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A kind of high-capacity cathode material for lithium ion battery

A cathode material, high-capacity technology, applied in battery electrodes, non-aqueous electrolyte battery electrodes, secondary batteries, etc., can solve the problems of small primary particle size, large specific surface area, poor cycle stability, etc.

Active Publication Date: 2017-08-25
INST OF CHEM CHINESE ACAD OF SCI +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Its current literature reports that the specific capacity at room temperature and low rate has exceeded 250mAh g -1 , but the rate performance and cycle stability need to be improved
The synthesis of lithium-rich manganese-based layered cathode materials is mainly based on sol-gel and co-precipitation methods. The raw material used in the sol-gel method is acetate, which is more expensive than the sulfate used in co-precipitation. In addition, the sol-gel method is used to synthesize The primary particle size of the material is small, the specific surface area is large, and the cycle stability is poor

Method used

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  • A kind of high-capacity cathode material for lithium ion battery
  • A kind of high-capacity cathode material for lithium ion battery
  • A kind of high-capacity cathode material for lithium ion battery

Examples

Experimental program
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Effect test

Embodiment 1

[0022]Prepare 1L of 2mol / L transition metal salt solution at room temperature of 25°C: 1.34mol of manganese sulfate monohydrate, 0.33mol of nickel sulfate hexahydrate, 0.33mol of cobalt sulfate heptahydrate, add ultrapure water to make a transition metal salt solution with a volume of 1L; configure 2mol 1 L of sodium carbonate solution per L: add 2 mol of anhydrous sodium carbonate and ultrapure water to make a solution with a volume of 1 L, and add 15 ml of commercially available ammonia (concentration is 0.5 mol / L) to the configured anhydrous sodium carbonate solution. The bottom liquid is equipped with 1mol / L sodium sulfate solution: add 284g (2mol) sodium sulfate and ultrapure water to make a 2L solution, add it to a 5L self-control reactor, add ammonia water dropwise to adjust the pH to 8.5, and the ionic strength of the bottom liquid at this time is 3mol / L, the speed of the reactor was adjusted to 800 rpm, the temperature was set to 60°C, and the transition metal salt sol...

Embodiment 2

[0030] The concentration of sodium sulfate in the bottom liquid is 1.5mol / L, and the concentration of ammoniacal liquor is 1mol / L, and the ionic strength of bottom liquid is 4.5mol / L, and other is identical with embodiment 1. The synthesized precursor still maintains spherical morphology.

[0031] A button battery was assembled using the same process as in Example 1. The charge and discharge rate is 0.05C, and the charge and discharge voltage range is 2-4.8V. The discharge capacity can reach 242mAh / g. The charge and discharge rate is 0.2C, the charge and discharge voltage range is 2-4.8V, the specific capacity is 180mAh / g after 70 cycles, and the capacity decays by 3.8%. The charge and discharge rate is 0.2C, the charge and discharge voltage range is 2-4.8V, and the average voltage decay is 0.25V in the 10th cycle and the 70th cycle.

Embodiment 3

[0033] The concentration of sodium sulfate in the bottom liquid is 0.5mol / L, and the concentration of ammoniacal liquor is 1mol / L, and the ionic strength of bottom liquid is 1.5mol / L, and other is identical with embodiment 1. The shape of the obtained precursor is not uniform.

[0034] A button battery was assembled using the same process as in Example 1. The charge and discharge rate is 0.05C, and the charge and discharge voltage range is 2-4.8V. The discharge capacity can reach 235mAh / g. The charge and discharge rate is 0.2C, the charge and discharge voltage range is 2-4.8V, the specific capacity is 172mAh / g after 70 cycles, and the capacity decays by 4.5%. The charge and discharge rate is 0.2C, the charge and discharge voltage range is 2-4.8V, and the average voltage decay is 0.35V at the 10th and 70th laps.

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Abstract

The invention discloses a preparation method of a high-capacity positive electrode material. The preparation method comprises the following steps: 1, preparing a transition metal salt solution, an alkaline solution and a base solution with certain ion strength; 2, adding the solutions to a reaction still and aging under the condition of controlled stirring rate, pH valve and reaction temperature; and 3, dissolving a lithium salt in ultrapure water to prepare a solution, adding a spherical precursor in the lithium salt solution, stirring and mixing, heating to evaporate water, drying and calcining to obtain the high-capacity positive electrode material 0.5Li2MnO3.0.5LiNi1 / 3Co1 / 3Mn1 / 3O2. By virtue of a mode of controlling the ion strength of the base solution, the precipitation reaction rate is controlled, and crystal nucleation and growth rate is controlled so that the uniform and controllable spherical precursor can be formed. The aim of uniformly mixing the precursor and the lithium salt is fulfilled through wet-process mixing, thus being beneficial to generation of the high-capacity positive electrode material with remarkable performance via calcining.

Description

technical field [0001] The invention relates to a preparation method of a lithium-rich layered cathode material for a lithium ion battery. Background technique [0002] Lithium-ion batteries are widely used as ideal power sources for mobile electronic devices due to their outstanding advantages such as high working voltage, high specific energy, large capacity, small self-discharge, good cycle performance, long service life, environmental friendliness, light weight, and small size. , laptops and other portable electronic devices. At the same time, with the rapid development of society, the depletion of oil resources, environmental pressure and other factors, hybrid and pure electric vehicles will become the mainstream of future transportation, which also puts forward higher requirements for large-scale power lithium-ion batteries. Require. At present, the development of lithium-ion batteries with high capacity, high power density and good cycle stability has become the foc...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/505H01M4/13H01M4/139
CPCH01M4/505H01M4/525H01M10/0525Y02E60/10
Inventor 郭玉国石吉磊江柯成卿任鹏万立骏张亚利李明文张风太
Owner INST OF CHEM CHINESE ACAD OF SCI