A lithium iron phosphate-based electrode with an embedded conductive carbon layer

Abstract

This utility model relates to the field of lithium iron phosphate (LFP) based electrode technology, and discloses an LFP based electrode with an embedded conductive carbon layer. The electrode includes an aluminum foil current collector, the top side of which is coated with a LFP positive electrode slurry. A connecting component is disposed on the top side of the LFP positive electrode slurry. The connecting component includes a conductive carbon layer, the bottom side of which is fixedly connected to the top side of the LFP positive electrode slurry. The connecting component also includes a first carbon nanotube layer, the bottom side of which is coated with the top side of the LFP positive electrode slurry, and a second carbon nanotube layer is coated with the top side of the first carbon nanotube layer. In this utility model, the conductive carbon layer is uniformly covered and tightly adhered to the surface of the LFP positive electrode slurry by a magnetron sputtering process, significantly reducing the electrode internal resistance, improving electron transport efficiency, and effectively optimizing the high-rate charge-discharge performance of the LFP battery.

Description

Technical Field

[0001] This utility model relates to the field of lithium iron phosphate-based electrode technology, and in particular to a lithium iron phosphate-based electrode with an embedded conductive carbon layer. Background Technology

[0002] Conductive agents, as a crucial component of batteries, primarily enhance the conductivity of active materials and improve battery cycle stability by establishing a stable conductive network within the electrodes. LiFePO4 is a promising candidate material for power batteries; however, the performance of LiFePO4 batteries is affected by the low conductivity of the cathode material itself, as well as by various factors such as conductive agents and other components. Regarding the use of conductive additives, the mainstream approach typically employs carbon materials such as carbon black to improve the battery's electrochemical performance. However, carbon nanotubes and graphene, as novel conductive agent materials, are emerging options. Carbon nanotubes, in particular, as one-dimensional carbon materials with a large aspect ratio, can form a relatively complete three-dimensional conductive network within the electrode material.

[0003] In existing technologies, some lithium iron phosphate electrodes typically only have the positive electrode paste coated on an aluminum foil current collector, lacking a dedicated conductive enhancement layer and edge reinforcement structure. Insufficient conductivity on the electrode surface and obstructed electron transport paths limit the battery's high-rate charge and discharge performance. Therefore, to address these shortcomings, a lithium iron phosphate-based electrode with an embedded conductive carbon layer is proposed to solve the aforementioned problems. Utility Model Content

[0004] To overcome the above shortcomings, this invention provides a lithium iron phosphate-based electrode with an embedded conductive carbon layer, aiming to improve the problem of insufficient conductivity on the surface of some electrodes in the prior art, which limits the high-rate charge and discharge performance of the battery.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A lithium iron phosphate-based electrode with an embedded conductive carbon layer includes an aluminum foil current collector, the top side of which is coated with a lithium iron phosphate positive electrode slurry, and a connecting component is disposed on the top side of the lithium iron phosphate positive electrode slurry.

[0007] As a further description of the above technical solution:

[0008] The connecting component includes a conductive carbon layer, the bottom side of which is fixedly connected to the top side of the lithium iron phosphate cathode slurry;

[0009] As a further description of the above technical solution:

[0010] The connecting component further includes a first carbon nanotube layer, the bottom side of which is coated on the top side of the lithium iron phosphate cathode slurry, and a second carbon nanotube layer is coated on the top side of the first carbon nanotube layer.

[0011] This utility model has the following beneficial effects:

[0012] In this invention, a conductive carbon layer is set on the top side of the lithium iron phosphate cathode slurry and prepared using a magnetron sputtering process. This allows the conductive carbon layer to uniformly cover and tightly adhere to the surface of the lithium iron phosphate cathode slurry, significantly reducing the internal resistance of the electrode, improving electron transport efficiency, and effectively optimizing the high-rate charge-discharge performance of the lithium iron phosphate battery. Furthermore, a connecting component can be constructed using two carbon nanotube layers. The two carbon nanotube layers use an aqueous solution containing carbon nanotubes as the conductive slurry. Utilizing the excellent conductivity and one-dimensional nanostructure of carbon nanotubes, a continuous and efficient electron transport network is built, which can significantly reduce the internal resistance of the electrode, improve the charge migration rate, and enhance the electrochemical performance of the battery. Attached Figure Description

[0013] Figure 1 This is a perspective view of a lithium iron phosphate-based electrode with an embedded conductive carbon layer proposed in this utility model.

[0014] Figure 2 This is a schematic diagram of the structure of the conductive carbon layer in a lithium iron phosphate-based electrode with an embedded conductive carbon layer proposed in this utility model.

[0015] Figure 3 This is a schematic diagram of the carbon nanotube layer of a lithium iron phosphate-based electrode with an embedded conductive carbon layer proposed in this utility model.

[0016] Figure 4 This is a schematic diagram of the carbon nanotube layer two of the lithium iron phosphate-based electrode with an embedded conductive carbon layer proposed in this utility model.

[0017] Legend:

[0018] 1. Aluminum foil current collector; 2. Lithium iron phosphate cathode slurry; 3. Connecting components; 301. Conductive carbon layer; 311. Carbon nanotube layer one; 312. Carbon nanotube layer two. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Example 1:

[0021] Reference Figures 1 to 2 The present invention provides an embodiment of a lithium iron phosphate based electrode with an embedded conductive carbon layer, comprising an aluminum foil current collector 1, the top side of which is coated with a lithium iron phosphate positive electrode slurry 2, which is the basic step in electrode preparation. Specifically, the uniformly mixed positive electrode slurry is uniformly coated on the surface of the aluminum foil current collector 1, and then baked at 120°C for 12 hours to achieve preliminary curing, and then pressed under a pressure of 8.0 MPa to lay a stable foundation for subsequent layer connection.

[0022] A connecting component 3 is provided on the top side of the lithium iron phosphate cathode slurry 2. This connecting component 3, which enhances conductivity and interlayer bonding, includes a conductive carbon layer 301. The bottom side of the conductive carbon layer 301 is fixedly connected to the top side of the lithium iron phosphate cathode slurry 2. The conductive carbon layer 301 can be prepared by magnetron sputtering. Specifically, after the lithium iron phosphate cathode slurry 2 is dried and pressed, conductive carbon is thermally sprayed onto its surface for 30 minutes using a precision etching and sputtering instrument with 99.99% conductive carbon as the target material to form a uniformly covered conductive carbon layer 301. Then, it is rolled under 8.0 MPa pressure using an experimental roller press to enhance interlayer adhesion. Finally, it is placed in a vacuum drying oven with a vacuum degree of 0.01 MPa and a temperature of 120°C for 10 hours to ensure a stable connection between the conductive carbon layer 301 and the lithium iron phosphate cathode slurry 2, thereby improving the conductivity and high-rate charge-discharge performance of the electrode.

[0023] Example 2:

[0024] Reference Figure 1 , Figure 3 and Figure 4 The carbon nanotube layer 311 is the first conductive slurry coated after the lithium iron phosphate cathode slurry 2 is processed. The bottom side of the carbon nanotube layer 311 is coated on the top side of the lithium iron phosphate cathode slurry 2. The conductive slurry used is an aqueous solution containing carbon nanotubes. The top side of the carbon nanotube layer 311 is coated with a second carbon nanotube layer 312, which is the second conductive slurry formed on the basis of the carbon nanotube layer 311. The coating method of the two-layer structure can be flexibly selected. It can be coated in two stages, that is, after the carbon nanotube layer 311 is dried and cured, the carbon nanotube layer 312 is coated. Alternatively, a coating equipment can be used, with two nozzles set in one conveyor belt process, to complete the coating of the two slurries in sequence, thereby improving production efficiency. The adjacent sides of the two concave layers 42 are fixedly connected to the left and right sides of the carbon nanotube layer 311, and the adjacent sides of the two concave layers 42 are also fixedly connected to the left and right sides of the carbon nanotube layer 312.

[0025] Working principle of Example 1:

[0026] An aluminum foil current collector 1 provides support, and the lithium iron phosphate cathode slurry 2 on its top side is processed to form the cathode substrate. The conductive carbon layer 301 on the top side of the lithium iron phosphate cathode slurry 2 is attached to the cathode substrate, reducing the internal resistance of the electrode, improving electron transport efficiency, and optimizing high-rate charge and discharge performance.

[0027] Working principle of Example 2:

[0028] The lithium iron phosphate cathode slurry 2 on the aluminum foil current collector 1 is processed to form a substrate, and the carbon nanotube layer 311 and carbon nanotube layer 312 on its top side constitute a conductive core. The two carbon nanotube layers are attached to the lithium iron phosphate cathode slurry 2, reducing internal resistance and improving charge migration rate.

[0029] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A lithium iron phosphate-based electrode embedded with a conductive carbon layer, comprising an aluminum foil current collector (1), characterized in that: The top side of the aluminum foil current collector (1) is coated with lithium iron phosphate cathode slurry (2), and a connecting component (3) is provided on the top side of the lithium iron phosphate cathode slurry (2).

2. The lithium iron phosphate-based electrode embedded with a conductive carbon layer according to claim 1, characterized in that: The connecting component (3) includes a conductive carbon layer (301), the bottom side of which is fixedly connected to the top side of the lithium iron phosphate cathode slurry (2).

3. The lithium iron phosphate-based electrode embedded with a conductive carbon layer according to claim 2, characterized in that: The connecting component (3) further includes a carbon nanotube layer (311), the bottom side of which is coated on the top side of the lithium iron phosphate cathode slurry (2), and a carbon nanotube layer (312) is coated on the top side of the carbon nanotube layer (311).

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