Battery and electronic device

Abstract

The present application provides a battery and an electronic device, which relates to the technical field of electronic devices. It is used to solve the problem that the existing battery cannot further increase the capacity, which is not conducive to improving the long-term battery life requirements of electronic devices. The above-mentioned battery includes positive electrode plates and negative electrode plates arranged alternately in sequence, and a separator is provided between the positive electrode plate and the negative electrode plate; the negative electrode plate includes a negative electrode collector and a negative electrode material layer provided on the surface of the negative electrode collector. The negative electrode material layer includes a first negative electrode material layer and a second negative electrode material layer, the material of the first negative electrode material layer includes graphite, and the material of the second negative electrode material layer includes graphite and silicon. The two negative electrode plates arranged on both sides of the positive electrode plate are respectively the first negative electrode plate and the second negative electrode plate, the first negative electrode plate is provided with a first negative electrode material layer on at least one surface of the negative electrode collector of the first negative electrode plate, and the second negative electrode material layer is provided on at least one surface of the negative electrode collector of the second negative electrode plate.

Description

Technical Field

[0001] The present application relates to the technical field of electronic equipment, and in particular to a battery and an electronic device. Background Art

[0002] With the development of technology, people's demand for long-lasting electronic devices is increasing. The batteries of electronic devices generally use graphite materials. However, the gram capacity of the graphite materials currently used has reached its limit. In other words, the use of graphite materials cannot further increase the battery capacity. Therefore, it is not conducive to improving the long-lasting battery life of electronic devices. Summary of the Invention

[0003] The embodiments of the present application provide a battery and an electronic device for solving the problem that the graphite material used in existing batteries cannot further increase the capacity of the battery, which is not conducive to the long-term battery life requirements of electronic devices.

[0004] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, a battery is provided, comprising alternating positive and negative electrode sheets, with a separator disposed between the positive and negative electrode sheets. The negative electrode sheet comprises a negative electrode current collector and a negative electrode material layer disposed on a surface of the negative electrode current collector. The negative electrode material layer comprises a first negative electrode material layer and a second negative electrode material layer, wherein the material of the first negative electrode material layer comprises graphite, and the material of the second negative electrode material layer comprises graphite and silicon. Two negative electrode sheets disposed on either side of the positive electrode sheet, respectively, are a first negative electrode sheet and a second negative electrode sheet. The first negative electrode material layer is disposed on at least one surface of the negative electrode current collector of the first negative electrode sheet, and the second negative electrode material layer is disposed on at least one surface of the negative electrode current collector of the second negative electrode sheet.

[0006] The battery provided in the first aspect of the present application comprises a portion of the negative electrode plates made of graphite-doped silicon material. Since silicon material has a much higher gram capacity than graphite material, doping the graphite material of some of the negative electrode plates with silicon material can increase the capacity of the negative electrode plates, and thus the capacity of the battery, to meet the long-life requirements of electronic devices. Furthermore, doping the graphite material with silicon material can compensate for the poor conductivity of silicon material, thereby increasing battery capacity while also ensuring a high charging rate.

[0007] In some embodiments of the present application, the first negative electrode plate includes a first negative electrode current collector, with a first negative electrode material layer disposed on both sides of the first negative electrode current collector. The second negative electrode plate includes a second negative electrode current collector, with a second negative electrode material layer disposed on both sides of the second negative electrode current collector. Specifically, a negative electrode plate made of graphite is disposed on one side of the positive electrode plate, while a negative electrode plate made of graphite-doped silicon is disposed on the other side of the positive electrode plate. This increases the capacity of the negative electrode plate, thereby increasing the overall capacity of the battery.

[0008] In some embodiments of the present application, the positive electrode plate includes a positive electrode current collector and a positive electrode material layer disposed on the surface of the positive electrode current collector, and the positive electrode material layer on both sides of the positive electrode current collector has the same capacity per unit area. Under this structure, the first negative electrode plate (negative electrode plate made of graphite material) and the second negative electrode plate (negative electrode plate made of graphite-doped silicon material) disposed on both sides of the positive electrode plate have the same capacity. Since the capacity of the silicon-containing negative electrode plate is high, the coating weight of the first negative electrode plate is less than the coating weight of the second negative electrode plate, so that the capacity of the first negative electrode plate is the same as that of the second negative electrode plate, thereby making the capacity per unit area of the positive electrode material layers on both sides of the positive electrode current collector the same, that is, the positive electrode material layers disposed on both sides of the positive electrode current collector are symmetrically distributed, that is, the total capacity of the positive electrode material layers is the same.

[0009] In some embodiments of the present application, the positive electrode plate includes a positive electrode current collector, a first positive electrode material layer, and a second positive electrode material layer. The first positive electrode material layer is disposed on the surface of the positive electrode current collector facing the first negative electrode plate, and the second positive electrode material layer is disposed on the surface of the positive electrode current collector facing the second negative electrode plate. The capacity of the first positive electrode material layer is less than the capacity per unit area of the second positive electrode material layer. Under this structure, the capacities of the first negative electrode plate and the second negative electrode plate disposed on both sides of the positive electrode plate are different, that is, the coating weight of the first negative electrode plate can be the same as the coating weight of the second negative electrode plate. Therefore, the capacities of the first positive electrode material layer and the second positive electrode material layer are arranged in an asymmetric distribution structure.

[0010] In some embodiments of the present application, the first negative electrode plate includes a first negative electrode current collector, a first negative electrode material layer is disposed on one surface of the first negative electrode current collector, and a second negative electrode material layer is disposed on the other surface of the first negative electrode current collector. The second negative electrode plate includes a second negative electrode current collector, a first negative electrode material layer is disposed on one surface of the second negative electrode current collector, and a second negative electrode material layer is disposed on the other surface of the second negative electrode current collector. In this structure, a first negative electrode material layer made of graphite material and a second negative electrode material layer made of graphite-doped silicon material are disposed on both sides of the negative electrode plate, respectively, forming a composite negative electrode plate, thereby increasing the capacity of each negative electrode plate, thereby increasing the overall capacity of the battery.

[0011] In some embodiments of the present application, the positive electrode plate includes a positive electrode current collector and a positive electrode material layer disposed on the surface of the positive electrode current collector, and the positive electrode material layer on both sides of the positive electrode current collector has the same capacity per unit area. Under this structure, the first negative electrode plate (negative electrode plate made of graphite material) and the second negative electrode plate (negative electrode plate made of graphite-doped silicon material) disposed on both sides of the positive electrode plate have the same capacity. Since the capacity of the silicon-containing negative electrode plate is high, the coating weight of the first negative electrode plate can be made less than the coating weight of the second negative electrode plate, so that the capacity of the first negative electrode plate is the same as that of the second negative electrode plate, thereby making the capacity per unit area of the positive electrode material layers on both sides of the positive electrode current collector the same, that is, the positive electrode material layers disposed on both sides of the positive electrode current collector are symmetrically distributed, that is, the total capacity of the positive electrode material layers is the same.

[0012] In some embodiments of the present application, the positive electrode plate includes a positive electrode current collector, a first positive electrode material layer, and a second positive electrode material layer. The first positive electrode material layer is disposed on the surface of the positive electrode current collector facing the first negative electrode plate, and the second positive electrode material layer is disposed on the surface of the positive electrode current collector facing the second negative electrode plate. The capacity of the first positive electrode material layer is greater than or less than the capacity per unit area of the second positive electrode material layer. Under this structure, the capacities of the first negative electrode plate and the second negative electrode plate disposed on both sides of the positive electrode plate are different, that is, the coating weight of the first negative electrode plate can be the same as the coating weight of the second negative electrode plate. Therefore, the capacities of the first positive electrode material layer and the second positive electrode material layer are arranged in an asymmetric distribution structure.

[0013] In some embodiments of the present application, the battery further includes a positive electrode tab and a negative electrode tab, wherein the positive electrode tab is electrically connected to the positive electrode sheet, and the negative electrode tab is electrically connected to the negative electrode sheet. In this way, electrical components can be connected via the positive electrode tab and the negative electrode tab to enable the battery to be charged or discharged.

[0014] In some embodiments of the present application, the negative electrode tab includes a first negative electrode tab and a second negative electrode tab, the first negative electrode tab being electrically connected to the first negative electrode tab, and the second negative electrode tab being electrically connected to the second negative electrode tab. This allows for separate charging of negative electrode tabs made of graphite and graphite-doped silicon material, thereby improving battery safety during charging.

[0015] In some embodiments of the present application, the battery further comprises a housing, wherein a plurality of positive and negative electrode sheets are provided and disposed within the housing. The positive and negative electrode tabs are both disposed on the outer wall of the housing. This allows the battery to form a single, independent component for easy installation and removal.

[0016] In some embodiments of the present application, the positive electrode tab and the negative electrode tab are respectively arranged on different side walls of the housing. In this structure, the positive electrode tab and the negative electrode tab can be arranged at different positions according to different application scenarios.

[0017] In some embodiments of the present application, the first negative electrode tab and the second negative electrode tab are respectively disposed on different side walls of the housing. In this structure, the first negative electrode tab and the second negative electrode tab can be disposed at different positions according to different application scenarios.

[0018] In a second aspect, an electronic device is provided. The electronic device includes a housing and a battery. The battery is a battery as described in any of the above technical solutions, and the battery is arranged inside the housing.

[0019] The electronic device provided in the second aspect of the present application, since it includes the battery provided by any of the above technical solutions, can solve the same technical problems and achieve the same technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A structural diagram of an electronic device provided in an embodiment of the present application;

[0021] Figure 2 An exploded diagram of an electronic device provided in an embodiment of the present application;

[0022] Figure 3 for Figure 2 A diagram of the structure of a battery in an electronic device is provided;

[0023] Figure 4 A structural diagram of a negative electrode sheet provided in an embodiment of the present application;

[0024] Figure 5 To set up Figure 4 Structural diagram of the battery with the provided negative electrode

[0025] Figure 6 A structural diagram of another battery provided in an embodiment of the present application;

[0026] Figure 7 A structural diagram of another battery provided in an embodiment of the present application;

[0027] Figure 8 for Figure 7 A structural diagram of another distribution method of the battery tabs provided;

[0028] Figure 9 A structural diagram of another battery provided in an embodiment of the present application;

[0029] Figure 10 A structural diagram of another battery provided in an embodiment of the present application;

[0030] Figure 11 A structural diagram of another battery provided in an embodiment of the present application;

[0031] Figure 12 This is a structural diagram of another battery provided in this application.

[0032] Reference numerals: 10 - electronic device; 100 - display module; 110 - transparent cover plate; 120 - display screen; 200 - housing; 210 - back cover; 220 - frame; 230 - middle plate; 300 - main board; 400 - battery; 410 - housing; 420 - diaphragm; 430 - positive electrode plate; 430a - first positive electrode plate; 430b - second positive electrode plate; 431 - positive electrode current collector; 432 - positive electrode material layer; 432a - first positive electrode material layer; 432b - second positive electrode material layer; 440 -Negative electrode sheet; 440a-first negative electrode sheet; 440b-second negative electrode sheet; 441-negative electrode current collector; 441a-first negative electrode current collector; 441b-second negative electrode current collector; 442-negative electrode material layer; 442a-first negative electrode material layer; 442b-second negative electrode material layer; 450-positive electrode tab; 450a-first positive electrode tab; 450b-second positive electrode tab; 460-negative electrode tab; 460a-first negative electrode tab; 460b-second negative electrode tab; 470-electrode unit. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0034] In the following, the terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the quantity of the technical features indicated. Therefore, a feature specified as "first," "second," etc. may explicitly or implicitly include one or more of the features.

[0035] In addition, in this application, directional terms such as "upper" and "lower" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to changes in the orientation of the components in the drawings.

[0036] In this application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0037] An embodiment of the present application provides an electronic device. Specifically, the electronic device may be a portable electronic device or other type of electronic device. For example, the electronic device may be a mobile phone, a tablet computer, a laptop computer, a personal digital assistant (PDA), a monitor, a camera, a personal computer, a notebook computer, a wearable device, etc. For ease of description, the following examples are all based on the example of a mobile phone as the electronic device.

[0038] See also Figure 1 and Figure 2 , Figure 1 This is a structural diagram of an electronic device 10 provided in an embodiment of the present application. Figure 2 This is an exploded view of an electronic device 10 provided in an embodiment of the present application. As can be seen from the above, in this embodiment, the electronic device 10 is a mobile phone, and the electronic device 10 can be in a substantially rectangular plate-like structure. The electronic device 10 can include a display module 100, a housing 200, a circuit board, and a battery 400, among other components.

[0039] It is understandable that Figure 1 and Figure 2 Only some components of the electronic device 10 are schematically shown, and the actual shapes, sizes, positions and structures of these components are not affected by the present invention. Figure 1 and Figure 2 restrictions.

[0040] The above-mentioned display module 100 is used to display images, videos, etc. The display module 100 may include a translucent cover plate 110 and a display screen 120 (English name: panel 1, also called a display panel), and the translucent cover plate 110 and the display screen 120 are stacked. The material of the translucent cover plate 110 includes but is not limited to glass. For example, the translucent cover plate 110 can adopt an ordinary translucent cover plate 110 to protect the display screen 120 to prevent the display screen 120 from being damaged due to external force collision, and can play a dust-proof role. A translucent cover plate 110 with a touch function can also be used to enable the electronic device 10 to have a touch function, thereby making it more convenient for users to use. Therefore, the present application does not specifically limit the specific material of the translucent cover plate 110.

[0041] In addition, the display screen 120 can be a flexible display screen or a rigid display screen. For example, the display screen 120 can be an organic light-emitting diode (OLED) display screen, an active-matrix organic light-emitting diode (AMOLED) display screen, a mini organic light-emitting diode (LED) display screen, a micro organic light-emitting diode (OLED) display screen, a micro organic light-emitting diode (OLED) display screen, a quantum dot light-emitting diode (QLED) display screen, or a liquid crystal display (LCD).

[0042] The housing 200 is used to protect the electronic components inside the electronic device 10. The housing 200 may include a back cover 210 and a frame 220. The back cover 210 is located on the side of the display screen 120 away from the transparent cover plate 110, and is stacked with the transparent cover plate 110 and the display screen 120 and spaced apart. The frame 220 is located between the transparent cover plate 110 and the back cover 210. The frame 220 is fixed to the back cover 210. For example, the frame 220 can be fixed to the back cover 210 by bonding, threading, welding, snapping, etc. The frame 220 can also be an integrally formed structure with the back cover 210, that is, the frame 220 and the back cover 210 are a single structural unit. The transparent cover plate 110 can be fixed to the frame 220 by gluing, so that the transparent cover plate 110, the back cover 210, and the frame 220 enclose an internal storage space of the electronic device 10. The above-mentioned electronic components, such as the motherboard 300 and the camera module, are all disposed in this internal storage space.

[0043] In some embodiments, the housing 200 may further include a middle plate 230, which is disposed in the internal accommodating space and is located on the side of the display screen 120 away from the light-transmitting cover plate 110. The middle plate 230 is fixedly connected to the frame 220 to form the middle frame of the electronic device 10. For example, the middle plate 230 and the frame 220 may be fixedly connected by gluing, threading, welding, snapping, etc. The middle plate 230 and the frame 220 may also be an integrally molded structure, that is, the two are a single structural component. The middle plate 230 divides the internal accommodating space into two independent spaces, one of which is located between the light-transmitting cover plate 110 and the middle plate 230, and the display screen 120 is located in this space. The other part is located between the middle plate 230 and the back cover 210, and the main board 300 is disposed in this space.

[0044] The motherboard 300 is used to house the electronic components within the electronic device 10 and to achieve electrical connections between the electronic components. For example, the electronic components may be a control chip (e.g., a system on a chip, SOC), a graphics processing unit (GPU), a universal storage (UFS), an earpiece, and a flash module.

[0045] In addition, the main board 300 may be fixed to the middle board 230 by gluing, welding, clamping or bolting. Therefore, the present application does not impose any special limitation on the fixing method of the main board 300.

[0046] The battery 400 is used to supply power to the display module 100, the mainboard 300 and the electronic components on the mainboard 300. Figure 3 , Figure 3 for Figure 2 A structural diagram of a battery 400 in an electronic device 10 is provided, wherein the battery 400 may include a housing 410 and a positive electrode sheet 430, a negative electrode sheet 440, a diaphragm 420, an electrolyte (not shown in the figure) arranged inside the housing 410, and a positive electrode tab 450 and a negative electrode tab 460 arranged on the surface of the housing 410.

[0047] The positive and negative electrode sheets 430 and 440 are alternately stacked, with a separator 420 disposed between each positive electrode sheet 430 and the adjacent negative electrode sheet 440. The positive and negative electrode sheets 430, 440, and separator 420 are all disposed within the electrolyte. The positive electrode tab 450 is electrically connected to the positive electrode sheet 430 within the housing 410, and the negative electrode tab 460 is electrically connected to the negative electrode sheet 440 within the housing 410. The battery 400 can be charged and discharged by electrically connecting the positive and negative electrode tabs 450, 460, to external components.

[0048] The battery 400 used in the electronic device 10 is a lithium-ion battery 400, and its charging and discharging process is the process of lithium ions moving between the positive and negative electrode sheets 440. Specifically, during the charging process of the battery 400, the lithium atoms on the positive electrode sheet 430 decompose into lithium ions and electrons. The electrons travel through the external circuit to the negative electrode sheet 440, and the lithium ions travel through the separator 420 to the negative electrode sheet 440. On the negative electrode sheet 440, the lithium ions and electrons form lithium atoms.

[0049] On the contrary, the discharge process of the battery 400 is opposite to the charging process. The lithium atoms on the negative electrode plate 440 are divided into lithium ions and electrons. The electrons reach the positive electrode plate 430 through the external circuit, and the lithium ions reach the positive electrode plate 430 through the diaphragm 420. On the positive electrode plate 430, the lithium ions and electrons form lithium atoms.

[0050] To prevent the negative electrode from being unable to fully accommodate electrons transferred from the positive electrode during the charging process of the battery 400, the negative electrode capacity needs to be greater than the positive electrode capacity, and thus the capacity of the battery 400 is also determined by the capacity of the negative electrode plate 440. Currently, the demand for long-lasting battery life for electronic devices 10 is increasing, and therefore, the mass energy density and volume energy density of the battery 400 are also increasing, that is, the capacity of the battery 400 needs to be increasing. Increasing the gram capacity of the positive and negative electrodes of the battery 400 is an important measure to increase the capacity of the battery 400.

[0051] Currently, the negative electrode plate 440 is generally made of graphite material. However, the gram capacity of the currently used graphite material (i.e., the capacity of one gram of graphite material) is close to the theoretical limit of graphite material (i.e., 372mAh / g). Therefore, it is difficult to further increase the gram capacity of graphite material.

[0052] Based on this, silicon offers a significantly higher gram capacity than graphite, with a theoretical limit of 4200 mAh / g. Silicon also offers several advantages, including moderate lithium insertion and extraction potentials, abundant reserves, low cost, environmental friendliness, and mature manufacturing processes. Therefore, silicon is an ideal alternative to graphite for the negative electrode active material in batteries with a 400V capacity.

[0053] Currently, batteries 400 using silicon materials are made by mixing a certain silicon material with a graphite material to form a negative electrode plate 440 made of a mixed material of graphite doped with silicon. The capacity of the battery 400 made of this negative electrode plate 440 is improved compared to the battery 400 made of a graphite negative electrode. However, due to the huge volume effect of silicon materials, during the repeated insertion and extraction of lithium (i.e., charging and discharging), the volume change rate caused by its expansion / contraction can reach 400%. Therefore, during the charging and discharging process of the battery 400, the negative electrode plate 440 will generate and accumulate large stress, resulting in a sharp deterioration of the performance of the battery 400. For example, the battery 400 will deform, decay at an accelerated rate, and expand beyond the specification. In addition, because the electronic conductivity and ionic conductivity of silicon materials are relatively poor, compared to the negative electrode plate 440 made of graphite material, under the same formula and the same coating weight and compaction density, after graphite is doped with silicon, the high-rate fast charging capability of the battery 400 will be reduced, and the charging speed will be limited.

[0054] To solve the above problems, the present application provides another battery 400, which is used in the above electronic device 10. The battery 400 includes the above-mentioned housing 410, a positive electrode sheet 430, a negative electrode sheet 440, a separator 420 and an electrolyte (not shown in the figure). Figure 4 and Figure 5 , Figure 4 This is a structural diagram of a negative electrode plate 440 provided in an embodiment of the present application. Figure 5 To set up Figure 4 A structural diagram of a battery 400 with a negative electrode plate 440 is provided.

[0055] See also Figure 4 The negative electrode sheet 440 includes a negative electrode current collector 441 and negative electrode material layers 442 coated on both sides of the negative electrode current collector 441. The negative electrode material layers 442 include a first negative electrode material layer 442a and a second negative electrode material layer 442b. The first negative electrode material layer 442a includes graphite, i.e., the first negative electrode material layer 442a is made of graphite. The second negative electrode material layer 442b includes graphite and silicon, i.e., the second negative electrode material layer 442b is made of graphite doped with silicon.

[0056] Also, see Figure 5 The two negative electrode sheets 440 disposed on both sides of the positive electrode sheet 430 are respectively a first negative electrode sheet 440a and a second negative electrode sheet 440b. The first negative electrode sheet 440a includes a first negative electrode current collector 441a, at least one surface of which is coated with a first negative electrode material layer 442a. The second negative electrode sheet 440b includes a second negative electrode current collector 441b, at least one surface of which is coated with a second negative electrode material layer 442b.

[0057] In this way, only the negative electrode material layer 442 of some of the negative electrode sheets 440 in the above-mentioned battery 400 adopts the above-mentioned second negative electrode material layer 442b, that is, only the negative electrode material layer 442 of some of the negative electrode sheets 440 is doped with silicon material. On the one hand, the gram capacity of the negative electrode sheet 440 is provided by doping with silicon material. On the other hand, by distributing the second negative electrode material layer 442b doped with silicon material at intervals in different negative electrode sheets 440, the stress accumulation generated by the negative electrode sheet 440 containing silicon material is reduced, thereby improving the cycle performance. In this way, while improving the capacity of the negative electrode sheet 440, it can also ensure that the battery 400 will not be deformed, accelerated attenuated, expanded, etc. due to the accumulation of large stress. That is, while improving the capacity of the battery 400, it can also ensure the service life of the battery 400.

[0058] Also, please continue to read Figure 5 The positive electrode sheet 430 may include a positive electrode current collector 431 and positive electrode material layers 432 disposed on both sides of the positive electrode current collector 431. Furthermore, both the positive electrode current collector 431 and the negative electrode current collector 441 are made of conductive metal materials. For example, the positive electrode current collector 431 may be aluminum foil, and the negative electrode current collector 441 may be copper foil. Therefore, this application does not impose any particular restrictions on the materials of the positive electrode current collector 431 and the negative electrode current collector 441.

[0059] In addition, to facilitate connection of the battery 400 with external devices for charging or discharging, the battery 400 further includes a positive electrode tab 450 and a negative electrode tab 460, both of which are fixed to the outer wall of the housing 410. The positive electrode tab 450 is electrically connected to the positive electrode sheet 430, and the negative electrode tab 460 is electrically connected to the negative electrode sheet 440 (including the first negative electrode sheet 440a and the second negative electrode sheet 440b). Thus, electrical connection with the battery 400 can be achieved by connecting the positive electrode tab 450 and the negative electrode tab 460.

[0060] For example, the housing 410 of the battery 400 may have a substantially rectangular parallelepiped structure, and the positive electrode tab 450 and the negative electrode tab 460 may be disposed on the same surface of the housing 410. Alternatively, the positive electrode tab 450 and the negative electrode tab 460 may be disposed on two adjacent surfaces of the housing 410. Alternatively, the positive electrode tab 450 and the negative electrode tab 460 may be disposed on two surfaces of the housing 410 that are opposite to each other. Therefore, the present application does not impose any particular limitation on the placement of the positive electrode tab 450 and the negative electrode tab 460.

[0061] Furthermore, the housing 410 of the battery 400 may further include three tabs. For example, one positive tab 450 and two negative tabs 460; or two positive tabs 450 and one negative tab 460. The specific arrangement of these tabs may be determined based on the specific structures of the positive electrode sheet 430 and the negative electrode sheet 440.

[0062] The various structural forms of the positive electrode sheet 430 , the negative electrode sheet 440 , the positive electrode tab 450 , and the negative electrode tab 460 are described in detail below.

[0063] In one possible embodiment, please refer to Figure 5 The first negative electrode material layer 442a is coated on both sides of the first negative electrode current collector 441a of the first negative electrode plate 440a. The second negative electrode material layer 442b is coated on both sides of the second negative electrode current collector 441b of the second negative electrode plate 440b. In this case, one positive electrode plate 430, one first negative electrode plate 440a, one positive electrode plate 430, and one second negative electrode plate 440b form a plate unit 470. Multiple plate units 470 can be provided inside the housing 200 of the battery 400.

[0064] Furthermore, a negative electrode current collector 441 may be provided at each end of the plurality of electrode units 470. A first negative electrode material layer 442a is provided on one surface of the negative electrode current collector 441, and the first negative electrode material layer 442a faces the electrode unit 470, thereby forming the positive and negative electrode sheet structure inside the battery 400.

[0065] One of the positive electrode material layers 432 on either side of the positive electrode current collector 431 is positioned opposite the first negative electrode material layer 442a, and the other of the positive electrode material layers 432 on either side of the positive electrode current collector 431 is positioned opposite the second negative electrode material layer 442b. To ensure that the two positive electrode material layers 432 on either side of the positive electrode current collector 431 are symmetrically coated, that is, the two positive electrode material layers 432 have the same capacity per unit area, that is, the total capacity of the positive electrode material layers 432 is the same, the first negative electrode material layer 442a and the second negative electrode material layer 442b on both sides must have the same capacity per unit area. Since the first negative electrode material layer 442a and the second negative electrode material layer 442b have the same total area, the first negative electrode material layer 442a and the second negative electrode material layer 442b have the same total capacity. Furthermore, since the second negative electrode material layer 442b is made of graphite and silicon, the second negative electrode material layer 442b has a higher specific capacity.

[0066] Based on this, the coating weight of the second negative electrode material layer 442b can be reduced, thereby reducing the total capacity of the second negative electrode material layer 442b, so that the capacity of the second negative electrode material layer 442b is the same as the total capacity of the first negative electrode material layer 442a, and the positive electrode material layer 432 on both sides of the positive electrode current collector 431 can be coated symmetrically. In other words, the positive electrode material layers 432 on both sides of the positive electrode current collector 431 have the same capacity per unit area and the same coating weight, and therefore, the total capacity of the positive electrode material layers 432 on both sides of the positive electrode current collector 431 is also the same.

[0067] Specifically, in the first negative electrode sheet 440a, the coating weight of the first negative electrode material layer 442a disposed on both sides of the first negative electrode current collector 441a is Wa1, the active material (i.e., graphite material) content in its formulation is A1, and the gram capacity is Ca1. In the second negative electrode sheet 440b, the coating weight of the second negative electrode material layer 442b disposed on both sides of the second negative electrode current collector 441b is Wa2, the active material (i.e., graphite and silicon material) content in its formulation is A2, and the gram capacity is Ca2. In the positive electrode sheet 430, the coating weights of the positive electrode material layers 432 disposed on both sides of the positive electrode current collector 431 are Wc1 (towards the first negative electrode material layer 442a) and Wc2 (towards the second negative electrode material layer 442b), respectively. The active material content in their formulations is B, and the gram capacity is Cc.

[0068] The NP (cathode / anode) ratio between the first negative electrode plate 440a and the adjacent positive electrode plate 430, i.e., the capacity ratio between the first negative electrode plate 440a and the positive electrode plate 430, is CB1 = (Ca1*Wa1*A1) / (Cc*Wc1*B). Similarly, the capacity ratio between the second negative electrode plate 440b and the positive electrode plate 430 is CB2 = (Ca2*Wa2*A2) / (Cc*Wc2*B). Furthermore, both CB1 and CB2 are greater than 1, indicating that the negative electrode capacity is greater than the positive electrode capacity.

[0069] As can be seen, when the positive electrode current collector 431 of the positive electrode sheet 430 is coated symmetrically on both sides, Wc1 = Wc2. Furthermore, the active material content in the material layer formula (including the positive electrode material layer 432, the first negative electrode material layer 442a, and the second negative electrode material layer 442b) is fixed (i.e., A1, A2, B, etc.), and the gram capacity is also fixed (i.e., Ca1, Ca2, and Cc). Therefore, CB1 and CB2 can be adjusted by adjusting the coating weight Wa1 of the first negative electrode material layer 442a and the coating weight Wa2 of the second negative electrode material layer 442b. For example, when CB1 and CB2 are equal, that is, by adjusting the coating weight of the first negative electrode material layer 442a and the second negative electrode material layer 442b so that the capacity of the first negative electrode material layer 442a is the same as the capacity of the second negative electrode material layer 442b, the capacity of the two positive electrode material layers 432 of the corresponding positive electrode sheet 430 can be made the same, that is, the positive electrode material layers 432 on both sides of the positive electrode current collector 431 are symmetrically distributed (that is, the coating weight is the same, and the capacity per unit area is also the same).

[0070] Alternatively, see Figure 6 , Figure 6 A structural diagram of another battery 400 provided in an embodiment of the present application. The positive electrode current collector 431 of the above-mentioned positive electrode plate 430 can also be asymmetrically distributed on both sides, that is, the capacity of the second negative electrode plate 440b is different from the capacity of the first negative electrode plate 440a. For example, the coating weight Wa1 of the first negative electrode material layer 442a can be the same as the coating weight Wa2 of the second negative electrode material layer 442b. Since the gram capacity Ca2 of the second negative electrode material layer 442b is greater than the gram capacity Ca1 of the first negative electrode material layer 442a, and the coating areas are the same, the capacity of the second negative electrode plate 440b is greater than the capacity of the first negative electrode plate 440a.

[0071] In this case, the positive electrode material layers 432 on both sides of the positive electrode current collector 431 may include a first positive electrode material layer 432a and a second positive electrode material layer 432b. The first positive electrode material layer 432a is disposed on the side facing the first negative electrode plate 440a, and the second positive electrode material layer 432b is disposed on the side facing the second negative electrode plate 440b. Furthermore, the coating weight Wc1 of the first positive electrode material layer 432a is less than the coating weight Wc2 of the second positive electrode material layer 432b, so that the capacity of the first positive electrode material layer 432a is smaller than that of the second positive electrode material layer 432b, thereby matching the capacity of the first negative electrode plate 440a and the capacity of the second negative electrode plate 440b, respectively.

[0072] It is understood that CB1 and CB2 represent the capacity ratio between the negative electrode sheet 440 and the positive electrode sheet 430. Since CB1 and CB2 are both greater than 1, the capacity of the negative electrode sheet 440 is greater than the capacity of the positive electrode sheet 430. This ratio can be determined based on the actual design and usage requirements of the battery 400, and therefore, this application does not impose any special restrictions on this ratio.

[0073] In the above case, the multiple positive electrode sheets 430 are arranged in different directions but have the same structure. The negative electrode sheet 440 is divided into a first negative electrode sheet 440a and a second negative electrode sheet 440b. Therefore, please refer to Figure 7 , Figure 7 This is a structural diagram of another battery 400 provided in an embodiment of the present application. The housing 410 of the battery 400 may be provided with three tabs, including a positive tab 450 and two negative tabs 460, wherein the two negative tabs 460 are respectively a first negative tab 460a and a second negative tab 460b.

[0074] The positive current collector 431 of the positive electrode sheet 430 is electrically connected to the positive electrode tab 450, the first negative current collector 441a of the first negative electrode sheet 440a is electrically connected to the first negative electrode tab 460a, and the second negative current collector 441b of the second negative electrode sheet 440b is electrically connected to the second negative electrode tab 460b. In this way, the charging of the first negative electrode sheet 440a and the second negative electrode sheet 440b can be managed separately through the first negative electrode tab 460a and the second negative electrode tab 460b.

[0075] Furthermore, because the first negative electrode material layer 442a of the first negative electrode plate 440a is made of graphite, and the second negative electrode material layer 442b of the second negative electrode plate 440b is made of graphite-doped silicon, the charging rates of the first negative electrode plate 440a and the second negative electrode plate 440b are different. Furthermore, because the positive electrode plate 430 shares a common positive electrode tab 450, it is necessary to ensure balanced charging on both sides of the positive electrode plate 430. To this end, the current flowing through the first negative electrode tab 460a and the second negative electrode tab 460b can be adjusted to achieve balanced charging on both sides of the positive electrode plate 430.

[0076] Specifically, according to Eq. Among them, I1(t) is the current of the first negative electrode tab 460a when charged to time t, I2(t) is the current of the second negative electrode tab 460b when charged to time t, N1 is the total number of first negative electrode plates 440a (the half-layer first negative electrode plates 440a at both ends are set as one plate), N2 is the total number of second negative electrode plates 440b, and S is the area of the negative electrode plate 440 (the area of the first negative electrode plate 440a is equal to the area of the second negative electrode plate 440b).

[0077] From this, it can be seen that the equation needs to be equal, that is, the two sides of the positive electrode plate 430 are charged evenly. By adjusting the current of the first negative electrode tab 460a and the second negative electrode tab 460b, both sides of the equation can be made equal, that is, the two sides of the positive electrode plate 430 are charged evenly, which is beneficial to improving the charging efficiency of the battery 400.

[0078] Furthermore, during the charging process, if the charge difference between the first negative electrode tab 460a and the second negative electrode tab 460b exceeds 2%, one side of the charging block can be controlled to pause charging, and the slower-charging side can be charged separately, thereby avoiding a large charge difference. For example, when the charge of the first negative electrode tab 440a connected to the first negative electrode tab 460a reaches 50%, the charge of the second negative electrode tab 440b connected to the second negative electrode tab 460b only reaches 43%. At this time, the first negative electrode tab 460a is controlled to pause charging, and the second negative electrode tab 460b is charged separately. When the charge of the second negative electrode tab 440b reaches the range of 48% to 52%, the first negative electrode tab 460a is controlled to continue charging. In this way, it is possible to avoid overcharging a fully charged negative electrode tab 440.

[0079] In addition, the positive electrode tab 450, the first negative electrode tab 460a and the second negative electrode tab 460b can be arranged on the same surface of the housing 410, or can be arranged on different surfaces. Figure 8 , Figure 8 for Figure 7 A structural diagram illustrating another arrangement of the tabs of a battery 400 is provided. The positive tab 450 and the first negative tab 460a are positioned on one surface, while the second negative tab 460b is positioned on an opposite surface, facilitating connection between the first and second negative tabs 460a, 460b, respectively. Therefore, the placement of the positive tab 450, the first and second negative tabs 460a, 460b can be determined based on actual design and usage requirements and is not specifically limited in this application.

[0080] In another possible embodiment, see Figure 9 , Figure 9 A structural diagram of another battery 400 provided in an embodiment of the present application. In this battery 400, the first negative electrode current collector 441a of the first negative electrode electrode sheet 440a may be provided with the first negative electrode material layer 442a on one side, and the second negative electrode material layer 442b on the other side. In the second negative electrode electrode sheet 440b, the second negative electrode current collector 441b may be provided with the first negative electrode material layer 442a on one side, and the second negative electrode material layer 442b on the other side.

[0081] For example, taking the aforementioned electrode unit 470 as an example, the electrode unit 470 includes a first positive electrode sheet 430a, a first negative electrode sheet 440a, a second positive electrode sheet 430b, and a second negative electrode sheet 440b. The first negative electrode material layer 442a of the first negative electrode sheet 440a faces the first positive electrode sheet 430a, and the second negative electrode material layer 442b of the first negative electrode sheet 440a faces the second positive electrode sheet 430b; the second negative electrode material layer 442b of the second negative electrode sheet 440b faces the second positive electrode sheet 430b, and the first negative electrode material layer 442a of the second negative electrode sheet 440b faces the first positive electrode sheet 430a of another adjacent electrode unit 470.

[0082] That is, the first negative electrode material layer 442a of the first negative electrode plate 440a and the first negative electrode material layer 442a of the second negative electrode plate 440b face different directions. Correspondingly, both sides of the first positive electrode plate 430a face the first negative electrode material layer 442a, and both sides of the second positive electrode plate 430b face the second negative electrode material layer 442b.

[0083] In this case, the first negative electrode sheet 440a and the second negative electrode sheet 440b are negative electrode sheets 440 with the same structure (only the arrangement direction is different). Therefore, the capacity of the first positive electrode sheet 430a and the capacity of the second positive electrode sheet 430b can be the same or different, that is, the capacity per unit area of the first positive electrode sheet 430a and the capacity per unit area of the second positive electrode sheet 430b can be the same or different.

[0084] It should be noted that since the positive electrode sheets 430 have the same area, the two positive electrode sheets 430 have the same capacity per unit area, and therefore have the same capacity, i.e., the same total capacity. Furthermore, when the positive electrode current collector 431 of the positive electrode sheet 430 is coated symmetrically on both sides, that is, the weight of the positive electrode material layer 432 coated on both sides of the positive electrode current collector 431 is the same, i.e., the capacity per unit area is the same, and therefore, the total capacity is the same. Furthermore, the negative electrode sheet 440 and the positive electrode sheet 430 are based on the same principle, and therefore, a repeated description is not provided.

[0085] For example, Figure 9 As shown in the figure, the capacity of the first positive electrode plate 430a is the same as the capacity of the second positive electrode plate 430b, that is, by adjusting the coating weight of the first negative electrode material layer 442a and the second negative electrode material layer 442b to make the capacity of the first negative electrode material layer 442a and the second negative electrode material layer 442b the same, the capacity of the first positive electrode plate 430a and the second positive electrode plate 430b can be made the same, that is, the first positive electrode plate 430a and the second positive electrode plate 430b also have the same structure, which is conducive to reducing the process difficulty.

[0086] Furthermore, the battery 400 is provided with a negative electrode sheet 440 and a positive electrode sheet 430. Therefore, the battery 400 can be provided with only one positive electrode tab 450 and one negative electrode tab 460. The positive electrode tab 450 is electrically connected to the positive electrode sheet 430, and the negative electrode tab 460 is electrically connected to the negative electrode sheet 440. Thus, the positive electrode tab 450 and the negative electrode tab 460 can be electrically connected to an external device to realize charging and discharging of the battery 400.

[0087] See also Figure 10 , Figure 10 A structural diagram of another battery 400 provided in an embodiment of the present application shows that when the capacity of the first positive electrode plate 430a is different from the capacity of the second positive electrode plate 430b, it is only necessary to adjust the coating weights of the first negative electrode material layer 442a and the second negative electrode material layer 442b respectively in the above-mentioned manner so that the capacity of the first negative electrode material layer 442a is different from the capacity of the second negative electrode material layer 442b. Therefore, a repeated description is not given.

[0088] Furthermore, if the capacity of the first positive electrode sheet 430a is different from the capacity of the second positive electrode sheet 430b, the battery 400 can be provided with two positive electrode tabs 450, namely a first positive electrode tab 450a and a second positive electrode tab 450b, and one negative electrode tab 460. The first positive electrode tab 450a is electrically connected to the first positive electrode sheet 430a, the second positive electrode tab 450b is electrically connected to the second positive electrode sheet 430b, and the negative electrode tab 460 is electrically connected to the negative electrode sheet 440. The specific arrangement of the two positive electrode tabs 450 and the one negative electrode tab 460 is the same as the principle described above, and therefore, a repeated description is not provided.

[0089] In other examples, the first negative electrode sheet 440a and the second negative electrode sheet 440b may also be arranged in the same direction, that is, the first negative electrode material layers 442a of the first negative electrode sheet 440a and the second negative electrode sheet 440b are both oriented in the same direction. Figure 11 , Figure 11 This is a structural diagram of another battery 400 provided in an embodiment of the present application. In this battery 400, the first negative electrode sheet 440a and the second negative electrode sheet 440b are both identical negative electrode sheets 440. The negative electrode sheet 440 includes a negative electrode current collector 441, with a first negative electrode material layer 442a and a second negative electrode material layer 442b disposed on either side of the negative electrode current collector 441. The first negative electrode material layer 442a of each negative electrode sheet 440 faces the first positive electrode sheet 430a, and the second negative electrode material layer 442b of each negative electrode sheet 440 faces the second positive electrode sheet 430b.

[0090] In this case, please continue to Figure 11The first positive electrode sheet 430a and the second positive electrode sheet 430b also have the same structure, that is, the first positive electrode sheet 430a and the second positive electrode sheet 430b are both positive electrode sheets 430, wherein the positive electrode current collector 431 of the positive electrode sheet 430 can be coated symmetrically on both sides. For example, by adjusting the coating weight of the first negative electrode material layer 442a and the second negative electrode material layer 442b on the negative electrode current collector 441, the capacity of the first negative electrode material layer 442a and the second negative electrode material layer 442b can be made the same, thereby making the capacity of the first positive electrode material layer 432a and the second positive electrode material layer 432b on both sides of the positive electrode current collector 431 the same, thereby reducing production difficulty.

[0091] Alternatively, see Figure 12 , Figure 12 This is a structural diagram of another battery 400 provided in the present application. When the capacities of the first positive electrode material layer 432a and the second positive electrode material layer 432b are different, it is only necessary to adjust the coating weights of the first negative electrode material layer 442a and the second negative electrode material layer 442b of the negative electrode plate 440 to make the capacities of the first negative electrode material layer 442a and the second negative electrode material layer 442b different, thereby making the capacities of the first positive electrode material layer 432a and the second positive electrode material layer 432b of the positive electrode plate 430 different, that is, the positive electrode current collector 431 of the positive electrode plate 430 is asymmetrically distributed on both sides, but multiple positive electrode plates 430 have the same structure.

[0092] Therefore, in the above Figure 11 and Figure 12 In the illustrated case, only one negative electrode sheet 440 and one positive electrode sheet 430 are provided in the battery 400. Therefore, the above two types of batteries 400 can be provided with only one positive electrode tab 450 and one negative electrode tab 460, the positive electrode tab 450 is electrically connected to the positive electrode sheet 430, and the negative electrode tab 460 is electrically connected to the negative electrode sheet 440. Thus, the positive electrode tab 450 and the negative electrode tab 460 can be electrically connected to an external device to realize charging and discharging of the battery 400. In summary, the battery 400 provided in the embodiment of the present application improves the capacity of part of the negative electrode sheet 440 by making part of the negative electrode material layer 442 in the multiple negative electrode sheets 440 with graphite-doped silicon material. In addition, since only part of the negative electrode material layer 442 is doped with silicon material, the stress accumulation generated during the process of lithium insertion and extraction can be reduced, thereby reducing the risk of deterioration of the performance of the battery 400. That is, on the one hand, the service life of the battery 400 is guaranteed, and on the other hand, the capacity of the battery 400 is increased, thereby improving the endurance of the electronic device 10.

[0093] It should be noted that the arrangement of the positive electrode sheets 430 and the negative electrode sheets 440 is not limited to the above examples. For example, the second negative electrode sheets 440b made of a graphite-doped silicon material can be irregularly arranged between multiple first negative electrode sheets 440a. Therefore, this application does not impose any specific limitations on the arrangement of the positive electrode sheets 430 and the negative electrode sheets 440.

[0094] Furthermore, the housing 410 of the battery 400 is not limited to a rectangular parallelepiped structure; the aforementioned structure is merely an example. For example, the housing 410 of the battery 400 may also be a cube, a cylinder, or the like. The positive electrode tab 450 and the negative electrode tab 460 of the battery 400 may be positioned at different locations on the housing 410 according to different design and usage requirements. Therefore, this application does not impose any particular limitations on this.

[0095] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0096] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A battery, characterized in that: The battery comprises positive and negative electrode sheets arranged alternately in sequence, with a separator arranged between the positive and negative electrode sheets; the negative electrode sheet comprises a negative electrode current collector and a negative electrode material layer arranged on the surface of the negative electrode current collector; the battery also comprises a positive electrode tab and a negative electrode tab; The negative electrode material layer includes a first negative electrode material layer and a second negative electrode material layer, the active material of the first negative electrode material layer is graphite, and the active material of the second negative electrode material layer is graphite and silicon; The two negative electrode sheets disposed on both sides of the positive electrode sheet are respectively a first negative electrode sheet and a second negative electrode sheet, the first negative electrode material layer is disposed on both sides of the negative electrode current collector of the first negative electrode sheet, and the second negative electrode material layer is disposed on both sides of the negative electrode current collector of the second negative electrode sheet, the negative electrode tabs include a first negative electrode tab and a second negative electrode tab, the first negative electrode sheet is electrically connected to the first negative electrode tab, the second negative electrode sheet is electrically connected to the second negative electrode tab, and the positive electrode sheets are electrically connected to the positive electrode tabs; When the difference in charge amount between the first negative electrode tab and the second negative electrode tab is greater than 2%, the faster-charging one of the first negative electrode tab and the second negative electrode tab is suspended from charging, and the slower-charging one of the first negative electrode tab and the second negative electrode tab is charged alone; when the difference in charge amount between the first negative electrode tab and the second negative electrode tab is less than or equal to 2%, the first negative electrode tab and the second negative electrode tab are charged simultaneously.

2. The battery according to claim 1, characterized in that The positive electrode plate includes a positive electrode current collector and a positive electrode material layer arranged on the surface of the positive electrode current collector, and the positive electrode material layers on both sides of the positive electrode current collector have the same capacity per unit area.

3. The battery according to claim 1, characterized in that The positive electrode plate includes a positive electrode collector, a first positive electrode material layer and a second positive electrode material layer. The first positive electrode material layer is arranged on the surface of the positive electrode collector facing the first negative electrode plate, and the second positive electrode material layer is arranged on the surface of the positive electrode collector facing the second negative electrode plate; the unit area capacity of the first positive electrode material layer is smaller than the unit area capacity of the second positive electrode material layer.

4. The battery according to any one of claims 1 to 3, characterized in that The battery further includes a shell, and a plurality of the positive electrode sheets and the negative electrode sheets are provided inside the shell; the positive electrode tabs and the negative electrode tabs are both provided on the outer wall of the shell.

5. The battery according to claim 4, characterized in that The positive electrode tab and the negative electrode tab are respectively arranged on different side walls of the shell.

6. The battery according to claim 4, characterized in that The first negative electrode tab and the second negative electrode tab are respectively arranged on different side walls of the shell.

7. An electronic device, characterized in that: include: case; The battery is the battery according to any one of claims 1 to 6, wherein the battery is arranged in the housing.

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