US-12620582-B2 - Negative electrode of lithium ion secondary battery, preparation method thereof and lithium ion secondary battery

US12620582B2US 12620582 B2US12620582 B2US 12620582B2US-12620582-B2

Abstract

The present invention provides a negative electrode of lithium ion secondary battery, a preparation method thereof and a lithium ion secondary battery. The negative electrode of the lithium ion secondary battery comprises a negative electrode active material, a pre-lithiated conductive layer and a negative electrode current collector. By using the negative electrode of lithium ion secondary battery, the preparation method thereof and the lithium ion secondary battery of the present invention, technical effects of excellent electrochemical performance, especially excellent first discharge capacity and first time efficiency are achieved, and excellent negative electrode plate binding force is achieved.

Inventors

Li Wang
Yan Zhou
Yuli Li

Assignees

MURATA MANUFACTURING CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20220328
Priority Date: 20210428

Claims (8)

1 . A negative electrode of lithium ion secondary battery, wherein, the negative electrode comprises: a negative electrode active material; a pre-lithiated conductive layer; and a negative electrode current collector, wherein the pre-lithiated conductive layer is a pre-lithiated material doped conductive material, wherein the pre-lithiated material doped conductive material includes a pre-lithiated material and a conductive material that are mixed to form a mixed homogeneous form, and wherein an amount of the pre-lithiated material is in a range of 10 wt % to 50 wt % based on a total weight of the pre-lithiated conductive layer.
2 . The negative electrode of lithium ion secondary battery according to claim 1 , wherein, a thickness of the pre-lithiated conductive layer is in a range of 1 μM to 50 μm.
3 . The negative electrode of lithium ion secondary battery according to claim 1 , wherein the amount of the pre-lithiated material is in the range of 10 wt % to 20 wt % based on the total weight of the pre-lithiated conductive layer.
4 . The negative electrode of lithium ion secondary battery according to claim 1 , wherein, the conductive material comprises carbon black, carbon nanotube, graphene, vapor grown carbon fiber, Ketjen black, polyacetylene, polythiophene, polypyrrole, polyaniline, polyphenylene, polyphenylene vinylene, polydiacetylene, or any combination thereof.
5 . The negative electrode of lithium ion secondary battery according to claim 1 , wherein, the negative electrode current collector comprises copper foil, copper mesh, foamy copper, nickel foil, nickel mesh, foamy nickel, stainless steel foil, stainless steel mesh, or any combination thereof.
6 . The negative electrode of lithium ion secondary battery according to claim 3 , wherein, the pre-lithiated conductive layer is a laminate of the pre-lithiated material layer and the conductive material layer, wherein the pre-lithiated conductive layer comprises a lithium diffusion region and the lithium diffusion region is 1% to 100% of the total thickness of the pre-lithiated conductive layer.
7 . The negative electrode of lithium ion secondary battery according to claim 1 , wherein, the negative electrode current collector is a pre-lithiated negative electrode current collector.
8 . A lithium ion secondary battery, wherein, the lithium ion secondary battery comprises: a positive electrode, a negative electrode a separator, and a nonaqueous electrolyte, wherein the negative electrode is the negative electrode of lithium ion secondary battery according to claim 1 .

Description

TECHNICAL FIELD The present invention relates to the field of lithium ion secondary batteries, in particular to an negative electrode of lithium ion secondary battery, preparation method thereof and lithium ion secondary battery. BACKGROUND In recent years, along with the continuous development of electronic technology, the requirements for people to a battery device for supporting the energy supply of electronic device are also increased. Nowadays, batteries capacity of storing a high amount of electricity and outputting high power are needed. Traditional lead-acid batteries, nickel-metal hydride batteries and the like may not meet the requirements of new electronic products. Therefore, lithium batteries have been attracted an extensive attention of the people. During the development process of lithium battery, capacity and performance thereof have been effectively improved. However, due to the active chemical properties of metal lithium, during the use of lithium ion secondary batteries, lithium ions may unevenly precipitate on the current collector during charging, so that the lithium dendrites are generated. Moreover, in the process of charging and discharging, undesired reactions between lithium ions and electrolyte may occur, resulting in problems such as lithium loss and the like. In order to solve the above problems, the prior art usually adopts the method of direct pre-lithiation of the negative electrode current collector. However, the direct pre-lithiation of the negative electrode current collector will lead to the disadvantages such as decreased adhesion of the negative electrode plate, lower first discharge capacity and the like. Therefore, it is still necessary to develop a novel pre-lithiation method of a negative electrode of lithium ion secondary battery and a negative electrode and lithium ion secondary battery manufactured therefrom. SUMMARY The main object of the present invention is to provide a negative electrode of lithium ion secondary battery, a preparation method thereof and a lithium ion secondary battery, so as to solve the problems such as decreased adhesion of the electrode plate, low first discharge capacity and the like in the prior art. For achieving the above object, according to one aspect of the present invention, a negative electrode of lithium ion secondary battery is provided. The negative electrode comprises a negative electrode active material, a pre-lithiated conductive layer and an negative electrode current collector. Further, in the above negative electrode of lithium ion secondary battery, the thickness of the pre-lithiated conductive layer is in a range of about 1 to about 50 μM, preferably about 1 to about 20 μM, and more preferably about 1 to about 10 μM. Further, in the above negative electrode of lithium ion secondary battery, the pre-lithiated conductive layer is a pre-lithiated material doped conductive material, or a laminate of the pre-lithiated material layer and the conductive material layer, wherein the amount of the pre-lithiated material is in a range of about 10 wt % to about 50 wt % based on the total weight of the pre-lithiated conductive layer. Further, in the above negative electrode of lithium ion secondary battery, the conductive material comprises carbon black, carbon nanotube, graphene, vapor grown carbon fiber, Ketjen black, polyacetylene, polythiophene, polypyrrole, polyaniline, polyphenylene, polyphenylene vinylene, polydiacetylene, or any combination thereof. Further, in the above negative electrode of lithium ion secondary battery, the negative electrode current collector comprises copper foil, copper mesh, foamy copper, nickel foil, nickel mesh, foamy nickel, stainless steel foil, stainless steel mesh, or any combination thereof. Further, in the above negative electrode of lithium ion secondary battery, the pre-lithiated conductive layer is a laminate of the pre-lithiated material layer and the conductive material layer, wherein the pre-lithiated conductive layer comprises a lithium diffusion region, and the lithium diffusion region is about 1% to about 100% of the total thickness of the pre-lithiated conductive layer. Further, in the above negative electrode of lithium ion secondary battery, the negative electrode current collector is a pre-lithiated negative electrode current collector. According to another aspect of the present invention, a method for preparing a negative electrode of lithium ion secondary battery is provided. The method comprises: step S1, doping a pre-lithiated material into a conductive material, and dispersing the pre-lithiated material and the conductive material in a solvent to form a conductive material slurry; step S2, coating the conductive material slurry on the negative electrode current collector, and curing to form a pre-lithiated conductive layer on the negative electrode current collector; and step S3, coating a negative electrode active material slurry on the pre-lithiated conductive layer, and cu