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A high-energy silicon-containing lithium battery and its preparation method

A high-energy, lithium battery technology, applied in battery electrodes, secondary batteries, circuits, etc., can solve the problems of silicon structure damage, easy thermal diffusion, poor safety performance of batteries, etc., to achieve enhanced expansion constraints, ensure cycle performance, Effect of reducing carbon shedding

Active Publication Date: 2021-01-19
广西卓能新能源科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Lithium-ion batteries on the market have many disadvantages such as poor safety performance, low capacity, low capacity per unit volume, low power, and poor cycle performance.
Secondly, the positive electrode materials lithium manganate and lithium iron phosphate of the existing 18650 lithium-ion battery have low specific energy, and the positive electrode material lithium cobalt oxide has a high price. The thickening of the material leads to unstable density of the coating surface, which leads to various problems, such as the qualified rate of the produced products is lower than 90%, the safety performance of the product is poor, the thermal stability of the battery is poor, and the internal short circuit is easy to heat diffusion and explosion. Fire, cycle performance 0.5C / 0.5C charge and discharge is less than 300 cycles, low power performance, low battery discharge platform is 3.6V and other shortcomings
[0005] Silicon carbon or silicon oxygen, as the negative electrode material of lithium battery, has high battery-specific capacity. However, compared with traditional negative electrode active materials, silicon-containing negative electrode materials often suffer from larger bulk capacity during charging and discharging. Changes, resulting in damage to the silicon structure and continued side reactions, reducing the cycle life of the battery

Method used

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  • A high-energy silicon-containing lithium battery and its preparation method
  • A high-energy silicon-containing lithium battery and its preparation method

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preparation example Construction

[0048] A kind of negative electrode active material, its preparation method comprises the following steps:

[0049] 1) Take commercially available SiO powder and add zirconia spheres with a diameter of 10mm to mill for 1 hour, add 25mol% of 200 mesh Mg powder and continue milling for 2 hours, add 1.5M dilute hydrochloric acid, shake for 6 hours, filter, wash the filter residue with water and dry it in vacuum;

[0050] 2) Spread the powder obtained by vacuum drying in step 1) on a vessel, put it into a CVD reaction chamber, introduce argon and gas-phase toluene, and deposit it until the carbon content is 15wt%, and obtain a porous carbon-silicon and / or oxygen-silicon composite Material.

[0051] The present invention also provides a method for preparing the above-mentioned high-energy silicon-containing lithium battery, comprising the following steps:

[0052] Preparation of positive electrode sheet: Preparation of positive electrode sheet: Add N-methylpyrrolidone to the posit...

Embodiment 1

[0055] A positive electrode sheet made of the following components by weight percentage: 98.0% lithium nickel cobalt aluminate, 0.03% single-walled carbon nanotubes, 0.2% graphene and 1.77% polyvinylidene fluoride.

[0056] Add N-methylpyrrolidone to the amount of nickel-cobalt-aluminate lithium, single-walled carbon nanotubes, graphene, and polyvinylidene fluoride. In a double planetary beater, the rotation speed is 48rpm, and the revolution speed is 1700rpm. Slurry under high-speed disperser at a speed of 3500rmp until the viscosity reaches 7000mPa•s to obtain positive electrode slurry, which is coated on a metal aluminum foil with a thickness of 13μm according to the surface density of 485g / ㎡, and dried After reaching a moisture content of ≤0.15%, roll compaction to obtain a positive electrode sheet.

Embodiment 2

[0058] A positive electrode sheet made of the following components by weight percentage: 97.8% nickel-cobalt lithium manganate, 0.03% single-walled carbon nanotubes, 0.3% graphene and 1.87% polyvinylidene fluoride.

[0059] Add N-methylpyrrolidone to the formulated amount of nickel-cobalt lithium manganese oxide, single-walled carbon nanotubes, and polyvinylidene fluoride, and make slurry in a double planetary beater at a stirring speed of 48rpm at a rotation speed and 1700rpm at a revolution speed ; Then disperse in a high-speed disperser at a speed of 4500rmp until the viscosity reaches 7000mPa•s to obtain the positive electrode slurry, and apply the positive electrode slurry on a metal aluminum foil with a thickness of 10μm according to the surface density of 400g / ㎡, and dry until the moisture content≤ After 0.15%, the positive electrode sheet was obtained by rolling compaction.

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Abstract

The invention discloses a high-energy silicon-containing lithium battery, wherein the conductive agent of the positive electrode is 0.02-0.06% single-walled carbon nanotubes and 0.2-0.6% graphene: Thenegative electrode sheet is made of the following ingredients in parts by weight: up to 100% of the negative electrode active material, 0-1% of conductive carbon black, 0.02-0.08% of single-walled carbon nanotubes, 1-2% of CMC and 1.2-2.5% of binder; The negative electrode active material is carbon silicon and / or oxygen silicon, and the gram capacity is more than or equal to 650 mAh / g; The binderis prepared from styrene-butadiene rubber, acrylic acid and PMMA in 5-7: 1: 2-4 by weight ratio. The high-energy silicon-containing lithium battery has better charging and discharging stability, volume expansion resistance, cycle performance and stability under the premise of high energy by optimizing the conductive agent composition of the positive and negative electrodes and optimizing the binder.

Description

technical field [0001] The invention relates to the technical field of secondary batteries, in particular to a high-energy silicon-containing lithium battery and a preparation method thereof. Background technique [0002] With the development of mobile electronic devices, the demand for batteries is increasing, and higher requirements are put forward for the capacity, voltage and service life of batteries. Lithium-ion battery is a secondary battery (rechargeable battery) that mainly relies on lithium ions to move between positive and negative electrodes to work. [0003] 18650 lithium-ion battery is a standard lithium-ion battery model first developed by Japan's SONY, which belongs to lithium-ion secondary batteries. Among them, 18 means a diameter of 18mm, 65 means a length of 65mm, and 0 means a cylindrical battery. 18650 lithium-ion battery products are used in 3C (computer, communication, consumer electronics) electronic products such as notebook power supplies and mob...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/36H01M4/505H01M4/525H01M4/62H01M10/0525
CPCH01M4/364H01M4/505H01M4/525H01M4/623H01M4/625H01M10/0525Y02E60/10
Inventor 刘国壮江利金郭校宇黄定东许欣凡谢永佳黄斌覃兴宁黄光炜
Owner 广西卓能新能源科技有限公司