High-power positive electrode material with specific core-shell structure and preparation method of high-power positive electrode material

A cathode material and core-shell structure technology, which is applied in the field of high-power cathode materials and their preparation, can solve the problem that the shrinkage rate of the inner core and the consistency of the morphology cannot be ensured, the collapse of the secondary agglomerated sphere structure cannot be effectively improved, and the shrinkage of the inner core cannot be guaranteed. rate and other issues, to achieve the effects of controllable morphology and size, good product consistency, and improved cycle and rate performance.

Pending Publication Date: 2022-01-07
HUNAN CHANGYUAN LICO CO LTD +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the preparation method by controlling the porosity of the precursor inside and outside cannot guarantee the shrinkage rate of the inner core, resulting in uneven size of the final pores, which affects the power performance of the material
In addition, the internal pores of the hollow material will cause the secondary agglomerated balls to be unable to withstand pressure, and the structure will peel off and collapse from the grain boundary under the condition of high voltage or large current charge and discharge, causing the battery capacity to decline greatly during high temperature cycling. hinder large-scale application
[0005] Although the patent CN107112515 A provides a positive electrode material different from the hollow shape, which is composed of a core, a shell and a buffer layer, its preparation method is similar to that of the hollow material, and the inner core and buffer layer are formed by shrinking inward after sintering. The method cannot ensure the shrinkage rate of the core and the consistency of the shape
And as described in the patent, the ratio of the radius of the nucleus to the radius of the positive electrode material is greater than 0 and less than 0.4, which cannot effectively improve the structural collapse of the secondary agglomerated balls under high voltage or large current charging and discharging conditions.

Method used

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  • High-power positive electrode material with specific core-shell structure and preparation method of high-power positive electrode material
  • High-power positive electrode material with specific core-shell structure and preparation method of high-power positive electrode material
  • High-power positive electrode material with specific core-shell structure and preparation method of high-power positive electrode material

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] (1) Add pure water, complexing agent solution, and precipitating agent solution into the reactor to prepare the bottom liquid of the reactor, and prepare nickel sulfate, cobalt sulfate, manganese sulfate, and aluminum sulfate according to the metal molar ratio of 92:3:4:1 Metal mixed salt solution, using sodium carbonate as a precipitating agent, ammonia water as a complexing agent is injected into the alkaline bottom liquid, and the phase I reaction is carried out. The flow rate of the mixed salt is 120ml / min, the pH value is controlled at 11.0-11.5, and the stirring speed is adjusted. to 700-1000rpm, control the reaction temperature to 52°C, stop feeding after the particle size grows to 4.0-4.5μm, and obtain a slurry with a solid content of about 260g / L, adjust the solid content of the slurry to 60g / L, Then adjust the flow rate of the mixed salt to 150ml / min, and after feeding for 2 hours, the slurry of the inner core is obtained.

[0047] (2) The mixed salt solution ...

Embodiment 2

[0054] (1) Add pure water, complexing agent solution, and precipitating agent solution into the reactor to prepare the bottom liquid of the reactor, and prepare nickel sulfate, cobalt sulfate, manganese sulfate, and aluminum sulfate according to the metal molar ratio of 70:15:13:2 solution, using ammonium carbonate as a precipitating agent, ammonium fluoride as a complexing agent and injecting it into the alkaline bottom solution to carry out the phase I reaction, the flow rate of the mixed salt is 120ml / min, the pH value is controlled at 10.5-11, and the stirring speed is adjusted to 800~1100rpm, control the reaction temperature at 55°C, stop feeding after the particle size grows to 6.0~6.5μm, obtain a slurry with a solid content of about 410g / L, adjust the solid content of the slurry to 80g / L, and then The flow rate of the mixed salt was adjusted to 180ml / min, and after feeding for 4 hours, the slurry of the inner core was obtained.

[0055] (2) In the core of step (1), nick...

Embodiment 3

[0059] (1) Add pure water, complexing agent solution, and precipitating agent solution into the reactor to prepare the bottom liquid of the reactor, and prepare nickel sulfate, cobalt sulfate, manganese sulfate, and aluminum sulfate according to the metal molar ratio of 80:9:10:1 The first mixed salt solution, using sodium carbonate as a precipitating agent, injecting ammonia water as a complexing agent into the alkaline bottom liquid, and performing phase I reaction, the flow rate of the first mixed salt is 120ml / min, and the pH value is controlled at 10.5-11, Adjust the stirring speed to 1000-1200rpm, and control the reaction temperature to 58°C. After the particle size grows to 3.0-3.5μm, stop feeding to obtain a slurry with a solid content of about 280g / L, and adjust the solid content of the slurry to 40g / L, and then adjust the flow rate of the first mixed salt to 120ml / min, after feeding for 2h, the inner core slurry is obtained.

[0060] (2) The second mixed salt soluti...

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Abstract

The invention provides a high-power positive electrode material with a specific core-shell structure, which is spherical or sphere-like particles with an average particle size of 3-15 [mu] m, and consists of a coronal inner core and an outer shell, wherein the average diameter of the coronal inner core is 2-10 [mu] m, the coronal inner core comprises a main core and protrusions distributed on the surface of the main core, and the average length of the protrusions is 0.05-0.8 [mu] m; the average thickness of the outer shell is 0.5-3 [mu] m, and the shell is formed by orderly arranging one or more primary particles on the surface of the inner core; and the protrusions distributed on the surface of the main core form a connecting layer, at least part of the protrusions are directionally connected with the outer shell, and the porosity of the connecting layer is 50%-90%. The invention also discloses a preparation method of the positive electrode material. The performance of the positive electrode material is not influenced by the shrinking percentage of the inner core, and the positive electrode material has the advantages of controllable size, good consistency, high compression strength, excellent power performance, good cycle stability and the like.

Description

technical field [0001] The invention belongs to the technical field of lithium ion battery materials, and in particular relates to a high-power positive electrode material with a specific core-shell structure and a preparation method thereof. Background technique [0002] Lithium-ion batteries have become a hot spot in battery research and development due to their advantages such as small memory effect, large specific energy, and long service life, and the development speed is very rapid. However, as lithium-ion batteries are widely used in new energy fields such as electric vehicles and hybrid vehicles, the performance of their power sources, especially power density, is increasingly demanding. [0003] The morphology of the cathode material has a great influence on the power performance. Porous materials with a pore structure are currently a common high-power material. The specific surface area of ​​the porous material itself is large. On the one hand, the material is in...

Claims

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Application Information

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IPC IPC(8): H01M4/36H01M4/485H01M4/525H01M4/505H01M10/0525H01M4/04
CPCH01M4/366H01M4/525H01M4/485H01M4/505H01M10/0525H01M4/04H01M4/0471H01M2004/028H01M2004/021H01M2220/20Y02E60/10
Inventor李旻李厦侯鑫宇周友元黄滔熊学赵俊豪苏帅
OwnerHUNAN CHANGYUAN LICO CO LTD