Preparation method of nano-lithium iron phosphate/carbon composite with stable low temperature performance

A technology of lithium iron phosphate and low-temperature performance, applied in the direction of nanotechnology, nanotechnology, nanotechnology, etc. for materials and surface science, can solve the problem of difficulty in forming uniform carbon coating, and achieve easy control of preparation conditions, The effect of rich raw materials and prevention of particle aggregation

Active Publication Date: 2014-10-15
吉林东驰新能源科技有限公司
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition, LiFePO was synthesized using a solid-phase method 4 Simple process and low cost, LiFePO 4 The most ideal method to achieve industrialization, however, the solid-phase synthesis method is used to prepare small-sized LiFePO 4 Particles, especially those below 200 nm, are still difficult, and it is even more difficult to form a uniform carbon coating on the surface

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
  • Preparation method of nano-lithium iron phosphate/carbon composite with stable low temperature performance
  • Preparation method of nano-lithium iron phosphate/carbon composite with stable low temperature performance
  • Preparation method of nano-lithium iron phosphate/carbon composite with stable low temperature performance

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Ferrous oxalate and lithium dihydrogen phosphate are directly mixed in the ball mill tank according to the Fe:Li:P molar ratio of 1:1:l, and 0.05 g of citric acid and 60% PVP (equivalent to the mass percentage of lithium iron phosphate) are added ), ball milled in an appropriate amount of absolute ethanol at 450 rpm / min for 20 hours, heated up in a nitrogen atmosphere after drying at a rate of 3°C / min, stayed at 350°C for 3 hours, stayed at 700°C for 8 hours, and then naturally cooling, and finally obtained nano-sized LiFePO with uniform carbon coating 4 / C complex. The particle size is 80 nm, and the discharge capacity at room temperature at 0.1 C rate can reach 160 mAh / g, at -20°C at 0.1 C rate, the discharge capacity can reach 126 mAh / g, at -20°C at 0.6C rate After 500 cycles, the discharge capacity remains above 97% of the initial capacity.

[0026] In order to reflect the role of composite carbon sources, LiFePO with a single carbon source was prepared at the same...

Embodiment 2

[0028] Ferrous oxalate, lithium carbonate, and ammonium dihydrogen phosphate are directly mixed in the ball mill tank according to the Fe:Li:P molar ratio of 1:1:l, and 0.5 g of citric acid and 10% PVP (equivalent to lithium iron phosphate mass percent), ball milled in an appropriate amount of absolute ethanol at 400 rpm / min for 15 hours, and after drying, heated up in a nitrogen atmosphere at a heating rate of 3°C / min, staying at 350°C for 3 hours, and staying at 700°C for 8 hours , followed by natural cooling, and finally obtained nano-sized LiFePO with uniform carbon coating 4 / C complex. The particle size is 140 nm, and the discharge capacity at 0.1 C rate at room temperature can reach 144 mAh / g, and the discharge capacity at 0.1 C rate at -20 °C can reach 130 mAh / g.

Embodiment 3

[0030] Ferrous oxalate, lithium carbonate, and ammonium dihydrogen phosphate are directly mixed in the ball mill tank according to the Fe:Li:P molar ratio of 1:1:l, and 0.5 g of citric acid and 30% of PVP (equivalent to lithium iron phosphate mass percent), ball milled in an appropriate amount of absolute ethanol at 400 rpm / min for 10 hours, and after drying, heated up in a nitrogen atmosphere at a heating rate of 3°C / min, stayed at 350°C for 3 hours, and stayed at 700°C for 8 hours , followed by natural cooling, and finally obtained nano-sized LiFePO with uniform carbon coating 4 / C complex. The size of the particles is 120 nm, and the discharge capacity at 0.1 C rate at room temperature can reach 131 mAh / g, and the discharge capacity at 0.1 C rate at -20 °C can reach 115 mAh / g.

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
particle sizeaaaaaaaaaa
thicknessaaaaaaaaaa
Login to view more

Abstract

The invention belongs to new energy materials, and in particular relates to a preparation method of nanometer lithium iron phosphate / carbon compound with stable low-temperature performance. In the present invention, iron source, lithium source, phosphorus source and composite carbon source are mixed in a certain proportion, ball milled, dried, and calcined in an inert atmosphere to obtain a lithium ferrous phosphate / carbon compound whose particle size is less than 150nm. The surface has a uniform carbon coating, and the thickness of the carbon layer is about 2nm. The use of composite carbon sources plays an important role in the control of the material structure. After the material is assembled into a button battery, the discharge capacity at room temperature at 0.1C rate is 160mAh / g, at -20°C at 0.1C rate, the discharge capacity is 126mAh / g, and at -20°C at 0.6C rate after 500 cycles , The capacity retention rate is still above 97%, thus solving the problem of unstable low-temperature performance of lithium-ion batteries. The invention has the advantages of low cost, simple production process and high safety, and the prepared compound can be applied to the fields of portable equipment, power electric vehicles and the like.

Description

technical field [0001] The invention belongs to the technical field of new energy materials, and particularly relates to a nano-sized lithium iron phosphate / carbon composite with excellent long-term cycle performance at low temperature (the capacity is almost no attenuation after charging and discharging for more than 500 times), and the surface is coated with uniform carbon. method of preparation. Background technique [0002] As the global energy and environmental problems are becoming more and more severe, lithium-ion batteries are considered to be one of the most ideal energy sources, and can be widely used in civilian small electrical appliances, electric vehicles and other fields. Lithium-ion battery is a new type of battery developed on the basis of lithium battery, and its research began in the 1980s. In 1980, the Goodenough group first proposed layered LiCoO 2 As a cathode material, it marks the birth of lithium-ion batteries. In 1982, Agarwal and Selman of the I...

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): H01M4/58H01M4/62B82Y30/00
CPCY02E60/10
Inventor 张景萍孙海珠黄国龙李微
Owner 吉林东驰新能源科技有限公司
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