Unlock instant, AI-driven research and patent intelligence for your innovation.

Surface modifying methal forlithium ion cell cathode active material

A technology for cathode active materials and lithium-ion batteries, applied in battery electrodes, electrode manufacturing, secondary batteries, etc., can solve problems such as limited improvement, increased difficulty in material synthesis, and attenuation of cycle capacity

Inactive Publication Date: 2006-03-08
XI AN JIAOTONG UNIV
View PDF0 Cites 13 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, LiCoO is mainly used as the cathode active material of commercialized lithium-ion batteries. 2 , the cathode active materials that have been intensively studied are LiNiO 2 , LiMn 2 o 4 、LiNi x co (1-x) o 2 、LiFePO 4 etc., but they all have a common problem: as the battery is repeatedly charged and discharged, its discharge capacity gradually decreases, that is, the cycle capacity decay
[0007] The above two methods have their own advantages and disadvantages. The larger the doping amount of bulk phase doping, the better the stability, but the synthesis of materials is more difficult; although the surface coating can be doped with less amount, the degree of improvement is limited.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Surface modifying methal forlithium ion cell cathode active material
  • Surface modifying methal forlithium ion cell cathode active material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Example 1: First the soluble Mg(NO 3 ) 2 It is prepared into an aqueous solution with a concentration of 0.2mol / l; then methanol is mixed with the aqueous solution at a volume ratio of 2:1, and then the cathode active material LiMn that needs to be modified is added to the mixed solution by 10g / l 2 o 4Stir the powder evenly to form a suspension; add urea to the suspension at a molar ratio of dopant ions to urea 1:1, reflux at 70°C, continue stirring and heating for 20 hours, then dry at 60°C in air for 20 hours, and then Treat at 600° C. for 5 hours at a constant temperature, then treat at 800° C. for 10 hours, and grind to obtain a modified cathode active material powder.

[0016] see figure 1 , LiMn 2 o 4 The initial capacity is 117.4mAh / g, and the cycle performance and stability are poor. After 190 cycles, the specific capacity is only 73.9mAh / g, and the specific capacity drops by as much as 37.1%. Modified LiMn 2 o 4 The specific capacity of LiMn decreased to...

Embodiment 2

[0018] Embodiment 2: at first the soluble ZnCl 2 Prepare an aqueous solution with a concentration of 0.08mol / l; then mix ethanol with the aqueous solution at a volume ratio of 1.5:1, and then add the cathode active material LiNiO to be modified at 300g / l in the mixed solution 2 Stir the powder evenly to form a suspension; add urea to the suspension at a molar ratio of dopant ion to urea 1:6, reflux at 90°C, continue stirring and heating for 8 hours, then dry at 60°C in air for 20 hours, and then Treat at 400° C. for 13 hours at a constant temperature, then treat at 1000° C. for 1 hour, and grind to obtain a modified cathode active material powder.

Embodiment 3

[0019] Embodiment 3: firstly the soluble Ni(CH 3 COO) 2 Prepare an aqueous solution with a concentration of 0.1mol / l; then mix the acetone and the aqueous solution at a volume ratio of 1:5, and then add the cathode active material LiCoO to be modified at 80g / l in the mixed solution. 2 Stir the powder evenly to form a suspension; add urea to the suspension at a molar ratio of dopant ion to urea 1:10, reflux at 100°C, keep stirring and heating for 2 hours, then dry at 60°C in air for 20 hours, and then Treat at 500° C. for 8 hours at a constant temperature, then treat at 800° C. for 10 hours, and grind to obtain a modified cathode active material powder.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The method includes steps: first, preparing water solution of soluble doped ionic salt; next, mixing organic solvent with water solution; then, adding powder of active material for cathode to be modified to mixed solution, and mixing them to form suspension liquid; urea reflow is added to the suspension liquid; heating the suspension liquid to obtain modified powder of active material for cathode. Using hydrolysis of urea, the invention promotes generation of precipitator, making premonitory ion of modified oxide generate precipitation reaction. Adjusting condition of reaction, controlling speed of releasing precipitator, satisfying condition of heterogeneous nucleation makes all modified oxide develop on surface of active material for cathode so as to produce even and dense cladding precursor. Finally, doping ions in high concentration are formed on surface of active material. The invention improves cycle performance of cathode material markedly.

Description

technical field [0001] The invention relates to a manufacturing method of a cathode active material of a lithium ion battery, in particular to a surface modification method of a cathode active material of a lithium ion battery. Background technique [0002] Due to the advantages of high working voltage, high energy density, small self-discharge, environmental friendliness, and no memory effect, lithium-ion batteries have been widely used in mobile phones, laptop computers, video cameras, cameras, portable entertainment audio-visual equipment, portable instruments and meters, and electric vehicles. , aerospace power and other fields have a wide range of applications, so lithium-ion batteries and related technologies have become the focus and focus of global research and development. [0003] At present, LiCoO is mainly used as the cathode active material of commercialized lithium-ion batteries. 2 , the cathode active materials that have been intensively studied are LiNiO 2 ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H01M4/04H01M10/40H01M4/505H01M4/525
CPCY02E60/122Y02E60/10
Inventor 徐友龙李喜飞张磊熊章艳
Owner XI AN JIAOTONG UNIV