Layered Lithium Battery Anode Structure for Adhesion and Fast Charging

Solution Overview

Problem

Rechargeable lithium batteries face challenges in achieving high adhesion of the active material layer to the current collector and fast charging performance.

Innovation Solution

A negative electrode for a rechargeable lithium battery is designed with a first and second negative electrode active material layer on the current collector, where the average inclination angle of the first layer is less than that of the second layer, and the porosity of the second layer is greater than that of the first layer, satisfying specific expressions to enhance adhesion and fast-charging capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single-layer negative electrode active material layer is used, then the structure is simple and easy to manufacture, but the adhesion to current collector and fast-charging performance are insufficient

Engineering Contradiction:

Improveadhesion to current collectorVSAvoidstructure of negative electrode

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The negative electrode active material layer is divided into two distinct layers: a first negative electrode active material layer with lower inclination angle (0-30 degrees) that provides strong adhesion to the current collector, and a second negative electrode active material layer with higher inclination angle (30-60 degrees) that enables fast charging. This segmentation allows each layer to be optimized for its specific function, resolving the contradiction between adhesion and fast-charging performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the negative electrode are given different properties through the two-layer structure. The first layer near the current collector has specific inclination angles and porosity optimized for adhesion, while the second layer has different parameters optimized for fast charging. This local differentiation of properties allows simultaneous achievement of both adhesion and fast-charging performance without requiring overall structural complexity.

Inventive Principle:

Principle #3Local quality

2Productivity

If the inclination angle of active material layer is increased to improve fast charging, then ion transport is enhanced, but adhesion to current collector deteriorates

Engineering Contradiction:

Improvefast-charging performanceVSAvoidadhesion to current collector

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The negative electrode active material layer is divided into two distinct layers: a first negative electrode active material layer with lower inclination angle (0-30 degrees) that provides strong adhesion to the current collector, and a second negative electrode active material layer with higher inclination angle (30-60 degrees) that enables fast charging. This segmentation allows each layer to be optimized for its specific function, resolving the contradiction between adhesion and fast-charging performance.

Inventive Principle:

Principle #1Segmentation

3Productivity

If porosity of active material layer is increased to enable fast charging, then ion diffusion is improved, but mechanical strength and adhesion are reduced

Engineering Contradiction:

Improvefast-charging performanceVSAvoidadhesion to current collector

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The negative electrode active material layer is divided into two distinct layers: a first negative electrode active material layer with lower inclination angle (0-30 degrees) that provides strong adhesion to the current collector, and a second negative electrode active material layer with higher inclination angle (30-60 degrees) that enables fast charging. This segmentation allows each layer to be optimized for its specific function, resolving the contradiction between adhesion and fast-charging performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the negative electrode are given different properties through the two-layer structure. The first layer near the current collector has specific inclination angles and porosity optimized for adhesion, while the second layer has different parameters optimized for fast charging. This local differentiation of properties allows simultaneous achievement of both adhesion and fast-charging performance without requiring overall structural complexity.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20260058132A1Negative electrode for rechargeable lithium battery and rechargeable lithium battery including the same

Publication Date: 2026.02.26 SAMSUNG SDI CO LTD

AI summary

A negative electrode for a rechargeable lithium battery and a rechargeable lithium battery including the negative electrode are provided. The negative electrode includes a current collector and a negative electrode active material layer formed on at least one surface of the current collector, wherein the negative electrode active material layer includes a first negative electrode active material layer and a second negative electrode active material layer, which are sequentially arranged on the current collector, and satisfies Expression 1:Average⁢ inclination⁢ angle⁢ of⁢ first⁢ negative⁢ electrode⁢ active⁢ material⁢ layer<Average⁢ inclination⁢ angle⁢ of⁢ second⁢ negative⁢ electrode⁢ active⁢ material⁢ layer. Expression⁢ 1