Pole piece for lithium ion battery, lithium ion battery and device

Abstract

The utility model discloses a kind of pole piece, lithium ion battery and device for lithium ion battery, pole piece includes current collector and the coating of the side of current collector, coating includes: the passage for lithium ion to pass, located at the surface of coating and / or inside coating;Multiple active material particles, located at the surface of coating and / or inside coating, multiple active material particles form the gap for lithium ion to pass between, active material particle is porous structure, porous structure can be used to accommodate redundant electrolyte.Using the above technical solution, the pole piece for lithium ion battery provided by the utility model embodiment improves the transmission efficiency of lithium ion, improves the charging speed of battery, and the charging time of 8~80% lithium ion battery can be shortened from 20min to 10min.Simultaneously through porous active material particle storage redundant electrolyte, improve electrolyte distribution, reduce polarization phenomenon, to improve the cycle life and safety of battery.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery electrode technology, and in particular to an electrode, lithium-ion battery and device for lithium-ion batteries. Background Technology

[0002] Currently, mainstream battery cell integration technologies in the market mostly use aluminum alloy forming and welding or sheet metal one-piece stamping and integration into the casing. Because the casing is mostly an integrated structure, the main body uses a segmented metal beam structure, requiring additional protective measures such as mica paper / ceramic tape to protect the cells during assembly and prevent scratches and short circuits. This patented design uses composite beam integration technology, integrating plastic beams into the casing. Because the composite beam body is a composite insulator design, it effectively resists short circuits and impacts from mechanical abuse, protecting the cells from the risk of internal and external short circuits and preventing later fires and explosions. Simultaneously, since the density of the composite beam body is much lower than that of metal, it provides favorable support for lightweight design. Furthermore, combined with the special continuous glass fiber material of the body, the tensile, bending, and ductility properties of the material are improved. Utility Model Content

[0003] This invention proposes an electrode, a lithium-ion battery, and a device for lithium-ion batteries to solve the above-mentioned problems.

[0004] In a first aspect, embodiments of this utility model disclose an electrode for a lithium-ion battery. The electrode includes a current collector and a coating located on one side of the current collector. The coating includes:

[0005] Channels through which lithium ions can pass are located on the surface of the coating and / or inside the coating;

[0006] Multiple active material particles are located on the surface and / or inside the coating. The active material particles form gaps between them to allow lithium ions to pass through. The active material particles have a porous structure, which can be used to accommodate redundant electrolyte.

[0007] By adopting the above technical solution, the electrode sheet for lithium-ion batteries provided by this utility model improves the lithium-ion transport efficiency and increases the battery charging speed. The charging time for 8-80% lithium-ion batteries can be shortened from 20 minutes to 10 minutes. Simultaneously, by storing redundant electrolyte through porous active material particles, the electrolyte distribution is improved, polarization is reduced, thereby enhancing the battery's cycle life and safety.

[0008] According to another specific embodiment of the present invention, the channel is straight and / or curved.

[0009] According to another specific embodiment of the present invention, the width of the channel is 10-20μm and the depth is 0.5-2μm.

[0010] According to another specific embodiment of this utility model, the active substance particles are spherical.

[0011] According to another specific embodiment of this utility model, the diameter of the active substance particles is 10~100μm.

[0012] According to another specific embodiment of this utility model, the gap between the active substance particles is 5-15 μm.

[0013] According to another specific embodiment of the present invention, the electrode is a negative electrode, and the active material particles include any one of graphite secondary particles, silicon particles, or silicon-carbon; and / or the electrode is a positive electrode, and the active material particles include any one of lithium iron phosphate particles, lithium cobalt oxide particles, or lithium manganese oxide particles.

[0014] According to another specific embodiment of the present invention, the distribution density of active material particles on the side of the coating closer to the current collector is greater than the distribution density of active material particles on the side of the coating farther from the current collector.

[0015] Secondly, this utility model provides a lithium-ion battery, including a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode and / or the negative electrode are the aforementioned electrodes for lithium-ion batteries.

[0016] By adopting the above technical solution, the lithium-ion battery provided by this utility model uses the above-mentioned electrode as the positive electrode and / or negative electrode, optimizes the ion transport path and electrolyte management, reduces polarization loss inside the battery, and improves lithium-ion insertion / extraction efficiency, thereby directly improving the battery's high-rate charge and discharge capability, long cycle life and safety.

[0017] Thirdly, this utility model provides an apparatus including the aforementioned lithium-ion battery.

[0018] By adopting the above technical solution, the device provided by the present invention uses the above-mentioned lithium-ion battery, which has the advantages of high energy density, fast charging and discharging and long service life, and meets the high power requirements. Attached Figure Description

[0019] Figure 1 This diagram shows the structural schematic of the coating of the lithium-ion battery in an embodiment of the present invention.

[0020] Figure label:

[0021] Coating 1; Channel 2; Active material particles 3. Detailed Implementation

[0022] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Although the description of this utility model will be presented in conjunction with preferred embodiments, this does not mean that the features of this utility model are limited to this embodiment. On the contrary, the purpose of describing the utility model in conjunction with the embodiments is to cover other options or modifications that may be derived based on the claims of this utility model. To provide a deep understanding of this utility model, many specific details will be included in the following description. This utility model may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this utility model, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0023] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0025] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0027] Firstly, reference Figure 1 The present invention discloses an electrode for a lithium-ion battery. The electrode includes a current collector and a coating 1 located on one side of the current collector. The coating 1 includes: channels 2 through which lithium ions can pass located on the surface and / or inside the coating 1; and multiple active material particles 3 located on the surface and / or inside the coating 1. The multiple active material particles 3 form gaps through which lithium ions can pass. The active material particles 3 have a porous structure, which can be used to accommodate redundant electrolyte.

[0028] The electrode for lithium-ion batteries provided by this invention improves lithium-ion transport efficiency and increases battery charging speed, reducing the charging time of 8-80% lithium-ion batteries from 20 minutes to 10 minutes. Simultaneously, the porous active material particles 3 store redundant electrolyte, improving electrolyte distribution and reducing polarization, thereby enhancing battery cycle life and safety. Specifically, the gap between the channel 2 and the active material particles 3 provides a rapid diffusion path for lithium ions, reducing ion transport resistance (i.e., reducing ion diffusion impedance), thus improving rate performance. The porous structure of the active material particles 3 increases the specific surface area, providing more lithium-ion insertion / extraction reaction sites. Simultaneously, the pores can store electrolyte, ensuring sufficient contact between the active material and the electrolyte, especially at high rates, preventing localized electrolyte depletion and reducing side reactions and capacity decay.

[0029] In this embodiment of the invention, the current collector (aluminum foil / copper foil) collects the current generated by the active material particles 3 and guides it to the external circuit. The active material particles 3 are the main component in the electrochemical reaction within the battery. During charging and discharging, they can reversibly "absorb" and "release" charged ions (such as lithium ions). In addition, the electrode also includes conductive agents (such as carbon black) and binders (such as PVDF and CMC). The conductivity of the active material particles 3 themselves is usually poor. The role of the conductive agent is to establish a conductive network between the active material particles 3 and between the active material and the current collector, ensuring the smooth flow of electrons. The binder firmly bonds the active material particles 3 and the conductive agent particles together and makes them adhere tightly to the current collector (aluminum foil or copper foil), preventing the electrode from falling off during use.

[0030] It should be noted that, in this embodiment, the distribution of channels 2 and / or active material particles 3 within and / or on the surface of the electrode can be uniform or relatively non-uniform. For example, channels 2 may not be a uniform array, but rather distributed in a specific pattern (such as a dot matrix or grid). The distribution of active material particles 3 is non-uniform. The width or thickness of channels 2 is less than any one of the dimensions of the length, width, or thickness of the electrode, meaning that channels 2 are not penetrating within the electrode, thus forming a three-dimensional, multi-directional ion transport network within the electrode.

[0031] In the above embodiments, channel 2 is linear and / or curved. Linear channels shorten the diffusion distance of lithium ions, reduce ion transport impedance, and are suitable for high-rate applications. Curved channels increase channel length and tortuosity, but promote more uniform penetration of the electrolyte into the electrode, avoiding polarization caused by concentration gradients and improving the structural stability of the electrode. In this embodiment, channel 2 can be achieved by controlling the electrode fabrication process.

[0032] In the above embodiment, the width of channel 2 is 10-20 μm and the depth is 0.5-2 μm.

[0033] In this embodiment, by controlling the width and depth of channel 2 (width 10-20μm, depth 0.5-2μm, rather than nanometer scale), while ensuring efficient lithium ion transport, the mechanical integrity of the electrode and the adhesion strength of coating 1 are maintained. This avoids the active material from falling off due to excessively large channels or the ion diffusion from being too small, thus ensuring that lithium ions can effectively reach the active material particles 3.

[0034] In the above embodiments, the active material particles 3 are spherical or near-spherical. Spherical particles have higher packing density and flowability, making it easier to form a uniform coating 1. The surface stress distribution of spherical particles is uniform, reducing crack generation during volume changes during charging and discharging, and enhancing cycle stability. Near-spherical refers to a shape similar to a sphere but less regular.

[0035] In the above embodiments, the diameter of the active material particles 3 is 10~100 μm. Too small a diameter (e.g., below 10 μm) would result in an excessively large specific surface area, increasing the risk of side reactions and electrolyte decomposition; too large a diameter (e.g., above 100 μm) would prolong the diffusion path of lithium ions within the particles, reducing rate performance. The 10~100 μm range balances high capacity (through sufficient active material) and rapid ion diffusion (through a short diffusion distance).

[0036] In the above embodiment, the gap between the active material particles 3 is 5-15 μm. By controlling the gap between the active material particles 3 (5-15 μm), the electrode is ensured to have appropriate porosity, which promotes electrolyte wetting and ion transport, while avoiding excessively large pores that reduce energy density.

[0037] In the above embodiments, the electrode is a negative electrode, and the active material particles 3 include any one of graphite secondary particles, silicon particles, or silicon-carbon; and / or the electrode is a positive electrode, and the active material particles 3 include any one of lithium iron phosphate particles, lithium cobalt oxide particles, or lithium manganese oxide particles. By selecting specific active materials (such as graphite secondary particles, silicon particles, or silicon-carbon for the negative electrode, and lithium iron phosphate, lithium cobalt oxide, or lithium manganese oxide for the positive electrode) and combining them with a porous structure, the energy density, cycle life, and safety of the battery can be improved.

[0038] In the above embodiment, the distribution density of active material particles 3 on the side of coating 1 closer to the current collector is greater than the distribution density on the side of coating 1 farther from the current collector. The higher density on the side closer to the current collector enhances electronic conductivity and facilitates current collection; the lower density on the side farther from the current collector increases porosity, promoting electrolyte penetration and ion diffusion. This gradient design balances electron transport (requiring high conductivity) and ion transport (requiring high porosity), reducing concentration polarization and ohmic polarization within the electrode, making it particularly suitable for thick electrodes.

[0039] In the above embodiments, the thickness of the electrode is 50-200 μm. The length and width of the electrode are not limited here.

[0040] In this embodiment, the formation or shape of the channel 2, the size of the channel 2, and the gap between the active material particles 3 can be achieved by controlling the sintering temperature of the coating 1 and adding crystal seeds.

[0041] Secondly, this utility model provides a lithium-ion battery, including a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode and / or the negative electrode are the aforementioned electrodes for lithium-ion batteries.

[0042] The lithium-ion battery provided by this utility model uses the above-mentioned electrode as the positive and / or negative electrode, which optimizes the ion transport path and electrolyte management, reduces polarization loss inside the battery, and improves lithium-ion insertion / extraction efficiency, thereby directly improving the battery's high-rate charge and discharge capability, long cycle life and safety.

[0043] Thirdly, this utility model provides a device including the aforementioned lithium-ion battery. The device provided by this utility model, using the aforementioned lithium-ion battery, has the advantages of high energy density, rapid charging and discharging, and long service life, thus meeting high power requirements.

[0044] Although the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions. Those skilled in the art can make various changes in form and detail, including some simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. An electrode for a lithium-ion battery, the electrode comprising a current collector and a coating located on one side of the current collector, characterized in that, The coating includes: Channels through which lithium ions can pass are located on the surface of the coating and / or inside the coating; Multiple active material particles are located on the surface and / or inside the coating, with gaps formed between the multiple active material particles to allow lithium ions to pass through. The active material particles have a porous structure that can accommodate redundant electrolyte.

2. The electrode for a lithium-ion battery according to claim 1, characterized in that, The channel is straight and / or curved.

3. The electrode for a lithium-ion battery according to claim 1, characterized in that, The channel has a width of 10-20 μm and a depth of 0.5-2 μm.

4. The electrode for a lithium-ion battery according to claim 1, characterized in that, The active substance particles are spherical.

5. The electrode for a lithium-ion battery according to claim 1, characterized in that, The diameter of the active substance particles is 10~100μm.

6. The electrode for a lithium-ion battery according to claim 1, characterized in that, The gap between the active substance particles is 5-15 μm.

7. The electrode for a lithium-ion battery according to claim 1, characterized in that, The electrode is a negative electrode, and the active material particles include any one of graphite secondary particles, silicon particles, or silicon-carbon; and / or the electrode is a positive electrode, and the active material particles include any one of lithium iron phosphate particles, lithium cobalt oxide particles, or lithium manganese oxide particles.

8. The electrode for a lithium-ion battery according to claim 1, characterized in that, The distribution density of the active material particles on the side of the coating closer to the current collector is greater than the distribution density of the active material particles on the side of the coating farther from the current collector.

9. A lithium-ion battery, comprising a positive electrode, a negative electrode, a separator, and an electrolyte, characterized in that, The positive electrode and / or the negative electrode are electrodes for lithium-ion batteries according to any one of claims 1 to 8.

10. An apparatus, characterized in that, Including the lithium-ion battery as described in claim 9.

Images