Lithium oxide-rich cathode material with nitrogen or carbon-doped surface and preparation method for cathode material

A lithium-rich cathode material and lithium-rich technology, applied in battery electrodes, electrical components, circuits, etc., can solve the problems of poor rate discharge performance of materials, low electronic and ionic conductivity, and low first charge and discharge efficiency. Good rate performance, high specific capacity, and the effect of improving Coulombic efficiency

Active Publication Date: 2012-09-26
NANKAI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are still some shortcomings in lithium-rich layered oxide cathode materials, mainly reflected in the irreversible loss of Li during the first charging process, which leads to l

Method used

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  • Lithium oxide-rich cathode material with nitrogen or carbon-doped surface and preparation method for cathode material
  • Lithium oxide-rich cathode material with nitrogen or carbon-doped surface and preparation method for cathode material
  • Lithium oxide-rich cathode material with nitrogen or carbon-doped surface and preparation method for cathode material

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Embodiment 1

[0023] 1) Lithium-rich cathode material Li 1.17 Ni 0.25 mn 0.58 o 2 Preparation: prepare NiCl separately according to the stoichiometric ratio 2 and MnCl 2 The mixed solution (150 ml, the total concentration of metal ions is 0.25 moles per liter), LiOH solution (170 milliliters, 0.5 moles per liter), NiCl 2 and MnCl 2 The mixed solution was added to the LiOH solution, centrifuged, washed, and dried to obtain a precipitate. Another 2.390 g of LiOH was weighed and mixed with the above dry precipitate, ground, roasted in air at 500°C for 2 hours, cooled, fully ground, roasted in air at 750°C for 20 hours, quenched and dried to obtain Li 1.17 Ni 0.25 mn 0.58 o 2 .

[0024] 2) Surface nitrogen-doped lithium-rich cathode material Li 1.17 Ni 0.25 mn 0.58 o 1.91 N 0.06 Preparation: the product Li prepared in step 1) 1.17 Ni 0.25 mn 0.58 o 2 placed in a tube furnace under flowing NH 3 Roasting at 400°C for 3 hours in air (gas flow rate 100 ml / min) and cooling down n...

Embodiment 2

[0029] 1) Lithium-rich cathode material Li 1.2 Ni 0.13 co 0.13 mn 0.54 o 2 The total concentration of metal ions prepared respectively by the stoichiometric ratio is 0.5 moles per liter), and the amount of citric acid solution (1.46 moles per liter) is prepared according to the molar ratio of metal ions and citric acid substances in addition (1.46 moles per liter), under strong stirring conditions , the CH 3 COOLi, Ni(CH 3 COO) 2 , Co(CH 3 COO) 2 , Mn(CH 3 COO) 2 The mixed solution was dropped into the citric acid solution, and the solution was evaporated to dryness at 120° C. with stirring to form a gel. Roast in air at 500°C for 2 hours, cool and grind thoroughly, calcinate in air at 750°C for 20 hours, quench and dry.

[0030] 2) Surface carbon-doped lithium-rich cathode material Li 1.2 Ni 0.13 co 0.13 mn 0.54 o 1.82 C 0.12 Preparation: the product Li prepared in step 1) 1.2 Ni 0.13 co 0.13 mn 0.54 o 2 Placed in a tube furnace, flowing CH 4 and H 2 I...

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Abstract

The invention relates to a lithium oxide-rich cathode material with a nitrogen or carbon-doped surface and a preparation method for the cathode material. The structural composition of the cathode material is Li[Li(1-2x)/3MxMn(2-x)/3]OyAz, wherein M is at least one of elements Co and Ni; A may be N or C; x is more than 0 and less than or equal to 0.33; y is more than 1.5 and less than 2; and z is more than 0 and less than or equal to 0.5. A lithium-rich oxide Li[Li(1-2)/3MxMn(2-x)/3]O2 and a nitrogen or carbon-containing gas (comprising NH3, N2+H2 and CH4, and C2H6, C3H8 and mixed gases of the C2H6, C3H8 and H2) are taken as raw materials, and the preparation method comprises the following steps of: introducing a lithium-rich cathode material Li[Li(1-2)/3MxMn(2-x)/3]O2 into a nitrogen or carbon-containing gas atmosphere, and performing reaction for 0.5 to 12 hours at 300 to 1,000 DEG C to obtain the lithium oxide-rich cathode material with the nitrogen or carbon-doped surface. The prepared cathode material has the characteristics of high electrochemical capacity, high cycling stability and the like; and a preparation process is simple, low in cost and high reproducibility.

Description

technical field [0001] The invention relates to a nitrogen or carbon lithium-rich oxide cathode material and a preparation method thereof, specifically a layered lithium-rich cathode material on the surface Li[Li (1-2x) / 3 m x mn (2-x) / 3 ]O 2 method of preparation. Background technique [0002] Lithium-ion batteries have the advantage of high energy density and thus are the most promising as power sources for electric vehicles (EVs). In lithium-ion batteries, the capacity of the cathode material is the most critical factor in determining the capacity of the entire battery. In order to meet the requirements of lithium-ion batteries, cathode materials with high specific capacity must be studied. In recent years, layered Li-rich oxide materials are the most promising for novel Li-ion batteries because of their high specific capacities exceeding 200 mAh / g. However, there are still some shortcomings in lithium-rich layered oxide cathode materials, mainly reflected in the irr...

Claims

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Application Information

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IPC IPC(8): H01M4/505H01M4/525H01M4/131
CPCY02E60/122Y02E60/10
Inventor 高学平张洪周李国然叶世海
Owner NANKAI UNIV
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