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A core-shell structure lithium-rich manganese-based composite cathode material and preparation method thereof

A composite positive electrode material, lithium-rich manganese-based technology, applied in structural parts, battery electrodes, electrical components, etc., can solve the problems of battery capacity decay, low working voltage platform, lithium sites are easily occupied by nickel, etc., to improve energy density Effect

Active Publication Date: 2020-07-10
GUANGDONG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Among them, the most widely used commercially is LiCoO 2 However, due to the high price of metal cobalt, the manufacturing cost of lithium-ion batteries is very high, which restricts the development of lithium-ion batteries to a certain extent, and will lead to a decline in electrochemical performance when overcharged; LiNiO 2 The synthesis conditions of the material are harsh, and the Ni + with Li + The radius is similar, so that some lithium sites are easily occupied by nickel, and the reversibility is poor; LiMn 2 o 4 During the cycling process, the crystal transformation Jahn-Teller effect and the dissolution of manganese ions are prone to occur, resulting in rapid capacity decay and poor high temperature performance of the battery; while LiFePO 4 Although it has the advantages of excellent cycle performance, safety performance and thermal stability, its working voltage platform is relatively low, which cannot meet the requirements of batteries for high energy density

Method used

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  • A core-shell structure lithium-rich manganese-based composite cathode material and preparation method thereof
  • A core-shell structure lithium-rich manganese-based composite cathode material and preparation method thereof
  • A core-shell structure lithium-rich manganese-based composite cathode material and preparation method thereof

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preparation example Construction

[0033] The invention provides a method for preparing a lithium-rich manganese-based composite cathode material with a core-shell structure, comprising:

[0034] A) core precursor is provided; the core precursor is Ni x mn y m z (OH) 2-4 , where 0≦x

[0035] B) Mix the cobalt source, the doping metal M' source and the core precursor to obtain a mixed source solution, and then mix it with a precipitating agent and a complexing agent to obtain a core-shell structure precursor; the doping metal M' is Mg, Ca , one or more of Ni, Mn, Cr, Al, Ti, Zr, Cu, Zn, Ce and Mo;

[0036] C) mixing a lithium source with the core-shell structure precursor, and calcining to obtain a lithium-rich manganese-based composite positive electrode material with a core-shell structure.

[0037] The preparation method of the lithium-rich manganese-based composite positive electrode material with a core-shell structure provided by the present...

Embodiment 1

[0061] This embodiment provides a lithium-rich manganese-based positive electrode material with a core-shell structure Li[Li 0.2 Ni 0.2 mn 0.58 Cr 0.02 ]O 2 @LiCo 0.98 al 0.02 o 2 preparation methods, including:

[0062] (1) Core precursor Ni 0.25 mn 0.725 Cr 0.025 (OH) 2 Preparation of:

[0063] According to the molar ratio Ni:Mn:Cr=0.25:0.725:0.025, take nickel nitrate, manganese nitrate, and chromium nitrate and dissolve them in deionized water to prepare a mixed solution with a total concentration of 1mol / L; weigh NaOH and dissolve them in deionized water Prepare a solution of 2mol / L; take ammonia solution and prepare a solution of 0.2mol / L; put the three solutions into the continuously stirring reaction kettle through a peristaltic pump under the protection of an inert gas at a flow rate of 10mL / min, and control the stirring The speed is 500r / min, the temperature of the reactor is 50°C, the pH value of the reaction system is controlled to be 11, and the reacti...

Embodiment 2

[0069] This embodiment provides a lithium-rich manganese-based positive electrode material with a core-shell structure Li[Li 0.2 Ni 0.2 mn 0.58 Zr 0.02 ]O 2 @LiCo 0.98 Mg 0.02 o 2 preparation methods, including:

[0070] (1) Core precursor Ni 0.25 mn 0.725 Zr 0.025 (OH) 2 Preparation of:

[0071] According to the molar ratio Ni:Mn:Zr=0.25:0.725:0.025, take nickel sulfate, manganese sulfate and zirconium sulfate and dissolve them in deionized water to prepare a mixed solution with a total concentration of 1mol / L; weigh NaOH and dissolve them in deionized water Prepare a solution of 2mol / L; take ammonia solution and prepare a solution of 0.2mol / L; put the three solutions into the constantly stirring reaction kettle at a flow rate of 8mL / min through a peristaltic pump under the protection of an inert gas, and control the stirring The speed is 500r / min, the temperature of the reactor is 50°C, the pH value of the reaction system is controlled to be 11, and the reaction ...

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Abstract

The invention provides a lithium-rich manganese-based composite anode material of a core-shell structure. The lithium-rich manganese-based composite anode material comprises a lamellar lithium-rich manganese-based inner core and a lamellar lithium cobalt oxide doped outer shell arranged outside the inner core, wherein the outer shell is prepared from the material of LiCobM'(1-b)O2, the b is largerthan 0 and smaller than 1, and the M' is one or several of Mg, Ca, Ni, Mn, Cr, Al, Ti, Zr, Cu, Zn, Ce and Mo. According to the lithium-rich manganese-based composite anode material disclosed by the invention, the surface of the lamellar lithium-rich manganese-based anode material Li(Lia(NixMnyMz)(1-a))O2 is covered by the lamellar LiCobM'(1-b)O2 through a hydroxide coprecipitation-high temperature solid phase method to form the composite anode material of the core-shell structure, the lamellar lithium-rich anode material Li(Lia(NixMnyMz)(1-a))O2 is utilized as the core, and the lamellar LiCobM'(1-b)O2 is utilized as the shell. Therefore, the problems of a low first charge-discharge efficiency, a low energy density and voltage attenuation in a cyclic process are solved, and an energy density, specific capacity, cycle performance and rate capability of the lithium-rich anode material are improved.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a lithium-rich manganese-based composite positive electrode material with a core-shell structure and a preparation method thereof. Background technique [0002] As issues such as energy, resources, and the environment are increasingly concerned by the society, lithium-ion batteries are more and more widely used in people's lives and production because of their outstanding advantages such as high specific energy, green environmental protection, and no memory effect. , are widely used in mobile power, electric vehicles and smart grid energy storage and other fields. Cathode materials are an important part of lithium-ion batteries and the key to restricting the development of lithium-ion batteries. [0003] Traditional lithium-ion battery cathode materials mainly include layered LiCoO 2 , LiNiO 2 , spinel-type LiMn 2 o 4 and olivine-type LiFePO 4 . Among them, t...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/36H01M4/505H01M4/525H01M10/0525
CPCH01M4/366H01M4/505H01M4/525H01M10/0525Y02E60/10
Inventor 卢璐李军蓝利芳许帅军黄思
Owner GUANGDONG UNIV OF TECH