Lithium manganate composite positive electrode material, a preparing method thereof and a lithium-ion battery

Abstract

The invention provides a lithium manganate composite positive electrode material, a preparing method thereof and a lithium-ion battery. The composite positive electrode material is of a core-shell structure. The inner layer of the composite positive electrode material is an in-situ composite of lithium manganate and nickel-rich concentration gradient type nickel cobalt manganese / lithium aluminate LiMn2O4-LiNi1-x-yCox(Al / Mn)yO2, wherein x is more than 0 and less than or equal to 0.25, and y is more than 0 and less than or equal to 0.15; the outer shell of the composite positive electrode material is a metal oxide coated layer. According to the lithium manganate composite positive electrode material and the preparing method thereof, the in-situ composite of lithium manganate and nickel-rich concentration gradient type nickel cobalt manganese / lithium aluminate is obtained after in-site sintering of a manganese source, a nickel-rich concentration gradient type nickel cobalt manganese / lithium aluminate precursor, and a lithium source, then shell-layer metal oxide is cladded by using spray drying, and finally the composite positive electrode material is obtained by combining a microwave sintering process. The composite positive electrode material provided by the invention has relatively high specific capacity, and excellent high temperature cycling and storage performances.

Description

technical field

[0001] The invention relates to the technical field of lithium-ion batteries, in particular to lithium-ion battery positive electrode materials and lithium-ion battery preparation technology, in particular to a lithium manganate composite positive electrode material and a lithium-ion battery using the positive electrode material as a positive electrode active material. Background technique

[0002] Lithium-ion batteries have many advantages such as high voltage, high energy density, good cycle performance, no memory effect, and low self-discharge. They are widely used in mobile power supplies, various portable electronic devices, high-end digital, electric vehicles and other fields. The corresponding cathode materials play a decisive role in the performance of lithium-ion batteries. For a long time, the development of cathode materials with excellent electrochemical performance, high capacity and good cycle performance has been a research hotspot in lithium-io...

Examples

Embodiment 1

[0054] The design scheme is LiMn 2 o 4 -LiNi 0.65 co 0.25 mn 0.15 o 2 , among them, nickel-rich concentration gradient type nickel-cobalt lithium manganese oxide LiNi 0.65 co 0.25 mn 0.15 o 2 The mass percent content is 15% of the total mass of the composite cathode material. The electrolytic manganese dioxide, nickel-rich concentration gradient nickel-cobalt-manganese carbonate precursor and lithium hydroxide were weighed according to the above ratio, mixed for 1 hour with a three-dimensional mixer, and then calcined in a muffle furnace at 850 °C for 8 hours, with a heating rate of 1°C / min, the entire calcination process is carried out in an oxygen atmosphere with a flow rate of 300ml / min, naturally cooled to room temperature, and after crushing and sieving, the in-situ composite of lithium manganate and nickel-rich concentration gradient nickel-cobalt lithium manganate is obtained The compound was added into 0.05mol / L dilute nitric acid solution and stirred to obtai...

Embodiment 2

[0057] The design scheme is LiMn 2 o 4 -LiNi 0.7 co 0.2 al 0.1 o 2 , among them, nickel-rich concentration gradient nickel-cobalt-aluminate LiNi 0.7 co 0.2 al 0.1 o 2 The mass percentage content is 10% of the total mass of the composite positive electrode material. The electrolytic manganese dioxide, nickel-rich concentration gradient type nickel-cobalt-aluminum hydroxide precursor and lithium hydroxide were weighed according to the above proportions, mixed for 10 hours with a three-dimensional mixer, and then calcined in a muffle furnace at 800 °C for 15 hours. The temperature is 5°C / min, and the whole calcination process is carried out in an oxygen atmosphere with a flow rate of 100ml / min, naturally cooled to room temperature, and after crushing and sieving, the in-situ lithium manganate and nickel-rich concentration gradient type nickel-cobalt aluminum oxide For the composite, the composite is added to 0.2mol / L dilute nitric acid solution and stirred to obtain a su...

Embodiment 3

[0060] The design scheme is LiMn 2 o 4 -LiNi 0.8 co 0.15 al 0.05 o 2 , among them, nickel-rich concentration gradient nickel-cobalt-aluminate LiNi 0.8 co 0.15 al 0.05 o 2 The mass percent content is 5% of the total mass of the composite cathode material. The electrolytic manganese dioxide, nickel-rich concentration gradient type nickel-cobalt-aluminum hydroxide precursor and lithium hydroxide were weighed according to the above proportions, and the mixture of deionized water and absolute ethanol was used as a solvent for ball milling in a high-energy ball mill for 8 hours. Calcined in a muffle furnace at 750°C for 20h, the heating rate is 10°C / min, the whole calcining process is carried out in an oxygen atmosphere with a flow rate of 150ml / min, naturally cooled to room temperature, after crushing and sieving, lithium manganate and rich The in-situ complex of nickel-cobalt-lithium-aluminate with gradient nickel concentration is added to 0.25mol / L dilute nitric acid sol...

technical field

[0001] The invention relates to the technical field of lithium-ion batteries, in particular to lithium-ion battery positive electrode materials and lithium-ion battery preparation technology, in particular to a lithium manganate composite positive electrode material and a lithium-ion battery using the positive electrode material as a positive electrode active material. Background technique

[0002] Lithium-ion batteries have many advantages such as high voltage, high energy density, good cycle performance, no memory effect, and low self-discharge. They are widely used in mobile power supplies, various portable electronic devices, high-end digital, electric vehicles and other fields. The corresponding cathode materials play a decisive role in the performance of lithium-ion batteries. For a long time, the development of cathode materials with excellent electrochemical performance, high capacity and good cycle performance has been a research hotspot in lithium-io...

Examples

Embodiment 1

[0054] The design scheme is LiMn 2 o 4 -LiNi 0.65 co 0.25 mn 0.15 o 2 , among them, nickel-rich concentration gradient type nickel-cobalt lithium manganese oxide LiNi 0.65 co 0.25 mn 0.15 o 2 The mass percent content is 15% of the total mass of the composite cathode material. The electrolytic manganese dioxide, nickel-rich concentration gradient nickel-cobalt-manganese carbonate precursor and lithium hydroxide were weighed according to the above ratio, mixed for 1 hour with a three-dimensional mixer, and then calcined in a muffle furnace at 850 °C for 8 hours, with a heating rate of 1°C / min, the entire calcination process is carried out in an oxygen atmosphere with a flow rate of 300ml / min, naturally cooled to room temperature, and after crushing and sieving, the in-situ composite of lithium manganate and nickel-rich concentration gradient nickel-cobalt lithium manganate is obtained The compound was added into 0.05mol / L dilute nitric acid solution and stirred to obtai...

Embodiment 2

[0057] The design scheme is LiMn 2 o 4 -LiNi 0.7 co 0.2 al 0.1 o 2 , among them, nickel-rich concentration gradient nickel-cobalt-aluminate LiNi 0.7 co 0.2 al 0.1 o 2 The mass percentage content is 10% of the total mass of the composite positive electrode material. The electrolytic manganese dioxide, nickel-rich concentration gradient type nickel-cobalt-aluminum hydroxide precursor and lithium hydroxide were weighed according to the above proportions, mixed for 10 hours with a three-dimensional mixer, and then calcined in a muffle furnace at 800 °C for 15 hours. The temperature is 5°C / min, and the whole calcination process is carried out in an oxygen atmosphere with a flow rate of 100ml / min, naturally cooled to room temperature, and after crushing and sieving, the in-situ lithium manganate and nickel-rich concentration gradient type nickel-cobalt aluminum oxide For the composite, the composite is added to 0.2mol / L dilute nitric acid solution and stirred to obtain a su...

Embodiment 3

[0060] The design scheme is LiMn 2 o 4 -LiNi 0.8 co 0.15 al 0.05 o 2 , among them, nickel-rich concentration gradient nickel-cobalt-aluminate LiNi 0.8 co 0.15 al 0.05 o 2 The mass percent content is 5% of the total mass of the composite cathode material. The electrolytic manganese dioxide, nickel-rich concentration gradient type nickel-cobalt-aluminum hydroxide precursor and lithium hydroxide were weighed according to the above proportions, and the mixture of deionized water and absolute ethanol was used as a solvent for ball milling in a high-energy ball mill for 8 hours. Calcined in a muffle furnace at 750°C for 20h, the heating rate is 10°C / min, the whole calcining process is carried out in an oxygen atmosphere with a flow rate of 150ml / min, naturally cooled to room temperature, after crushing and sieving, lithium manganate and rich The in-situ complex of nickel-cobalt-lithium-aluminate with gradient nickel concentration is added to 0.25mol / L dilute nitric acid sol...