Positive Electrode Binder Composition for Ambient-Temperature Processing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for manufacturing composite electrodes for lithium-ion batteries often require high temperatures and use petrochemical solvents, which can be inefficient and environmentally unfriendly.

Innovation Solution

The use of a polymer binder mixture comprising a PVDF homopolymer and a copolymer, such as poly(vinylidene fluoride-co-tetrafluoroethylene), in combination with green solvents like γ-valerolactone, to manufacture composite electrodes at ambient temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional manufacturing methods are used, then electrodes can be produced, but high temperatures and petrochemical solvents are required which are inefficient and environmentally unfriendly

Engineering Contradiction:

Improveenvironmental friendlinessVSAvoidmanufacturing process complexity

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent changes the chemical composition parameters of the binder system by introducing a copolymer with specific fluorinated side chains that have high affinity for green solvents like γ-valerolactone. This compositional modification enables dissolution at ambient temperatures without requiring harsh petrochemical solvents or high temperature processing, thus resolving the contradiction between environmental friendliness and manufacturing ease.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite binder system comprising PVDF homopolymer combined with a copolymer containing perfluorinated side chains. This composite material approach creates synergistic effects where the copolymer's fluorinated groups enhance solvent interaction while the PVDF provides structural integrity, enabling the use of environmentally friendly solvents without compromising electrode manufacturing quality.

Inventive Principle:

Principle #40Composite materials

2Reliability

If PVDF homopolymer is used as binder, then good electrochemical performance is achieved, but solubility in green solvents is poor requiring high temperatures

Engineering Contradiction:

Improveelectrochemical performanceVSAvoidprocessing temperature

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The copolymer acts as an intermediary substance between the PVDF homopolymer and the green solvent. Its perfluorinated side chains serve as molecular mediators that enhance the interaction between PVDF and environmentally friendly solvents like γ-valerolactone, enabling dissolution at ambient temperatures while preserving the electrochemical performance provided by PVDF.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the thermal processing parameters by changing the binder composition to include copolymer components with lower thermal processing requirements. This compositional parameter change allows the electrode slurry to be processed at ambient temperatures, eliminating the need for high temperature drying or curing steps while maintaining PVDF's electrochemical functionality.

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

This method allows for the efficient and environmentally friendly production of composite electrodes at lower temperatures, improving the solubility and processing of PVDF homopolymer, and enhancing the performance and sustainability of lithium-ion batteries.

Implementation Method 1

The copolymer has the formula (1) where R1 is F or a perfluorinated alkyl group, and X is an acidic functional group. The copolymer may comprise poly(vinylidene fluoride-co-tetrafluoroethylene) (PVDF-TFE), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). This molecular structure enables improved solubility in green solvents like γ-valerolactone at ambient temperatures.

Methodology Applied

Scientific EffectSolubility enhancement through copolymer structure: Solvation

Implementation Method 2

The polymer binder mixture comprises a polyvinylidene fluoride (PVDF) homopolymer and a copolymer. The PVDF homopolymer may have a molecular weight of greater than or equal to 500 kilodaltons and less than or equal to 1500 kilodaltons. The binder mixture constitutes, by weight, greater than or equal to 0.5% and less than or equal to 5% of the positive electrode, providing structural integrity and particle adhesion.

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS20250192180A1Positive electrodes comprising vinylidene fluoride and perfluorinated olefin copolymer-containing binders for batteries that cycle lithium ions

Publication Date: 2025.06.12 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A battery that cycles lithium ions includes a positive electrode including an electroactive positive electrode material and a polymer binder mixture. The polymer binder mixture includes a polyvinylidene fluoride (PVDF) homopolymer and a copolymer including vinylidene fluoride (VDF) monomers and at least one perfluorinated olefin monomer. The positive electrode may be manufactured by depositing a precursor mixture on a substrate at a temperature of less than or equal to 30 degrees Celsius to form a precursor layer. The precursor mixture may include the electroactive positive electrode material, the polymer binder mixture, and an organic solvent comprising γ-valerolactone, dihydrolevoglucosenone, cyclopentanone, or a combination thereof. The organic solvent may be removed from the precursor layer to form the positive electrode on the substrate.