A new type of high voltage battery

Abstract

The present invention relates to a single cell, a battery pack and an electric vehicle. The single cell comprises a shell and two pole cores, the shell having a partition and four poles, wherein two poles are positive poles, the other two poles are negative poles, and the partition divides the interior of the shell into two cavities. Each of the two pole cores has a positive pole ear and a negative pole ear arranged on the same side of the pole core at intervals, and the two pole cores are placed relative to the positive pole ear and the negative pole ear in the shell so that the positive pole ear and the negative pole ear of the two pole cores are interlaced. The four poles are arranged in polarity, the four pole ears are connected and arranged on the four poles in polarity, and are separated by a partition so that the two pole cores are respectively located in two cavities. In addition, the two positive and negative poles in the middle are connected to each other so that the two pole cores are connected in series, and the other two positive and negative poles are used as the positive pole column and negative pole column of the single cell, respectively.

Description

Technical Field

[0001] The present invention relates to the field of single cells, and in particular to a single cell, a battery pack equipped with the single cell, and an electric vehicle equipped with the battery pack. Background Art

[0002] Nowadays, with the continuous development of new energy vehicles, the requirements for on-board batteries are getting higher and higher. This requirement is reflected in the continuous increase in the total power requirements of the battery pack of new energy vehicles, and all this is based on the continuous increase in the mileage of new energy vehicles. For example, in order to improve power performance, electric vehicles use high-voltage battery packs, and their battery capacity is usually greater than 800V.

[0003] Traditionally, there is only one bare cell or multiple bare cells in parallel in the battery shell, and a single bare cell or multiple bare cells in parallel cannot increase the voltage of the entire battery. Since the voltage of a single cell is usually <4.5V (for example, the voltage of a lithium titanate battery is 2.4V, the voltage of a lithium iron phosphate battery is 3.2V, the voltage of a ternary battery is 3.7V, and the voltage of a multi-polymer battery is 4.3V), it is usually necessary to increase the number of batteries in the battery pack. The more batteries there are, the higher the weight of the battery shell, which leads to a significant decrease in the energy density of the battery pack.

[0004] There are usually two ways to solve the high voltage of single cells. The first is to develop a high-voltage chemical system (>5V); the second is to double the battery voltage by "internal series" of bare cells. However, the voltage increase of the first method is limited, and the high-voltage liquid electrolyte technology is not yet mature, and it cannot be industrialized for the time being; the second method uses the "internal series" method. If the "internal series" units inside the battery are connected, the liquid electrolyte cannot withstand the high voltage, and the electrolyte decomposition occurs, causing the battery to fail. Therefore, solid electrolytes are needed, but this technology is not yet mature. If the "internal series" units are isolated, the space utilization rate of the single cell is low, and the weight of the isolated part accounts for a high proportion. Although the voltage of the cell is increased, the energy density is reduced. Summary of the invention

[0005] The purpose of the present invention is to provide a single cell battery that can overcome the above-mentioned disadvantages, wherein the voltage of the single cell battery is twice that of a conventional battery cell, and compared with batteries of traditional structures, the energy density is improved, and the normal operation of the battery can be achieved by using conventional low-pressure electrolyte.

[0006] In addition, the present invention is also intended to solve or alleviate other technical problems existing in the prior art.

[0007] According to the first aspect of the present invention, the technical solution adopted by the present invention to solve the technical problem is to provide a single cell battery, which includes a shell and two pole cores, the shell having a partition and four poles, wherein two poles are positive poles, and the other two poles are negative poles, and the partition divides the interior of the shell into two cavities, each of the two pole cores has a positive pole ear and a negative pole ear arranged on the same side of the pole core at intervals, and the two pole cores are placed relative to the positive pole ear and the negative pole ear in the shell so that the positive pole ear and the negative pole ear of the two pole cores are staggered with each other, wherein the four pole columns are arranged according to polarity, the four pole ears are respectively connected and arranged on the four pole columns according to polarity, and are separated by the partition so that the two pole cores are respectively located in the two cavities; and wherein the two middle positive and negative poles are connected to each other so that the two pole cores are connected in series, and the other two positive and negative poles are respectively used as the positive pole column and negative pole column of the single cell.

[0008] Optionally, according to one embodiment of the present invention, the two middle positive and negative poles are connected to each other through a metal conductor, and an insulating sleeve covers the two middle positive and negative poles, so that the two middle positive and negative poles are separated from the outside of the battery.

[0009] Optionally, according to an embodiment of the present invention, at a position where a partition is provided on the shell, a recess is provided on the upper shell cover of the shell, and the four poles are arranged on the recess in a mutually spaced and staggered manner.

[0010] Optionally, according to an embodiment of the present invention, the shell has a separator located in a middle area of ​​the shell and separating the positive electrode tabs and the negative electrode tabs of the two pole cores.

[0011] Optionally, according to an embodiment of the present invention, the material constituting the shell is aluminum, steel or a polymer material, and the pole core is in the form of a winding core or a lamination.

[0012] Optionally, according to an embodiment of the present invention, the partition is made of an insulating material, and the insulating material is polyvinyl chloride, polyethylene, polytetrafluoroethylene, polyimide, or polyamide-imide.

[0013] Optionally, according to an embodiment of the present invention, when the single cell is a lithium-ion battery, the electrode core comprises a positive electrode, a negative electrode, a separator and an electrolyte, and the positive electrode is a lithium-containing compound, and the negative electrode comprises a carbon material.

[0014] Optionally, according to an embodiment of the present invention, a liquid injection hole and an explosion-proof valve are provided in the two cavities of the shell.

[0015] According to a second aspect of the present invention, a battery pack is provided, comprising the above-mentioned single battery.

[0016] According to a third aspect of the present invention, there is provided an electric vehicle having a battery pack including the above-mentioned single battery.

[0017] Compared with the prior art, the single cell of the present invention has the following beneficial effects: the present invention can shorten the distance between adjacent pole cores and further improve the energy density, and eliminate the connection through hole in the separator and the packaging structure required to close the connection through hole and further simplify the structure of the battery. In addition, the present invention can preset the position of the pole cores in series, and facilitate the pre-manufacturing of the separator and thus the mass production of the battery.

[0018] In the following description of the drawings and specific embodiments, the details of one or more embodiments of the present invention will be described. Other features, objects and advantages of the present invention can be clearly seen from these descriptions, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be described in more detail by way of example with reference to the accompanying drawings, which are not drawn to scale, in which:

[0020] Figure 1 A schematic diagram showing two pole cores constituting a single cell according to the present invention is shown;

[0021] Figure 2 It is shown that according to the present invention Figure 1 A side view of a single pole core shown in FIG.

[0022] Figure 3 A top view of a housing of a single cell according to the present invention is shown;

[0023] Figure 4 It shows that Figure 3 A front view of a housing of a single cell shown in FIG.

[0024] Figure 5 It shows that Figure 3 A bottom view of the housing of the single cell shown in FIG.

[0025] Figure 6 Shows Figure 1 The two pole cores are inserted into Figure 3 A top view of the shell in FIG.

[0026] Figure 7 shows a top view of the housing after the insulating sleeve is installed;

[0027] Figure 8 Shown along Figure 7 A cross-sectional view of the shell taken along line AA' in FIG.

[0028] Fig. 9 An alternative partition is shown that divides the interior of the housing into two chambers. DETAILED DESCRIPTION

[0029] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or restriction to the technical solution of the present invention.

[0030] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings. They are relative concepts and may change accordingly according to their different positions and different usage states. Therefore, these or other directional terms should not be interpreted as restrictive terms. In addition, the terms "first", "second", "third", etc. or similar expressions are only used for description and distinction purposes, and cannot be understood as indicating or implying the relative importance of the corresponding components.

[0031] like Figure 1 As clearly shown in the figure, a schematic diagram of two pole cores constituting a single cell according to the present invention is provided. The single cell may be a lithium-ion battery. In the pole core of the lithium-ion battery, there are at least a positive electrode, a negative electrode, a separator and an electrolyte. The positive electrode may be a lithium-containing compound, and the negative electrode may contain a carbon material. When the battery is charged, lithium ions are generated on the positive electrode of the battery, and the generated lithium ions move to the negative electrode through the electrolyte. When the battery is discharged, the lithium ions embedded in the negative electrode carbon layer are released and move back to the positive electrode. In addition, the pole core may be wound and therefore may be called a roll core. Alternatively, the pole core may be in the form of a laminate.

[0032] Different from the positive and negative tabs in the prior art, which are respectively arranged on opposite sides of the pole core, such as Figure 1 and Figure 2 As shown, according to one embodiment of the present invention, each pole core 1, 1' has a positive pole ear 2, 2' and a negative pole ear 3, 3', and the positive pole ear 2, 2' and the negative pole ear 3, 3' are arranged on the same side of the pole core 1, 1' and are spaced a certain distance apart from each other. In addition, compared with the common "head-to-tail" arrangement of multiple pole cores in a shell, the two pole cores 1, 1' of the present invention are relatively placed in the separated cavities 8, 8' of the shell 4 with respect to the side where the pole ears are arranged, so that the positive pole ears 2, 2' and the negative pole ears 3, 3' are interlaced or meshed with each other, thereby improving the space utilization in the shell 4, and thus improving the battery energy density. The relatively placed Figure 6 , which is further clearly shown in 9.

[0033] In the case 4 of the single cell according to the present invention, Figure 3 In the embodiment, the shell 4 is used to improve the strength of the battery and ensure the safe use of the battery to prevent the corrosive electrolyte from overflowing to the outside of the battery and causing negative effects. The shell 4 can be made of plastic or metal, and when the shell 4 is made of metal, the metal is preferably aluminum or steel to facilitate heat dissipation of the battery and improve the strength of the battery, and when the shell 4 is made of plastic, the plastic can be a polymer material such as polypropylene (PP). The shell 4 can be a rectangular parallelepiped, a cube, or a rectangular parallelepiped or cube with chamfers, partial radians, or partial bends.

[0034] A zigzag partition 9 is provided inside the housing 4 to separate the inside of the housing 4 into two chambers 8, 8'. The partition 9 is made of an insulating material, and the insulating material may be, for example, polyvinyl chloride, polyethylene, polytetrafluoroethylene, polyimide, polyamide-imide, etc. Alternatively, in addition to the above-mentioned zigzag shape, the partition 9 may be in other shapes that completely separate the positive tabs 2, 2' and the negative tabs 3, 3' that are arranged on the same side of the pole core 1, 1' and face each other, such as Fig. 9 The stepped partition 19 shown in FIG. In addition, preferably, the housing 4 may be a housing with an inner surface insulated.

[0035] The partition plate 9 includes a side surface facing the adjacent pole cores 1, 1' and a circumferential surface adjacent to the side surface. The circumferential surface cooperates with the housing 4 to separate the interior of the housing 4 into two cavities 8, 8'.

[0036] The two cavities 8, 8' can be used to receive the oppositely arranged pole cores 1, 1', and thus significantly reduce the distance between the two pole cores 1, 1', and effectively improve the space utilization of the housing 4. In this case, the cruising range of an electric vehicle using the single cell and battery pack can be effectively improved.

[0037] In addition, if Figure 3 and 4 As further shown in the figure, at the position where the partition 9 is set on the shell 4, that is, preferably, at the middle position of the shell 4, the upper shell cover of the shell 4 is provided with a recess. Four poles 6, 6' and 7, 7' (that is, positive poles 6, 6' and negative poles 7, 7') are arranged on the recess in a mutually spaced and staggered manner, so that when the two pole cores 1, 1' are placed in the two cavities 8, 8' of the shell 4, the positive pole ears 2, 2' and negative pole ears 3, 3' of the pole cores 1, 1' are respectively received, thereby realizing the electrical connection between the positive pole ears 2, 2' and negative pole ears 3, 3' of the pole cores 1, 1' and the positive pole columns 6, 6' and negative pole columns 7, 7' of the shell 4.

[0038] like Figure 5 As shown, the edge of the lower shell cover 5 of the shell 4 is sealed and connected to the shell 4, and the circumferential surface of the partition 9 and the lower shell cover 5 are connected by laser welding, thereby achieving isolation between the cavity 8 and the cavity 8'. Of course, in addition to laser welding, the above connection can also be a soft soldering connection, a hard soldering connection, an adhesive connection, a snap-fit ​​connection, or other forms of connection known to those skilled in the art.

[0039] In another embodiment, the single cell may further include an isolating film located in the housing 4 and having insulation and electrolyte corrosion resistance. The material of the isolating film may include polypropylene, polyethylene, etc. In addition, the isolating film may include multiple layers, such as an outer layer, an intermediate layer, and an inner layer, wherein the outer layer may be made of polyester or nylon material to prevent external forces from causing damage to the battery, such as puncturing the battery; the intermediate layer may be made of metal material to prevent water vapor penetration from the outside of the battery and electrolyte overflow; and the inner layer may be made of polypropylene, polyethylene, or other materials that react less with the electrolyte of the battery and have insulation.

[0040] In addition, the cavity 8, 8' of the shell 4 may have an injection hole, and the injection hole may be located in the large face or side face of the battery as required. For example, the injection hole may be provided in the partition 9 (preferably, provided or inserted in the circumferential face of the partition 9) to inject the electrolyte from the outside of the battery into the cavity 8, 8' of the shell 4. In this case, the shell 4 is provided with a through hole at a position corresponding to the injection hole of the partition 9, for connecting the injection hole with the external fluid of the battery. Furthermore, in the case where the battery includes a separator, a passage corresponding to the injection hole and the through hole is provided in the separator for the injection of electrolyte from the outside of the battery. The battery also includes a plugging member or a sealing member, which is used to seal the injection hole after the electrolyte injection is completed.

[0041] Next, refer to Figure 6-8 , Figure 6 Shows Figure 1 The two pole cores are inserted into Figure 3 A top view of the shell in Figure 7 shows a top view of the housing after the insulating sleeve is installed, and Figure 8 Shown along Figure 7 A cross-sectional view of the shell taken along line AA' in FIG.

[0042] Figure 6-8 Clearly describe the installation process of a single cell battery, which includes the following three steps:

[0043] In the first step, the pole core 1 is placed in a cavity 8 of the shell 4 separated by a sawtooth partition 9, and the positive tab 2 and the negative tab 3 of the pole core 1 are respectively received by the positive pole post 6 and the negative pole post 7 of the shell 4 and thus an electrical connection is formed between them. At the same time, the pole core 1' is placed in another cavity 8' of the shell 4 separated by a sawtooth partition 9, and the positive tab 2' and the negative tab 3' of the pole core 1' are respectively received by the positive pole post 6' and the negative pole post 7' of the shell 4 and thus an electrical connection is formed between them. The state where the pole core 1 and the pole core 1' are placed in the two separated cavities 8, 8' of the shell 4 is Figure 6 The positive tabs 2, 2' and negative tabs 3, 3' of the pole cores 1, 1' are arranged in a continuous sequence in the order of "positive, positive, negative, negative". Fig. 9 In the embodiment, the positive electrode tabs 2, 2' and the negative electrode tabs 3, 3' of the electrode cores 1, 1' are arranged continuously in the order of "positive, negative, positive, negative".

[0044] In the second step, the lower shell cover 5, which is preferably in the shape of a cuboid, is sealed to the shell 4 at the peripheral edge, and the sealed connection can be achieved by laser welding, soldering, brazing, adhesive, snap-fit ​​connection, etc. At the same time, the partition 9 is sealed to the lower shell cover 5 at the circumferential surface, thereby isolating the two cavities 8, 8' of the shell 4, and the sealed connection can also be achieved by laser welding, soldering, brazing, adhesive, snap-fit ​​connection, etc.

[0045] In the third step, in the recessed portion of the shell 4 located in the middle region, the positive pole column 6' and the negative pole column 7 of the shell 4 are connected by the external metal conductor 11, thereby realizing the connection between the positive pole ear 2' of the pole core 1' and the negative pole ear 3 of the pole core 1. In this case, the two middle pole ears 2' and 3 are connected to each other, so that the two pole cores 1 and 1' are connected in series, and the other two pole ears 2 and 3' are used as the positive pole ear and negative pole ear of the single battery, respectively. Furthermore, by covering the positive pole column 6' and the negative pole column 7 of the shell 4, and thus the positive pole ear 2' of the pole core 1' and the negative pole ear 3 of the pole core 1, and sealing the insulating sleeve 10 with the shell 4, the positive pole column 6' and the negative pole column 7 of the shell 4, and thus the positive pole ear 2' of the pole core 1' and the negative pole ear 3 of the pole core 1 are separated and insulated from the outside of the battery. Likewise, the sealing connection of the insulating sleeve 10 to the housing 4 can be achieved via laser welding, soft soldering, brazing, adhesives, snap-fit ​​connections, etc. The insulating sleeve 10 can be made of the same material as the partition 9, and the material can be, for example, polyvinyl chloride, polyethylene, polytetrafluoroethylene, polyimide, polyamide-imide, etc.

[0046] After the battery is sealed, an injection hole is provided in the cavity 8, 8' of the housing 4, and the injection hole (and the related plugging member or sealing member) can be located in the large face or side face of the battery as required. For example, the injection hole can be provided in the separator 9 (preferably, in the circumferential face of the separator 9) to inject the electrolyte from the outside of the battery into the cavity 8, 8' of the housing 4.

[0047] The above-mentioned single battery may also include other necessary components to realize its functions (for example, explosion-proof valve, current interruption device, etc.), which are well known to those skilled in the art and will not be described in detail herein.

[0048] Compared with the prior art, the single cell of the present invention has the following beneficial effects. Although the prior art discloses the technical idea of ​​arranging pole core groups in each separated accommodating cavity and connecting the pole core groups in each accommodating cavity in series, thereby effectively improving the capacity and voltage of the battery, the present invention can further shorten the spacing between adjacent pole cores and further improve the energy density on the basis of the prior art, and eliminate the connection through holes in the partition and the packaging structure required to close the connection through holes and further simplify the structure of the battery. In addition, the prior art is that the pole cores are directly connected in series through the pole ears without the pole column of the shell as an intermediary, while the present invention is that the pole ears of the pole cores are connected to the pole column of the shell, and then the middle pole column is connected to form the pole core series connection, so the present invention can preset the position of the pole core series connection, and facilitate the pre-manufacturing of the partition and the mass production of the battery.

[0049] The present invention also provides a battery pack including the single cell, and an electric vehicle using the battery pack as a power source. Due to the use of the battery pack according to the present invention, the endurance of the electric vehicle is significantly improved, and the production and manufacturing costs are further reduced.

[0050] It should be understood that the above description is only used to exemplify the present invention and is not used to limit the present invention. It should be pointed out that for ordinary technicians in this field, several improvements, modifications and variations can be made to the present invention, but these improvements, modifications and variations should be regarded as falling within the scope of protection of the present invention without departing from the spirit of the present invention.

[0051] Parts List

[0052] 1,1' core

[0053] 2,2' positive tab

[0054] 3,3' negative terminal lug

[0055] 4 Housing

[0056] 5 Lower case cover

[0057] 6,6' positive column

[0058] 7,7' negative pole

[0059] 8,8' cavity

[0060] 9,19 Partition

[0061] 10 Insulation sleeve

[0062] 11 External metal conductor.

Claims

1. A single cell battery, characterized in that: It includes a shell and two pole cores, wherein the shell has a partition and four poles, two of which are positive poles and the other two are negative poles, and the partition divides the interior of the shell into two cavities. Each of the two pole cores has a positive pole lug and a negative pole lug disposed on the same side of the pole core at intervals from each other, and the two pole cores are placed opposite to each other in the housing with respect to the positive pole lug and the negative pole lug so that the positive pole lug and the negative pole lug of the two pole cores are interlaced with each other, The four poles are arranged according to polarity, the four pole ears are connected and arranged on the four poles according to polarity, and are separated by the partition so that the two pole cores are located in the two cavities respectively; and The two middle positive and negative poles are connected to each other so that the two pole cores are connected in series, and the other two positive and negative poles are used as the positive pole and negative pole of the single battery respectively.

2. The single cell according to claim 1, characterized in that: The two positive and negative poles in the middle are connected to each other through a metal conductor, and an insulating sleeve covers the two positive and negative poles in the middle, so that the two positive and negative poles in the middle are separated from the outside of the battery.

3. The single cell according to claim 1, characterized in that: The upper shell cover of the housing is provided with a recess at a position where the partition is provided on the housing, and the four poles are arranged on the recess in a mutually spaced and staggered manner.

4. The single cell according to claim 3, characterized in that: The shell has a separator located in a middle region of the shell and separating the positive electrode tab and the negative electrode tab of the two electrode cores.

5. The single cell according to claim 1, characterized in that: The shell is made of aluminum, steel or polymer material, and the pole core is in the form of a winding core or a lamination.

6. The single cell according to claim 1, characterized in that: The partition is made of an insulating material, and the insulating material is polyvinyl chloride, polyethylene, polytetrafluoroethylene, polyimide, or polyamide-imide.

7. The single cell according to claim 1, characterized in that: When the single cell is a lithium-ion battery, the electrode core comprises a positive electrode, a negative electrode, a separator and an electrolyte, and the positive electrode is a lithium-containing compound, while the negative electrode comprises a carbon material.

8. The single cell according to claim 1, characterized in that: A liquid injection hole and an explosion-proof valve are arranged in the two cavities of the shell.

9. A battery pack, characterized in that: It has a single cell according to any one of claims 1 to 8.

10. An electric vehicle, characterized in that: The battery has a battery pack according to claim 9.

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