Alternating Silicon-Graphite Anode Layout for Swelling Control

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Solution Overview

Problem

Rechargeable lithium-ion batteries face challenges in maintaining structural integrity and cycling capacity due to the swelling of silicon anode materials during charge-discharge cycles, leading to delamination and disintegration of the negative electrode.

Innovation Solution

The anode features an active layer with alternating layers of graphite and silicon-based materials, arranged in a specific pattern to constrain silicon swelling and ensure reliable adhesion to the current collector, thereby enhancing structural integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If silicon-based materials are used in the anode to increase capacity, then the energy storage capacity is improved, but the structural integrity deteriorates due to swelling during charge-discharge cycles

Engineering Contradiction:

Improveenergy storage capacityVSAvoidstructural integrity

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The anode active layer is divided into multiple discrete sections arranged in an alternating pattern, with silicon-based material sections interspersed with graphite-based material sections. This segmentation prevents uniform swelling across the entire anode, allowing localized volume changes while maintaining overall structural integrity and adhesion to the current collector.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the anode are assigned different material properties: silicon-based sections provide high capacity where needed, while graphite-based sections provide dimensional stability. This local differentiation allows the anode to simultaneously achieve high energy storage capacity and maintain structural integrity during cycling.

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If silicon-based materials are used to increase capacity, then the energy storage capacity is improved, but the adhesion to current collector deteriorates due to delamination

Engineering Contradiction:

Improveenergy storage capacityVSAvoidadhesion to current collector

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The anode is segmented into alternating silicon-based and graphite-based sections, where graphite sections act as anchor points that maintain adhesion to the current collector. This segmentation prevents continuous delamination that would occur in pure silicon anodes, while still allowing silicon sections to provide high capacity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Graphite-based material sections serve as intermediary elements between the silicon-based sections and the current collector. These graphite sections maintain stable adhesion to the current collector and provide a buffer that prevents direct mechanical stress transmission from swelling silicon to the current collector interface, thereby preventing delamination.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Quantity of substance

If pure silicon is used to maximize capacity, then the energy storage capacity is improved, but the cycling life deteriorates due to disintegration

Engineering Contradiction:

Improveenergy storage capacityVSAvoidcycling life

Core Design Contradiction:

Quantity of substanceVSDuration of action of stationary object

Solution Approach 1:

The anode active layer is segmented into alternating sections of silicon-based material and graphite-based material. This segmentation distributes the mechanical stress of swelling and contracting across multiple discrete regions, preventing the cumulative damage that leads to disintegration in pure silicon anodes, thereby extending cycling life.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The anode employs a composite structure combining silicon-based materials (for high capacity) with graphite-based materials (for structural stability). This composite approach leverages the advantages of both materials: silicon provides high energy storage capacity while graphite provides dimensional stability and resistance to disintegration during extended cycling.

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

This configuration allows for repeated intercalation and deintercalation of lithium ions, significantly increasing the number of charge-discharge cycles while maintaining structural integrity and cycling capacity.

Implementation Method 1

The active layer is configured to intercalate transient ions during charging of the battery cell and de-intercalate the transient ions during discharging of the battery cell

Methodology Applied

Scientific EffectIntercalation: Absorption (physical)

Data Source

PatentUS20250029973A1Battery anode with alternating active layers

Publication Date: 2025.01.23 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

An anode for a rechargeable battery cell includes an electrode substrate and a current collector fixed to the electrode substrate. The anode also includes an active layer arranged on the current collector and having discrete first material sections and at least one second material section arranged in an alternating pattern. Each discrete material section is aligned parallel to the current collector. The active layer is configured to intercalate transient ions during charging of the battery cell and de-intercalate the transient ions during discharging of the battery cell. A method of manufacturing such an anode for a rechargeable battery cell is also considered.