Lithium battery

Abstract

The utility model relates to a lithium battery which comprises an outer shell and a plurality of battery cells arranged in the outer shell, the plurality of battery cells are sequentially connected in series, tabs of positive and negative electrodes of adjacent battery cells are mutually crimped, the tab of the positive electrode of the first battery cell is also crimped with a positive electrode lead-out wire, and the tab of the negative electrode of the last battery cell is also crimped with a negative electrode lead-out wire. A protective circuit board is also connected in series on the positive lead-out wire or the negative lead-out wire; and a lead connected to the protective circuit board is also crimped on each battery cell. According to the utility model, the tabs of the plurality of battery cells are connected in a crimping manner, the operation is convenient, the connection is firm, and the whole process is cold operation, so that potential safety hazards possibly existing when the tabs of the battery cells are welded at high temperature conventionally are avoided, and the influence on the overall performance of the battery cells is also reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium batteries, and particularly relates to a lithium battery for an electric bicycle. Technical Field

[0003] In modern life, electric bicycles have become essential travel tools in people's daily lives. An electric bicycle refers to a vehicle that uses a battery as an auxiliary energy source and is based on an ordinary bicycle, with a motor, a controller, a battery, a handlebar brake, and other control components and a display instrument system installed. Currently, the main batteries used in electric bicycles include lead-acid batteries and lithium batteries.

[0004] Lithium batteries have the characteristics of high energy density, high power density, long cycle life, long storage time, and environmental protection. Compared with lead-acid batteries that can also be used as power batteries, their single-cell core voltage is higher, power density is higher, self-discharge rate is lower, and there is no memory effect. However, lithium batteries are a type of battery with a lithium metal or lithium alloy as the negative electrode material and a non-aqueous electrolyte solution. Due to the very active chemical properties of lithium metal, the processing, storage, and use of lithium metal have very high environmental requirements. During the charging and discharging process of lithium batteries, when the temperature is too high or the pressure is too large, safety accidents such as explosions are likely to occur.

[0005] In addition, lithium batteries are usually composed of multiple cells connected in series or in parallel. Adjacent cells are connected by wires or tab welding, and wires connected to the circuit board are welded to each cell. When the above wires or tabs are welded at high temperatures, there are safety hazards. Moreover, according to the existing cell connection process, short circuits, loose connections that are not firm, and connection errors are likely to occur during the operation process. This process greatly affects the performance of the battery after grouping, and the operability of the connection process also affects the manufacturing efficiency of the product. Summary of the Utility Model

[0006] In order to solve the above technical problems, the purpose of the utility model is to provide a lithium battery that is convenient to assemble, has a firm circuit connection, and high safety.

[0007] In order to achieve the above utility model purpose, the utility model adopts the following technical solutions:

[0008] A lithium battery includes an outer shell and a plurality of cells arranged in the outer shell. The plurality of cells are connected in series in sequence, and the tabs of the positive and negative electrodes of adjacent cells are pressed against each other. A positive lead-out wire is also pressed against the tab of the positive electrode of the first cell, and a negative lead-out wire is also pressed against the tab of the negative electrode of the last cell. A protection circuit board is also connected in series on the positive lead-out wire or the negative lead-out wire, and a wire connected to the protection circuit board is pressed against each cell.

[0009] As a preferred solution: The crimping structure is to crimp two pole tabs and a wire using a crimping ring or a nail gun, or to crimp a pole tab and a positive lead or a negative lead using a crimping ring or a nail gun.

[0010] As a preferred solution: An insulating sheath is also provided at the connection of the pole tabs of two adjacent battery cells, and insulating sheaths are also provided on the pole tab of the positive electrode of the first battery cell and the pole tab of the negative electrode of the last battery cell.

[0011] As a preferred solution: A high-temperature circuit breaker is also connected in series on the positive lead or the negative lead, and the protection circuit board is connected to the positive lead or the negative lead through a terminal block.

[0012] As a preferred solution: It further includes a bent-angle plug. After passing through the outer casing, the bent-angle plug is connected to the positive lead and the negative lead through a terminal block.

[0013] As a preferred solution: The outer casing includes a casing and a cover plate. The cover plate is provided with a long strip-shaped through hole. The cover plate is buckled on the casing and fastened by bolts passing through the long strip-shaped through hole.

[0014] As a preferred solution: The outer casing further includes a bottom plate. At least two opposite sides of the bottom plate are folded and fixed to the casing.

[0015] As a preferred solution: A pressure relief component is also provided on at least one side wall of the outer casing. The pressure relief component is a rubber plug that can be melted at high temperature.

[0016] As a preferred solution: Vibration damping plates are provided on the four side walls and the upper and lower parts of the outer casing, and insulating plates are provided on the inner sides of the vibration damping plates.

[0017] As a preferred solution: A handle assembly is also provided on the outer casing.

[0018] The pole tabs of multiple battery cells of the present utility model are connected by crimping, which is convenient to operate, has a firm connection, and the whole process is cold working, avoiding potential safety hazards that may exist during conventional high-temperature welding of battery cell pole tabs, and also reducing the impact on the overall performance of the battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The schematic diagrams in the specification that form a part of this application are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation to this application.

[0020] Figure 1 is a schematic diagram of the overall structure of the present utility model;

[0021] Figure 2 is a schematic diagram of the structure of the casing, vibration damping plate and insulating plate of the present utility model;

[0022] Figure 3 It is a schematic diagram of the connection structure of multiple battery cells and a protection circuit board of the present utility model;

[0023] Figure 4 and Figure 5 are schematic diagrams of two crimping structures of a single battery cell of the present utility model with a wire or positive and negative lead-out wires Figure 6 is a schematic diagram of the structure of an insulating sheath provided on the tab of a single battery cell of the present utility model.

[0024] Reference numerals are: 1, housing; 11, pressure relief member; 2, cover plate; 21, long strip-shaped through hole; 22, handle assembly; 3, bottom plate; 4, angled plug; 5, shock-absorbing plate; 6, insulating plate; 7, battery cell; 71, tab; 72, pressure ring; 73, nail gun; 74, insulating sheath; 75, high-temperature circuit breaker; 8, protection circuit board; 9, terminal. Detailed implementation manners

[0025] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0026] It should be noted that the terms used herein are only for describing the specific implementation manners and are not intended to limit the exemplary implementation manners according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0027] In addition, in the description of the present utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality of" is two or more, unless otherwise clearly defined.

[0029] In the present utility model, unless otherwise clearly specified and defined, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0030] In the present utility model, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0031] The present utility model will be further described below in conjunction with the accompanying drawings and embodiments:

[0032] As Figure 1 shown, a lithium battery includes an outer casing and a plurality of battery cells 7 disposed inside the outer casing. The outer casing is made of metal material, has high strength and impact resistance, and good safety performance; the outer casing includes a housing 1 and a cover plate 2. A long strip-shaped through hole 21 is provided on the cover plate 2. The cover plate 2 is buckled on the housing 1 and fastened by bolts passing through the long strip-shaped through hole 21. The setting of the long strip-shaped through hole can enable the cover plate to have a certain installation margin during installation, and can meet the battery cells of different height specifications.

[0033] The outer casing further includes a bottom plate 3. At least two opposite sides of the bottom plate 3 are folded and fixed to the housing 1. The above structure enables both ends of the outer casing to be detachable. When the cover plate is deformed, rusted, etc. and cannot be disassembled after long-term use, the internal battery cells can be repaired and maintained by disassembling the bottom plate; in addition, when the internal battery cells are deformed and expanded and stuck to the housing, the cover plate and the bottom plate can be removed simultaneously to facilitate pushing out the battery cells from the housing.

[0034] At least one side wall of the outer casing is further provided with a pressure relief member 11, and the pressure relief member 11 is a pressure relief valve or a rubber plug that can be melted at high temperature. When the internal pressure of the outer casing is too high, the pressure can be released through the pressure relief member to avoid safety accidents.

[0035] As Figure 2 As shown in the figure, shock-absorbing plates 5 are provided on the peripheral side walls and the upper and lower parts of the outer casing, and insulating plates 6 are provided on the inner sides of the shock-absorbing plates 5. The setting of the shock-absorbing plates 5 can enable the internal battery cells to have a stable environment, avoiding the collision between the battery cells and the outer casing in a bumpy environment, causing damage to the battery cells and affecting the service life. The setting of the insulating plates 6 can prevent the battery cells from leaking electricity and transmitting it to the outer casing, forming a safety hazard.

[0036] A handle assembly 22 is further provided on the outer casing. As a preference, the handle assembly 22 can be fixed on the cover plate 2, which is convenient for the overall extraction of the battery and also convenient for the removal of the cover plate.

[0037] As Figure 3 As shown in the figure, a plurality of battery cells 7 are connected in series in sequence, the tabs 71 of the positive and negative electrodes of adjacent battery cells 7 are pressed against each other, a positive electrode lead-out wire is further pressed against the tab 71 of the positive electrode of the first battery cell 7, a negative electrode lead-out wire is further pressed against the tab 71 of the negative electrode of the last battery cell 7, a protection circuit board 8 is further connected in series on the positive electrode lead-out wire or the negative electrode lead-out wire, and a wire connected to the protection circuit board 8 is further pressed against each battery cell 7.

[0038] A high-temperature circuit breaker 75 is further connected in series on the positive electrode lead-out wire or the negative electrode lead-out wire. When the temperature exceeds a certain value, the high-temperature circuit breaker 75 disconnects, so that the entire circuit is disconnected, avoiding potential safety hazards. The high-temperature short-circuit device 75 can be a device such as a fuse or a fuse resistor.

[0039] The protection circuit board 8 is connected to the positive electrode lead-out wire or the negative electrode lead-out wire through a terminal block 9. A corner plug 4 is further provided outside the outer casing. After the corner plug 4 penetrates the outer casing, it is also connected to the positive electrode lead-out wire and the negative electrode lead-out wire through the terminal block 9. The connection method using the terminal block is convenient for installation and operation. At the same time, due to the use of the corner plug 4, after the battery is installed on the electric bicycle, the entire connecting wire forms a corner, which is more firmly and tightly connected compared to the conventional straight plug-in line, and can avoid problems such as wire loosening caused by bumping and pulling.

[0040] The tabs of the multiple battery cells of the present utility model are connected by pressing, which is convenient for operation, firm in connection, and the whole process is a cold operation, avoiding potential safety hazards that may exist during the conventional high-temperature welding of the battery cell tabs and also reducing the impact on the overall performance of the battery cells.

[0041] As Figure 4and Figure 5 As shown, the above-mentioned crimping connection methods include but are not limited to the following two:

[0042] 1. Using a pressure ring structure: First, punch holes on the tabs 71 of the battery cell 7, and then insert the pressure ring 72 through the punched holes of the two tabs 71.

[0043] Holes are punched, and the wire is wound around the outer periphery of the pressure ring 72, and finally the pressure ring 72 is pressed, the pressure ring 72 is riveted with the pole ear 71, and the wire is also firmly fixed; two holes are punched on the pole ear of the positive electrode of the first battery cell, one hole is riveted and fixed to the wire connected to the protection circuit board with a pressure ring 72, and the other hole is riveted and fixed to the positive lead wire with a pressure ring 72; two holes are also punched on the pole ear of the negative electrode of the last battery cell, one hole is riveted and fixed to the wire connected to the protection circuit board with a pressure ring 72, and the other hole is riveted and fixed to the negative lead wire with a pressure ring 72; because the wire, the positive lead wire, and the negative lead wire are all in contact with the entire outer circumference of the pressure ring, the overall contact area is larger and the connection is more secure. At the same time, in order to ensure the conductivity, the pressure ring is preferably a copper pressure ring.

[0044] 2. Using a nail gun structure: directly use the nail gun 73 to fix the two tabs 71 and the corresponding wires together.

[0045] The positive electrode lug is fixed with a wire connected to the protection circuit board and the positive electrode lead wire by means of nails; the negative electrode lug of the last battery cell is fixed with a wire connected to the protection circuit board and the negative electrode lead wire by means of nails; the nail fixing structure is adopted, which makes the operation more convenient.

[0046] In order to further improve safety, an insulating sheath 74 is provided at the connection between the tabs 71 of two adjacent cells 7, and an insulating sheath 74 is also provided on the tab 71 of the positive electrode of the first cell 7 and the tab 71 of the negative electrode of the last cell 7. Figure 6 This can prevent the tabs from contacting each other to form a short circuit. The insulating sheath 74 is an insulating tape or a heat shrink sleeve, and the heat shrink sleeve can be fixed by a plastic clip.

[0047] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0048] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention. Any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A lithium battery, comprising an outer shell and a plurality of battery cells (7) arranged in the outer shell, characterized in that: A plurality of battery cells (7) are sequentially connected in series, the positive and negative pole ears (71) of adjacent battery cells (7) are crimped to each other, a positive pole lead wire is crimped to the positive pole ear (71) of the first battery cell (7), and a negative pole lead wire is crimped to the negative pole ear (71) of the last battery cell (7), a protection circuit board (8) is also connected in series to the positive pole lead wire or the negative pole lead wire, and a wire connected to the protection circuit board (8) is also crimped to each battery cell (7); The crimping structure uses a crimping ring (72) or a gun nail (73) to crimp the two pole ears (71) and the wire, or uses a crimping ring (72) or a gun nail (73) to crimp the pole ears (71) and the positive electrode lead wire or the negative electrode lead wire; An insulating sheath (74) is also provided at the connection between the pole ears (71) of two adjacent battery cells (7), and an insulating sheath (74) is also provided on the pole ear (71) of the positive pole of the first battery cell (7) and the pole ear (71) of the negative pole of the last battery cell (7); A high-temperature circuit breaker (75) is also connected in series to the positive electrode lead wire or the negative electrode lead wire, and the protection circuit board (8) is connected to the positive electrode lead wire or the negative electrode lead wire via a connection terminal (9).

2. A lithium battery according to claim 1, characterized in that: It also comprises an angled plug (4), which, after penetrating the outer shell, is connected to the positive lead wire and the negative lead wire via a connection terminal (9).

3. A lithium battery according to claim 1, characterized in that: The outer shell comprises a shell (1) and a cover plate (2); the cover plate (2) is provided with an elongated through hole (21); the cover plate (2) is buckled onto the shell (1) and is fastened by bolts penetrating the elongated through hole (21).

4. A lithium battery according to claim 1, characterized in that: The outer shell further comprises a bottom plate (3), and at least two opposite sides of the bottom plate (3) are folded and fixed to the shell (1).

5. A lithium battery according to claim 1, characterized in that: A pressure relief piece (11) is also provided on at least one side wall of the outer shell, and the pressure relief piece (11) is a rubber plug that can be melted at high temperature.

6. A lithium battery according to claim 1, characterized in that: The surrounding side walls and the upper and lower parts of the outer shell are all provided with a vibration-proof plate (5), and the inner side of the vibration-proof plate is provided with an insulating plate (6).

7. A lithium battery according to claim 1, characterized in that: The outer shell is also provided with a handle assembly (22).

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