatively high capacitance, and can meet the requirements of the large voltage and high capacitance of the solid - state battery cell 10.

[0046] Furthermore, as Figure 1 shown, the composite current collector 1 includes a composite layer 11, a conductive connecting member 12, a first metal layer 13, and a second metal layer 14. The conductive connecting member 12 is arranged in the composite layer 11, and the first metal layer 13 and the second metal layer 14 are respectively arranged on the opposite two surfaces of the composite layer 11, and the first metal layer 13 and the second metal layer 14 are respectively in contact with the conductive connecting member 12.

[0047] By arranging the conductive connecting member 12 in the composite layer 11, then arranging the first metal layer 13 and the second metal layer 14 on the opposite two surfaces of the composite layer 11 respectively, and making the first metal layer 13 and the second metal layer 14 respectively in contact with the conductive connecting member 12, the formed entire composite current collector 1 can conduct electricity, ensuring that the composite current collector 1 can provide an electron conduction path; the composite current collector 1 formed in the above - mentioned manner, on the one hand, has a simple structure, a relatively light weight, is simple and fast to process, and saves costs; on the other hand, it can make the structure of the composite current collector 1 have better stability, can be better applied to the solid - state battery cell 10, and ensure that the working reliability of the solid - state battery cell 10, battery module, and battery pack is relatively high.

[0048] Specifically, as Figure 1As shown, the composite layer 11 includes a first surface 111 and a second surface 112 that are oppositely arranged. A through hole 113 is provided at one end of the composite layer 11, and the through hole 113 penetrates through the first surface 111 and the second surface 112; the conductive connecting member 12 is disposed in the through hole 113; the first metal layer 13 is provided on the first surface 111 of the composite layer 11, and the first metal layer 13 covers the opening of the through hole 113 facing the first surface 111 and is in contact with the conductive connecting member 12; the second metal layer 14 is provided on the second surface 112 of the composite layer 11, and the second metal layer 14 covers the opening of the through hole 113 facing the second surface 112 and is in contact with the conductive connecting member 12. That is, the ends of the composite layer 11, the first metal layer 13, and the second metal layer 14 are aligned.

[0049] Specifically, the composite layer 11 includes a conductive agent, a binder, an active material, and metal powder; for the structural setting of the composite layer 11, it can refer to the common current collector structure in the prior art, and here, the specific structural setting of the composite layer 11 will not be described in detail.

[0050] Further, a tab is welded on the first part 131 of the first metal layer 13 that covers the opening of the through hole 113 facing the first surface 111, so as to provide a weldable space for welding the tab through the first part 131 of the first metal layer 13 and ensure the smooth welding of the tab on the composite current collector 1; or a tab is welded on the second part 141 of the second metal layer 14 that covers the opening of the through hole 113 facing the second surface 112, so as to provide a weldable space for welding the tab through the second part 141 of the second metal layer 14 and ensure the smooth welding of the tab on the composite current collector 1. Among them, both the first metal layer 13 and the second metal layer 14 are metal foils formed by rolling or electrolysis.

[0051] Specifically, the first metal layer 13 can be a copper foil or an aluminum foil, and the second metal layer 14 can be a copper foil or an aluminum foil. The specific types of the first metal layer 13 and the second metal layer 14 need to be determined according to the requirements of the positive and negative electrodes; for example, when the formed composite current collector 1 is a positive electrode composite current collector, both the first metal layer 13 and the second metal layer 14 are aluminum foils; when the formed composite current collector 1 is a negative electrode composite current collector, both the first metal layer 13 and the second metal layer 14 are copper foils; when the formed composite current collector 1 is a positive and negative electrode composite current collector, one of the first metal layer 13 and the second metal layer 14 is a copper foil and the other is an aluminum foil.

[0052] Further, as Figure 1As shown in the figure, in a battery cell unit 2, a plurality of double-sided positive electrode sheets 21 and double-sided negative electrode sheets 22 are respectively provided, and one double-sided positive electrode sheet 21 is connected in parallel with one double-sided negative electrode sheet 22; specifically, the parallel connection is formed by a stacking method to form a battery cell unit 2, that is, the double-sided positive electrode sheet 21 and the double-sided negative electrode sheet 22 are stacked in sequence to form a parallel connection structure of double-sided negative electrode sheet 22, double-sided positive electrode sheet 21, double-sided negative electrode sheet 22, double-sided positive electrode sheet 21, double-sided negative electrode sheet 22... , so as to be able to form a battery cell unit 2 by parallel connection.

[0053] Specifically, the voltage between a pair of positive and negative electrodes is A, the capacitance is B, the number of parallel connections between the double-sided positive electrode sheet 21 and the double-sided negative electrode sheet 22 is M, the voltage of the battery cell unit 2 is A, and the capacitance is M*B; moreover, the number of series-connected battery cell units 2 is N, and the voltage of the solid-state battery 10 is N*A, and the capacitance is M*B.

[0054] For example, if the voltage A between a pair of positive and negative electrodes is 3.6V, the capacitance B is 1Ah, and the number of parallel connections M between the double-sided positive electrode sheet 21 and the double-sided negative electrode sheet 22 is 10, then the voltage A of the formed battery cell unit 2 is 3.6V, and the capacitance M*B = 10*1Ah = 10Ah.

[0055] In addition, for another example, after forming the battery cell unit 2 with the above voltage A of 3.6V and capacitance of 10Ah, the formed battery cell units 2 are stacked in a series connection manner to form a solid-state battery 10; for example, the number of series-connected battery cell units 2 is N = 6, then the voltage of the formed solid-state battery 10 is N*A = 6*3.6V = 21.6V, and the capacitance of the solid-state battery 10 is the capacitance of one battery cell unit 2, M*B = 10Ah, so as to be able to form a solid-state battery 10 with a voltage of 21.6V and a capacitance of 10Ah, thereby ensuring that the voltage and capacitance of the formed solid-state battery 10 are both relatively high.

[0056] It should be noted that the capacitance of the solid-state battery 10 can be adaptively adjusted according to the number of parallel connections M between the double-sided positive electrode sheet 21 and the double-sided negative electrode sheet 22 in one battery cell unit 2 to ensure that the capacitance of the formed solid-state battery 10 meets the requirements; the voltage of the solid-state battery 10 can be adaptively adjusted according to the number of series connections N between the formed battery cell units 2 to ensure that the voltage of the formed solid-state battery 10 meets the requirements.

[0057] In this embodiment, as Figure 1As shown, a battery cell unit 2 includes a double-sided positive electrode sheet 21 and two double-sided negative electrode sheets 22. That is, a double-sided positive electrode sheet 21 is connected in parallel between two double-sided negative electrode sheets 22, and a solid-state battery cell 10 has at least two battery cells 2 connected in series. Here, there is no limit on the number M of double-sided positive electrode sheets 21 and double-sided negative electrode sheets 22 connected in parallel, and the number N of battery cells 2 connected in series.

[0058] Specifically, if Figure 1 As shown, the double-sided positive electrode sheet 21 also includes a first active material layer 211 and a second active material layer 212; wherein, the first active material layer 211 is arranged on the first metal layer 13 in the composite current collector 1, and the first part 131 of the first metal layer 13 for welding the electrode tab extends to the outside of the first active material layer 211; the second active material layer 212 is arranged on one side of the second metal layer 14 in the composite current collector 1, and the second part 141 of the second metal layer 14 for welding the electrode tab extends to the outside of the second active material layer 212, and the first active material layer 211 and the second active material layer 212 are both positive electrode materials to form the double-sided positive electrode sheet 21.

[0059] By extending the first part 131 on the first metal layer 13 for welding the electrode tab to the outside of the first active material layer 211, an avoidance space is formed between the first part 131 of the first metal layer 13 and the first active material layer 211, thereby ensuring that the first active material layer 211 will not interfere with the operation of welding the electrode tab on the first part 131 of the first metal layer 13, thereby ensuring the simplicity, convenience and smoothness of welding the electrode tab on the first part 131.

[0060] By extending the second part 141 on the second metal layer 14 for welding the electrode tab to the outside of the second active material layer 212, an avoidance space is formed between the second part 141 of the second metal layer 14 and the second active material layer 212, thereby ensuring that the second active material layer 212 will not interfere with the operation of welding the electrode tab on the second part 141 of the second metal layer 14, thereby ensuring the simplicity, convenience and smoothness of welding the electrode tab on the second part 141.

[0061] Furthermore, if Figure 1As shown, the double-sided negative electrode sheet 22 further includes a third active material layer 221 and a fourth active material layer 222; the third active material layer 221 is disposed on the first metal layer 13 in the composite current collector 1, and the first portion 131 on the first metal layer 13 for welding the tab extends outside the third active material layer 221; the fourth active material layer 222 is disposed on one side of the second metal layer 14 in the composite current collector 1, and the second portion 141 on the second metal layer 14 for welding the tab extends outside the fourth active material layer 222. Both the third active material layer 221 and the fourth active material layer 222 are negative electrode materials to form the double-sided negative electrode sheet 22.

[0062] Among them, as Figure 1 shown, the portions of the conductive connection members 12 provided in the composite layer 11 in the double-sided positive electrode sheet 21 and the portions of the conductive connection members 12 provided in the composite layer 11 in the adjacent double-sided negative electrode sheet 22 are located on opposite sides respectively, so as to be conducive to the subsequent series connection of the formed cell units 2.

[0063] It should be noted that in the double-sided negative electrode sheet 22, the first portion 131 on the first metal layer 13 for welding the tab extends outside the third active material layer 221, and the second portion 141 on the second metal layer 14 for welding the tab extends outside the fourth active material layer 222. The function generated by this technical feature is the same as that generated in the above double-sided positive electrode sheet 21, and the function generated here will not be described in detail.

[0064] Furthermore, as Figure 2 shown, the solid-state battery cell 10 further includes a positive and negative series electrode sheet 3. The positive and negative series electrode sheet 3 is connected in series between two adjacent cell units 2, so as to be able to connect the cell units 2 in series to form the solid-state battery cell 10; and solid-state electrolytes 23 are provided between the adjacent positive and negative series electrode sheets 3 and the double-sided positive electrode sheet 21, and between the adjacent positive and negative series electrode sheets 3 and the double-sided negative electrode sheet 22.

[0065] Specifically, as Figure 2 shown, the positive and negative series electrode sheet 3 includes the above-mentioned composite current collector 1, a fifth active material layer 31 and a sixth active material layer 32; among them, the fifth active material layer 31 is disposed on the first metal layer 13 in the composite current collector 1; the sixth active material layer 32 is disposed on one side of the second metal layer 14 in the composite current collector 1; one of the fifth active material layer 31 and the sixth active material layer 32 is a positive electrode material, and the other is a negative electrode material to form the positive and negative series electrode sheet 3.

[0066] It should be noted that, as Figure 2As shown, in the positive and negative series-connected electrode plate 3, no conductive connection member 12 is provided within the composite body 11, that is, the part of the composite body 11 for providing the through hole 113 is omitted; and the end of the first metal layer 13 is aligned with the end of the fifth active material layer 31, that is, the first part 131 of the first metal layer 13 is omitted; and the end of the second metal layer 14 is aligned with the end of the sixth active material layer 32, that is, the second part 141 of the second metal layer 14 is omitted; so that the structure of the formed positive and negative series-connected electrode plate 3 can be simple and compact, with a smaller occupied area, and can ensure the conductive connection of the formed positive and negative series-connected electrode plate 3 in subsequent series connection.

[0067] In this embodiment, as Figure 1 shown, in a formed battery cell unit 2, a solid electrolyte 23 is provided between the first active material layer 211 and the fourth active material layer 222 in one of the double-sided negative electrode plates 22, a solid electrolyte 23 is provided between the second active material layer 212 and the third active material layer 221 in the other double-sided negative electrode plate 22, and a solid electrolyte 23 is provided on one side of the fourth active material layer 222 in the other double-sided negative electrode plate 22.

[0068] In this embodiment, by sequentially connecting a plurality of double-sided negative electrode plates 22 and a plurality of double-sided positive electrode plates 21 in parallel to form a battery cell unit 2, and the capacitance of the battery cell unit 2 and the solid-state battery 10 can be adjusted by adjusting the number of parallel connections between the double-sided negative electrode plates 22 and the double-sided positive electrode plates 21; then by connecting a plurality of battery cell units 2 in series to form a solid-state battery 10, and the voltage of the solid-state battery 10 can be adjusted by adjusting the number of series connections of the battery cell units 2; thus, a solid-state battery 10 with a large voltage and a high capacitance can be obtained, and furthermore, the designability of the voltage and capacitance of the solid-state battery 10 can be realized, reducing resource waste.

[0069] The above content is only a preferred embodiment of the present invention. For those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. The content of this specification should not be construed as a limitation to the present invention.

Claims

1. A solid-state battery cell, characterized in that, It includes multiple battery cell units (2), and the battery cell units (2) are connected in series with each other. The battery cell unit (2) includes: A double-sided positive electrode sheet (21); A double-sided negative electrode sheet (22), which is connected in parallel with the double-sided positive electrode sheet (21); A solid electrolyte (23), and the solid electrolyte (23) is arranged between the adjacent double-sided positive electrode sheet (21) and the double-sided negative electrode sheet (22) to form the battery cell unit (2); Wherein, the double-sided positive electrode sheet (21) and the double-sided negative electrode sheet (22) respectively include a composite current collector (1).

2. The solid-state battery cell according to claim 1, wherein, The composite current collector (1) includes a composite layer (11), a conductive connection member (12), a first metal layer (13) and a second metal layer (14). The conductive connection member (12) is arranged in the composite layer (11), and the first metal layer (13) and the second metal layer (14) are respectively arranged on the opposite two surfaces of the composite layer (11), and the first metal layer (13) and the second metal layer (14) are respectively in contact with the conductive connection member (12).

3. The solid-state battery cell according to claim 1, wherein A plurality of the double-sided positive electrode sheets (21) and the double-sided negative electrode sheets (22) are respectively provided, and one double-sided positive electrode sheet (21) is connected in parallel with one double-sided negative electrode sheet (22).

4. The solid-state battery cell according to claim 3, wherein The voltage between a pair of positive and negative electrodes is A, and the capacitance is B. The number of the double-sided positive electrode sheets (21) and the double-sided negative electrode sheets (22) connected in parallel is M. The voltage of the battery cell unit (2) is A, and the capacitance is M*B; the number of the battery cell units (2) connected in series is N, and the voltage of the solid-state battery cell is N*A, and the capacitance is M*B.

5. The solid-state battery cell according to claim 2, wherein, The double-sided positive electrode sheet (21) further includes: A first active material layer (211), which is arranged on the first metal layer (13), and a first part (131) of the first metal layer (13) for welding the tab extends outside the first active material layer (211); A second active material layer (212), which is arranged on one side of the second metal layer (14), and a second part (141) of the second metal layer (14) for welding the tab extends outside the second active material layer (212). Both the first active material layer (211) and the second active material layer (212) are positive electrode materials.

6. The solid-state battery cell according to claim 5, wherein, The double-sided negative electrode sheet (22) further includes: A third active material layer (221), which is arranged on the first metal layer (13), and a first part (131) of the first metal layer (13) for welding the tab extends outside the third active material layer (221); A fourth active material layer (222), which is arranged on one side of the second metal layer (14), and a second part (141) of the second metal layer (14) for welding the tab extends outside the fourth active material layer (222). Both the third active material layer (221) and the fourth active material layer (222) are negative electrode materials; Among them, a part of the conductive connection member (12) provided in the composite layer (11) of the double-sided positive electrode sheet (21) and a part of the conductive connection member (12) provided in the composite layer (11) of the adjacent double-sided negative electrode sheet (22) are located on opposite sides respectively.

7. The solid-state battery cell according to claim 2, wherein The solid-state battery cell further includes: Positive and negative series-connected electrode sheets (3), which are connected in series between two adjacent battery cell units (2), and a solid electrolyte (23) is provided between the adjacent positive and negative series-connected electrode sheets (3) and the double-sided positive electrode sheet (21), and between the adjacent positive and negative series-connected electrode sheets (3) and the double-sided negative electrode sheet (22).

8. The solid-state battery cell according to claim 7, wherein, The positive and negative series-connected electrode sheet (3) includes: The composite current collector (1); A fifth active material layer (31), which is provided on the first metal layer (13); A sixth active material layer (32), which is provided on one side of the second metal layer (14), and one of the fifth active material layer (31) and the sixth active material layer (32) is a positive electrode material, and the other is a negative electrode material.

9. Battery module, characterized in that, Including a plurality of solid-state battery cells according to any one of claims 1-8.

10. Battery pack, characterized in that, Including a plurality of battery modules according to claim 9.

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