A square battery structure of a bipolar lithium battery and a bipolar lithium battery

Abstract

The embodiment of the utility model provides a square battery structure of a bipolar lithium battery and a bipolar lithium battery, which belongs to the technical field of lithium batteries. The bipolar lithium battery includes: a minimum battery cell unit, including: a diaphragm pole piece, which is arranged on both sides of the diaphragm; a substrate, which is arranged between every two of the minimum battery cells and on one side of the first battery cell unit and on the other side of the last battery cell unit, wherein the substrate includes: a first electrode layer, which is used to contact with the pole piece of one of the minimum battery cell units; a substrate middle layer, which is arranged on the other side of the first electrode layer away from the minimum battery cell unit; a second electrode layer, which is arranged on the other side of the substrate middle layer away from the first electrode layer; wherein the electrode materials of the second electrode layer and the first electrode layer are different. The coating materials on both sides of the substrate middle layer are different, and the same pole piece can be used as a negative electrode and a positive electrode at the same time during the charging and discharging process, which increases the rated voltage of the battery and is suitable for a variety of application scenarios.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, and in particular to a square battery structure of a bipolar lithium battery and a bipolar lithium battery. Background Art

[0002] With the rapid development of science and technology and the continuous growth of human demand for energy, battery technology, as an important means of energy storage and conversion, has always been a hot topic of research. Existing batteries have the following main problems: on the one hand, traditional unipolar batteries have low energy conversion efficiency and slow charging speed during energy storage and release; on the other hand, the energy density and power density of existing batteries are difficult to meet the battery needs of electric vehicles, aerospace, military and other fields. Therefore, there is an urgent need to develop a type of battery to improve the energy storage and conversion efficiency and adapt to a variety of application scenarios. Utility Model Content

[0003] The utility model provides a square battery structure of a bipolar lithium battery and a bipolar lithium battery, which solves the problem that the existing battery conversion efficiency is slow and difficult to adapt to a variety of application scenarios.

[0004] In order to achieve the above-mentioned object, the utility model provides a square battery structure of a bipolar lithium battery on one hand, and the bipolar lithium battery comprises:

[0005] The smallest battery cell unit includes:

[0006] Diaphragm;

[0007] Pole pieces, arranged on both sides of the diaphragm;

[0008] A substrate is disposed between every two of the minimum battery cell units and on one side of the first battery cell unit and on the other side of the last battery cell unit, wherein the substrate comprises:

[0009] A first electrode layer, used for contacting an electrode sheet of one of the minimum battery cell units;

[0010] A substrate intermediate layer, disposed on the other side of the first electrode layer away from the minimum battery cell unit;

[0011] A second electrode layer is disposed on the other side of the substrate intermediate layer away from the first electrode layer;

[0012] The second electrode layer and the first electrode layer have different electrode materials.

[0013] Optionally, the material of the first electrode layer is lithium iron phosphate, ternary, lithium cobalt oxide or lithium manganese oxide;

[0014] The material of the second electrode layer is graphite or silicon carbon.

[0015] Optionally, the electrode sheet includes a positive electrode sheet and a negative electrode sheet, and the positive electrode sheet and the negative electrode sheet are symmetrically arranged outward along the central axis.

[0016] Optionally, the square battery structure includes a connecting piece, which is arranged on the top of the bipolar lithium battery, and the connecting piece includes:

[0017] A positive electrode connecting sheet, disposed on the top of the positive electrode sheet, and used to be connected to the positive electrode sheet;

[0018] The negative electrode connecting sheet is arranged on the top of the negative electrode sheet and is used for connecting with the negative electrode sheet.

[0019] Optionally, the square battery structure includes a top cover, which is arranged on the top of the connecting piece, and the top cover includes:

[0020] A cover body, wherein the cover body has a liquid injection hole penetrating along a thickness direction thereof;

[0021] An explosion-proof valve is arranged in the middle of the cover body;

[0022] The poles are symmetrically arranged on the cover body, and the poles include a positive pole and a negative pole.

[0023] Optionally, the square battery structure includes a liner, which is arranged outside the bipolar lithium battery to protect the bipolar lithium battery.

[0024] Optionally, the square battery structure includes a shell, which is arranged outside the bushing and is used to fix the bipolar lithium battery.

[0025] Optionally, the shell and the top cover are made of aluminum, stainless steel or plastic, and the substrate, the positive electrode connecting plate and the negative electrode connecting plate are made of copper.

[0026] On the other hand, the utility model provides a bipolar lithium battery, which includes a bipolar lithium battery body and any of the square battery structures described above.

[0027] Through the above technical scheme, the utility model provides a square battery structure of a bipolar lithium battery and a bipolar lithium battery, the bipolar lithium battery includes a minimum battery cell unit and a base layer. Among them, the minimum battery cell unit includes a diaphragm and a pole piece, and the pole piece is arranged on both sides of the diaphragm. The substrate is arranged between every two of the minimum battery cells and on one side of the first battery cell unit and on the other side of the last battery cell unit. The substrate includes a first electrode layer, a substrate middle layer and a second electrode layer, and the electrode materials of the second electrode layer and the first electrode layer are different. The battery cell is formed by stacking a number of pole pieces, the positive pole piece is conductively connected to the positive pole column of the top cover through the positive pole connecting piece, and the negative pole piece is conductively connected to the negative pole column of the top cover through the negative pole connecting piece, and finally through the sealing welding of the top cover and the shell. The coating materials on both sides of the substrate middle layer of the bipolar lithium battery are different, and the same pole piece can be used as a negative electrode and a positive electrode at the same time during the charging and discharging process, which increases the rated voltage of the battery and is suitable for a variety of application scenarios.

[0028] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the embodiments of the present utility model and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present utility model, but do not constitute a limitation on the embodiments of the present utility model. In the accompanying drawings:

[0030] Figure 1 is an exploded view of a square battery structure according to one embodiment of the utility model;

[0031] Figure 2 is a schematic diagram of a substrate according to one embodiment of the present invention.

[0032] Description of Reference Numerals

[0033] 1. Minimum battery cell 2. Diaphragm

[0034] 3. Pole piece 4. Substrate

[0035] 5. First electrode layer 6. Substrate intermediate layer

[0036] 7. Second electrode layer 8. Connecting sheet

[0037] 9. Top cover 10. Cover body

[0038] 11. Explosion-proof valve 12. Pole

[0039] 13. Bushing 14. Housing DETAILED DESCRIPTION

[0040] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0041] In the embodiments of the present invention, unless otherwise specified, directional words such as "up, down, top, bottom" are usually used with reference to the directions shown in the drawings or are used to describe the relative positional relationships of components in the vertical, perpendicular or gravity direction.

[0042] In addition, if there are descriptions involving "first", "second", etc. in the implementation of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various implementations can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0043] Figure 1 is an exploded view of a square battery structure according to an embodiment of the present utility model. Figure 2 It is a schematic diagram of a substrate according to an embodiment of the utility model, in which the bipolar lithium battery includes a minimum battery cell unit 1 and a substrate 4. Among them, the minimum battery cell unit 1 includes a diaphragm 2 and a pole piece 3, and the pole piece 3 is arranged on both sides of the diaphragm 2. The substrate 4 is arranged between every two minimum battery cell units 1 and on one side of the first battery cell unit and on the other side of the last battery cell unit. The substrate 4 includes a first electrode layer 5, a substrate intermediate layer 6 and a second electrode layer 7. The first electrode layer 5 is in contact with the pole piece 3 of a minimum battery cell unit 1, the substrate intermediate layer 6 is arranged on the other side of the first electrode layer 5 away from the minimum battery cell unit 1, and the second electrode layer 7 is arranged on the other side of the substrate intermediate layer 6 away from the first electrode layer 5, and the electrode materials of the second electrode layer 7 and the first electrode layer 5 are different. The coating materials on both sides of the substrate intermediate layer 6 of the bipolar lithium battery are different. The same pole piece 3 can be used as a negative electrode and a positive electrode at the same time during the charging and discharging process, and the rated voltage of the battery can be increased, which is suitable for a variety of application scenarios.

[0044] In this embodiment, the materials of the first electrode layer 5 and the second electrode layer 7 can be various materials known to those skilled in the art. In one example of the present invention, the material of the first electrode layer 5 is lithium iron phosphate, ternary, lithium cobalt oxide or lithium manganese oxide, and the material of the second electrode layer 7 is graphite or silicon carbon. The materials coated on both sides of the substrate intermediate layer 6 have different positive and negative polarities, which improves the high-voltage platform of the bipolar lithium battery, thereby improving the applicability of the lithium battery.

[0045] In this embodiment, the electrode sheet 3 also includes a positive electrode sheet and a negative electrode sheet. The arrangement of the positive electrode sheet and the negative electrode sheet can be various known to those skilled in the art. In one example of the present invention, the positive electrode sheet and the negative electrode sheet are symmetrically arranged outward along the central axis. Stacking several electrode sheets 3 effectively improves the energy density and increases the rate performance of the battery.

[0046] In this embodiment, the square battery structure may include a connecting piece 8. The installation position and distribution of the connecting piece 8 can be selected within a wide range. In one example of the utility model, the connecting piece 8 is disposed on the top of the bipolar lithium battery. Further, the connecting piece 8 includes a positive connecting piece and a negative connecting piece. The positive connecting piece is disposed on the top of the positive electrode sheet and connected to the positive electrode sheet, and the negative electrode connecting piece is disposed on the top of the negative electrode sheet and connected to the negative electrode sheet. The positive connecting piece and the negative connecting piece jointly transfer the current from the inside of the bipolar lithium battery to the external circuit.

[0047] In this embodiment, the specific composition of the square battery structure can be various known to those skilled in the art. In one example of the present utility model, the square battery structure can include a cover 10, an explosion-proof valve 11 and a pole 12. The cover 10 has a liquid injection hole penetrating along its thickness direction to inject the electrolyte of the lithium-ion battery. The explosion-proof valve 11 is arranged in the middle of the cover 10. The explosion-proof valve 11 can rupture when the internal pressure of the battery is too high to prevent the battery from exploding. The pole 12 is symmetrically arranged on the cover 10, and the pole 12 includes a positive pole and a negative pole.

[0048] In this embodiment, considering the need to protect the bipolar lithium battery from damage, the square battery structure further includes a bushing 13. The bushing 13 is disposed outside the bipolar lithium battery. The material of the bushing 13 can be a variety of materials known to those skilled in the art. In an example of the present invention, the bushing 13 can be made of PP or PET, which has good insulation properties, thereby improving the safety of the bipolar lithium battery.

[0049] In this embodiment, the specific composition of the square battery structure can be various known to those skilled in the art. In one example of the present invention, considering the need to fix the battery cell unit, the square battery structure also includes a shell 14. The shell 14 is arranged outside the bushing 13, and the top cover 9 and the shell 14 are combined into an integrated structure through sealing, thereby ensuring that the battery cell, the connecting piece 8 and the bushing 13 are fixed inside the square battery structure, thereby enhancing the vibration resistance of the lithium-ion battery, and further preventing a series of risks such as micro-short circuit, open circuit, and electrical performance attenuation caused by the vibration of the internal battery cell during the use of the lithium-ion battery.

[0050] In this embodiment, the materials of the substrate 4, the positive electrode connecting sheet and the negative electrode connecting sheet can be selected in a wide range, but in order to further improve the performance of the battery, preferably, the substrate 4, the positive electrode connecting sheet and the negative electrode connecting sheet are made of copper. Considering the manufacturing cost, the material of the housing 14 and the top cover 9 can be aluminum, stainless steel or plastic.

[0051] On the other hand, the utility model provides a bipolar lithium battery, which includes a bipolar lithium battery body and any of the above-mentioned square battery structures.

[0052] Through the above technical scheme, the utility model provides a square battery structure of a bipolar lithium battery and a bipolar lithium battery, the bipolar lithium battery includes a minimum battery cell unit and a base layer. Among them, the minimum battery cell unit includes a diaphragm and a pole piece, and the pole piece is arranged on both sides of the diaphragm. The substrate is arranged between every two of the minimum battery cells and on one side of the first battery cell unit and on the other side of the last battery cell unit. The substrate includes a first electrode layer, a substrate middle layer and a second electrode layer, and the electrode materials of the second electrode layer and the first electrode layer are different. The battery cell is formed by stacking a number of pole pieces, the positive pole piece is conductively connected to the positive pole column of the top cover through the positive pole connecting piece, and the negative pole piece is conductively connected to the negative pole column of the top cover through the negative pole connecting piece, and finally through the sealing welding of the top cover and the shell. The coating materials on both sides of the substrate middle layer of the bipolar lithium battery are different, and the same pole piece can be used as a negative electrode and a positive electrode at the same time during the charging and discharging process, which increases the rated voltage of the battery and is suitable for a variety of application scenarios.

[0053] The optional implementation modes of the utility model examples are described in detail above in conjunction with the accompanying drawings. However, the implementation modes of the utility model are not limited to the specific details in the above implementation modes. Within the technical concept of the implementation modes of the utility model, various simple modifications can be made to the technical solutions of the implementation modes of the utility model. These simple modifications all belong to the protection scope of the implementation modes of the utility model.

[0054] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the various possible combinations of the embodiments of the present utility model will not be described separately.

[0055] In addition, various different embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims

1. A square battery structure of a bipolar lithium battery, characterized in that: The bipolar lithium battery comprises: The smallest battery cell unit includes: Diaphragm; Pole pieces, arranged on both sides of the diaphragm; A substrate is disposed between every two of the minimum battery cell units and on one side of the first battery cell unit and on the other side of the last battery cell unit, wherein the substrate comprises: A first electrode layer, used for contacting an electrode sheet of one of the minimum battery cell units; A substrate intermediate layer, disposed on the other side of the first electrode layer away from the minimum battery cell unit; A second electrode layer is disposed on the other side of the substrate intermediate layer away from the first electrode layer; The second electrode layer and the first electrode layer have different electrode materials.

2. The square battery structure according to claim 1, characterized in that: The material of the first electrode layer is lithium iron phosphate, ternary, lithium cobalt oxide or lithium manganese oxide; The material of the second electrode layer is graphite or silicon carbon.

3. The square battery structure according to claim 1, characterized in that: The pole pieces include a positive pole piece and a negative pole piece, and the positive pole piece and the negative pole piece are symmetrically arranged outwardly along the central axis.

4. The square battery structure according to claim 3, characterized in that: The square battery structure includes a connecting piece, which is arranged on the top of the bipolar lithium battery, and the connecting piece includes: A positive electrode connecting sheet, disposed on the top of the positive electrode sheet, and used to be connected to the positive electrode sheet; The negative electrode connecting sheet is arranged on the top of the negative electrode sheet and is used for connecting with the negative electrode sheet.

5. The square battery structure according to claim 4, characterized in that: The square battery structure includes a top cover, which is arranged on the top of the connecting piece, and the top cover includes: A cover body, wherein the cover body has a liquid injection hole penetrating along a thickness direction thereof; An explosion-proof valve is arranged in the middle of the cover body; The poles are symmetrically arranged on the cover body, and the poles include a positive pole and a negative pole.

6. The square battery structure according to claim 5, characterized in that: The square battery structure includes a bushing, which is arranged outside the bipolar lithium battery and is used to protect the bipolar lithium battery.

7. The square battery structure according to claim 6, characterized in that: The square battery structure includes a shell, which is arranged outside the bushing and is used to fix the bipolar lithium battery.

8. The square battery structure according to claim 7, characterized in that: The shell and the top cover are made of aluminum, stainless steel or plastic, and the substrate, the positive electrode connecting piece and the negative electrode connecting piece are made of copper.

9. A bipolar lithium battery, characterized in that: The bipolar lithium battery comprises a bipolar lithium battery body and a square battery structure as claimed in any one of claims 1 to 8.

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