All-solid-state rechargeable batteries and manufacturing method thereof

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Solution Overview

Problem

Current all-solid-state rechargeable batteries face limitations in thinning highly reactive sulfide-based solid electrolytes due to the limitations of existing slurry solvent and binder technology, leading to issues with lithium dendrite formation and interfacial bonding between electrodes.

Innovation Solution

The battery design incorporates a multilayer solid electrolyte structure with different binders having varying glass transition temperatures, where the binder for the negative electrode has a higher glass transition temperature than that for the positive electrode, enhancing interfacial bonding and suppressing lithium dendrite formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a thin film-type solid electrolyte membrane is manufactured to increase energy density, then energy density is improved, but lithium dendrite formation increases and interfacial bonding deteriorates

Engineering Contradiction:

Improveenergy densityVSAvoidlithium dendrite formation

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The solid electrolyte layer is divided into multiple sub-layers with different binder glass transition temperatures. The first sub-layer (in contact with negative electrode) uses a binder with higher Tg to suppress lithium dendrite formation, while the second sub-layer (in contact with positive electrode) uses a binder with lower Tg to enhance interfacial bonding. This segmentation allows each sub-layer to perform its specific function optimally.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the solid electrolyte layer are assigned different binder properties tailored to local requirements. The region near the negative electrode uses high-Tg binder for dendrite suppression, while the region near the positive electrode uses low-Tg binder for bonding enhancement. This local quality differentiation resolves the contradiction between dendrite suppression and bonding strength.

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If existing slurry solvent and binder technology is used for sulfide-based solid electrolytes, then manufacturing is simplified, but thinning capability is limited and interfacial bonding deteriorates

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidsolid electrolyte thickness

Core Design Contradiction:

Ease of manufactureVSLength of stationary object

Solution Approach 1:

The invention changes the key parameter of binder glass transition temperature to overcome the limitations of existing slurry technology. By selecting binders with appropriate Tg values for different locations, the patent achieves both thin film formation and good interfacial bonding, while maintaining compatibility with conventional slurry processing methods.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If a single binder is used in the solid electrolyte layer, then device complexity is reduced, but interfacial bonding at both electrodes cannot be simultaneously optimized

Engineering Contradiction:

Improvebinder composition complexityVSAvoidinterfacial bonding strength

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The binder system is segmented into two distinct types with different glass transition temperatures, positioned in different sub-layers of the solid electrolyte. This segmentation enables independent optimization of bonding at each electrode interface without compromising the other, while maintaining relatively simple overall device structure.

Inventive Principle:

Principle #1Segmentation

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 design improves electrochemical performance by enhancing initial charge and discharge capacity, rate capability, and cycle-life characteristics of the battery.

Implementation Method 1

a glass transition temperature of the first binder is higher than a glass transition temperature of the second binder

Methodology Applied

Scientific EffectGlass transition temperature:

Implementation Method 2

a glass transition temperature of the first binder is higher than a glass transition temperature of the second binder

Methodology Applied

Scientific EffectGlass transition temperature:

Data Source

PatentUS20260011773A1All-solid-state rechargeable batteries and manufacturing method thereof

Publication Date: 2026.01.08 SAMSUNG SDI CO LTD

AI summary

Disclosed are an all-solid-state rechargeable battery, and a method of manufacturing the same, the all-solid-state rechargeable battery including a negative electrode, a positive electrode, and a solid electrolyte layer between the negative electrode and positive electrode, wherein the solid electrolyte layer includes a first solid electrolyte layer in contact with the negative electrode, and a second solid electrolyte layer in contact with the positive electrode, the first solid electrolyte layer includes a first solid electrolyte and a first binder, the second solid electrolyte layer includes a second solid electrolyte and a second binder, and a glass transition temperature of the first binder is higher than a glass transition temperature of the second binder.