Plastic-Free Wound Capacitor Stack for High Capacitance and Voltage

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Solution Overview

Problem

Current condensers, such as film and stacked ceramic condensers, face challenges in achieving high electrostatic capacitance and high voltage withstand while being miniaturized and easy to manufacture, with difficulties in controlling capacitance and voltage withstand due to limitations in dielectric materials and manufacturing processes.

Innovation Solution

A winding-type stacked body for a condenser is proposed, comprising a metal layer and a dielectric layer without a plastic film, where the dielectric layer is formed on the metal layer, and a pair of metal layers with dielectric layers are stacked and wound, allowing for high electrostatic capacitance and easy handling and manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If polypropylene film is used as dielectric to achieve low dielectric loss tangent, then dielectric loss tangent is reduced to 0.05% or less, but permittivity becomes very low (about 2.2) making sufficient electrostatic capacitance difficult to obtain

Engineering Contradiction:
Improvedielectric loss tangentVSAvoidelectrostatic capacitance
Core Design Contradiction:
Loss of energyVSQuantity of substance

Solution Approach 1:

The patent changes the dielectric material from polypropylene film (low permittivity) to a sol-gel derived dielectric layer (high permittivity of 50 or more), fundamentally altering the material parameter to simultaneously achieve high capacitance and acceptable loss characteristics

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure combining metal electrode layers with a sol-gel derived dielectric layer, forming a new material system that achieves high permittivity while maintaining manufacturing feasibility and electrical performance

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If polypropylene film is stretched into ultra thin film of 2 μm or less to obtain high capacitance, then electrostatic capacitance increases, but the film becomes susceptible to blocking and breakdown by introversion, unsuitable for high speed winding, and difficult to handle in manufacturing process

Engineering Contradiction:
Improveelectrostatic capacitanceVSAvoidhandling in manufacturing process
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical stretching process with a chemical deposition process (sol-gel method), forming the dielectric layer in-situ on the metal electrode without requiring mechanical manipulation of ultra-thin films, thereby eliminating handling difficulties

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent forms the dielectric layer on the metal electrode before winding, using sol-gel deposition to create a robust initial layer that prevents blocking and breakdown during subsequent high-speed winding operations

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If film condenser structure is used with flexible resin film as dielectric, then manufacturing flexibility is improved, but controlling capacitance and voltage withstand becomes difficult due to low permittivity of the dielectric film

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidcontrol of capacitance and voltage withstand
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent fundamentally changes the dielectric parameter (permittivity) from ~2.2 (polypropylene) to 50 or more (sol-gel derived), enabling precise control of capacitance values while maintaining the flexibility of the film condenser structure

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent adopts the successful film condenser manufacturing approach (metal films on flexible substrate) but replaces the dielectric material with a sol-gel derived layer that copies the flexible form factor while achieving superior electrical properties

Inventive Principle:
Principle #26Copying

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration achieves electrostatic capacitance per unit area that is theoretically 100 times higher, with the flexibility to select materials for the metal and dielectric layers, and eliminates the handling difficulties of ultra-thin plastic films, enabling high voltage withstand and easy manufacturing.

Implementation Method 1

a dielectric layer, and a pair of two metal layers each having the dielectric layer are stacked and wound

Methodology Applied
Scientific EffectDeposition: Deposition (physical)

Implementation Method 2

the electrostatic capacitance C[F] of the condenser is expressed as the following equation 1, in which the electrode area is A[m 2

Methodology Applied
Scientific EffectElectrostatic capacitance: Capacitance

Data Source

PatentEP3091546B1Winding-type stacked body for condenser with high electrostatic capacitance and stacked winding-type condenser using same
Publication Date: 2024.11.13 LG CHEM LTD
  • EP3091546B1 patent drawingFigure 1
  • EP3091546B1 patent drawingFigure 2
  • EP3091546B1 patent drawingFigure 3

AI summary

The purpose of the present invention is to provide a winding-type stacked body for a condenser capable of realizing a high electrostatic capacitance and a high degree of withstand voltage. The purpose is accomplished by a winding-type stacked body for a condenser, comprising a metal layer and a dielectric layer, wherein the dielectric layer exists on the metal layer, two metal layers having the dielectric layers constitute a pair and are stacked and wound to configure the winding-type stacked body, which comprises no plastic film.