Electrode Mixed Phase Interface for Battery Delamination

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Solution Overview

Problem

Existing electricity-storing devices, such as wound-electrode batteries and electrochemical capacitors, face issues with delamination or loss of short circuit prevention layers and active material layers during manufacturing and use, leading to potential short circuits and heat generation.

Innovation Solution

A high-resistance layer is formed on the current collector foil adjacent to the active material layer, with a mixed phase interface to enhance bonding and prevent delamination, comprising inorganic and organic microparticles and a binder, which has a higher electrical resistance than the active material layer to suppress short circuits and abnormal heat generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a short circuit prevention layer is provided adjacent to the active material layer, then short circuit prevention is improved, but delamination or loss of the layer occurs during manufacturing and use

Engineering Contradiction:
Improveshort circuit preventionVSAvoidlayer adhesion
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention changes the physical-chemical parameters at the interface between layers by creating a mixed phase region where inorganic and organic components intermingle. This mixed phase, formed by controlling the application process so that the high-resistance layer paste contacts the active material layer before complete drying, creates strong intermolecular forces and chemical bonding that prevent delamination while maintaining short circuit prevention functionality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure at the layer interface where inorganic microparticles (from the high-resistance layer) and organic components (from the active material layer) form a mixed phase. This composite interface combines the adhesion benefits of organic materials with the structural stability of inorganic particles, preventing layer separation while maintaining electrical insulation properties.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If the high-resistance layer is formed with strong bonding to prevent delamination, then layer stability is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvelayer adhesionVSAvoidmanufacturing process
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The invention performs preliminary action by applying the high-resistance layer paste to the current collector foil before the active material layer is completely dried. This timing allows the paste to contact and bond with the still-moist active material layer, creating strong adhesion through intermolecular forces and chemical bonding during the drying process itself, rather than requiring separate bonding steps afterward.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention merges the adhesion promotion function with the short circuit prevention function into a single high-resistance layer application step. By applying the high-resistance layer paste before complete drying of the active material layer, the layer simultaneously achieves strong bonding (through mixed phase formation) and electrical insulation (through the high-resistance material), eliminating the need for separate adhesion treatment steps.

Inventive Principle:
Principle #5Merging (Combining)

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

The solution significantly reduces the tendency for delamination and loss of the high-resistance and active material layers, thereby enhancing the stability and reliability of the electricity-storing devices during manufacturing and use.

Implementation Method 1

a high-resistance layer formed on the at least one surface of the current collector foil so as to be adjacent to and in direct contact with the active material layer... which has a higher electrical resistance than the active material layer to suppress short circuits

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Implementation Method 2

at at least a portion of an interface between the active material layer and the high-resistance layer, a mixed phase is formed where constituents from the two layers intermingle

Methodology Applied
Scientific EffectIntermingling of constituents forming mixed phase: Diffusion

Data Source

PatentEP2450989B1Electrode for electricity-storing device, electricity-storing device employing such electrode, and method of manufacturing electrode for electricity-storing device
Publication Date: 2017.11.29 GS YUASA INT LTD
  • EP2450989B1 patent drawingFigure 1
  • EP2450989B1 patent drawingFigure 2
  • EP2450989B1 patent drawingFigure 3

AI summary

PROBLEM: To provide an electricity-storing device and an electrode for an electricity-storing device which, during manufacture and use, have less tendency to experience delamination or loss at active material layer(s) and/or layer(s) provided for short circuit prevention or serving other function(s). SOLUTION MEANS: Electricity-storing device electrode 10 comprises current collector foil 11; active material layer 12 formed on at least one surface of current collector foil 11; and high-resistance layer 40 formed on surface(s) of current collector foil 11 so as to be adjacent to and in direct contact with active material layer 12; wherein, at at least a portion of interface 50 between active material layer 12 and high-resistance layer 40, mixed phase 51 is formed where constituents from the two layers 12, 40 intermingle. By causing mixed phase 51 to be present at interface 50 between active material layer 12 and high-resistance layer 40, the bond between the two adjacent layers 12, 40 is made strong.