Negative active material and preparation method and application thereof

A negative electrode active material and carbon-based material technology, applied in the field of electrochemistry, can solve the problems of limiting the capacity and power performance of lithium-ion batteries, low volume specific capacity, and low tap density, and achieve battery capacity that is not easily attenuated and has high battery capacity , long service life effect

Inactive Publication Date: 2015-11-11
TSINGHUA UNIV
View PDF3 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the above-mentioned negative electrode materials generally have the disadvantages of low tap density and low volume specific capacity, which limits the capacity and power performance of lithium-ion batteries per unit chip area. In addition, they are also difficult to be compatible with microelectronics manufacturing processes.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Negative active material and preparation method and application thereof
  • Negative active material and preparation method and application thereof
  • Negative active material and preparation method and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0056] The process of preparing negative electrode active materials by template method, such as figure 2 As mentioned, the specific method is as follows:

[0057] (a) Ultrasonically disperse 1.5g of silicon particles with an average particle size of 30-50nm in a system of 200mL of ethanol and 50mL of water, then add 10mL of 28%-30% ammonia water, and add 13.5g of tetraethyl orthosilicate (TEOS) dropwise , continuously stirred for 12 hours, hydrolyzed and oxidized on the surface of silicon particles to generate SiO 2 Layer, centrifuged and washed repeatedly to obtain composite particles;

[0058] (b) Mix the above-mentioned composite particles with 13.5g SU-8 photoresist evenly, and spin-coat on the silicon wafer;

[0059] (c) at 900°C, N 2 Carry out high-temperature carbonization of the material in the environment, and the SU-8 photoresist becomes a self-supporting porous carbon skeleton;

[0060] (d) The obtained material is immersed in 4wt% HF, 46wt% water, 50wt% ethano...

Embodiment 2

[0066] Utilize the negative electrode active material prepared in embodiment 1 to prepare button type half battery, concrete processing method is as follows:

[0067] (1) Get the negative electrode active material of silicon content 35% that the embodiment 1 of 4g prepares as active material, 0.5gSuperP is as conductive agent, 0.5g carboxymethyl cellulose (CMC) is as binding agent, is coated on after being dispersed uniformly placed on a copper foil and dried overnight in a vacuum oven at 80°C.

[0068] (2) the product that step (1) obtains at 100kg / cm 2 Down punched into pieces.

[0069] (3) The products stamped into sheets in step (2) are assembled in the glove box as image 3 The shown CR2025 button battery 1, wherein the above-mentioned material is used as the negative electrode, the lithium disc is used as the positive electrode, and the Celgard film is used as the diaphragm, 1mol / LLiPF 6 Mix solution with EC:DEC:DMC (volume ratio 1:1:1) as electrolyte.

[0070] Accor...

Embodiment 3

[0072] The CR2025 button battery obtained in Example 2 was electrochemically tested on a lithium battery charging and discharging system.

[0073] 1. Charge and discharge experiment

[0074] The button battery 1 with a silicon content of 35% obtained in Example 2 is subjected to a charge and discharge test, as follows:

[0075] (1) Test method

[0076] At room temperature, the button battery 1 was tested on a battery testing system (Newwell, CT-3008W).

[0077] Before the test, the battery needs to be aged for 24 hours to allow the electrolyte to fully infiltrate the electrode material.

[0078] The charge cut-off voltage is set to 1.2V, and the discharge cut-off voltage is set to 0.01V.

[0079] The first three cycles are charged and discharged with a small 0.1C rate (current 0.2mA), and the current is increased by 3 times in the subsequent cycle, and the charge and discharge are performed at a rate of 0.3C, that is, a current of 0.6mA. A total of 30 charge and discharge c...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
particle diameteraaaaaaaaaa
particle sizeaaaaaaaaaa
Login to view more

Abstract

The invention discloses a negative active material and a preparation method and application thereof. The negative active material comprises silica nanoparticles and a carbon-based material layer, wherein the carbon-based material layer is formed on at least part of outer surfaces of the silica nanoparticles, and gaps exist between at least one part of the carbon-based material layer and the outer surfaces of the silica nanoparticles. A battery prepared from the negative active material is high in capacity, good in circularity and long in service life, and is difficult to attenuate.

Description

technical field [0001] The present invention relates to the field of electrochemistry, in particular, to a negative electrode active material and its preparation method and application, more specifically, to a negative electrode active material, a method for preparing the negative electrode active material, a negative electrode and a battery. Background technique [0002] Due to the advantages of high open circuit voltage, high energy density, low self-discharge rate and no pollution, lithium-ion batteries are widely used in electronic equipment, electric transportation, aerospace, military, medical and other fields. The charging and discharging process of lithium-ion batteries is based on the repeated intercalation and deintercalation of lithium ions between the positive and negative electrode materials. At present, commercial lithium-ion batteries mainly use carbon materials as negative electrodes, and graphite is the most widely used due to its layered structure that faci...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/139H01M10/058
CPCH01M4/139H01M4/36H01M4/364H01M10/058Y02E60/10Y02P70/50
Inventor 王晓红李晓钊
Owner TSINGHUA UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap