Preparation method and application of lithium battery negative plate

Abstract

The preparation method specifically comprises the following steps: uniformly mixing a core-shell structure magnetic nano template which takes polyaniline as a shell and Fe3O4 as a core with a negative electrode material, a binder, a conductive agent and a solvent water to prepare negative electrode slurry, coating the surface of a current collector with the negative electrode slurry, and drying to obtain the lithium battery negative electrode plate. The preparation method comprises the following steps: preparing a thick electrode from magnetic nano Fe3O4, directionally assembling the magnetic nano Fe3O4 on the surface of a current collector by loading a magnetic field, recycling the magnetic nano Fe3O4 in the thick electrode through microwave heating and a magnetic recycling device, and constructing a three-dimensional network channel with high conductivity in the thick electrode to effectively improve the conductivity of the electrode, shorten ion and electron migration paths and improve the conductivity of the electrode. A multi-dimensional open permeation channel is provided, the wettability of an electrolyte is enhanced, the electrode tortuosity is reduced, the gradient porosity is generated, a molecular-level channel beneficial to lithium ion transportation is formed, and high-speed conduction of lithium ions is promoted.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a preparation method and application of a lithium battery negative electrode sheet. Background technique [0002] Lithium-ion batteries have the advantages of small self-discharge, high specific energy, long cycle life, environmental protection and no pollution, and are widely used in portable electronic products, electric vehicles, reserve power sources, and aviation fields. With the development of lithium-ion battery technology and the continuous advancement of the country's new energy industry, people's requirements for high energy density, high power and light weight of lithium-ion batteries are getting higher and higher. [0003] The preparation of ultra-thick pole pieces with high coating weight is one of the most direct ways to improve the specific energy of batteries. However, thick electrodes can negatively affect battery performance while incr...

AI Technical Summary

Problems solved by technology

However, thick electrodes can also negatively impact battery performance while increasing energy density

As the thickness of the electrode increases, it becomes more difficult for the electrolyte to penetrate from the interface between the separator and the coating layer to the interface between the coating layer and the current collector, and it is easy to cause the electrode to be incompletely wetted, resulting in lithium deposition in the battery at a high rate of full charge, reducing the battery capacity, and even pose a safety hazard

When the thickness of the electrode increases, the distance between the active material on the surface of the pole piece and the current collector increases, which makes the path of electron transmission longer, and it is easy to produce a large concentration polarization, resulting in a non-uniform distribution of the electrochemical reaction rate, and the battery capacity cannot be normal. A series of problems such as performance, rate and cycle performance deterioration

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