Carbon coated lithium manganese phosphate/lithium iron phosphate core-shell structure material as well as preparation method thereof

A core-shell structure, lithium manganese phosphate technology, applied in structural parts, electrical components, battery electrodes, etc., can solve the problems of reducing the tap density of materials, unfavorable for large-scale preparation, and unsuitable for large-scale industrial production, and achieves a simple and easy process. effect of operation

Active Publication Date: 2014-01-15
中科致良新能源材料(浙江)有限公司
View PDF3 Cites 33 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Coating of lithium iron phosphate improves the effect of carbon coating and improves the cycle stability of the material, but the material has a porous structure, which reduces the tap density of the material; and the preparation method of th

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
  • Carbon coated lithium manganese phosphate/lithium iron phosphate core-shell structure material as well as preparation method thereof
  • Carbon coated lithium manganese phosphate/lithium iron phosphate core-shell structure material as well as preparation method thereof
  • Carbon coated lithium manganese phosphate/lithium iron phosphate core-shell structure material as well as preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044]Weigh 0.03mol manganese carbonate, 0.03mol diammonium hydrogen phosphate, and 0.015mol lithium carbonate according to an equimolar ratio, add them to a corundum ball mill jar, and add an appropriate amount of ethanol, and ball mill them in a vibratory ball mill for 1 hour to obtain the first reaction precursor. The first reaction precursor was heat-treated at 600 °C for 5 hours in an Ar flow to obtain LiMnPO 4 Materials, scanning electron microscope photographs (SEM) of samples such as figure 1 As shown, the particle size is between 300-500nm, and the transmission electron micrograph (TEM) of the sample is shown as figure 2 It can be seen that the particle surface is relatively smooth. Weigh 1.5g LiMnPO 4 With 0.91g iron phosphate (FePO 4 4H 2 O), 0.186g lithium hydroxide (LiOH·H 2 O), 0.5g of glucose were mixed, and 5mL of ethanol ball milling was added to obtain the second reaction precursor. The second reaction precursor was heat-treated at 600°C for 10 hours i...

Embodiment 2

[0047] Weigh 0.03 mol of manganese carbonate, 0.03 mol of diammonium hydrogen phosphate, and 0.015 mol of lithium carbonate, put them into a corundum ball mill jar, add 5 mL of ethanol, and mill in a planetary ball mill for 6 hours to prepare a lithium manganese phosphate reaction precursor. The reaction precursor was heat-treated at 600 °C for 5 hours in Ar flow to prepare LiMnPO 4 Material. Weigh 1.5g LiMnPO 4 , with 0.91g iron phosphate (FePO 4 4H 2 O), 0.161g lithium carbonate (Li 2 CO 3 ), 0.4 g of glucose were mixed, and ball milled to obtain a reaction precursor. The reaction precursor was heat-treated at 600°C for 10 hours in an Ar flow to obtain the target product, and the target product was characterized by the same method as in Example 1, and it was confirmed that the target product was LiFePO 4 Coated LiMnPO 4 The material, the molar ratio of Mn:Fe in the composite material is 7:3. By adopting the same method as in Example 1, the first discharge specific ca...

Embodiment 3

[0049] Weigh 0.03mol of manganese carbonate, 0.03mol of diammonium hydrogen phosphate, and 0.015mol of lithium carbonate, and mix them uniformly by ball milling to prepare a lithium manganese phosphate reaction precursor. The reaction precursor was heat-treated at 600 °C for 5 hours in Ar flow to prepare LiMnPO 4 Material. Weigh 1.5g LiMnPO 4 , with 1.82g iron phosphate (FePO 4 4H 2 O), 0.372g lithium hydroxide, 1.29g sucrose are mixed, and ball milling makes reaction precursor. The reaction precursor was heat-treated at 600°C for 10 hours in an Ar flow to obtain the target product, and the target product was characterized by the same method as in Example 1, and it was confirmed that the target product was LiFePO 4 Coated LiMnPO 4 The material, the molar ratio of Mn:Fe in the composite material is 54:46. The inner core is LiMnPO prepared by the first solid-phase reaction 4 , the size is about 300nm, the outer core is composed of lithium iron phosphate particles of about...

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

PropertyMeasurementUnit
Sizeaaaaaaaaaa
Average sizeaaaaaaaaaa
Login to view more

Abstract

The invention discloses a carbon coated lithium manganese phosphate/lithium iron phosphate core-shell structure material as well as a preparation method thereof. The constitutional general formula of the core-shell structure material is LiMnFe(1-x)PO4.a[LiFeyMn(1-y)PO4], wherein the constitutional general formula of a core material is LiMnxFe(1-x)PO4, and the constitutional general formula of a shell material is LiFeyMn(1-y)PO4, x is greater than or equal to 0.8 but less than or equal to 1, y is greater than or equal to 0.8 but less than or equal to 1, and a is greater than or equal to 0.2 but less than or equal to 0.5. Meanwhile, the core-shell structure material further comprises 0.2-50wt% of carbon element which is distributed in the shell. The method comprises the following steps: firstly, carrying out solid phase sintering of a lithium manganese phosphate/manganese phosphate material; and then, after ball-milling and mixing the material with ferric salt, phosphate, a lithium source and the like, sintering in a protective atmosphere to obtain a target product. The carbon coated lithium manganese phosphate/lithium iron phosphate core-shell structure material as an anode material for a lithium ion battery, disclosed by the invention, has higher volume and better cycling stability, is concise in process, easy to operate, high in efficiency, and beneficial to industrial production on a large scale.

Description

technical field [0001] The invention relates to a lithium ion battery cathode material with a carbon-coated lithium manganese phosphate / lithium iron phosphate core-shell structure, belonging to the field of new energy materials. Background technique [0002] Phosphate-based material LiMPO 4 (M=Fe, Mn, Ni, Co) is used as the positive electrode material of lithium-ion batteries, and its theoretical capacity is about 170mAh / g. It also has stable structure, low reactivity with electrolyte, high safety, and good battery cycle performance, etc. With many advantages, since the discovery of the material, it has quickly become a research focus. Among such phosphate materials, LiFePO 4 The synthesis of the material is relatively simple, the electrical performance is also good, and it is the fastest to be commercialized, and has achieved large-scale production and sales. However, LiFePO 4 Due to the low potential platform of lithium deintercalation, the overall energy density of th...

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): H01M4/58H01M4/62
CPCH01M4/58H01M4/625Y02E60/10
Inventor 刘涛吴晓东
Owner 中科致良新能源材料(浙江)有限公司
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