A method for preparing lithium-ion battery carbon fiber/antimony sulfide composite negative electrode

Abstract

The invention discloses a method for preparing a lithium-ion battery carbon fiber / antimony sulfide composite negative electrode, which can directly use natural stibnite as an electrode active material, carbon fiber as a conductive matrix, and synthesize nano-scale antimony sulfide-coated carbon fiber substrates by fusion. Negative electrode material, this structure effectively releases the stress change inside the antimony sulfide grains during the lithium intercalation process, and at the same time shortens the Li + And the path of electron transmission inside the material, the carbon fiber matrix provides an excellent conductive network for the composite material, and because the natural stibnite can be used as the direct raw material of the electrode active material, the metallurgical purification process with high energy consumption and high pollution is removed; Preparation of nanocomposites by solid-phase mixing and melting method, which eliminates the waste disposal process.

Description

technical field

[0001] The invention relates to the technical field of lithium ion batteries, in particular to a method for preparing a carbon fiber / antimony sulfide composite negative electrode of a lithium ion battery. Background technique

[0002] In lithium-ion batteries, the performance of electrode materials directly determines the energy density, service life and sales price of the battery. As one of the main bodies of lithium storage, the comprehensive performance of the negative electrode is very important. When graphite materials are used as negative electrodes, they have the advantages of stable structure, high first efficiency, and good electrical conductivity. However, its low theoretical specific capacity can no longer meet the needs of the future market for high specific energy lithium-ion batteries. Among many new anodes, antimony sulfide has attracted extensive attention of researchers due to its high theoretical specific capacity, moderate plateau potenti...

Examples

Embodiment 1

[0023] Weigh stibnite and carbon fiber according to the mass ratio of 1:1, add them to the ball milling tank, add ball milling beads according to the mass ratio of balls to material 20:1, and add ball milling media according to the mass ratio of alcohol to material 2:1. Start the ball mill, ball mill at 450r / min for 4 hours, and filter and dry after stopping to obtain the mixture. figure 1 It is a scanning electron microscope picture of the carbon fiber conductive matrix used, it can be seen that the diameter of the carbon fiber is 50-150 nm, and the length is 1-10 μm.

[0024] Place the above dry mixture in an argon atmosphere, raise the temperature to 620°C at 3°C / min, and keep it warm for 5 hours. After natural cooling, the molten stibnite adheres to the carbon fiber and recrystallizes to form nano-sized antimony sulfide grains , and thus obtain a carbon fiber@stibnite composite anode.

[0025] figure 2 The scanning electron microscope image of the carbon fiber@stibnite ...

Embodiment 2

[0028] Weigh high-purity antimony sulfide and carbon fiber according to the mass ratio of 80:20, add them to the ball milling tank, add ball milling beads according to the mass ratio of balls to material 15:1, ball mill in air medium at 600r / min for 1h, filter and dry after stopping, and obtain Mixture.

[0029] Place the above dry mixture in an argon atmosphere, raise the temperature to 580°C at 1°C / min, and keep it warm for 10 hours. After natural cooling, the molten stibnite adheres to the carbon fiber and recrystallizes to form nano-sized antimony sulfide grains , and thus obtain a carbon fiber@stibnite composite anode.

Embodiment 3

[0031] Weigh stibnite and carbon fiber according to the mass ratio of 10:90, add them to the ball milling tank, add ball milling beads according to the mass ratio of balls to material 20:1, ball mill in argon medium at 400r / min for 5h, filter and dry after stopping, and obtain Mixture.

[0032] Place the above dry mixture in an argon atmosphere, raise the temperature to 650°C at 10°C / min, and keep it warm for 5 hours. After natural cooling, the molten stibnite adheres to the carbon fiber and recrystallizes to form nano-sized antimony sulfide grains , and thus obtain a carbon fiber@stibnite composite anode.

technical field

[0001] The invention relates to the technical field of lithium ion batteries, in particular to a method for preparing a carbon fiber / antimony sulfide composite negative electrode of a lithium ion battery. Background technique

[0002] In lithium-ion batteries, the performance of electrode materials directly determines the energy density, service life and sales price of the battery. As one of the main bodies of lithium storage, the comprehensive performance of the negative electrode is very important. When graphite materials are used as negative electrodes, they have the advantages of stable structure, high first efficiency, and good electrical conductivity. However, its low theoretical specific capacity can no longer meet the needs of the future market for high specific energy lithium-ion batteries. Among many new anodes, antimony sulfide has attracted extensive attention of researchers due to its high theoretical specific capacity, moderate plateau potenti...

Examples

Embodiment 1

[0023] Weigh stibnite and carbon fiber according to the mass ratio of 1:1, add them to the ball milling tank, add ball milling beads according to the mass ratio of balls to material 20:1, and add ball milling media according to the mass ratio of alcohol to material 2:1. Start the ball mill, ball mill at 450r / min for 4 hours, and filter and dry after stopping to obtain the mixture. figure 1 It is a scanning electron microscope picture of the carbon fiber conductive matrix used, it can be seen that the diameter of the carbon fiber is 50-150 nm, and the length is 1-10 μm.

[0024] Place the above dry mixture in an argon atmosphere, raise the temperature to 620°C at 3°C / min, and keep it warm for 5 hours. After natural cooling, the molten stibnite adheres to the carbon fiber and recrystallizes to form nano-sized antimony sulfide grains , and thus obtain a carbon fiber@stibnite composite anode.

[0025] figure 2 The scanning electron microscope image of the carbon fiber@stibnite ...

Embodiment 2

[0028] Weigh high-purity antimony sulfide and carbon fiber according to the mass ratio of 80:20, add them to the ball milling tank, add ball milling beads according to the mass ratio of balls to material 15:1, ball mill in air medium at 600r / min for 1h, filter and dry after stopping, and obtain Mixture.

[0029] Place the above dry mixture in an argon atmosphere, raise the temperature to 580°C at 1°C / min, and keep it warm for 10 hours. After natural cooling, the molten stibnite adheres to the carbon fiber and recrystallizes to form nano-sized antimony sulfide grains , and thus obtain a carbon fiber@stibnite composite anode.

Embodiment 3

[0031] Weigh stibnite and carbon fiber according to the mass ratio of 10:90, add them to the ball milling tank, add ball milling beads according to the mass ratio of balls to material 20:1, ball mill in argon medium at 400r / min for 5h, filter and dry after stopping, and obtain Mixture.

[0032] Place the above dry mixture in an argon atmosphere, raise the temperature to 650°C at 10°C / min, and keep it warm for 5 hours. After natural cooling, the molten stibnite adheres to the carbon fiber and recrystallizes to form nano-sized antimony sulfide grains , and thus obtain a carbon fiber@stibnite composite anode.

Images