Electrode Structure With Variable Thickness Separator Layer

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Solution Overview

Problem

Nonaqueous electrolyte secondary batteries face challenges in achieving high energy density while ensuring safety, as increased discharge capacity per unit weight or volume leads to safety concerns, and all-solid secondary batteries struggle with lithium ion conductivity between electrodes.

Innovation Solution

The electrode structure includes a current collector with an active material layer and a separator layer, where the separator layer has a thicker first region overlapping the active material layer, inhibiting electrode breakage and improving cycle life time properties by maintaining ion conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the discharge capacity per unit weight or unit volume is increased to achieve high energy density, then the energy density is improved, but the safety deteriorates due to flammability risks of organic electrolytic solutions

Engineering Contradiction:
Improveenergy densityVSAvoidsafety
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the physical state of the electrolyte from liquid (organic electrolytic solution) to solid (solid electrolyte), fundamentally altering the safety parameter by eliminating flammability while maintaining ion conductivity for high energy density operation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite structure combining solid electrolyte with positive and negative electrodes, creating an all-solid secondary battery that integrates multiple functions (ion conduction, electrochemical reaction, structural support) into a unified safe system

Inventive Principle:
Principle #40Composite materials

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 proposed electrode structure enhances cycle life time and safety by preventing electrode breakage and undesirable side reactions, thereby achieving excellent performance in secondary batteries.

Implementation Method 1

lithium ion conductivity of the all solid secondary battery tends to be lowered between a positive electrode and a negative electrode

Methodology Applied
Scientific EffectLithium ion conductivity:

Data Source

PatentEP3379607B1Electrode structure, secondary battery, battery pack, and vehicle
Publication Date: 2020.04.08 KK TOSHIBA
  • EP3379607B1 patent drawingFigure 1~2
  • EP3379607B1 patent drawingFigure 3~4
  • EP3379607B1 patent drawingFigure 5

AI summary

According to one approach, an electrode structure (1) is provided. The electrode structure (1) includes a current collector (2), an active material layer (8) provided on at least one surface of the current collector (2), and a separator layer (9) provided on the active material layer (8). The separator layer (9) includes a first region (101), and a second region (102) which is adjacent to the first region (101) and exists in the inside of the first region (101). An outline of a principal surface of the active material layer (8) overlaps the first region (101) of the separator layer (9), and a thickness of at least a part of the first region (101) is thicker than a thickness of the second region (102).