A kind of cathode material and preparation method thereof

A cathode material, lithium-rich manganese-based technology, applied in the field of lithium-rich manganese-based solid solution cathode material and its preparation, can solve the problems of poor rate performance, large irreversible capacity loss, poor conductivity of lithium-rich manganese-based solid solution, etc., to achieve Effects of Avoiding Direct Contact, Improving Cycle Performance and Rate Performance

Inactive Publication Date: 2018-04-06
XIANGTAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

During the first charge, when the voltage reaches 4.5V, the Li 2 MnO 3 will irreversibly release Li 2 O, forming MnO 2 , which leads to a large irreversible capacity loss and a decrease in the first Coulombic efficiency
In addition Li 2 MnO 3 The insulating properties also lead to poor conductivity of lithium-rich manganese-based solid solutions, resulting in poor rate performance
These two problems have seriously hindered the widespread application of lithium-rich manganese-based solid solutions in lithium-ion batteries.

Method used

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  • A kind of cathode material and preparation method thereof
  • A kind of cathode material and preparation method thereof
  • A kind of cathode material and preparation method thereof

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preparation example Construction

[0041] The present invention also provides a method for preparing the positive electrode material described in the above technical solution, comprising the following steps:

[0042] (1) dissolving the organic carbon source and ammonium metavanadate in a solvent to obtain a mixed solution;

[0043] (2) dispersing the lithium-rich manganese-based solid solution in the mixed solution obtained in the step (1) to form a suspension;

[0044] (3) removing the solvent in the suspension obtained in the step (2), drying the obtained solid to obtain a positive electrode material precursor;

[0045] (4) heat-treating the positive electrode material precursor obtained in step (3) to obtain the positive electrode material.

[0046] In the invention, the organic carbon source and the ammonium metavanadate are mixed and dissolved in a solvent to obtain a mixed solution. In the present invention, there is no special limitation on the operation of preparing the mixed solution, and the technic...

Embodiment 1

[0067] Weigh 19.286g ammonium metavanadate, dissolve 11.875g sucrose in 500ml deionized water, then add 100g lithium-rich manganese-based solid solution 0.5Li 2 MnO 3 0.5Li(Mn 1 / 3 co 1 / 3 Ni 1 / 3 )O 2 , stir evenly; heat in an oil bath at 120°C until the water is evaporated to dryness, transfer to an oven, and dry at a constant temperature of 120°C for 10 hours to obtain a dry powder; finally place it in a tube furnace, first vacuum, and then pass through N 2 , from room temperature to 450°C at a rate of 10°C / min, calcined for 6 hours, and cooled with the furnace body to obtain 15% V 2 o 5 and 0.5Li coated with 5% C 2 MnO 3 0.5Li(Mn 1 / 3 co 1 / 3 Ni 1 / 3 )O 2 , the sample is denoted as LMSSVC.

[0068] The present invention carries out SEM and TEM analysis to the product that embodiment obtains, and result is as follows figure 1 and figure 2 as shown, figure 1 for V 2 o 5 SEM images of lithium-rich manganese-based solid solution LMSSVC coated with / C hybrid layer, ...

Embodiment 2

[0072] Weigh 12.857g ammonium metavanadate, 7.125g sucrose and dissolve in 500ml deionized water, add 100g lithium-rich manganese-based solid solution 0.4Li 2 MnO 3 0.6Li(Mn 1 / 3 co 1 / 3 Ni 1 / 3 )O 2 , stir evenly, heat in an oil bath at 120°C until the water is evaporated to dryness, transfer to an oven, and dry at a constant temperature of 120°C for 10 hours, place the dried powder in a tube furnace, vacuumize, and pass through N 2 , was calcined from room temperature to 450°C at a rate of 10°C / min for 5h, and cooled naturally with the furnace to obtain 10% V 2 o 5 and 0.4Li coated with 3% C 2 MnO 3 0.6Li(Mn 1 / 3 co 1 / 3 Ni 1 / 3 )O 2 . According to the method of Example 1, its electrochemical performance was tested, and the irreversible capacity of the first charge and discharge was 51mAh / g, and the capacity retention rate was 85% after 50 cycles at 0.1C. The initial discharge capacities of 0.1C, 0.2C, 0.5C, 1C, 2C and 5C rates are 272, 238, 215, 189, 167 and 146mAh / g...

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Abstract

The invention provides a hybridization layer-cladded lithium-enriched manganese-based solid solution anode material and a preparation method thereof. The anode material provided by the invention comprises a lithium-enriched manganese-based solid solution with the chemical formula of xLi2MnO3.yLiMO2, and a V2O5 and C hybridization layer cladded on the surface of the lithium-enriched manganese-based solid solution, wherein M is one or several of metal elements in the transition group, x is larger than 0 and smaller than 1, and x+y is equal to 1; the V2O5 and C hybridization layer is excellent in electronic conductivity and low first-time irreversible capacity loss. The preparation method comprises the following steps: uniformly dispersing lithium-enriched manganese-based solid solution powder into a mixed solution of an organic carbon source and a vanadium source, drying to obtain an anode material precursor, calcining the anode material precursor under an inert gas environment, and synthesizing the V2O5 / C hybridization layer-cladded lithium-enriched manganese-based solid solution anode material. According to the preparation method provided by the invention, the cladding of V2O5 and the cladding of C are synchronously completed, so that the preparation method is easy and convenient to operate, and suitable for industrial production.

Description

technical field [0001] The invention relates to the technical field of energy materials, in particular to a lithium-rich manganese-based solid solution cathode material coated with a hybrid layer and a preparation method thereof. Background technique [0002] Today, lithium-ion batteries have been widely used in some portable electronic devices, such as mobile phones and notebook computers, due to their high voltage, high capacity, good safety performance, rechargeable and non-polluting advantages. However, lithium-ion batteries still have shortcomings, such as low energy density, poor cycle performance and rate performance, which limit their wider application. At present, the specific capacity of positive electrode materials of lithium-ion batteries is lower than that of negative electrode materials, which is a key factor limiting the development of lithium-ion batteries. Therefore, it is imminent to find a cathode material with high energy density. [0003] Lithium-rich ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/36H01M4/505H01M4/525H01M4/62H01M4/131H01M4/1391H01M10/0525
CPCH01M4/131H01M4/1391H01M4/366H01M4/505H01M4/525H01M4/62H01M10/0525H01M2004/028H01M2220/30Y02E60/10
Inventor 李朝晖孙凯玲雷钢铁肖启振
Owner XIANGTAN UNIV
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