Coated composite pole piece and electrode body and battery comprising same

Abstract

The utility model provides a coated composite pole piece as well as an electrode body and a battery comprising the coated composite pole piece. The coated composite pole piece comprises: an electrode layer, the length of which is 20-1200 mm, the width of which is 20-300 mm and the thickness of which is 3-1000 [mu] m; the active material layer is positioned on one surface of the electrode layer, the active material layer is a positive electrode active material layer or a negative electrode active material layer, and the size of the active material layer is smaller than that of the electrode layer; the solid electrolyte layer is located on the side, away from the electrode layer, of the active material layer, the length and width of the solid electrolyte layer are larger than those of the active material layer but not larger than those of the electrode layer, and the solid electrolyte layer has the thickness of 3-100 microns and completely covers the active material layer.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to a coated composite electrode sheet for a solid-state battery, an electrode body and a battery comprising the coated composite electrode sheet. Background Art

[0002] A solid-state battery is a new type of battery technology, which mainly focuses on the application and improvement of solid electrolytes and the innovation of the overall battery structure. It has significant advantages over traditional liquid batteries in terms of safety, energy density and cycle life.

[0003] Patent CN107452985B discloses a method for manufacturing a solid-state battery, in which a current collector layer, a positive electrode mixture layer, a solid electrolyte layer and a negative electrode mixture layer are stacked respectively to obtain a stacked battery having two end faces and a side face in the stacking direction. In order to avoid short circuit between the positive and negative electrodes, it is also necessary to pour resin into the side face of the stacked battery through a complex process to play an insulating role. The production cost is relatively high and the production process needs to be further optimized. Summary of the Utility Model

[0004] In view of these problems, the utility model provides a coated composite electrode sheet and an electrode body and a battery comprising the same, which fundamentally solve the problem of short circuit between the positive and negative electrodes and greatly simplify the production process of solid-state batteries.

[0005] One aspect of the utility model provides a coated composite electrode sheet, which comprises:

[0006] An electrode layer, which has a length of 20 - 1200 mm, a width of 20 - 300 mm and a thickness of 3 - 1000 μm;

[0007] An active material layer located on one surface of the electrode layer, the active material layer being a positive electrode active material layer or a negative electrode active material layer, and the size of the active material layer being smaller than that of the electrode layer; and

[0008] A solid electrolyte layer located on the side of the active material layer away from the electrode layer, the length and width dimensions of the solid electrolyte layer being larger than those of the active material layer but not larger than those of the electrode layer, the solid electrolyte layer having a thickness of 3 - 100 μm, wherein the part of the solid electrolyte layer exceeding the active material layer is in contact with the electrode layer, so as to completely cover and wrap the active material layer.

[0009] In the context of the utility model, the electrode layer can also be called a current collector layer, and the two have the same meaning.

[0010] Optionally, the coated composite electrode also includes another active material layer with properties opposite to those of the active material layer on the other side of the electrode layer. That is, if one side of the electrode layer is the positive electrode active material, the other side is the negative electrode active material, and vice versa.

[0011] Optionally, the active material layer is composed of a positive electrode active material. One side of the electrode layer is compounded with a positive electrode active material layer, and the solid electrolyte layer completely coats the positive electrode active material layer, which is called a positive-coated current collector electrode.

[0012] Optionally, the active material layer is composed of a negative electrode active material. One side of the electrode layer is compounded with a negative electrode active material layer, and the solid electrolyte layer completely coats the negative electrode active material layer, which is called a negative-coated current collector electrode.

[0013] Optionally, one side of the electrode layer is compounded with a positive electrode active material layer, the solid electrolyte layer completely coats the positive electrode active material layer, and the other side of the electrode layer is compounded with a negative electrode active material layer, which is called a positive-coated composite electrode.

[0014] Optionally, one side of the electrode layer is compounded with a negative electrode active material layer, the solid electrolyte layer completely coats the negative electrode active material layer, and the other side of the electrode layer is compounded with a positive electrode active material layer, which is called a negative-coated current collector electrode.

[0015] Optionally, the active material layer has a peripheral portion, and the peripheral portion is more than 1 mm away from the edge of the electrode layer.

[0016] Optionally, one end of the electrode layer that is not covered by the solid electrolyte layer serves as an electrode connection end, which is a positive electrode connection end or a negative electrode, depending on the electrode active material thereon.

[0017] Optionally, except for the electrode connection end, the entire electrode layer is covered by the solid electrolyte layer.

[0018] Optionally, the solid electrolyte includes inorganic solid electrolytes (such as oxide solid electrolytes, sulfide solid electrolytes), polymer solid electrolytes, and composite electrolytes (such as composite electrolytes of oxides and polymers).

[0019] Optionally, the polymer electrolyte material includes lithium polyacrylate (LiPAA), polyethylene glycol (PEO), and electrolytes formed by their combination with lithium salts.

[0020] The present invention also provides an electrode body, which includes the above-mentioned coated composite electrode.

[0021] Optionally, the electrode body comprises a plurality of stacked coated composite pole pieces, wherein each coated composite pole piece comprises an active material layer completely coated by a solid electrolyte layer on one side of the electrode layer and another active material layer with opposite properties on the other side of the electrode layer, and every two adjacent coated composite pole pieces are stacked in such a manner that the active material layer completely coated by the solid electrolyte layer of one of them faces the other active material layer of the other.

[0022] Optionally, the first coated composite electrode sheet among the stacked multiple coated composite electrode sheets does not have another active material layer with opposite properties located on the other side of the electrode layer, and the electrode layer has an end not covered by the solid electrolyte layer as an electrode connection end.

[0023] Optionally, the electrode body also includes a bus electrode located on the last coated composite electrode of the multiple stacked coated composite electrodes, the bus electrode including another active material layer opposite to the active material layer of the last coated composite electrode that is completely coated by the solid electrolyte layer, and another electrode layer located on the other active material layer, the other electrode layer having an end extending beyond the other active material layer as another electrode connection end.

[0024] Optionally, the electrode body is composed of a positive coated bus electrode and at least one positive coated composite electrode. The positive coated bus electrode is located at the outermost side, and the solid electrolyte layer of the positive coated bus electrode is laminated with the negative active material layer of the positive coated composite electrode. Between the positive coated composite electrodes, the solid electrolyte layer of one composite electrode is laminated with the negative active material layer of another composite electrode. A negative bus electrode is also required to be provided at the other end opposite to the positive coated bus electrode, and the negative bus electrode is composed of a negative electrode layer and a negative active material layer.

[0025] Optionally, the electrode body is composed of a negative-coated busbar and at least one negative-coated composite electrode. The negative-coated busbar is located at the outermost side, and the solid electrolyte layer of the negative-coated busbar is laminated with the positive active material layer of the negative-coated composite electrode. Between the negative-coated composite electrodes, the solid electrolyte layer of one composite electrode is laminated with the positive active material layer of another composite electrode. A positive busbar is also required to be provided at the other end opposite to the negative-coated busbar, and the positive busbar is composed of a positive electrode layer and a positive active material layer.

[0026] Another aspect of the present invention provides a battery, which includes the above-mentioned composite electrode sheet or electrode body.

[0027] Optionally, the battery comprises the above-mentioned coated composite electrode sheet.

[0028] Optionally, the battery is a solid-state battery including the above-mentioned electrode body.

[0029] In the present utility model, by using a solid-state electrolyte layer to completely coat one of the positive electrode active material layer or the negative electrode active material layer, the short circuit of the positive and negative electrode active substances is avoided. To achieve this purpose, different methods can be adopted for different types of solid-state electrolytes to realize the coating of the solid-state electrolyte. For example, for oxide solid-state electrolytes, the atmospheric plasma spraying (APS) process can be used; for polymer electrolytes, methods such as spraying after liquefying the solid-state electrolyte can be adopted, and then curing to obtain the solid-state electrolyte layer; for the formed solid-state electrolyte film, methods such as pressure compounding and isostatic pressing can be used to coat the active material with the solid-state electrolyte layer.

[0030] The present utility model has at least the following advantages:

[0031] 1. The solid-state electrolyte completely coats one of the positive and negative electrode active substances, fundamentally avoiding the short circuit of the positive and negative electrode active substances;

[0032] 2. Using the composite pole piece of the present utility model to assemble the electrode body or the battery, the structure is simple and convenient;

[0033] 3. The voltage can be designed, and the number of coated composite pole pieces can be determined according to needs, so that the battery voltage is controllable;

[0034] 4. The battery voltage is high. Using the coated composite pole piece of the present utility model, the electrode body formed by laminating is in a series structure, and an extremely high voltage can be applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of a positive bus bar pole piece.

[0036] Figure 2a It is a schematic diagram of a positive coated bus bar pole piece of the present utility model.

[0037] Figure 2b It is a cross-sectional schematic diagram of the positive coated bus bar pole piece of the present utility model

[0038] Figure 3a It is a schematic diagram of a positive coated composite pole piece of the present utility model.

[0039] Figure 3b It is a cross-sectional schematic diagram of the positive coated composite pole piece of the present utility model.

[0040] Figure 4 It is a schematic diagram of a negative bus bar pole piece.

[0041] Figure 5a It is a schematic diagram of a negative coated bus bar pole piece of the present utility model.

[0042] Figure 5b Schematic cross-sectional view of the negative-clad current collector plate of the present utility model

[0043] Figure 6a Schematic view of the negative-clad composite electrode plate of the present utility model

[0044] Figure 6b Schematic cross-sectional view of the negative-clad composite electrode plate of the present utility model

[0045] Figure 7a Schematic view of an embodiment of the electrode body composed of the positive-clad composite electrode plate of the present utility model

[0046] Figure 7b is Figure 7a Schematic cross-sectional view of the electrode body embodiment in

[0047] Figure 8a Schematic view of an embodiment of the electrode body composed of the negative-clad composite electrode plate of the present utility model

[0048] Figure 8b Schematic cross-sectional view of the electrode body embodiment in 8a

[0049] Explanation of figure numbers:

[0050] 1 Positive electrode active material layer, 2 Negative electrode active material layer, 3 Electrode layer, 4 Solid electrolyte layer, 11 Positive current collector plate, 12 Positive-clad current collector plate, 13 Positive-clad composite electrode plate, 21 Negative current collector plate, 22 Negative-clad current collector plate, 23 Negative-clad composite electrode plate, 31 Positive electrode layer, 311 Positive electrode connection end, 32 Negative electrode layer, 321 Negative electrode connection end, 50a Electrode body, 50b Electrode body Detailed implementation manners

[0051] In order to make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0052] Figure 1 Schematic view of the positive current collector plate. As Figure 1 shown, the positive current collector plate 11 is composed of the positive electrode layer 31 and the positive electrode active material layer 1. The size of the positive electrode active material layer 1 is smaller than that of the positive electrode layer 31. The part of the positive electrode layer 31 that extends beyond the positive electrode active material layer 1 is the positive electrode connection end 311, which is used to connect the positive terminal of the battery. The thickness of the positive electrode layer 31 is 10 - 1000 μm.

[0053] Figure 2a Schematic view of the positive-clad current collector plate of the present utility model Figure 2bThis is a schematic cross-sectional view of the positive encapsulation type current collecting electrode plate of the present utility model. The positive encapsulation type current collecting electrode plate 12 is composed of a positive electrode layer 31, a positive electrode active material layer 1, and a solid electrolyte layer 4. The positive electrode active material layer 1 and the solid electrolyte layer 4 are located on the same side of the positive electrode layer 31. The positive electrode active material layer 1 is attached to the positive electrode layer 31, and the length and width dimensions of the positive electrode active material layer 1 are smaller than those of the solid electrolyte layer 4. The solid electrolyte layer 4 has a length or width smaller than that of the positive electrode layer 31. The solid electrolyte layer 4 completely covers the positive electrode active material layer 1, and the part of the solid electrolyte layer 4 that extends beyond the positive electrode active material layer 1 is attached to the positive electrode layer 31. The part of the positive electrode layer 31 that extends beyond the solid electrolyte layer 4 is the positive electrode connection end 311, which is used to connect the positive terminal of the battery. The thickness of the positive electrode layer 31 is 10 - 1000 μm.

[0054] Figure 3a This is a schematic diagram of the positive encapsulation type composite electrode plate of the present utility model. Figure 3b This is a schematic cross-sectional view of the positive encapsulation type composite electrode plate of the present utility model. The positive encapsulation type composite electrode plate 13 is composed of an electrode layer 3, a positive electrode active material layer 1, a negative electrode active material layer 2, and a solid electrolyte layer 4. The positive electrode active material layer 1 and the solid electrolyte layer 4 are located on the same side of the electrode layer 3. The positive electrode active material layer 1 is attached to the electrode layer 3, and the length and width dimensions of the positive electrode active material layer 1 are smaller than those of the electrode layer 3. The length and width dimensions of the solid electrolyte layer 4 are equivalent to those of the electrode layer 3. The solid electrolyte layer 4 completely covers the positive electrode active material layer 1, and the part of the solid electrolyte layer 4 that extends beyond the positive electrode active material layer 1 is attached to the electrode layer 3. The negative electrode active material layer 2 is compounded on the other side of the electrode layer 3. The length and width dimensions of the negative electrode active material layer 2 are equivalent to those of the electrode layer 3. The thickness of the electrode layer 3 is 3 - 20 μm.

[0055] Figure 4 This is a schematic diagram of the negative current collecting electrode plate. As Figure 4 shown, the negative current collecting electrode plate 21 is composed of a negative electrode layer 32 and a negative electrode active material layer 2. The size of the negative electrode active material layer 2 is smaller than that of the negative electrode layer 32. The part of the negative electrode layer 32 that extends beyond the negative electrode active material layer 2 is the negative electrode connection end 321, which is used to connect the negative terminal of the battery. The thickness of the negative electrode layer 32 is 10 - 1000 μm.

[0056] Figure 5a This is a schematic diagram of the negative encapsulation type current collecting electrode plate of the present utility model. Figure 5bThis is a schematic cross-sectional view of the negative-clad current collector plate of the present utility model. The negative-clad current collector plate 22 is composed of a negative electrode layer 32, a negative electrode active material layer 2, and a solid electrolyte layer 4. The negative electrode active material layer 2 and the solid electrolyte layer 4 are located on the same side of the negative electrode layer 32. The negative electrode active material layer 2 is in contact with the negative electrode layer 32, and the length and width dimensions of the negative electrode active material layer 2 are smaller than those of the solid electrolyte layer 4. The solid electrolyte layer 4 has a length or width smaller than that of the negative electrode layer 32. The solid electrolyte layer 4 completely covers the negative electrode active material layer 2, and the part of the solid electrolyte layer 4 that extends beyond the negative electrode active material layer 2 is in contact with the negative electrode layer 32. The part of the negative electrode layer 32 that extends beyond the solid electrolyte layer 4 is the negative electrode connection end 321, which is used to connect the negative terminal of the battery. The thickness of the negative electrode layer 32 is 10 - 1000 μm.

[0057] Figure 6a This is a schematic view of the negative-clad composite electrode plate of the present utility model. Figure 6b This is a schematic cross-sectional view of the negative-clad composite electrode plate of the present utility model. The negative-clad composite electrode plate 23 is composed of an electrode layer 3, a positive electrode active material layer 1, a negative electrode active material layer 2, and a solid electrolyte layer 4. The negative electrode active material layer 2 and the solid electrolyte layer 4 are located on the same side of the electrode layer 3. The negative electrode active material layer 2 is in contact with the electrode layer 3, and the length and width dimensions of the negative electrode active material layer 2 are smaller than those of the electrode layer 3. The length and width dimensions of the solid electrolyte layer 4 are comparable to those of the electrode layer 3. The solid electrolyte layer 4 completely covers the negative electrode active material layer 2, and the part of the solid electrolyte layer 4 that extends beyond the negative electrode active material layer 2 is in contact with the electrode layer 3. The positive electrode active material layer 1 is laminated on the other side of the electrode layer 3. The length and width dimensions of the positive electrode active material layer 1 are comparable to those of the electrode layer 3. The thickness of the electrode layer 3 is 3 - 20 μm.

[0058] Figure 7a This is a schematic view of an embodiment of an electrode body composed of a positive-clad composite electrode plate of the present utility model. Figure 7b For Figure 7aSchematic cross-sectional view of an embodiment of the middle electrode body. As shown in the figure, the electrode body 50a is composed of a positive-clad current collector plate 12, a positive-clad composite electrode plate 13, and a negative current collector plate 21. The number of positive-clad composite electrode plates 13 is at least one. If a high-voltage battery is required, the number of positive-clad composite electrode plates 13 can be designed to be multiple according to requirements. The stacking directions of the positive-clad composite electrode plates 13 are the same, that is, the negative active material layer 2 of the positive-clad composite electrode plate 13 is attached to the solid electrolyte layer 4 of the previous sheet, and the solid electrolyte layer 4 is attached to the negative active material layer 2 of the next sheet, and they are stacked in sequence. The positive-clad current collector plate 12 is located on one side of the negative active material layer 2 of the positive-clad composite electrode plate 13, and the electrolyte layer of the positive-clad current collector plate 12 is attached to the negative active material layer 2 of the positive-clad composite electrode plate 13. The negative current collector plate 21 is located on the side of the positive-clad composite electrode plate 13 away from the positive-clad current collector plate 12, and the negative active material layer 2 in the negative current collector plate 21 is attached to and stacked with the solid electrolyte layer 4 of the positive-clad composite electrode plate 13. The positive connection end 311 on the positive-clad current collector plate 12 and the negative connection end 321 on the negative current collector plate 21 are preferably on the same side or opposite sides.

[0059] Figure 8a Schematic diagram of an embodiment of the electrode body composed of a negative-clad composite electrode plate of the present invention Figure 8b is Figure 8a Schematic cross-sectional view of an embodiment of the middle electrode body. As shown in the figure, the electrode body 50b is composed of a negative-clad current collector plate 22, a negative-clad composite electrode plate 23, and a positive current collector plate 11. The number of negative-clad composite electrode plates 23 is at least one. If a high-voltage battery is required, the number of negative-clad composite electrode plates 23 can be designed to be multiple according to requirements. The stacking directions of the negative-clad composite electrode plates 23 are the same, that is, the positive active material layer 1 of the negative-clad composite electrode plate 23 is attached to the solid electrolyte layer 4 of the previous sheet, and the solid electrolyte layer 4 is attached to the positive active material layer 1 of the next sheet, and they are stacked in sequence. The negative-clad current collector plate 22 is located on one side of the positive active material layer 1 of the negative-clad composite electrode plate 23, and the electrolyte layer of the negative-clad current collector plate 22 is attached to the positive active material layer 1 of the negative-clad composite electrode plate 23. The positive current collector plate 11 is located on the side of the negative-clad composite electrode plate 23 away from the negative-clad current collector plate 22, and the positive active material layer 1 in the positive current collector plate 11 is attached to and stacked with the solid electrolyte layer 4 of the negative-clad composite electrode plate 23. The negative connection end 321 on the negative-clad current collector plate 22 and the positive connection end 311 on the positive current collector plate 11 are preferably on the same side or opposite sides.

[0060] When the electrode bodies 50a and 50b prepared in FIGS. 7 and 8 of the present invention are used to prepare a finished battery, it is necessary to apply pressure to the electrode bodies in the stacking direction to compact them, and then encapsulate them to obtain a solid-state battery.

[0061] It should be understood that the above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A coated composite pole piece, characterized in that: The coated composite pole piece comprises: An electrode layer having a length of 20-1200 mm, a width of 20-300 mm, and a thickness of 3-1000 μm; An active material layer located on one side of the electrode layer, the active material layer is a positive electrode active material layer or a negative electrode active material layer, and the size of the active material layer is smaller than the size of the electrode layer; and A solid electrolyte layer is located on a side of the active material layer away from the electrode layer, the length and width of the solid electrolyte layer are larger than the active material layer but not larger than the electrode layer, and the solid electrolyte layer has a thickness of 3-100 μm, wherein a portion of the solid electrolyte layer exceeding the active material layer is in contact with the electrode layer, thereby completely covering and encapsulating the active material layer.

2. The coated composite pole piece according to claim 1, characterized in that: The coated composite electrode sheet further includes another active material layer located on the other side of the electrode layer and having properties opposite to those of the active material layer.

3. The coated composite pole piece according to claim 1, characterized in that: The active material layer has a peripheral portion that is 1 mm or more away from an edge of the electrode layer.

4. The coated composite pole piece according to claim 1, characterized in that: The electrode layer has one end not covered by the solid electrolyte layer, which serves as an electrode connection end, and the electrode connection end is a positive electrode connection end or a negative electrode.

5. The coated composite pole piece according to claim 4, characterized in that: The electrode layer, except for the electrode connection end, is entirely covered by the solid electrolyte layer.

6. An electrode body, characterized in that: The electrode body comprises the coated composite electrode sheet according to any one of claims 1 to 5.

7. The electrode body according to claim 6, characterized in that: The electrode body comprises a plurality of stacked coated composite pole pieces as described in any one of claims 1 to 5, wherein each coated composite pole piece comprises an active material layer completely coated by a solid electrolyte layer on one side of the electrode layer and another active material layer with opposite properties on the other side of the electrode layer, and every two adjacent coated composite pole pieces are stacked in such a manner that the active material layer completely coated by the solid electrolyte layer of one of them faces the other active material layer of the other.

8. The electrode body according to claim 7, characterized in that: The first coated composite electrode sheet among the stacked multiple coated composite electrode sheets does not have another active material layer with opposite properties located on the other side of the electrode layer, and the electrode layer has an end not covered by the solid electrolyte layer as an electrode connection end.

9. The electrode body according to claim 8, characterized in that: The electrode body also includes a bus electrode located on the last coated composite electrode of the multiple stacked coated composite electrodes, the bus electrode including another active material layer opposite to the active material layer of the last coated composite electrode that is completely coated by the solid electrolyte layer, and another electrode layer located on the other active material layer, the other electrode layer having an end extending beyond the other active material layer as another electrode connection end.

10. A battery, characterized in that: The battery comprises the coated composite pole piece according to any one of claims 1 to 5, or is a solid-state battery comprising the electrode body according to any one of claims 6 to 9.

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