Core-shell structure positive material based on phase diagram design and design method of core-shell structure positive material

A core-shell structure and design method technology, applied in battery electrodes, structural parts, circuits, etc., can solve the problems of seldom commercialization, reduced material cycle performance, affected safety performance, etc., and achieve good cycle stability and thermal stability. Safety and safety performance, electrochemical performance improvement, high discharge specific capacity effect

Inactive Publication Date: 2015-10-14
张联齐
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, when the material is charged at about 220°C, Ni4+, Co4+ and NiO on the surface of the material react with the electrolyte, releasing a lot of heat and oxygen, which reduces the cycle performance of the material and affects its safety performance, and the pressure of the material It is difficult to match the solid density with lithium cobalt oxide, so it is rarely commercialized in China at present
A large number of recent studies have found that coating a "thick" shell on the surface of the core material can effectively protect the core material and improve the service life and safety performance of the material. However, from the literature reports and related invention patents, the current core-shell structure materials The design is still only on the synthesis experiment of a single component point, and a systematic and effective method has not been found to design the core-shell structure of a series of ternary materials conveniently and quickly. High security, high capacity and high compaction for corresponding structural design, which is still a blank in the field of research and production of ternary materials at home and abroad

Method used

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  • Core-shell structure positive material based on phase diagram design and design method of core-shell structure positive material
  • Core-shell structure positive material based on phase diagram design and design method of core-shell structure positive material
  • Core-shell structure positive material based on phase diagram design and design method of core-shell structure positive material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] Prepare 23.5L of 2M salt solution with 11233g of nickel sulfate, 676g of cobalt sulfate and 397g of manganese sulfate. Inject the prepared solution into the reaction kettle at a speed of 1.5L / h at a speed of 400rps, and at the same time inject 4M NaOH solution, pay attention to adjusting the flow rate of the alkali solution, and keep the pH value between 10-11 until the salt solution is completely injected into the reaction In the kettle, continue to inject 26.5L of a salt solution with a concentration of 2M prepared by 4692g of nickel sulfate, 5078g of cobalt sulfate, and 2986g of manganese sulfate into the reactor until the salt solution is completely injected into the reactor, and the precursor preparation reaction is completed. After the reaction, the solid-liquid mixture was separated by centrifugation, washed to neutrality and then dried at 120°C for 24 hours. The dried precursor and lithium carbonate were evenly mixed in a molar ratio of 1:1.05, and then calcined...

Embodiment 2

[0043]With 12747g of nickel sulfate, 1724g of cobalt sulfate and 1014g of manganese sulfate, 30L of salt solution with a concentration of 2M was prepared. Inject the prepared solution into the reaction kettle at a speed of 1.5L / h at a speed of 400rps, and at the same time inject 4M NaOH solution, pay attention to adjusting the flow rate of the alkali solution, and keep the pH value between 10-11 until the salt solution is completely injected into the reaction In the kettle, continue to inject 10L of a salt solution with a concentration of 2M prepared by 3540g of nickel sulfate, 3830g of cobalt sulfate, and 2246g of manganese sulfate into the reactor until the salt solution is completely injected into the reactor, and the precursor preparation reaction is completed. After the reaction, the solid-liquid mixture was separated by centrifugation, washed to neutrality and then dried at 120°C for 24 hours. The dried precursor and lithium carbonate were evenly mixed in a molar ratio o...

Embodiment 3

[0045] Prepare 16.7L of 2M salt solution with 7082g of nickel sulfate, 958g of cobalt sulfate and 552g of manganese sulfate. Inject the prepared solution into the reaction kettle at a speed of 1.5L / h at a speed of 400rps, and at the same time inject 4M NaOH solution, pay attention to adjusting the flow rate of the alkali solution, and keep the pH value between 10-11 until the salt solution is completely injected into the reaction In the kettle, continue to pour 8852g of nickel sulfate, 4792g of cobalt sulfate, and 2818g of manganese sulfate to prepare 33.3L of a salt solution with a concentration of 2M into the reactor until the salt solution is completely injected into the reactor, and the precursor preparation reaction is completed. After the reaction, the solid-liquid mixture was separated by centrifugation, washed to neutrality and then dried at 120°C for 24 hours. The dried precursor and lithium carbonate were evenly mixed in a molar ratio of 1:1.05, and then calcined in ...

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Abstract

The invention discloses a design method of a spherical or sphere-like lithium ion battery material based on Ni-Co-Mn ternary phase diagram analysis. A positive material is designed as follows: a core component is positioned at a high-capacity area (Ni is more than or equal to 0.7 and less than or equal to 1, and Co is more than or equal to 0 and less than or equal to 0.3) of a phase diagram according to the influence of different contents of Ni, Co and Mn to the performances of the positive material, and a shell material is positioned in a high-safety area (Ni is more than or equal to 1/3 and less than or equal to 0.5, and Mn is more than or equal to 1/3 and less than or equal to 0.5), so that the Li[(NinCo(1-m-n)Mnm)b(NicCodMn(1-c-d)a)]O2 material has high safety and compounding performances of a high-capacity material, wherein a is more than or equal to 0, b is less than or equal to 1, a+b is equal to 1, n is more than or equal to 1/3 and less than or equal to 0.5, m is more than or equal to 1/3 and less than or equal to 0.5, d is more than or equal to 0.7 and less than or equal to 1, c is more than or equal to 0 and less than or equal to 0.3, and d+c is less than or equal to 1. A core-shell structure material can show high specific capacity, high circulatory stability and high safety by the complementation of core and shell functions of the core-shell structure. Compared with a homogeneous-phase multielement material, the material disclosed by the invention has the advantages that the large-scale preparation cost is not increased, the repeatability is high, the batch stability is good, the production management is facilitated, and the large-scale commercialization application needs can be met.

Description

technical field [0001] The invention belongs to the technical field of positive electrode materials for lithium ion batteries, and in particular relates to a method for designing a core-shell structure ternary material by using a phase diagram and a preparation method for the positive electrode material and its precursor. Background technique [0002] Since Japan's Sony Corporation commercialized lithium-ion secondary batteries in 1991, lithium-ion secondary batteries have been widely used in "3C" products. At present, lithium cobalt oxide is still the main anode material for lithium-ion secondary batteries, but because cobalt ore is scarce, expensive, and toxic, it is necessary to study other anode materials as its substitutes. In recent years, the ternary material Li[NixCoyMn1-x-y]O2 has attracted extensive attention of researchers due to its high capacity and low cost. However, when the material is charged at about 220°C, Ni4+, Co4+ and NiO on the surface of the material...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/1391H01M4/505H01M4/525H01M4/58
CPCY02E60/10
Inventor 张联齐郭建
Owner 张联齐
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