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

A preparation method for improving the rate performance of lithium iron phosphate cathode material

A technology of rate performance and positive electrode materials, applied in the direction of positive electrodes, battery electrodes, active material electrodes, etc., can solve problems such as unsatisfactory rate performance, reduced discharge capacity, and serious polarization, and achieve excellent cycle performance and specific capacity. High, uniform size effect

Active Publication Date: 2017-06-23
SHENZHEN GRADUATE SCHOOL TSINGHUA UNIV
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] LiFePO 4 The lower ionic conductivity and electronic conductivity make the actual discharge capacity lower, the polarization phenomenon is serious, and the rate performance is not ideal.

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
  • A preparation method for improving the rate performance of lithium iron phosphate cathode material
  • A preparation method for improving the rate performance of lithium iron phosphate cathode material
  • A preparation method for improving the rate performance of lithium iron phosphate cathode material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] First, ferrous oxalate, lithium carbonate, ammonium dihydrogen phosphate and ethyl orthosilicate are mixed according to the molar ratio of iron, lithium, phosphorus and silicon: 1:1:0.97:0.03, and an appropriate amount of acetone is added as a dispersant, at 350rpm Ball milling at a rotating speed of 12 hours, after drying, the resulting product was sintered at 450°C (heating rate: 5°C / min) for 10 hours under an argon protective atmosphere, cooled to room temperature with the furnace, and the obtained product was ground in an agate mortar to obtain The calcined product, the silicon-doped matrix.

[0029] Then coat amorphous carbon and nano-lithium silicate: mix the calcined product with potato starch and lithium silicate in deionized water, fully mix under the action of magnetic stirring, raise the temperature to 50°C to gelatinize the starch, and heat it up to Evaporate to dryness at 70°C, heat the product at 700°C (heating rate: 5°C / min) in a tube furnace with an argo...

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

A preparing method for improving rate capability of a lithium iron phosphate anode material comprises following steps: mixing a divalent iron salt, a lithium salt, a phosphate salt and a silicon source according to a molar ratio of Fe:Li:P:Si being 1:0.95-1.05:0.90-0.99:0.10-0.10, adding a dispersant, ball-grinding for 4 to 16 hours at a 200 to 500rpm, sintering for 6 to 12 hours at 300 to 500DEG C under protection atmosphere after drying a ball-ground product, cooling to room temperature along with a furnace, grinding to obtain a presintering product, namely the silicon doped-substrate; mixing the presintering product, a carbon source and lithium silicate, adding into deionized water, stirring for 0.5 to 4 hours, performing constant temperature roasting for 6 to 12 hours at 600 to 900DEG C under protection atmosphere after drying, cooling to room temperature along with a furnace, and grinding to obtain the modified lithium iron phosphate powder. The method can be widely used for industrial production and electrochemical performance is obviously improved.

Description

technical field [0001] The invention relates to a preparation method of lithium iron phosphate cathode material, belonging to the field of lithium ion batteries. Background technique [0002] In 1997, Goodenough's research group reported for the first time that the lithium-ion cathode material LiFePO 4 , its theoretical specific capacity is 170mAh / g, which is larger than commercialized LiCoO 2 actual discharge specific capacity. And LiFePO 4 It has good cycle performance and a stable discharge platform near 3.45V. LiFePO 4 It is currently the main electrode material used in power batteries. Its main advantages are stable voltage platform, cheap and abundant raw materials, environmental friendliness, low toxicity and high safety due to good high temperature stability. [0003] LiFePO 4 It is an orthorhombic olivine structure, belonging to the Pmnb space group, and its lattice constant is LiFePO 4 The crystal structure of LiCoO remains stable at 400 °C, but LiCoO 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
Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/36H01M4/58H01M4/62H01M4/136H01M4/1397H01M10/0525
CPCH01M4/136H01M4/1397H01M4/362H01M4/5825H01M4/624H01M10/0525H01M2004/028Y02E60/10
Inventor 赵世玺赵建伟程红美陈昌科
Owner SHENZHEN GRADUATE SCHOOL TSINGHUA UNIV