Modified positive electrode material and preparation method thereof and secondary battery

A positive electrode material and modification technology, applied to battery electrodes, circuits, electrical components, etc., can solve problems such as reducing the capacity and energy density of single batteries, affecting the cycle life of fast-charging batteries, and reducing the first Coulombic efficiency. Effects on Structural Stability and Dynamic Properties

Inactive Publication Date: 2018-03-06
CONTEMPORARY AMPEREX TECH CO
View PDF7 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Judging from the existing technology, the lithium-ion secondary battery mixed with hard carbon negative electrode reduces the first Coulombic efficiency, reduces the capacity and energy density of the single battery; similarly, the lithium titanate negative electrode has a relatively high potential for intercalation of Li, resulting in lithium ion The overall energy density of the secondary battery is lost
However, coating the surface of the positive electrode material with oxides such as Al, Zr, and Ti with a simple structure stabilizes the surface structure of the positive electrode material, but it cannot take into account the needs of ion transport and electron transport on the positive electrode surface.
In addition, during the high-rate charging process at room temperature, the overpotential borne by the positive electrode is relatively large, accompanied by obvious temperature rise and other problems, which affect the cycle life of the fast-charge battery at room temperature

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
  • Modified positive electrode material and preparation method thereof and secondary battery
  • Modified positive electrode material and preparation method thereof and secondary battery

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0022] According to the preparation method of the modified positive electrode material described in the second aspect of the present invention, it is used to prepare the modified positive electrode material described in the first aspect of the present invention, comprising the steps of: (1) combining Ma source, Mo source and P source by atoms The ratio Ma:Mo:P=x:y:z is uniformly mixed and processed to obtain Ma with a NASICON-like crystal structure x Mo y P z o n ; (2) will get Ma x Mo y P z o n After being uniformly mixed with the positive active material, calcining is carried out to obtain a coating layer Ma on the surface of the positive active material. x Mo y P z o n modified cathode materials. Wherein, Ma is selected from Li or Na, x is an integer within 1 to 3, and y, z, n are integers greater than 0.

[0023] In the preparation method of the modified cathode material according to the second aspect of the present invention, the Ma source is selected from one ...

Embodiment 1

[0044] (1) Mo source MoO 3 After mixing with oxalic acid and stirring evenly (MoO 3 The molar ratio to oxalic acid is 1:3~1:4) dissolved in deionized water at 75°C, and then added P source NH 4 h 2 PO 4 with Ma Yuan Li 2 CO 3 , and control the molar ratio of Li, Mo, P to 3:4:5. Then the mixed solution was stirred for 4 hours and then heated in an oven at 100 °C, dried with deionized water to prepare a gel, and then sintered at 650 °C for 6 hours to obtain Li 3 Mo 4 P 5 o 24 . Will Li 3 Mo 4 P 5 o 24 Grind and sieve to ensure that the particle size of the particles is within 10 μm.

[0045] (2) The sieved Li 3 Mo 4 P 5 o 24 and positive active material LiNi 0.3 co 0.2 mn 0.5 o 2 According to the mass ratio of 0.5:100 solid-phase ball milling and mixing, and then calcining the mixed powder at 450 ° C for 3 hours, the modified positive electrode material is obtained, and the modified positive electrode material obtained after calcining is sieved, and the par...

Embodiment 2

[0047] (1) Mo source H 2 MoO 4 After mixing with oxalic acid and stirring evenly (H 2 MoO 4 The molar ratio to oxalic acid is 1:3~1:4) dissolved in deionized water at 75°C, and then added P source NH 4 h 2 PO 4 with Ma Yuan Li 2 CO 3 , and control the molar ratio of Li, Mo, P to 3:4:5. Then, the mixed solution was stirred for 4 hours and then heated in an oven at 100°C, dried with deionized water to prepare a gel, and then sintered at 700°C for 6 hours to obtain Li 3 Mo 4 P 5 o 24 . Will Li 3 Mo 4 P 5 o 24 Grind and sieve to ensure that the particle size of the particles is within 15 μm.

[0048] (2) The sieved Li 3 Mo 4 P 5 o 24 and positive active material LiNi 0.3 co 0.3 mn 0.4 o 2 According to the mass ratio of 1:100, solid-phase ball milling and mixing, and then calcining the mixed powder at 480°C for 3.5h, the modified positive electrode material is obtained, and the modified positive electrode material obtained after calcining is sieved, and the pa...

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
Particle sizeaaaaaaaaaa
Particle sizeaaaaaaaaaa
Login to View More

Abstract

The invention provides a modified positive electrode material and a preparation method thereof and a secondary battery. The modified positive electrode material comprises a positive active material and a coating layer, wherein the coating layer coats the surface of the positive active material; the general formula of the coating layer is Ma<x>Mo<y>P<z>O<n>; and the coating layer has an NASICON-like crystal structure, wherein Ma is selected from Li or Na; x is an integer within a range of 1-3; and y, z and n are integer greater than 0. After the modified positive electrode material is applied to the secondary battery, the structure stability and the dynamic performance of the secondary battery in high-rate charging and discharging processes can be improved.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a modified positive electrode material, a preparation method thereof, and a secondary battery. Background technique [0002] Secondary batteries, especially the advancement of lithium-ion secondary battery technology and its application in emerging key markets (electric vehicle field), have stimulated a worldwide research and development boom, so lithium-ion secondary batteries are bound to be used in electric vehicles and new The energy sector occupies an important position. In the existing high-power lithium-ion secondary batteries in the field of commercial electric vehicles, the negative electrode material is usually mixed with hard carbon or lithium titanate with good kinetic properties to improve its room temperature cycle performance, while the positive electrode is mostly used In the coating process, some oxides with simple structures such as transition metals Al, Zr, ...

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): H01M4/36H01M4/62
CPCH01M4/366H01M4/62Y02E60/10
Inventor李鲲阮丁山汪龙柳娜
OwnerCONTEMPORARY AMPEREX TECH CO