Layered Battery Electrode Binder Layout for Adhesion and High-Rate Output

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Solution Overview

Problem

Lithium secondary batteries face issues with adhesion force between the electrode and the active material layer, leading to increased resistance on the outer interface of the active material layer, which deteriorates battery performance.

Innovation Solution

The development of an electrode with multiple active material layers, where at least one layer includes a binder with a specific content range of 1.0 to 1.7 parts by weight based on 100 parts by weight of the total active material layers, to enhance adhesion and reduce interfacial resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the binder content is increased to improve adhesion force between the current collector and the active material layer, then the adhesion force increases, but the resistance on the upper interface of the active material layer increases and battery characteristics at high rate deteriorate

Engineering Contradiction:

Improveadhesion force between current collector and active material layerVSAvoidbattery characteristics at high rate

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The active material layer is divided into multiple layers (first active material layer and second active material layer) with different binder contents. The first layer near the current collector has higher binder content for strong adhesion, while the second layer has lower binder content for low resistance and high rate performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the active material layer have different binder contents tailored to their specific functions. The region near the current collector (first layer) has higher binder content for adhesion, while the region away from the collector (second layer) has lower binder content for electrical performance.

Inventive Principle:

Principle #3Local quality

2Reliability

If the binder content is decreased to reduce resistance on the upper interface of the active material layer, then the resistance decreases, but the adhesion force between the current collector and the active material layer decreases

Engineering Contradiction:

Improvebattery characteristics at high rateVSAvoidadhesion force between current collector and active material layer

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The active material layer is segmented into multiple layers with different binder contents. The first layer near the current collector contains sufficient binder for adhesion, while the second layer has reduced binder for low resistance, achieving both requirements simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The binder content is locally optimized: higher concentration near the current collector for adhesion strength, and lower concentration away from the collector for reduced resistance and improved high rate characteristics.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12211994B2Electrode and lithium secondary battery comprising same

Publication Date: 2025.01.28 SAMSUNG SDI CO LTD

AI summary

Provided an electrode for secondary batteries, the electrode including: a substrate; and a plurality of active material layers arranged on the substrate and each including an active material, wherein at least one of the plurality of active material layers includes a binder, and a content of the binder is about 1.0 part by weight to about 1.7 parts by weight based on 100 parts by weight of a total weight of the plurality of active material layers.