Secondary battery negative electrode, secondary battery, and methods for manufacturing these

A secondary battery and manufacturing method technology, applied in electrode manufacturing, battery electrodes, electrode rolling/calendering, etc., can solve the problems of low charging and discharging efficiency, large volume change, easy deformation, etc., and achieve high productivity, high capacity, and energy density. Large, not easy to reduce effect

Active Publication Date: 2020-07-17
THE UNIV OF TOKYO
View PDF12 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For negative electrode active materials, Si and Si compounds that react with more electrons than carbon materials have been developed, but such Si compounds have low charge-discharge efficiency and large irreversible capacity at the beginning of the charge-discharge cycle. In addition, it is said that It has the problems of large volume change and easy deformation accompanying charging and discharging, and has not yet been put into practical use.

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
  • Secondary battery negative electrode, secondary battery, and methods for manufacturing these
  • Secondary battery negative electrode, secondary battery, and methods for manufacturing these
  • Secondary battery negative electrode, secondary battery, and methods for manufacturing these

Examples

Experimental program
Comparison scheme
Effect test

other Embodiment approach

[0138] As other embodiments, it can be listed that: Figure 10 In the predoping apparatus 20 shown, it is a method of increasing the productivity by further expanding the length range of the predoping in the electrolytic solution 5 using a plurality of rollers.

[0139] Figure 11 It is a schematic diagram showing another example of the predoping apparatus 20A that performs the predoping step. This device 20A is a device in which two rollers are arranged horizontally, and the sheet-shaped object provided with the negative electrode active material layer 3 ′ on the current collector 14 travels therebetween, and when it is sandwiched and pressed by the two rollers, the A device for pre-doping with pressurized electrolysis by dripping electrolyte solution from above. For the composition of the device 20A, with Figure 10 The pre-doping device 20 described in 20 is the same, and therefore its details are omitted. It should be noted that this pre-doping device is not limited to...

Embodiment 1

[0150] (Production of secondary battery)

[0151] 7.0 g of Si powder, 1.5 g of acetylene black, and 15 g of a 10% aqueous solution of sodium polyacrylate having an average molecular weight of 450,000 were weighed, and purified water was added and kneaded while uniformly mixing to prepare a mixture. Purified water was further added to this mixture to adjust the viscosity to prepare a negative electrode slurry for coating the negative electrode active material layer. This slurry was coated on a Cu foil having a thickness of 20 μm with a coating thickness of 100 μm and a width of 130 mm using a knife roll coater, and dried at 80° C. Thereafter, by performing roll pressing, coating was performed with a thickness of 30 μm on Cu foil as a current collector. Through the step of forming the negative electrode active material layer, a negative electrode in which the gray negative electrode active material layer 3' containing Si as the active material was provided on the current collec...

Embodiment 2

[0166] (Fabrication of Coated Negative Electrode 2-1)

[0167] Weigh 7.0 g of Si powder, 1.5 g of acetylene black, and 15 g of a 10% solution of N-methylpyrrolidone of polyvinylidene fluoride with an average molecular weight of 50,000, and then add N-methylpyrrolidone to adjust the viscosity to prepare a coating. Negative ink. This ink was applied on a Cu foil having a thickness of 20 μm with a coating thickness of 100 μm and a width of 130 mm using a knife roll coater, and dried at 80° C. Thereafter, by performing roll pressing, a negative electrode active material layer with a thickness of 40 μm was formed on Cu foil as a current collector, and a coated negative electrode 2-1 with Si as an active material and polyvinylidene fluoride as a binder was obtained. .

[0168] (Fabrication of Coated Negative Electrode 2-2)

[0169] 7.0 g of Si powder, 1.5 g of acetylene black, and 5 g of a 50% aqueous solution of a polyacrylonitrile copolymer with an average molecular weight of 2...

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
strengthaaaaaaaaaa
diameteraaaaaaaaaa
thicknessaaaaaaaaaa
Login to view more

Abstract

[Problem] To provide: a secondary battery negative electrode which has a large energy density and in which the capacity is less likely to drop even after undergoing repeated charging and discharging;a secondary battery; and methods for manufacturing these. [Solution] This secondary battery negative electrode comprises a negative electrode collector and a negative electrode active material layer including at least a silicon active material and a binder, and has a structural morphology in which the silicon active material has an amorphous region including lithium, and in which lithium carbonateis distributed in the amorphous region in an island-like manner. This secondary battery negative electrode is manufactured by a method having: a step for forming the negative electrode active material layer which includes a Si active material and a binder; and a pre-doping step for bringing an electrolytic solution containing Li into contact with the negative electrode active material layer, applying pressure thereon, and introducing Li ions by an electrochemical method.

Description

technical field [0001] The present invention relates to a negative electrode for a secondary battery, a secondary battery, and methods for producing them. In more detail, the present invention relates to a negative electrode for a secondary battery through a predoping process of electrochemically introducing Li ions into the negative electrode while applying pressure, a secondary battery, and a method for producing the same, and a method for manufacturing the same. , the energy density is high and the capacity is not easily reduced even if the charge and discharge are repeated. Background technique [0002] With the expansion of the market for mobile phones, portable electronic devices, and the like, higher energy density and higher output are required for batteries used in these devices. In order to meet such demands, a secondary battery obtained by using an alkali metal ion such as Li as a charge carrier and utilizing an electrochemical reaction accompanying charge transf...

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): H01M4/1395H01M4/139H01M4/38H01M4/48H01M4/62
CPCH01M4/1395Y02E60/10H01M2004/027H01M4/0459H01M4/0445H01M4/134H01M4/386H01M4/622H01M10/052H01M4/0435C01B33/06H01M4/0452H01M2004/021H01M2004/028
Inventor 西原宽宫地麻里子佐藤正春
Owner THE UNIV OF TOKYO
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