LSO Negative Electrode Polymer Barrier for Stable Aqueous Processing

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Solution Overview

Problem

Existing methods for manufacturing negative electrodes for lithium-ion batteries using silicon oxide-based electroactive materials face challenges such as undesirable chemical reactions with solvents, leading to reduced specific capacity and adhesion issues.

Innovation Solution

A method involving the deposition of a precursor mixture on a substrate, comprising lithiated silicon suboxide (LSO) material, a polymer binder, a functional polymer with acidic functional groups, and an aqueous solvent. The functional polymer reacts with the LSO material to neutralize the pH and form a physical barrier, preventing chemical reactions with the solvent.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If silicon oxide-based electroactive materials are used in negative electrodes, then theoretical specific capacity is improved, but undesirable chemical reactions with solvents occur leading to reduced specific capacity and adhesion issues

Engineering Contradiction:

Improvespecific capacityVSAvoidadhesion and chemical stability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

A functional polymer coating is applied to the silicon oxide-based electroactive material to act as an intermediary layer. This coating prevents direct contact and chemical reactions between the electroactive material and the solvent, while maintaining lithium ion transport. The polymer binder also serves as a mediator to improve adhesion between the electrode components and the current collector, resolving both the chemical stability and adhesion issues.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The negative electrode is designed as a composite structure combining silicon oxide-based electroactive material with polymer binder and functional polymer coating. This composite approach allows the system to benefit from the high specific capacity of silicon oxide while the polymer components provide chemical stability, adhesion, and solvent resistance, thus resolving the contradiction between capacity and reliability.

Inventive Principle:

Principle #40Composite materials

2Reliability

If polymer binder and solvent are selected to avoid chemical reactions with electroactive material, then chemical stability is improved, but solubility of polymer binder in solvent may be compromised

Engineering Contradiction:

Improvechemical stabilityVSAvoidsolubility of polymer binder

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The system uses different polymer components with tailored properties: the functional polymer coating is designed to be insoluble or less soluble in the solvent to provide stable protective function, while the polymer binder is selected to have appropriate solubility for slurry preparation and processing. This local differentiation of polymer properties allows the system to achieve both chemical stability and ease of manufacture.

Inventive Principle:

Principle #3Local quality

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 improves the adhesion of the negative electrode to the substrate, reduces undesirable chemical reactions, and maintains the specific capacity of the battery, leading to enhanced cycling stability and safety.

Implementation Method 1

The functional polymer comprises an acidic functional group formulated to react with the basic compound in the LSO material to neutralize the pH of the precursor mixture

Methodology Applied

Scientific EffectpH neutralization reaction: Chemical Bonding

Implementation Method 2

the lithium salt of the functional polymer may be configured to deposit on surfaces of the LSO material to form a physical barrier that prevents chemical reactions from occurring between the LSO material and the aqueous solvent

Methodology Applied

Scientific EffectPhysical barrier formation: Deposition (physical)

Implementation Method 3

The aqueous solvent is removed from the precursor layer to form the negative electrode on the substrate

Methodology Applied

Scientific EffectSolvent removal: Evaporation

Data Source

PatentUS20250167214A1Methods of manufacturing lithiated silicon oxide-containing negative electrodes including functional polymers and batteries that cycle lithium ions including the same

Publication Date: 2025.05.22 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A battery that cycles lithium ions includes a negative electrode comprising an electroactive material comprising a lithiated silicon suboxide (LSO) material, a polymer binder, and a functional polymer. The negative electrode is manufactured from a precursor mixture including an electroactive material comprising a lithiated silicon suboxide (LSO) material, a polymer binder, a functional polymer, and an aqueous solvent. The LSO material includes a basic compound, and the functional polymer includes an acidic functional group formulated to react with the basic compound in the LSO material to neutralize the pH of the precursor mixture. The precursor mixture is deposited on a substrate to form a precursor layer, and then the aqueous solvent is removed from the precursor layer to form the negative electrode on the substrate.