Gradient-coated lithium ion battery graphite cathode material and preparation method thereof

Abstract

The invention relates to a coated lithium ion battery graphite cathode material and a preparation method thereof, and in particular relates to a gradient-coated lithium ion battery graphite cathode material prepared by ultrasonic spraying and a preparation method thereof. The gradient-coated lithium ion battery graphite cathode material prepared by ultrasonic spraying is mainly characterized by comprising the following components in parts by weight: 100 parts of graphite powder on a surface, 1-10 parts of a first layer of silicon-coating material and 5-10 parts of a second layer of carbon-coating material. The lithium ion battery graphite cathode material has the characteristics of uniform lamination, gradient coating and easiness for large-scale production.

Description

technical field [0001] The invention relates to a method for a coated lithium ion battery graphite negative electrode material, in particular to a method for preparing a gradient coated lithium ion battery graphite negative electrode material by ultrasonic spraying. Background technique [0002] In recent years, lithium-ion batteries have become more and more popular due to their excellent performance in terms of high energy density, high voltage, no pollution, long cycle life, fast charging and discharging, and decreasing production costs. With the continuous development of the information industry, the requirements for lithium-ion batteries are also getting higher and higher. For a long time, improving the specific capacity of lithium-ion battery anode materials, reducing the first irreversible capacity, improving cycle stability, and improving fast charge and discharge performance have always been the focus of research and development in the industry. [0003] The carbon...

AI Technical Summary

Problems solved by technology

Patent CN102255077A covers different materials successively on the surface of graphite powder to form a double-layer carbon shell, which has excellent low-temperature electrical properties; but the carbon shell is too thick and easy to stick, so it needs to be washed with an organic solvent in time during the preparation process

Patent CN101339987A first mixes silicon powder and graphite for ball milling, then adds pitch or polymer for secondary ball milling, and produces a core / shell structure material after carbonization, which has large capacity, high efficiency, and excellent cycle performance; poor consistency

In patent CN102244240A, the organic carbon source, silicon source, graphitized carbon, etc. are firstly spray-dried to nucleate, then dissolved in the organic carbon source solution and spray-dried for the second time to obtain a silicon-carbon composite material, which has the characteristics of large reversible capacity and good cycle performance. ; but when spray drying, it is easy to destroy the shell structure

Patent CN101153358A first forms a conductive film on the surface of nano-scale silicon powder, then coats the silicon powder on the surface of spherical graphite, and then coats asphalt after carbonization, and finally obtains a silicon-carbon nanocomposite structure negative electrode material through secondary carbonization treatment; but in fact, nanometer Grade silicon powder has very high activity and is easy to agglomerate, so it is difficult to cover the surface of graphite powder uniformly and orderly

Patent CN102214817A adopts the chemical vapor deposition method to successively coat nano-silicon and nano-carbon on the carbon-based conductive material, and the obtained silicon-carbon composite material has a complete structure, a controllable volume, and excellent electrical properties; but the preparation cost is high, the cycle is long, and the efficiency is high. Low

Images