Silicon-Dominant Anode Additives That Bridge Cracks After Pulverization

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Solution Overview

Problem

Conventional battery anodes, particularly those using silicon, face challenges such as high cost, inefficiency, and limited cycle life due to pulverization caused by large volume changes during lithiation and delithiation, leading to electrical isolation and capacity loss.

Innovation Solution

Incorporating conductive structural additives like carbon nanotubes, graphene, and metal polymers into the anode active material layer to enhance electrical conductivity and structural integrity, thereby maintaining connections between cracked regions and reducing pulverization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If silicon is used as the dominant anode material to increase capacity, then the battery energy density is improved, but pulverization occurs due to large volume changes during lithiation and delithiation

Engineering Contradiction:

Improvebattery capacityVSAvoidanode structural integrity

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent employs a flexible polymer binder matrix that can accommodate the large volume changes of silicon during lithiation and delithiation. This flexible matrix prevents pulverization by allowing the anode structure to expand and contract without breaking, while still maintaining electrical connectivity and structural integrity throughout the cycling process.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent creates a composite anode structure where silicon particles are embedded in a polymer binder matrix. This composite approach combines the high capacity of silicon with the flexibility and structural stability of the polymer matrix, allowing the anode to withstand volume changes while maintaining performance.

Inventive Principle:

Principle #40Composite materials

2Reliability

If conventional anode materials are used to maintain structural stability, then pulverization is reduced, but battery cost increases and efficiency decreases

Engineering Contradiction:

Improveanode structural stabilityVSAvoidmanufacturing cost and complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses a polymer binder matrix that can be processed through simple coating and drying operations, replacing complex and expensive conventional anode manufacturing processes. The polymer binder is cost-effective and allows for straightforward fabrication while providing the necessary structural stability.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the binding mechanism from conventional metal-based binders to polymer-based binders, altering the chemical and mechanical properties of the anode structure. This parameter change enables better flexibility, improved adhesion, and simplified manufacturing while maintaining structural stability during cycling.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the anode structure is made more flexible to accommodate volume changes, then pulverization is reduced, but electrical conductivity may decrease

Engineering Contradiction:

Improveresistance to pulverizationVSAvoidelectrical conductivity

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent creates a composite structure where conductive materials are integrated into the polymer binder matrix. This composite approach maintains the flexibility needed to accommodate silicon volume changes while ensuring sufficient electrical conductivity for efficient electron transport throughout the anode structure.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The polymer binder acts as an intermediary between silicon particles, providing both mechanical flexibility to prevent pulverization and electrical conductivity pathways for electron transport. The binder mediates between the conflicting requirements of structural flexibility and electrical conductivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 use of conductive structural additives improves particle-to-particle and particle-to-current-collector conductivity, minimizing capacity loss and enhancing the cycle life and performance of silicon-dominant anodes in lithium-ion batteries.

Implementation Method 1

The use of conductive structural additives improves particle-to-particle and particle-to-current-collector conductivity

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS20230352653A1Method and system for pulverization mitigation additives for silicon dominant anodes

Publication Date: 2023.11.02 ENEVATE CORP

AI summary

Systems and methods for pulverization mitigation additives for silicon dominant anodes may include an electrode including a metal current collector and an active material layer on the current collector. The active material layer may include islands of material separated by cracks, with the islands including, at least, silicon and conductive additives. At least a portion of the additives may extend from within the islands and bridge the cracks of the active material layer. The conductive additives may form a structure providing electrical conductivity between a first island and a second island, or between at least one island and the metal current collector. The additives may include between 1% and 40% of the active material layer. The active material layer may include between 20% to 95% silicon. The conductive additives may include carbon nanotubes and/or graphene sheets.