Carbon modified material for lithium ion secondary battery negative pole and preparation thereof

A technology for secondary batteries and modified materials, applied in battery electrodes, circuits, electrical components, etc., can solve problems such as poor cycle stability, many uncertain factors, and difficulty in mass production, to improve processing performance, eliminate air Sensitive, process-controlled effects

Inactive Publication Date: 2008-07-02
RIGHTFUL TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the past, alloy materials were once the first choice for people's research, but their poor cycle stability caused by low initial efficiency and high volume effect has not been well resolved. For example, tin oxide prepared by CVD method such as Hironorid can reversibly The capacity reaches 600mAh / g, but its irreversible capacity reaches 800mAh / g [J.PowerSources, 2001, 97-98: 229], the efficiency is obviously low for the first time, and its shortcomings limit its application in lithium-ion batteries
The composite system of silicon particles wrapped with an amorphous carbon layer prepared by MAXwell, a subsidiary of Hitachi, has improved the structure and electrical conductivity of silicon materials, but due to the difficulty in controlling the process and many uncertain factors, it is difficult to achieve mass production.

Method used

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  • Carbon modified material for lithium ion secondary battery negative pole and preparation thereof
  • Carbon modified material for lithium ion secondary battery negative pole and preparation thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Take by weighing 150 grams of glucose and pour it into a clean beaker of 500 milliliters, then add 300 grams of solvent carbon disulfide, fully stir for 2 hours under the mixer, and adjust the rotating speed to 1000 rpm to make it fully dissolve to form a homogeneous dispersion system; Add 20 grams of 50% styrene-butadiene rubber and 3 grams of 3% span80 to the dispersion system for activation, continue to stir for 1 hour, then place it in a 1-liter pressure vessel with a stirrer, start stirring while heating, the stirring speed The temperature was raised to 350°C at a rate of 10°C / min at 500 rpm, held for 12 hours, then taken out and cooled to room temperature, then dispersed and passed through a 325-mesh sieve to obtain a precursor.

[0032] Then take 100 grams of precursor and 10 grams of petroleum pitch with a softening point of 200°C and a median diameter of 3um for mixing. After mixing evenly, take it out and put it into a graphite crucible for medium-temperature h...

Embodiment 2

[0036] Take by weighing 120 grams of fructose and put it in a clean beaker of 500 milliliters, then add 250 grams of solvent carbon disulfide to form a homogeneous dispersion system; add 30 grams of 50% styrene-butadiene rubber and 5 grams of 3% span80 in the homogeneous dispersion system Activation is performed to obtain a precursor.

[0037] Then take 100 grams of precursor and 12 grams of coal tar pitch with a softening point of 220 °C for mixing coating modification.

[0038] Other parts of this embodiment are identical to Embodiment 1.

[0039] The first discharge capacity of the material is 384.7mAh / g, and the first charge and discharge efficiency is 93.9%.

Embodiment 3

[0041] Weigh 100 grams of glucose and 80 grams of fructose and put them in a 500-ml clean beaker, then add 320 grams of solvent xylene, stir fully under the mixer for 2 hours, and adjust the speed to 1200 rpm to fully dissolve and form a homogeneous dispersion System; add 35 grams of 50% styrene-butadiene rubber and 4 grams of 3% span80 into the homogeneous dispersion system to activate the precursor.

[0042] Then take 100 grams of precursor and 15 grams of coal tar pitch with a softening point of 240°C and a median diameter of 3um for mixing and coating modification. The medium-temperature heat treatment time is 12 hours, followed by high-temperature treatment at 2800°C for 24 hours.

[0043] Other parts of this embodiment are identical to Embodiment 1.

[0044] It was detected that the first discharge capacity of the material was 398.9mAh / g, and the first charge and discharge efficiency was 94.5%.

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Abstract

The invention relates to a carbon modified material applied in cathode of lithium-ion secondary batteries. The carbon modified material takes one or more of glucose, fructose, cane sugar, cellulose and starch as raw material, which is dissolved in organic solvent and treated by liquid phase dehydration processing in a pressure container, then is subject to surface coating modification, low temperature curing, carbonization and finally is heat treated at high temperature, cooled and sieved; the coating modification technique adopted by the invention overcomes defect of the prior thermolysis hard carbon material, and compared with common carbon material, the invention improves specific volumetric capacity and initial efficiency and reduces specific surface area, thus eliminating loss of reversible capacity due to sensitivity of thermolysis hard carbon material to air and improving processing property of material.

Description

technical field [0001] The invention relates to a carbon material and a preparation method thereof, in particular to a carbon microsphere modified material for a negative electrode of a lithium ion secondary battery, a preparation method and an application thereof. Background technique [0002] At present, with the widespread use and rapid development of various portable electronic devices and power tools, the requirements for chemical power sources have also been increased. Lithium-ion batteries are currently a relatively successfully developed portable chemical power source. It has high voltage and specific energy. Large, stable discharge voltage, good low temperature performance, excellent safety performance, easy storage and long working life. However, the miniaturization and miniaturization of today's electronic equipment is getting higher and higher, and the research and application of lithium-ion batteries are also in-depth. [0003] At present, most of the negative ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/00H01M4/38
CPCY02E60/10
Inventor 程先桃岳永军
Owner RIGHTFUL TECH
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