Battery and electronic equipment

Abstract

The utility model discloses a battery, which comprises a battery cell, the battery cell comprises a positive plate, a first negative plate and a second negative plate, the positive plate, the first negative plate and the second negative plate are laminated, the first negative plate is positioned on the outermost layer of the battery cell, and the first negative plate comprises an empty foil area; and the lithium supplementing layer is arranged in the empty foil area. According to the battery disclosed by the utility model, the lithium supplementing layer is arranged on the empty foil area of the first negative plate, so that the lithium supplementing layer can play a lithium supplementing effect on the battery when the battery is in the first effect, and the problem that the cycle performance of the battery is poorer due to the lack of a large amount of lithium is effectively avoided. In the prior art, a battery is not provided with a lithium supplementing layer, so that a large amount of active lithium is lost in the first cycle process of the battery, and the subsequent cycle performance of the battery is relatively poor, but the battery provided by the utility model can effectively solve the problem. Specifically, the battery can have relatively good cycle performance.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery and an electronic device. Background Art

[0002] In related technologies, lithium-ion batteries have the characteristics of long life, high energy density, high voltage, etc. Among them, lithium-ion batteries include silicon-doped batteries. A large amount of active lithium is lost during the first cycle of a silicon-doped battery, which will result in poor subsequent cycle performance of the battery. Content of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides a battery that can have good cycle performance.

[0004] The utility model also provides an electronic device.

[0005] The battery according to the first aspect embodiment of the utility model includes:

[0006] A battery cell, including a positive electrode sheet, a first negative electrode sheet, and a second negative electrode sheet. The positive electrode sheet, the first negative electrode sheet, and the second negative electrode sheet are stacked, and the first negative electrode sheet is located on the outermost layer of the battery cell. The first negative electrode sheet includes an empty foil area;

[0007] A lithium compensation layer is disposed in the empty foil area.

[0008] The battery according to the embodiment of the utility model has at least the following beneficial effects: By disposing the lithium compensation layer on the empty foil area of the first negative electrode sheet, in this way, during the first efficiency of the battery, the lithium compensation layer can play a role in compensating lithium for the battery, thereby effectively avoiding the problem of poor cycle performance caused by the lack of a large amount of lithium in the battery. In the prior art, since the battery is not provided with a lithium compensation layer, a large amount of active lithium is lost during the first cycle of the battery, resulting in poor subsequent cycle performance of the battery, while the battery of the present application can effectively solve this problem. Specifically, the battery can have good cycle performance.

[0009] In some embodiments of the battery according to the utility model, the lithium compensation layer is bonded to the empty foil area.

[0010] In some embodiments of the battery according to the utility model, the thickness of the lithium compensation layer is A, and the thickness of the first negative electrode sheet is B, and 0.01 ≤ A / B ≤ 1.

[0011] In some embodiments of the battery according to the utility model, the thickness of the lithium compensation layer is 1 μm to 300 μm.

[0012] For a battery according to some embodiments of the present utility model, a groove is provided in the empty foil area, and the lithium supplement layer is disposed in the groove.

[0013] For a battery according to some embodiments of the present utility model, the battery further includes a housing, the housing is provided with a storage cavity, and the battery cell is disposed in the storage cavity.

[0014] For a battery according to some embodiments of the present utility model, the lithium supplement layer is disposed on a side of the first negative electrode sheet close to the housing.

[0015] For a battery according to some embodiments of the present utility model, the housing is made of stainless steel.

[0016] For a battery according to some embodiments of the present utility model, the battery further includes an isolation layer, the housing is an aluminum plastic film, and the isolation layer is disposed between the lithium supplement layer and the housing.

[0017] An electronic device according to an embodiment of the second aspect of the present utility model includes the battery according to any one of the embodiments of the first aspect.

[0018] The electronic device according to the embodiment of the present utility model has at least the following beneficial effects: By disposing the lithium supplement layer on the empty foil area of the first negative electrode sheet, in this way, at the first efficiency of the battery, the lithium supplement layer can supplement lithium for the battery, thereby effectively avoiding the problem of poor cycle performance of the battery caused by the lack of a large amount of lithium. In the prior art, since the battery is not provided with a lithium supplement layer, a large amount of active lithium is lost during the first cycle of the battery, resulting in poor subsequent cycle performance of the battery, while the battery of the present application can effectively solve this problem. Specifically, the battery can have good cycle performance. Further, since the battery has good cycle performance, the electronic device having the battery has good battery life.

[0019] The additional aspects and advantages of the present utility model will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following further describes the present utility model in conjunction with the drawings and embodiments, where:

[0021] Figure 1 is a schematic diagram of the battery according to the first embodiment of the present utility model;

[0022] Figure 2 is an exploded schematic diagram of the battery according to some embodiments of the present utility model;

[0023] Figure 3 is a schematic diagram of the battery according to the second embodiment of the present utility model;

[0024] Figure 4 Schematic diagram of the first negative electrode sheet and the lithium supplement layer in the battery of some embodiments of the present invention;

[0025] Figure 5 Cross-sectional schematic diagram of the battery of some embodiments of the present invention;

[0026] Figure 6 Schematic diagram of the battery cell and the lithium supplement layer in the battery of the first embodiment of the present invention;

[0027] Figure 7 Schematic diagram of the battery cell and the lithium supplement layer in the battery of the second embodiment of the present invention.

[0028] Reference numerals:

[0029] Battery 10, battery cell 100, positive electrode sheet 110, first negative electrode sheet 120, empty foil area 121, second negative electrode sheet 130, lithium supplement layer 200, housing 300, storage cavity 310. Detailed description of the embodiments

[0030] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0031] In the description of the present invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention 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 thus should not be construed as a limitation to the present invention.

[0032] In the description of the present invention, the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If the first and second are described only for the purpose of distinguishing technical features, they should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0033] In the description of the present invention, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0034] In the description of the present utility model, the descriptions referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0035] In the related art, lithium-ion batteries have characteristics such as long life, high energy density, and high voltage. Among them, lithium-ion batteries include silicon-doped batteries. The initial efficiency of battery 10 refers to the percentage of the electricity that battery 10 can discharge after the first charge from factory to the start of use in its rated capacity. Specifically, it reflects the ratio of the actually available electricity to the nominal electricity when battery 10 is used for the first time. Since the silicon anode of the silicon-doped battery has a low initial efficiency, a large amount of active lithium is lost during the first cycle of the silicon-doped battery, which will result in poor subsequent cycle performance of battery 10. For this reason, this application proposes a battery 10.

[0036] Please refer to Figures 1 to 7 , in some embodiments, battery 10 includes: a battery cell 100, a housing 300, and a lithium supplement layer 200. The battery cell 100 includes a positive electrode sheet 110, a first negative electrode sheet 120, and a second negative electrode sheet 130. The positive electrode sheet 110 is generally composed of a current collector, an active material, a binder, a conductive agent, etc. Among them, the active material is the core of the positive electrode sheet 110, which determines the performance and characteristics of battery 10. In lithium-ion batteries, common positive electrode materials include lithium cobaltate (LiCoO2), ternary materials (such as lithium nickel cobalt manganese oxide LiNi1-x-yCoxMnyO2), lithium manganate (LiMn2O4), and lithium iron phosphate (LiFePO4), etc. The negative electrode sheets (including the first negative electrode sheet 120 and the second negative electrode sheet 130) are also composed of various materials, mainly including: an active material, a conductive agent, and an adhesive. The active material is the core of the negative electrode sheet, which determines the energy density and charge-discharge efficiency of battery 10. Common negative electrode active materials are graphite because it has high electrochemical stability and good ion conduction performance. The conductive agent is used to improve the electron conduction performance of the negative electrode sheet, and common conductive agents include carbon black, graphite, and conductive polymers, etc. The binder is used to bond the active material and the conductive agent together, and at the same time maintain the stability of the structure of battery 10. Common binders include polyvinyl alcohol and polyurethane, etc. The battery cell 100 can be a wound battery cell or a stacked battery cell. Please refer to Figure 6, when the battery cell 100 is a wound battery cell, the positive electrode sheet 110, the first negative electrode sheet 120, and the second negative electrode sheet 130 are stacked, the first negative electrode sheet 120 and the second negative electrode sheet 130 are connected, and after the positive electrode sheet 110, the first negative electrode sheet 120, and the second negative electrode sheet 130 are stacked, they are wound. Among them, the positive electrode sheet 110 is strip-shaped, the first negative electrode sheet 120 and the second negative electrode sheet 130 are also strip-shaped, one end of the second negative electrode sheet 130 far from the first negative electrode sheet 120 is aligned with one end of the positive electrode sheet 110, and then winding is performed. It can be imagined that in the wound battery cell, the second negative electrode sheet 130 will be located inside the battery cell 100, and the first negative electrode sheet 120 will be located on the outer layer of the battery cell 100. An active material layer is provided on the second negative electrode sheet 130, and no active material layer is provided on the first negative electrode sheet 120. That is, the first negative electrode sheet 120 is located on the outermost layer of the battery cell 100, and the first negative electrode sheet 120 includes an empty foil area 121. Please refer to Figure 7 , when the battery cell 100 is a stacked battery cell, the positive electrode sheet 110, the first negative electrode sheet 120, and the second negative electrode sheet 130 are stacked. Specifically, the stacking method is: the first negative electrode sheet 120 - the positive electrode sheet 110 - the second negative electrode sheet 130 - the positive electrode sheet 110 - the first negative electrode sheet 120. Among them, the number of the second negative electrode sheet 130 and the positive electrode sheet 110 is not specifically limited. It can be imagined that in the stacked battery cell, the second negative electrode sheet 130 will be located inside the battery cell 100, and the first negative electrode sheet 120 will be located on the outer layer of the battery cell 100. An active material layer is provided on the second negative electrode sheet 130, and no active material layer is provided on the first negative electrode sheet 120. That is, the first negative electrode sheet 120 is located on the outermost layer of the battery cell 100, and the first negative electrode sheet 120 includes an empty foil area 121. The lithium supplement layer 200 is provided in the empty foil area 121. Specifically, by providing the lithium supplement layer 200 on the empty foil area 121 of the first negative electrode sheet 120, in this way, when the battery 10 has its first efficiency, the lithium supplement layer 200 can supplement lithium to the battery 10, thereby effectively avoiding the problem of poor cycle performance of the battery 10 caused by the lack of a large amount of lithium. In the prior art, since the battery 10 is not provided with the lithium supplement layer 200, a large amount of active lithium is lost during the first cycle of the battery 10, resulting in poor subsequent cycle performance of the battery 10, while the battery 10 of the present application can effectively solve this problem. Specifically, the battery 10 can have good cycle performance.

[0037] The effects of the battery 10 will be described again below. Please refer to the following table. Through the first-efficiency experiment, the first-efficiency test method is: constant current and constant voltage charging at 0.7C to 4.5V, cut-off current 0.05C, constant current discharging at 0.2C to 3.0V. First efficiency = (0.2C discharge capacity) / (first-week 0.7C charging capacity) × 100%. It can be known that through the setting of the lithium compensation layer 200, the percentage of the electric quantity that the battery 10 can discharge after the first charge in its rated capacity is 92.3%. In the prior art, the percentage of the electric quantity that the battery 10 can discharge after the first charge in its rated capacity is 85.8%. Therefore, the discharged electric quantity of the battery 10 in this application is much higher than that of the battery 10 in the prior art. Therefore, the setting of the lithium compensation layer 200 can enable the battery 10 to have good cycle performance.

[0038]

[0039] Table 1

[0040] The following will be described again according to Table 1. Through the setting of the lithium compensation layer 200, the cycle performance of the battery 10 can also be improved. The cycle test of the battery 10 is as follows: in an environment of 25°C, the battery 10 after grading is charged at a constant current of 1.5C and a constant voltage of 5 to 4.5V, cut-off current 0.05C, and then discharged at a constant current of 0.5C to 3.0V, and this cycle is repeated. After 600 charge-discharge cycles, calculate the capacity retention rate of the 600th week. The calculation formula is as follows: Capacity retention rate of the 600th week cycle (%) = (600th week cycle discharge capacity / first cycle discharge capacity) × 100%. In summary, through the setting of the lithium compensation layer 200, the cycle performance of the battery 10 in this application is also higher than that of the battery 10 in the prior art.

[0041] The lithium compensation layer 200 will be introduced again below. The structure of the lithium compensation layer 200 is graphene and molten metal lithium. That is, the lithium compensation layer 200 is made by melting metal lithium and then pouring it into a graphene film. The graphene film has the characteristics of high strength, high thermal conductivity, high electrical conductivity, and flexibility. In addition, in some embodiments, the manufacturing process of the battery 10 is as follows: Step 1, coat the silicon-doped electrode sheet, and the surface density of the electrode sheet is 0.05 g / 1540.25 mm 2 to 0.5 g / 1540.25 mm 2 ; Step 2, melt the metal lithium and pour it into the graphene film to obtain the lithium compensation layer 200; Step 3, after the winding of the battery core 100 is completed, stick the lithium compensation layer 200 on the empty foil area 121 at the end and perform encapsulation; or, after the battery core 100 is laminated, stick the lithium compensation layer 200 on the outermost empty foil area 121.

[0042] Further, the specific manner of disposing the lithium - supplement layer 200 in the empty foil area 121 will be introduced below. In some embodiments, the lithium - supplement layer 200 is adhered to the empty foil area 121. Specifically, the lithium - supplement layer 200 can be pasted on the empty foil area 121 through adhesive tape. That is, one end of the adhesive tape is used to adhere the lithium - supplement layer 200, and then the other end of the adhesive tape is adhered to the empty foil area 121. The method of adhesion can facilitate the setting of the lithium - supplement layer 200 in the empty foil area 121, which can facilitate the processing and manufacturing of the battery 10. In addition, besides the method of adhesive tape, the method of hot - melt adhesive can also be used. Hot - melt adhesive is a kind of plastic adhesive, whose physical state changes with the change of temperature while its chemical properties remain unchanged. It is usually solid at room temperature. When heated to a certain temperature, it will melt into a viscous liquid. After coating, wetting the adherends, and through pressing and cooling to room temperature, the adhesion can be completed in a short time. Among them, by placing the hot - melt adhesive between the lithium - supplement layer 200 and the empty foil area 121 and then heating, the lithium - supplement layer 200 can be adhered to the empty foil area 121.

[0043] Further, please refer to Figure 4 , in some embodiments, the thickness of the lithium - supplement layer 200 is A, and the thickness of the first negative electrode sheet 120 is B, where 0.01 ≤ A / B ≤ 1. Specifically, the lithium - supplement layer 200 can completely cover the first negative electrode sheet 120. That is, the length of the lithium - supplement layer 200 is equal to the length of the first negative electrode sheet 120, and the width of the lithium - supplement layer 200 is equal to the width of the first negative electrode sheet 120. Among them, the thickness of the lithium - supplement layer 200 can be 1%, 10%, 20%, 50%, 80% or 100% of the thickness of the first negative electrode sheet 120. When the ratio of A / B is less than 0.01, the thickness of the lithium - supplement layer 200 is too small, which will lead to insufficient lithium - supplement amount of the lithium - supplement layer 200 for the battery 10 and no obvious improvement in the first - cycle efficiency of the battery 10. When the ratio of A / B is greater than 1, it will cause lithium precipitation during the formation stage, resulting in poor performance of the battery 10.

[0044] Further, in some embodiments, the thickness of the lithium - supplement layer 200 is 1um - 300um. Specifically, the thickness of the lithium - supplement layer 200 can be 1um, 10um, 20um, 50um, 100um, 150um, 200um or 300um. When the thickness of the lithium - supplement layer 200 is less than 1um, due to the too - small thickness size of the lithium - supplement layer 200, it will lead to difficult manufacturing of the lithium - supplement layer 200 and increased manufacturing cost. When the thickness of the lithium - supplement layer 200 is greater than 300um, the thickness size of the lithium - supplement layer 200 is larger, which will lead to an increase in the volume of the final battery 10 and a lower energy density of the battery 10. In addition, too much lithium - supplement layer 200 will also lead to a decline in the performance of the battery 10.

[0045] Further, in some embodiments, the empty foil area 121 is provided with a groove, and the lithium supplement layer 200 is disposed in the groove. Specifically, the groove in the empty foil area 121 can be formed by a stamping process. After the groove is provided in the empty foil area 121, it is convenient for the lithium supplement layer 200 to be disposed therein, and the groove wall can play a role in stabilizing the lithium supplement layer 200, effectively preventing the lithium supplement layer 200 from shifting.

[0046] Further, please refer to Figures 1 to 5 , in some embodiments, the battery 10 further includes a housing 300. The housing 300 is provided with a storage cavity 310, and the battery cell 100 is disposed in the storage cavity 310. The housing 300 has the following functions: First, physical protection. The housing 300 of the battery 10 mainly serves as the outer shell of the battery 10, playing a role in physically protecting the internal components of the battery 10. It can resist the influence of the external environment and prevent damage to the battery 10 caused by mechanical damage, vibration, impact, etc. Second, isolation. The housing 300 of the battery 10 usually has isolation performance to prevent direct contact between the internal components of the battery 10 and the external environment. Third, heat dissipation. The housing 300 can play a role in heat dissipation, helping to regulate the temperature of the battery 10, helping to maintain the battery 10 within an appropriate operating temperature range, and improving performance and lifespan. Fourth, electrical insulation. The housing 300 has electrical insulation performance to prevent the battery 10 from short-circuiting with the external circuit. Specifically, after the battery cell 100 is disposed in the housing 300, it helps to improve the reliability of the battery 10.

[0047] Further, please refer to Figures 1 to 5 , in some embodiments, the lithium supplement layer 200 is disposed on the side of the first negative electrode sheet 120 close to the housing 300. That is, the lithium supplement layer 200 is located between the first negative electrode sheet 120 and the housing 300. Among them, the manner in which the lithium supplement layer 200 is located between the first negative electrode sheet 120 and the housing 300 can effectively prevent the lithium supplement layer 200 from contacting the active material, thereby ensuring better performance of the battery 10. If the lithium supplement layer 200 is in direct contact with the active material layer, the lithium supplement layer 200 may damage the active material layer, resulting in a decrease in the performance of the battery 10.

[0048] Further, in some embodiments, the material of the housing 300 is stainless steel. The stainless-steel housing 300 has good corrosion resistance, high strength, and hardness. Specifically, the housing 300 may include two parts, namely a cover plate and a cavity. When the stainless-steel housing 300 contacts the lithium supplement layer 200, the lithium supplement layer 200 will not affect the housing 300. That is, the stainless-steel housing 300 has good stability, thus ensuring high reliability of the battery 10. In addition, when the housing 300 is made of stainless steel, an opening is provided on the housing 300, which can facilitate the discharge of the gas inside the housing 300 during the formation stage of the battery 10, improving the performance of the battery 10. Specifically, the design of the stainless-steel housing 300 in cooperation with the lithium supplement layer 200 can further enhance the cycle performance and safety performance of the battery 10 after the two cooperate synergistically. That is, using the stainless-steel housing 300 improves the safety performance of the battery 10 on the one hand, and using the design of the lithium supplement layer 200 can improve the cycle performance of the battery 10 on the other hand. In this way, the battery 10 has excellent cycle performance and safety performance.

[0049] Further, as introduced above, the material of the housing 300 is stainless steel. Among them, the housing 300 of the battery 10 can also be an aluminum-plastic film. The aluminum-plastic film has the characteristic of lower cost. Specifically, in some embodiments, the battery 10 further includes an isolation layer. The housing 300 is an aluminum-plastic film, and the isolation layer is disposed between the lithium supplement layer 200 and the housing 300. Specifically, the isolation layer can be an insulating film, and the insulating film can play a role in protecting the aluminum-plastic film, effectively preventing the direct contact between the lithium supplement layer 200 and the aluminum-plastic film, thereby causing damage to the aluminum-plastic film.

[0050] In some embodiments, the electronic device includes the battery 10 according to any one of the above embodiments. By disposing the lithium supplement layer 200 on the empty foil area 121 of the first negative electrode sheet 120, in this way, when the battery 10 has its first efficiency, the lithium supplement layer 200 can supplement lithium to the battery 10, thus effectively avoiding the problem of poor cycle performance of the battery 10 caused by the lack of a large amount of lithium. In the prior art, since the battery 10 does not have the lithium supplement layer 200, a large amount of active lithium is lost during the first cycle of the battery 10, resulting in poor subsequent cycle performance of the battery 10, while the battery 10 of the present application can effectively solve this problem. Specifically, the battery 10 can have good cycle performance. Further, since the battery 10 has good cycle performance, the battery life of the electronic device having the battery 10 is better.

[0051] The embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings. However, the present utility model is not limited to the above embodiments, and various changes can be made without departing from the gist of the present utility model within the scope of knowledge possessed by those of ordinary skill in the relevant technical field. In addition, the embodiments of the present utility model and the features in the embodiments can be combined with each other without conflict.

Claims

1. A battery, characterized in that, Comprising: A battery cell, including a positive electrode sheet, a first negative electrode sheet, and a second negative electrode sheet, the positive electrode sheet, the first negative electrode sheet, and the second negative electrode sheet are stacked, the first negative electrode sheet is located on the outermost layer of the battery cell, and the first negative electrode sheet includes an empty foil area; A lithium supplement layer is disposed in the empty foil area.

2. The battery according to claim 1, wherein The lithium supplement layer is adhered to the empty foil area.

3. The battery according to claim 1, wherein The thickness of the lithium supplement layer is A, and the thickness of the first negative electrode sheet is B, where 0.01 ≤ A / B ≤ 1.

4. The battery according to claim 1, characterized in that, The thickness of the lithium supplement layer is 1 μm to 300 μm.

5. The battery according to claim 1, characterized in that, The empty foil area is provided with a groove, and the lithium supplement layer is disposed in the groove.

6. The battery according to claim 1, characterized in that, The battery further includes a housing, the housing is provided with a storage cavity, and the battery cell is disposed in the storage cavity.

7. The battery according to claim 6, characterized in that, The lithium supplement layer is disposed on a side of the first negative electrode sheet close to the housing.

8. The battery according to claim 6, wherein The material of the housing is stainless steel.

9. The battery according to claim 6, characterized in that, The battery further includes an isolation layer, the housing is an aluminum plastic film, and the isolation layer is disposed between the lithium supplement layer and the housing.

10. An electronic device, characterized in that, Including the battery according to any one of claims 1 to 9.

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