Three-dimensional nanoporous copper/two-dimensional cuprous oxide nanosheet array type lithium-ion battery negative electrode and its one-step preparation method

Abstract

The invention provides a three-dimensional nanometer porous copper / two-dimensional cuprous oxide nanosheet array type lithium ion battery negative electrode. The lithium ion battery negative electrode comprises a three-dimensional nanometer porous copper substrate and a cuprous oxide nanosheet array layer, the three-dimensional nanometer porous copper substrate is used as a current collector, the cuprous oxide nanosheet array layer is used as an active lithium storage layer, the cuprous oxide nanosheet array is arranged on a surface of the substrate and is integrated with the substrate, and the cuprous oxide nanosheet array layer comprises cuprous oxide nanosheets formed on the substrate through in-situ growth, and the cuprous oxide nanosheets are perpendicular to the three-dimensional nanometer porous copper substrate and are arranged in a staggered manner to form an array structure. By the lithium ion battery negative electrode, the cycle performance and the specific capacity of the lithium ion battery can be improved. The invention also provides a one-step preparation method of the abovementioned lithium ion battery negative electrode. By the method, the production process of the lithium ion battery negative electrode can be effectively simplified.

Description

technical field [0001] The invention belongs to the field of negative poles of lithium ion batteries, in particular to a negative pole of lithium ion batteries and a preparation method thereof. Background technique [0002] At present, the negative electrode material of commercial lithium-ion batteries is generally graphite. Although graphite has a stable structure and has a stable reversible capacity in the charge-discharge cycle, its disadvantage is that its theoretical specific capacity is only 372mAh / g, which is difficult to meet the current rapid development. Electronic equipment requires higher energy density of lithium-ion batteries. At the same time, the commercial development of a new generation of electric vehicles and hybrid vehicles also puts forward higher requirements for the energy density and performance of lithium-ion batteries, so it has a higher ratio A new type of negative electrode with high capacity is a research hotspot in the field of lithium batterie...

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Problems solved by technology

[0002] At present, the negative electrode material of commercial lithium-ion batteries is generally graphite. Although graphite has a stable structure and has a stable reversible capacity in the charge-discharge cycle, its disadvantage is that its theoretical specific capacity is only 372mAh / g, which is difficult to meet the current rapid development. Electronic equipment requires higher energy density of lithium-ion batteries. At the same time, the commercial development of a new generation of electric vehicles and hybrid vehicles also puts forward higher requirements for the energy density and performance of lithium-ion batteries, so it has a higher ratio A new type of negative electrode with high capacity is the current research hotspot in the field of lithium batteries

This method and the lithium-ion battery negative electrode prepared thereof have the following disadvantages: (1) the method needs to prepare nanoporous copper first, then coordinate the binder and solvent to prepare the slurry and coat it on the foamed nickel current collector, then dry and heat Oxidation forms a cuprous oxide film on the pore wall of nanoporous copper, and the operation steps are many, and the production process is cumbersome; (2) due to the use of a binder in the process of preparing the negative electrode of the lithium-ion battery, the binder itself is not conductive and cannot contribute (3) The structure of the negative electrode is complex, the cuprous oxide film is located on the pore wall of the nanoporous copper, and the nanoporous copper is bonded to the surface of the foamed nickel, and the electrons are conducted to the surface of the current collector. The path is long, coupled with the hindrance of the binder, this structure will seriously hinder the electron conduction, resulting in a decrease in the cycle performance of the lithium-ion battery; (4) cuprous oxide covers the hole wall of nanoporous copper in the form of a film, which The specific surface area of ​​cuprous oxide with this structure is relatively small, so that the conductivity of cuprous oxide as a semiconductor cannot be effectively improved, which is also not conducive to electron conduction, and the hindered electron conduction will lead to poor cycle performance of lithium-ion batteries.

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