All-Solid-State Battery Cathode Binder Blend for Stronger Adhesion

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing all-solid-state batteries face challenges in achieving high adhesion between the positive electrode current collector and the positive electrode active material layer, leading to potential stability and electrochemical performance issues.

Innovation Solution

Incorporating a positive electrode active material layer with a sulfide-based solid electrolyte, a fluorine-based binder, and an acrylate-based binder in a non-polar solvent, enhancing adhesion and stability through a specific manufacturing process involving slurry preparation and coating on the current collector.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a conventional binder is used in the positive electrode, then the manufacturing process is simple, but the adhesion between the positive electrode current collector and the positive electrode active material layer is insufficient

Engineering Contradiction:

Improveadhesion between current collector and active material layerVSAvoidbinder composition complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent uses a composite binder system comprising both a fluorine-based binder and a carboxylic acid-based binder. The fluorine-based binder provides baseline adhesion and electrochemical stability, while the carboxylic acid-based binder enhances interfacial bonding through chemical interactions with the sulfide-based solid electrolyte. This composite approach resolves the contradiction by achieving superior adhesion strength without sacrificing manufacturing feasibility.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent optimizes the weight ratio of the fluorine-based binder to carboxylic acid-based binder within specific ranges (0.5:99.5 to 49.5:50.5). By adjusting these compositional parameters, the invention achieves optimal adhesion strength while maintaining manufacturing simplicity. The controlled parameter changes allow tuning of binder performance to match specific application requirements.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a single non-aqueous binder is used, then the manufacturing process is simpler, but the electrochemical stability and performance are insufficient

Engineering Contradiction:

Improveelectrochemical stabilityVSAvoidbinder system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines a fluorine-based binder (providing electrochemical stability and compatibility with sulfide electrolytes) with a carboxylic acid-based binder (providing enhanced interfacial adhesion and stability). This composite binder system achieves superior electrochemical reliability by leveraging the complementary strengths of both binder types, resolving the contradiction between reliability and complexity.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The carboxylic acid-based binder acts as an intermediary between the fluorine-based binder and the sulfide-based solid electrolyte, forming a stable interfacial layer that enhances overall electrochemical stability. This intermediary role allows the system to achieve high reliability while maintaining a manageable binder system complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Strength

If aqueous binders are used, then the binder provides good adhesion, but the all-solid-state battery safety is compromised due to flammable organic dispersion mediums

Engineering Contradiction:

Improveadhesion strengthVSAvoidfire or explosion risk

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent transitions from aqueous binder systems to non-aqueous binder systems by changing the fundamental chemical composition parameters. The fluorine-based and carboxylic acid-based binders are formulated to provide adhesion strength comparable to or exceeding aqueous systems while eliminating the flammability hazard associated with organic dispersion mediums, thus resolving the safety-strength contradiction.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent eliminates the harmful flammability of organic dispersion mediums while maintaining or improving adhesion performance. By using non-aqueous binders that are inherently non-flammable or have superior safety profiles, the invention converts the potential harm (fire risk) into a benefit (enhanced safety) without sacrificing adhesion strength.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS20260074216A1Positive electrode for all-solid-state battery, all-solid-state battery including the same, and method of manufacturing the same

Publication Date: 2026.03.12 SAMSUNG SDI CO LTD

AI summary

Disclosed are positive electrodes, all-solid-state batteries, and fabrication methods thereof. The positive electrode includes a positive electrode current collector, and a positive electrode active material layer on the positive electrode current collector. The positive electrode active material layer includes a sulfide-based solid electrolyte, a binder that includes a first non-aqueous binder and a second non-aqueous binder, and a positive electrode active material. The first non-aqueous binder includes a fluorine-based binder. The second non-aqueous binder includes an acrylate-based binder.