PTFE Anode Electrolyte Additives for SEI-Mediated Side-Reaction Isolation

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Solution Overview

Problem

Lithium batteries face issues with undesirable side reactions between electroactive negative electrode particles and the polytetrafluoroethylene binder, leading to reduced coulombic efficiency and capacity due to physical and chemical interactions during cycling.

Innovation Solution

Incorporating a functional additive with a bis(trifluoromethanesulfonimide group and a substituted phenyl group in the electrolyte that forms a solid electrolyte interface on the electroactive negative electrode particles during initial charge, isolating them from the polymeric matrix and preventing such interactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If polytetrafluoroethylene binder is used in the negative electrode, then cohesive properties and thermal resistance are improved, but side reactions with electroactive particles occur reducing coulombic efficiency

Engineering Contradiction:

Improvecohesive propertiesVSAvoidcoulombic efficiency

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

A solid electrolyte interface layer is formed as an intermediary between the electroactive negative electrode particles and the polytetrafluoroethylene binder. This interface layer prevents direct physical contact and chemical reactions between the binder and electroactive particles, eliminating the harmful interactions while preserving the cohesive properties provided by the PTFE binder.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The solid electrolyte interface is formed during initial charge of the battery before normal cycling operations begin. This preliminary formation process creates a protective layer that prevents subsequent side reactions between the binder and electroactive particles throughout the battery's service life, improving coulombic efficiency without requiring changes to the electrode composition.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If functional additive is added to electrolyte, then solid electrolyte interface formation is enabled improving coulombic efficiency, but electrolyte complexity increases

Engineering Contradiction:

Improvecoulombic efficiencyVSAvoidelectrolyte composition

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The electrolyte is modified by incorporating a functional additive with specific chemical characteristics (bis(trifluoromethanesulfonimide group and substituted phenyl group) that enables solid electrolyte interface formation. This parameter change in the electrolyte composition allows the desired protective interface to form during initial charge, improving coulombic efficiency while maintaining reasonable electrolyte simplicity through targeted additive selection.

Inventive Principle:

Principle #35Parameter changes

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 solid electrolyte interface enhances coulombic efficiency and extends battery life by preventing side reactions, maintaining robust cohesive properties and improving cycling stability while maintaining high thermal and chemical resistance.

Implementation Method 1

During initial charge of the battery, the functional additive may decompose and form a solid electrolyte interface on surfaces of the electroactive negative electrode particles

Methodology Applied

Scientific EffectDecomposition: Decomposition (biological)

Implementation Method 2

the functional additive may decompose and form a solid electrolyte interface on surfaces of the electroactive negative electrode particles that isolates the electroactive negative electrode particles from physical contact with the polymeric matrix component

Methodology Applied

Scientific EffectSolid electrolyte interface formation: Electrolysis

Implementation Method 3

the solid electrolyte interface may prevent chemical reactions between the electroactive negative electrode particles and the polytetrafluoroethylene in the polymeric matrix component

Methodology Applied

Scientific EffectPhysical isolation: Physical Containment

Data Source

PatentUS20250006990A1Electrolyte additives for solid electrolyte interface formation on polytetrafluoroethylene-containing negative electrodes and batteries including the same

Publication Date: 2025.01.02 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A battery that cycles lithium ions includes a negative electrode and an ionically conductive electrolyte. The negative electrode includes electroactive negative electrode particles embedded in a polytetrafluoroethylene matrix. The electrolyte includes an organic solvent, an inorganic lithium salt, and a functional additive consisting of a chemical compound including a bis(trifluoromethanesulfonimide group and a substituted phenyl group.