Sulfide Solid Electrolyte Surface Oxygen for Battery Bonding

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Solution Overview

Problem

All-solid state secondary batteries face challenges with poor bonding properties between solid particles and between layers, which affect handleability and battery performance, particularly due to inadequate adhesiveness and ion conductivity.

Innovation Solution

Incorporating sulfide-based inorganic solid electrolyte particles and non-oxide-based electrode active material particles with a surface oxygen element proportion of 3.0 atm% or more, enhanced by actinic ray treatment, such as plasma exposure, to improve bonding and adhesiveness between layers and with collectors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If solid electrolyte particles and electrode active material particles are used in all-solid state secondary batteries, then ion conductivity and battery performance are improved, but bonding property between particles and between layers deteriorates

Engineering Contradiction:

Improveion conductivityVSAvoidbonding property

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent introduces a binder as an intermediary substance between solid electrolyte particles and electrode active material particles. This binder mediates the bonding between particles and layers, resolving the contradiction by providing adhesive force without interfering with the ion conductivity of the solid electrolyte particles. The binder acts as a bridge that connects particles while allowing ions to pass through the solid electrolyte pathways.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite structure combining solid electrolyte particles, electrode active material particles, and binder in specific proportions. This composite material approach allows the system to simultaneously achieve good bonding properties (through the binder) and maintain ion conductivity (through the solid electrolyte particles). The composite structure integrates the advantages of different materials while mitigating their individual shortcomings.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If solid electrolyte particles are used to improve battery performance, then energy density is increased, but handleability and manufacturing suitability deteriorate due to poor bonding

Engineering Contradiction:

Improveenergy densityVSAvoidhandleability

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The binder serves as a mediator that improves handleability during manufacturing by providing cohesive force between particles. This allows the battery components to be handled and assembled more easily without compromising the high energy density achieved through solid electrolyte usage. The binder enables practical manufacturing operations while maintaining the performance benefits of solid-state architecture.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Quantity of substance

If solid electrolyte particles are densely packed to increase energy density, then stacking efficiency is improved, but bonding property between layers deteriorates

Engineering Contradiction:

Improvestacking efficiencyVSAvoidbonding property between layers

Core Design Contradiction:

Quantity of substanceVSStrength

Solution Approach 1:

The binder acts as an intermediary layer between stacked battery elements, ensuring good bonding between layers even when particles are densely packed. This allows maximum stacking efficiency to be achieved while maintaining adequate inter-layer bonding strength for structural integrity and handling during manufacturing and assembly.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 improved bonding properties lead to enhanced handleability and manufacturing suitability, as well as improved battery performance by increasing ion conductivity and stability.

Implementation Method 1

Methodology Applied

Scientific EffectPlasma treatment: Plasma

Data Source

PatentUS10892516B2All-solid state secondary battery, particles for all-solid state secondary battery, solid electrolyte composition for all-solid state secondary battery, and electrode sheet for all-solid state secondary battery, and methods for manufacturing same

Publication Date: 2021.01.12 FUJIFILM CORP

AI summary

Provided are all-solid state secondary battery containing sulfide-based inorganic solid electrolyte particles having conductivity for ions of metals belonging to Group I or II of the periodic table and non-oxide-based electrode active material particles, in which a proportion of an oxygen element in an element composition of a surface of at least one kind of the sulfide-based inorganic solid electrolyte particles or the non-oxide-based electrode active material particles is 3.0 atm % or more, particles for an all-solid state secondary battery, a solid electrolyte composition for an all-solid state secondary battery, an electrode sheet for an all-solid state secondary battery, and an all-solid state secondary battery for which the particles for an all-solid state secondary battery are used, and methods for manufacturing the same.