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Negative electrode material capable of being charged at low temperature and preparation method thereof

A negative electrode material and low-temperature technology, applied in battery electrodes, circuits, electrical components, etc., can solve problems such as decreased conductivity, slow Li+ transmission rate, and reduced Li+ solid-liquid phase diffusion rate

Active Publication Date: 2021-09-21
LUOYANG YUEXING NEW ENERGY TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This problem of traditional lithium-ion batteries obviously cannot meet some outdoor applications, such as military weapons, aerospace, vehicle power supply, polar scientific research, cold rescue, power communication, public safety, railways, ships, robots, etc.
[0003] In a low-temperature environment, the main factors affecting the charge and discharge of lithium-ion batteries are: 1) The viscosity of the electrolyte increases significantly with the decrease of temperature, the Li+ transmission rate is slow, and the conductivity drops sharply; 2) The solid-liquid phase diffusion rate of Li+ The lower the kinetic performance, the lower the transmission rate of electrons and Li+ at the negative electrode interface, especially for graphite negative electrode systems, this point is becoming more and more obvious, which greatly affects the low temperature performance of lithium-ion batteries

Method used

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Effect test

preparation example Construction

[0020] A method for preparing a chargeable negative electrode material at low temperature, comprising the following preparation steps:

[0021] Step 1, crushing the isotropic coke and shaping it into a spherical shape;

[0022] Step 2. Carbonize the material treated in step 1 at a temperature of 800-1300°C for 1-5 hours. The purpose of this step is to remove some volatiles inside the particles, make the particles shrink locally, and improve the shape and compaction of the material. density;

[0023] Step 3. The material obtained in step 2 is subjected to graphitization treatment at a temperature of 2800-3200° C., demagnetized and screened for later use;

[0024] Step 4, adding the graphitized material in step 3 into the lithium dihydrogen phosphate solution, and simultaneously adding a cosolvent and stirring evenly;

[0025] Step 5. Filter the mixture in step 4, vacuum dry at a temperature of 50-120°C for 12-24 hours, and heat-treat at a temperature of 300-700°C to decompose...

Embodiment 1

[0034] A method for preparing a chargeable negative electrode material at low temperature, comprising the following preparation steps:

[0035] Step 1: Pulverize the pitch coke and shape it into a ball-like shape with a particle size of 5-7 μm;

[0036] Step 2. Carbonize the material treated in step 1 at a temperature of 1200°C for 1 to 5 hours. The purpose of this step is to remove some volatiles inside the particles, make the particles shrink locally, and improve the shape and tap density of the material;

[0037] Step 3. The material obtained in Step 2 is subjected to graphitization treatment at a temperature of 3000° C., demagnetized and screened for later use;

[0038] Step 4. Add the graphitized material in step 3 into lithium dihydrogen phosphate solution with a mass concentration of 0.1-5%, and at the same time add a cosolvent and stir evenly. The cosolvent is one of isopropanol, propylene glycol, and butanediol. One or more combinations; the mass ratio of the graphit...

Embodiment 2

[0041] A method for preparing a chargeable negative electrode material at low temperature, comprising the following preparation steps:

[0042] Step 1, crushing the pitch coke and shaping it into a ball-like shape with a particle size of 6 μm;

[0043] Step 2. Carbonize the material treated in step 1 for 3 hours at a temperature of 1100°C. The purpose of this step is to remove some volatiles inside the particles, make the particles shrink locally, and improve the shape and tap density of the material;

[0044] Step 3. The material obtained in step 2 is subjected to graphitization treatment at a temperature of 2900° C., demagnetized and sieved for later use;

[0045] Step 4. Add the graphitized material in step 3 into a lithium dihydrogen phosphate solution with a mass concentration of 3%, and at the same time add a cosolvent and stir evenly. The cosolvent is one of isopropanol, propylene glycol, butanediol or Various combinations; the mass ratio of graphitized material to lit...

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Abstract

The invention provides a negative electrode material capable of being charged at low temperature and a preparation method thereof. The preparation method comprises the following preparation steps of crushing isotropic coke, and shaping the isotropic coke into a sphere-like shape, carrying out carbonization treatment for 1-5 hours, graphitizing, demagnetizing and screening for later use, adding the material graphitized in the step 3 into a lithium dihydrogen phosphate solution, adding a cosolvent at the same time, and uniformly stirring, filtering the uniformly stirred mixture, carrying out vacuum drying, carrying out heat treatment to decompose lithium dihydrogen phosphate on the surface of the powder to generate a Li3PO4 coating layer, and carrying out 300-400-mesh screening treatment to obtain a finished product. The lithium ion battery negative electrode material used under the condition of -40 DEG C is prepared by adopting crushing, shaping, carbonization, graphitization and secondary coating carbonization process technologies; and the requirements of people on the ultra-low-temperature lithium ion battery are met.

Description

technical field [0001] The invention belongs to the technical field of negative electrode materials for lithium ion batteries, and in particular relates to a low temperature chargeable negative electrode material and a preparation method thereof. Background technique [0002] With the increasingly prominent problems of energy crisis, environmental pollution, and greenhouse effect, lithium-ion batteries have been widely used in various fields as a green energy source. The advantages of performance are widely used in various electronic devices, and the market demand has shown a steady growth trend in the past five years. With the wide application of lithium-ion batteries, the operating conditions of various electronic devices also have more stringent requirements on lithium-ion batteries. For example, the temperature characteristics of lithium-ion batteries. Ordinary lithium-ion batteries, at -20°C, discharge only 50% to 60% of their initial capacity, and low-temperature cha...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/583H01M4/62H01M10/0525
CPCH01M4/366H01M4/583H01M4/62H01M4/624H01M10/0525Y02E60/10
Inventor 徐军红陈和平陈玉
Owner LUOYANG YUEXING NEW ENERGY TECH