A polycrystalline positive electrode material simultaneously modified by doping and impregnation coating and its solid phase preparation method and application

A cathode material and solid-phase preparation technology, which is applied in the field of lithium/sodium-ion battery polycrystalline cathode materials and their solid-phase preparation, can solve the problems of destroying the surface structure of cathode materials, failing to prevent electrolyte corrosion, and difficulty in obtaining coating materials, etc. , to achieve the effect of improving structural stability, improving charge and discharge efficiency and rate performance, and energy density will not decrease

Active Publication Date: 2021-09-24
CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, doping modification can only be limited to the protection inside the bulk phase, and cannot prevent the electrolyte from corroding the surface of the positive electrode material.
During the heat treatment process of the solid phase coating method, metal oxides, etc. will form grains, which cannot be uniformly coated, and it is difficult to obtain a more consistent coating material
The traditional doping and coating double-modified positive electrode materials need to first synthesize ion-doped samples, then coat them, and finally heat treat to obtain doped and coating double-modified materials. It can be seen that the traditional doping and coating double modification The modification process is complicated and the process is long
Liquid-phase impregnation coating first needs to synthesize the required positive electrode material, then use the liquid phase method to coat the positive electrode material, and then perform low-temperature heat treatment. A total of one liquid phase treatment and two heat treatments are required, and the process is also very complicated. The surface structure of the positive electrode material may also be destroyed during the liquid phase impregnation coating process

Method used

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  • A polycrystalline positive electrode material simultaneously modified by doping and impregnation coating and its solid phase preparation method and application
  • A polycrystalline positive electrode material simultaneously modified by doping and impregnation coating and its solid phase preparation method and application
  • A polycrystalline positive electrode material simultaneously modified by doping and impregnation coating and its solid phase preparation method and application

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Select transition metal oxide precursors (Ni 0.8 co 0.1 mn 0.1 (OH) 2 ) with excess lithium hydroxide and the compound LiBO weighed according to molar weight 2 with V 2 o 5 (precursor and compound LiBO 2 , V 2 o 5 The molar ratio of the mixture is 1:0.5%:2%, and the mixture is placed in a tube furnace. Under an oxygen atmosphere, the temperature is raised to the first-stage sintering temperature of 690°C at a rate of 5°C / min (V 2 o 5 melting point) and keep it warm for 3 hours, then raise the temperature to the second-stage sintering temperature of 750°C and keep it warm for 12 hours, then naturally cool to room temperature, crush and grind, and obtain a lithium-ion battery positive electrode material that is simultaneously modified by doping and impregnation coating.

[0040] The B element doping amount of the positive electrode material is 0.5%, the thickness of the coating layer on the surface of the primary particle is 1 nm, and the thickness of the coating...

Embodiment 2

[0051] Select transition metal oxide precursors (Ni 0.6 co 0.2 mn 0.2 (OH) 2 ) with excess lithium hydroxide and the compound BeF weighed according to the molar weight 2 with MnO 2 (precursor and compound BeF 2 , MnO 2 The molar ratio is 1:1.5%:2%) and mixed evenly, the mixture is placed in a tube furnace, and in an oxygen atmosphere, the temperature is raised to the first stage sintering temperature of 555°C at a rate of 5°C / min (BeF 2 melting point) and keep it warm for 5 hours, then raise the temperature to the second-stage sintering temperature of 850°C and keep it warm for 18 hours, then naturally cool to room temperature, crush and grind, and obtain a lithium-ion battery positive electrode material that is simultaneously modified by doping and impregnation coating.

[0052] The doping amount of Be and F elements in the positive electrode material is 1.5% and 3%, the thickness of the coating layer on the surface of the primary particle is 0.8nm, and the thickness of...

Embodiment 3

[0056] Select transition metal oxide precursors (Ni 0.7 Co 0.1 mn 0.2 (OH) 2 ) with excess lithium hydroxide and the compound Sb taken according to the molar weight 2 O 3 with LiBF 4 (precursor and compound Sb 2 O 3 、LiBF 4 The molar ratio is 1:8%:0.5%) and mixed evenly, the mixture is placed in a tube furnace, and in an oxygen atmosphere, the temperature is raised to the first stage sintering temperature of 655°C at a rate of 5°C / min (Sb 2 O 3 melting point) and keep it warm for 6 hours, then raise the temperature to the second-stage sintering temperature of 800°C and keep it warm for 15 hours, then naturally cool to room temperature, crush and grind, and obtain a lithium-ion battery positive electrode material that is simultaneously modified by doping and impregnation coating.

[0057] The doping amount of B and F elements in the positive electrode material is 0.5% and 2%, the thickness of the coating layer on the surface of the primary particle is 3nm, and the thic...

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Abstract

The invention belongs to the technical field of lithium / sodium ion battery materials, and specifically discloses a positive electrode material synchronously modified by doping and impregnation coating, as well as a solid-phase preparation method and application thereof. The solid-phase preparation method mixes raw materials including low-melting point compounds, lithium sources / sodium sources, and precursors to obtain a mixture. First, the solid-phase mixture is heated to the melting point of the low-melting point compound, and then continues to heat up for sintering, and then After cooling to room temperature, a polycrystalline positive electrode material with synchronous modification of doping and impregnation coating is prepared. The polycrystalline positive electrode material provided by the invention has uniform particle size, complete crystal form, optimized material morphology, small gaps between primary particles of the material, increased compaction density, improved diffusion coefficient of lithium / sodium ions, and enhanced material At the same time, it reduces the side reaction that occurs when the electrolyte is in contact with the positive electrode material, and improves the structural stability and cycle performance of the material.

Description

technical field [0001] The invention relates to the technical field of battery materials, in particular to a lithium / sodium ion battery polycrystalline cathode material which is simultaneously modified by doping and impregnation coating, and a solid-phase preparation method and application thereof. Background technique [0002] Lithium / sodium ion battery is the most promising electrochemical energy storage device because of its high energy density, low cost, and small self-discharge, and the discharge specific capacity of the positive electrode material determines the energy of lithium / sodium ion battery The key to high and low density, and the cathode material accounts for more than 40% of the cost of battery development, and is an important part of lithium / sodium-ion batteries. The performance of the positive electrode material seriously restricts the performance of the lithium / sodium ion battery. The positive electrode material affects the reversible capacity and rate per...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/36H01M4/505H01M4/525H01M4/485H01M4/62H01M10/0525H01M10/054C01G53/00
CPCC01G53/44C01P2002/72C01P2004/03C01P2004/50C01P2004/60C01P2004/61C01P2004/62C01P2004/64C01P2006/11C01P2006/12C01P2006/40H01M4/366H01M4/485H01M4/505H01M4/525H01M4/624H01M4/628H01M10/0525H01M10/054H01M2004/021H01M2004/028Y02E60/10
Inventor 李灵均赵子祥谭磊宋刘斌董婷冉高涛
Owner CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY
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