Mixed lithium-rich positive electrode material and preparation method and application thereof

Abstract

The invention discloses a mixed lithium-rich positive electrode material and a preparation method and application thereof. The mixed lithium-rich positive electrode material is prepared by mixing a layered lithium-rich manganese-based positive electrode material and a lithium-rich disordered rock salt structure positive electrode material, wherein the chemical general formula of the layered lithium-rich manganese-based positive electrode material is xLi2MnO3.(1-x) LiMO2, and x is greater than 0 and less than 1; the chemical general formula of the lithium-rich disordered rock salt structure positive electrode material is Li1 + aTibMcNidO2, wherein 0.1<a<0.3, 0.1<b<0.4, 0.1<c<0.4, 0.2<d<0.4 and a+4b+6c+2d=3. The lithium-rich manganese-based positive electrode material component in the positive electrode material has a typical layered structure, transition metal redox and lattice oxygen redox exist in the charging / discharging process at the same time, and the lithium-rich disordered rock salt structure positive electrode material component has a three-dimensional disordered cation skeleton structure, which can stabilize the oxygen lattices and oxygen variable valence reaction in the lithium-rich oxide positive electrode material, and improve the lithium ion migration capability; the two positive electrode materials generate a specific synergistic effect, advantage complementation is realized, the material consistency is good, the performance is controllable, and the defects in the prior art are overcome.

Description

technical field

[0001] The invention relates to the technical field of lithium ion battery manufacturing, in particular to a mixed lithium-rich positive electrode material and its preparation method and application. Background technique

[0002] Rechargeable batteries have seen tremendous development and progress in commercial applications in recent years, especially in the electric vehicle industry. However, the rapidly advancing technology and society have higher standards and requirements for lithium-ion batteries, and the energy density of current commercial lithium-ion batteries is not enough to meet people's growing needs. The most critical factor and difficulty restricting the development of lithium-ion batteries lies in the positive electrode materials of lithium-ion batteries. In today's positive electrode material research system and practical application, lithium-ion secondary batteries with high energy density are basically ordered structure positive electrode m...

Examples

Embodiment 1

[0054] A mixed Li 1.2 Ni 0.2 mn 0.6 o 2 / Li 1.2 Ti 0.33 Mo 0.13 Ni 0.33 o 2 The lithium-rich positive electrode material, its preparation method comprises the following steps:

[0055] S1. Weigh and mix manganese sulfate and nickel sulfate with a molar ratio of 3:1 according to the composition of the lithium-rich cathode material, add distilled water to make a 2mol / L metal salt solution (the total molar number of transition metals is 2mol), and then weigh 2mol sodium carbonate Prepare a 2mol / L solution, use ammonia water as a complexing agent, slowly add the three solutions into the reaction kettle, react at 55°C for 12 hours at pH = 8, filter to obtain a precipitate, and vacuum dry to obtain a carbonate precursor;

[0056] S2, mix and stir the carbonate precursor and lithium carbonate (the molar ratio of precursor and lithium source: 1:1.05) with absolute ethanol as solvent until the solvent evaporates completely, then transfer the mixture to the crucible, In the Fur...

Embodiment 2

[0064] A mixed Li 1.2 Ni 0.2 mn 0.6 o 2 / Li 1.2 Ti 0.33 Mo 0.13 Ni 0.33 o 2 The lithium-rich positive electrode material, its preparation method comprises the following steps:

[0065] S1. Weigh and mix manganese sulfate and nickel sulfate with a molar ratio of 3:1 according to the composition of the lithium-rich cathode material, add distilled water to make a 2mol / L metal salt solution (the total molar number of transition metals is 2mol), and then weigh 2mol sodium carbonate Prepare a 2mol / L solution, use ammonia water as a complexing agent, slowly add the three solutions into the reaction kettle, react at 55°C for 12 hours at pH = 8, filter to obtain a precipitate, and vacuum dry to obtain a carbonate precursor;

[0066] S2, mix and stir the carbonate precursor and lithium carbonate (the molar ratio of precursor and lithium source: 1:1.05) with absolute ethanol as solvent until the solvent evaporates completely, then transfer the mixture to the crucible, In the Fur...

Embodiment 3

[0074] A mixed Li 1.2 Ni 0.13 co 0.13 mn 0.54 o 2 / Li 1.2 Ti 0.33 Cr 0.13 Ni 0.33 o 2 The lithium-rich positive electrode material, its preparation method comprises the following steps:

[0075] S1. Weigh and mix manganese sulfate, cobalt sulfate and nickel sulfate with a molar ratio of 4:1:1 according to the composition of the lithium-rich positive electrode material, add distilled water to form a 2mol / L metal salt solution (the total molar number of transition metals is 2mol), and then Weigh 2 mol of sodium carbonate to prepare a 2 mol / L solution, use ammonia water as a complexing agent, slowly add the three solutions into the reaction kettle, react at 55°C for 12 hours at pH = 8, filter to obtain a precipitate, and vacuum dry to obtain carbonic acid salt precursor;

[0076] S2, mix and stir the carbonate precursor and lithium carbonate (the molar ratio of precursor and lithium source: 1:1.05) with absolute ethanol as solvent until the solvent evaporates completely...

technical field

[0001] The invention relates to the technical field of lithium ion battery manufacturing, in particular to a mixed lithium-rich positive electrode material and its preparation method and application. Background technique

[0002] Rechargeable batteries have seen tremendous development and progress in commercial applications in recent years, especially in the electric vehicle industry. However, the rapidly advancing technology and society have higher standards and requirements for lithium-ion batteries, and the energy density of current commercial lithium-ion batteries is not enough to meet people's growing needs. The most critical factor and difficulty restricting the development of lithium-ion batteries lies in the positive electrode materials of lithium-ion batteries. In today's positive electrode material research system and practical application, lithium-ion secondary batteries with high energy density are basically ordered structure positive electrode m...

Examples

Embodiment 1

[0054] A mixed Li 1.2 Ni 0.2 mn 0.6 o 2 / Li 1.2 Ti 0.33 Mo 0.13 Ni 0.33 o 2 The lithium-rich positive electrode material, its preparation method comprises the following steps:

[0055] S1. Weigh and mix manganese sulfate and nickel sulfate with a molar ratio of 3:1 according to the composition of the lithium-rich cathode material, add distilled water to make a 2mol / L metal salt solution (the total molar number of transition metals is 2mol), and then weigh 2mol sodium carbonate Prepare a 2mol / L solution, use ammonia water as a complexing agent, slowly add the three solutions into the reaction kettle, react at 55°C for 12 hours at pH = 8, filter to obtain a precipitate, and vacuum dry to obtain a carbonate precursor;

[0056] S2, mix and stir the carbonate precursor and lithium carbonate (the molar ratio of precursor and lithium source: 1:1.05) with absolute ethanol as solvent until the solvent evaporates completely, then transfer the mixture to the crucible, In the Fur...

Embodiment 2

[0064] A mixed Li 1.2 Ni 0.2 mn 0.6 o 2 / Li 1.2 Ti 0.33 Mo 0.13 Ni 0.33 o 2 The lithium-rich positive electrode material, its preparation method comprises the following steps:

[0065] S1. Weigh and mix manganese sulfate and nickel sulfate with a molar ratio of 3:1 according to the composition of the lithium-rich cathode material, add distilled water to make a 2mol / L metal salt solution (the total molar number of transition metals is 2mol), and then weigh 2mol sodium carbonate Prepare a 2mol / L solution, use ammonia water as a complexing agent, slowly add the three solutions into the reaction kettle, react at 55°C for 12 hours at pH = 8, filter to obtain a precipitate, and vacuum dry to obtain a carbonate precursor;

[0066] S2, mix and stir the carbonate precursor and lithium carbonate (the molar ratio of precursor and lithium source: 1:1.05) with absolute ethanol as solvent until the solvent evaporates completely, then transfer the mixture to the crucible, In the Fur...

Embodiment 3

[0074] A mixed Li 1.2 Ni 0.13 co 0.13 mn 0.54 o 2 / Li 1.2 Ti 0.33 Cr 0.13 Ni 0.33 o 2 The lithium-rich positive electrode material, its preparation method comprises the following steps:

[0075] S1. Weigh and mix manganese sulfate, cobalt sulfate and nickel sulfate with a molar ratio of 4:1:1 according to the composition of the lithium-rich positive electrode material, add distilled water to form a 2mol / L metal salt solution (the total molar number of transition metals is 2mol), and then Weigh 2 mol of sodium carbonate to prepare a 2 mol / L solution, use ammonia water as a complexing agent, slowly add the three solutions into the reaction kettle, react at 55°C for 12 hours at pH = 8, filter to obtain a precipitate, and vacuum dry to obtain carbonic acid salt precursor;

[0076] S2, mix and stir the carbonate precursor and lithium carbonate (the molar ratio of precursor and lithium source: 1:1.05) with absolute ethanol as solvent until the solvent evaporates completely...

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