Lithium ion battery negative electrode active material, preparation method thereof, negative electrode and battery

A negative electrode active material, lithium ion battery technology, applied in battery electrodes, secondary batteries, circuits, etc., can solve the problems of battery cyclability and initial charge-discharge efficiency, low conductivity of silicon carbon negative electrode, etc.

Active Publication Date: 2017-10-24
BYD CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The invention solves the technical problems of low electrical conductivity of the silicon-carbon negative electrode in the prior art, and unsatisfactory cycleability and initial charge-discharge efficiency of the produced battery, and provides a lithium-ion battery with good cycle performance and high initial charge-discharge efficiency Negative electrode active material, preparation method thereof, negative electrode and battery

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  • Lithium ion battery negative electrode active material, preparation method thereof, negative electrode and battery
  • Lithium ion battery negative electrode active material, preparation method thereof, negative electrode and battery
  • Lithium ion battery negative electrode active material, preparation method thereof, negative electrode and battery

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preparation example Construction

[0044] Preparation method of the present invention can specifically be as follows:

[0045] Step 1. Combine nano-silicon particles with a particle size of 30nm~300nm, the first additive and the first organic carbon source (the mass ratio of nano-silicon particles, the first organic carbon source, and the first additive is 2:8:1~ 8:2:1) After dispersion by ball milling (the ball milling process was carried out under an inert atmosphere in the experiment, no special instructions will be given later), the ball milling time is 4 hours, and the ball milling speed is 230r / min. Under an inert atmosphere, the temperature was raised at 2°C / min, and the temperature was kept at 500°C~1200°C for 2h. After cooling down to room temperature, it was pulverized by ball milling at 210r / min for 40min to obtain silicon-carbon composite particles with a particle size of 0.5μm~10μm, marked as A.

[0046] Step 2. Combine the second organic carbon source, the second auxiliary agent and the porogen (...

Embodiment 1

[0055] Step 1, the nano-silicon particles (particle size 100nm), phenolic resin and carbon nanotubes (the mass ratio of nano-silicon particles, phenolic resin, carbon nanotubes is 2:8:1, the total dosage is 165g) through ball milling (in the experiment The ball milling process is all carried out under a nitrogen atmosphere, and there will be no special instructions in the follow-up) After dispersion, the ball milling time is 4 hours, and the ball milling speed is 230r / min. Place in an atmosphere furnace, bake under the protection of nitrogen, heat up at 2°C / min, and keep at 500°C for 2h. After cooling down to room temperature, it was pulverized by ball milling at 210 r / min for 40 min to obtain silicon-carbon composite particles with a particle size of 5 μm, and the product was marked as A1.

[0056] Step 2. Mix nano-silica (particle size 30~40nm), pitch and carbon nanotubes (the mass ratio of nano-silica, pitch, and carbon nanotubes is 30:10:1, and the total dosage is 155g), a...

Embodiment 2

[0064] Step 1, the nano-silicon particles (particle size 100nm), phenolic resin and carbon nanotubes (the mass ratio of nano-silicon particles, phenolic resin and carbon nanotubes is 10:20:1, the total dosage is 165g) through ball milling (in the experiment The ball milling process is all carried out under a nitrogen atmosphere, and there will be no special instructions in the follow-up) After dispersion, the ball milling time is 4 hours, and the ball milling speed is 230r / min. Place in an atmosphere furnace, bake under the protection of nitrogen, heat up at 2°C / min, and keep at 700°C for 2h. After cooling down to room temperature, it was ball milled at 210 r / min for 40 minutes to obtain silicon-carbon composite particles with a particle size of 2 μm, and the product was marked as A2.

[0065] Step 2. After ball milling and dispersing nano-calcium carbonate (particle size 80nm), pitch and carbon nanotubes (the mass ratio of nano-silicon dioxide, pitch, and carbon nanotubes is ...

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Abstract

The invention provides a lithium ion battery negative electrode active material. The lithium ion battery negative electrode active material has a three-layer composite structure and comprises an inner core, an intermediate layer and an outermost layer, wherein the inner core is silicon carbon composite particles, the intermediate layer is a porous carbon layer, and the outermost layer is a compact carbon layer. The invention also provides a preparation method of the lithium ion battery negative electrode active material, a negative electrode comprising the negative electrode active material and a battery. By the lithium ion battery negative electrode active material, the technical problems that the volume of nanometer silicon particles in the silicon carbon negative electrode lithium ion battery in the prior art is expanded and the electrical conductivity is reduced are solved, meanwhile, an electrolyte can be effectively isolated by the compact carbon layer of the prepared negative electrode material, the electrolyte invasion is prevented, and the initial efficiency and the cycle property of the battery are improved.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a lithium ion battery negative electrode active material, a preparation method thereof, a negative electrode and a battery. Background technique [0002] With the rapid development of electric vehicles, there is an increasingly urgent demand for high specific capacity, long cycle life and high safety power lithium-ion batteries. Among the anode materials for lithium-ion batteries, silicon has attracted extensive attention from researchers for its incomparable capacity advantages (theoretical specific capacity is as high as 4200mAh·g-1) and high safety. However, the volume expansion of the silicon-based negative electrode is as high as 300% during the cycle, which is easy to cause material pulverization and loss of electrical contact with the current collector, resulting in a rapid decline in its cycle performance. At present, the methods to solve the shortcomings of silicon ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/583H01M10/0525
CPCH01M4/366H01M4/38H01M4/583H01M10/0525Y02E60/10
Inventor 朱光耀刘会权
Owner BYD CO LTD
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