Lithium Battery Electrode Body with Composite Solid Electrolyte

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Solution Overview

Problem

Lithium batteries face safety concerns due to dendrite growth between the negative and positive electrodes, leading to short-circuiting and capacity limitations, as existing ceramic electrolyte methods fail to provide stable interface contact and sufficient capacity.

Innovation Solution

The electrode body configuration includes a collector electrode, a negative electrode active material layer, a soggy sand electrolyte layer impregnated with ordinary temperature molten salt, and an inorganic solid electrolyte layer, which blocks dendrite growth and prevents short-circuiting, using a laminated structure for enhanced safety and capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a ceramic electrolyte is used to prevent short-circuiting and improve safety, then safety is improved, but interface contact becomes insufficient and battery output deteriorates

Engineering Contradiction:
ImprovesafetyVSAvoidbattery output
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent employs a composite electrolyte structure combining ceramic electrolyte particles (inorganic solid electrolyte) with a polymer matrix material. This composite approach allows the electrolyte to maintain the safety benefits of ceramic materials while the polymer matrix ensures adequate interface contact and flexibility, thereby preventing short-circuiting without compromising battery output.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The ceramic electrolyte is used in the form of particles creating a porous structure within the polymer matrix. This porous configuration increases the surface area for interface contact between the electrolyte and electrode active material, improving both safety and electrical performance simultaneously.

Inventive Principle:
Principle #31Porous materials

2Quantity of substance

If the total thickness of active material is increased to obtain sufficient capacity, then capacity is improved, but the method of JP-A-2004-179158 cannot achieve thickness greater than 100 μm

Engineering Contradiction:
Improvebattery capacityVSAvoidactive material layer thickness
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent changes the manufacturing parameters by using a casting method instead of vapor phase deposition, enabling the production of active material layers with thickness exceeding 100 μm. This parameter change in the manufacturing process allows sufficient battery capacity to be achieved while maintaining manufacturing feasibility.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If an ordinary temperature molten salt electrolyte is used to improve safety, then safety is improved, but dendrite growth occurs during overcharging leading to short-circuiting

Engineering Contradiction:
ImprovesafetyVSAvoiddendrite growth
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent combines ordinary temperature molten salt electrolyte with ceramic electrolyte particles in a composite structure. The ceramic component provides physical barriers that suppress dendrite growth during overcharging, while the molten salt maintains good ionic conductivity and safety characteristics, thereby preventing both short-circuiting and dendrite-related hazards.

Inventive Principle:
Principle #40Composite materials

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 configuration effectively prevents short-circuiting and dendrite growth, enabling the use of high-capacity metal lithium, improving battery output, safety, and reducing size and weight while maintaining high safety standards.

Implementation Method 1

an inorganic solid electrolyte layer which is provided on a side of the soggy sand electrolyte layer which is opposite to a negative electrode active material layer side

Methodology Applied
Scientific EffectPhysical barrier effect:

Implementation Method 2

a soggy sand electrolyte layer that is provided on a side of the negative electrode active material layer which is opposite to a collector electrode side, and in the soggy sand electrolyte layer, a plurality of particles is impregnated with an ordinary temperature molten salt electrolyte

Methodology Applied
Scientific EffectImpregnation: Absorption (physical)

Data Source

PatentEP2996176B1Electrode body for lithium battery, and lithium battery
Publication Date: 2017.04.26 SEIKO EPSON CORP
  • EP2996176B1 patent drawingFigure 1~3
  • EP2996176B1 patent drawingFigure 4~5
  • EP2996176B1 patent drawingFigure 6~8

AI summary

An electrode body for a lithium battery includes a collector electrode, a negative electrode active material layer which is provided to come into contact with one surface of the collector electrode and contains a Li metal or a Li alloy, a soggy sand electrolyte layer that is provided on a side of the negative electrode active material layer which is opposite to a collector electrode side, and an inorganic solid electrolyte layer that is provided on a side of the soggy sand electrolyte layer which is opposite to a negative electrode active material layer side. In the soggy sand electrolyte layer, a plurality of particles is impregnated with an ordinary temperature molten salt electrolyte.