Defective-structure LiFePO4 surface-modified lithium-enriched layer-layer cathode material and preparation method thereof

A lithium-rich positive electrode material and surface modification layer technology, which is applied in the field of lithium-ion battery positive electrode material manufacturing, can solve the problems of limited rate characteristic effect, no electrochemical activity, and reduced material discharge capacity, so as to reduce irreversible capacity loss, Good reversibility and high capacity effect

Inactive Publication Date: 2013-05-22
NINGBO UNIV
View PDF4 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the current surface modification components usually only protect the surface structure of the electrode active material, and have limited effect on improving its rate characteristics; moreover, surface modification substances are often not electrochemically active, which reduces the overall discharge capacity of the material.

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Example 1: LiNO 3 :Mn(CH 3 COO) 2 4H 2 O:Ni(CH 3 COO) 2 4H 2 The ratio of O=1.1: 0.55: 0.45 (molar ratio) is uniformly mixed, dissolved in deionized water, and the amount of added substance is tartaric acid which is 1.2 times of the total amount of all metal ions and fully stirred until completely dissolved; the temperature of the system is raised to 70 °C Stirring was continued until 71% of the water evaporated, at which point the solution gradually became viscous and formed a jelly. The jelly-like substance was dried in an oven at 130° C. for 22 hours and then ground in a mortar for 10 minutes. The obtained powder was heated up to 500°C at a rate of 2°C / min in a tube furnace and calcined at this temperature for 3 hours. After cooling, the powder was taken out and continued to grind in a mortar for 10 minutes, and the powder was pressed with a pressure of 100MPa. After being formed into a sheet, the temperature was raised to 850° C. for 5 hours in a tube furnace...

Embodiment 2

[0013] Example 2: LiNO 3 :Mn(CH 3 COO) 2 4H 2 O:Ni(CH 3 COO) 2 4H 2 The ratio of O=1.5: 0.75: 0.25 (molar ratio) is evenly mixed, dissolved in deionized water, and the amount of the added substance is fully stirred until completely dissolved until the tartaric acid which is 1.6 times of the total amount of all metal ions is dissolved; the temperature of the system is raised to 80 °C Stirring was continued until 75% of the water evaporated, at which point the solution gradually became viscous and formed a jelly. The jelly-like substance was dried in an oven at 150° C. for 40 hours and then ground in a mortar for 20 minutes. The obtained powder was heated up to 550°C at a rate of 5°C / min in a tube furnace and calcined at this temperature for 4 hours. After cooling, the powder was taken out and continued to grind in a mortar for 20 minutes, and the powder was pressed with a pressure of 200MPa. Form into a sheet, then heat up to 900° C. for 5 hours in a tube furnace at a ra...

Embodiment 3

[0014] Embodiment 3: LiNO 3 :Mn(CH 3 COO) 2 4H 2 O:Ni(CH 3 COO) 2 4H 2The ratio of O=1.2: 0.6: 0.4 (molar ratio) is uniformly mixed, dissolved in deionized water, and the amount of added substance is tartaric acid 2.0 times of the total amount of all metal ions, fully stirred until completely dissolved; the temperature of the system is raised to 85 °C Stirring was continued until 83% of the water evaporated, at which point the solution gradually became viscous and formed a jelly. The jelly-like mass was dried in an oven at 200° C. for 48 hours and then ground in a mortar for 30 minutes. The obtained powder was heated up to 600°C at a rate of 10°C / min in a tube furnace and calcined at this temperature for 5 hours. After cooling, the powder was taken out and continued to grind in a mortar for 30 minutes, and the powder was pressed with a pressure of 300MPa. Form into a sheet, then heat up to 950°C for 15 hours in a tube furnace at a rate of 9°C / min and calcinate for 15 ho...

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 invention relates to a defective-structure LiFePO4 surface-modified lithium-enriched layer-layer composite cathode material. According to the defective-structure LiFePO4 surface-modified lithium-enriched layer-layer composite cathode material, the stoichiometric equation of a surface-modified layer is LiFe1-2yP1-yO4-sigma, wherein sigma= 4-[(1-2y)*2+1+(1-y)*5] / 2, and y is 0.01 to 0.06; the stoichiometric equation of the lithium-enriched layer-layer composite cathode material is xLi2MnO3.(1-x)LiMnO.5Ni0.5O2 (x is not smaller than 0 and not more than 0.5); and the amount of substances of the surface-modified layer is 1-10% that of the cathode material. The surface-modified cathode material has the advantages of high cycle capacity retentiveness and excellent power multiplying characteristic.

Description

technical field [0001] The invention relates to the field of manufacturing positive electrode materials of lithium ion batteries. Background technique [0002] Lithium-ion batteries have absolute advantages such as high volume, high weight-to-energy ratio, high voltage, low self-discharge rate, no memory effect, long cycle life, and high power density. They have an annual share of more than 30 billion US dollars in the global mobile power market and far exceed other The market share of batteries is the most promising chemical power source [Wu Yuping, Wan Chunrong, Jiang Changyin, Lithium-ion Secondary Batteries, Beijing: Chemical Industry Press, 2002.]. However, since the commercialization of lithium-ion batteries in 1991, the actual specific capacity of cathode materials has always hovered between 100-180mAh / g, and the low specific capacity of cathode materials has become a bottleneck for improving the specific energy of lithium-ion batteries. In order to effectively incre...

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
Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/505H01M4/525H01M4/58H01M4/131
CPCY02E60/122Y02E60/10
Inventor 水淼杨天赐舒杰程亮亮冯琳任元龙郑卫东高珊
Owner NINGBO UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap