Olivine Electrode Assembly for Low-Resistance Solid-State Batteries

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

All-solid-state batteries using ceramic-based solid electrolytes face high interfacial resistance and reduced efficiency due to repeated contraction and expansion during charging and discharging, leading to a decrease in capacity.

Innovation Solution

The use of an electrode assembly with a solid electrolyte layer and internal electrodes made of the same active material with an olivine-type crystal structure, which includes compounds like Li3V2(PO4)3, to reduce interfacial resistance and maintain capacity during repeated charge and discharge cycles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a ceramic-based solid electrolyte is used in an all-solid-state battery, then stability is improved, but interfacial resistance increases and efficiency decreases

Engineering Contradiction:

ImprovestabilityVSAvoidinterfacial resistance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

A buffer layer is introduced between the ceramic-based solid electrolyte and the electrode as an intermediary component. This buffer layer mediates the interface between the solid electrolyte and electrode, reducing interfacial resistance while preserving the stability benefits of the ceramic electrolyte. The buffer layer acts as a transition zone that facilitates ion transport and reduces contact resistance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The battery structure employs composite materials by combining the ceramic-based solid electrolyte with a buffer layer material that has complementary properties. This composite structure leverages the high stability of the ceramic electrolyte while the buffer layer component provides low interfacial resistance, achieving a synergistic effect that resolves the contradiction between stability and efficiency.

Inventive Principle:

Principle #40Composite materials

2Reliability

If a ceramic-based solid electrolyte is used in an all-solid-state battery, then stability is improved, but the battery contracts and expands repeatedly during charging and discharging, shortening lifespan

Engineering Contradiction:

ImprovestabilityVSAvoidlifespan

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The buffer layer serves as a cushioning layer that is pre-positioned between the ceramic electrolyte and electrode to absorb and mitigate the mechanical stress of repeated contraction and expansion during charge-discharge cycles. This beforehand cushioning prevents direct mechanical contact and damage between the rigid ceramic electrolyte and electrode, thereby extending battery lifespan while maintaining stability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The buffer layer functions as a flexible thin film that can accommodate the volume changes and mechanical deformations occurring during battery operation. This flexible layer protects the rigid ceramic-based solid electrolyte from mechanical damage caused by repeated contraction and expansion, enabling longer operational life while preserving the electrochemical stability of the ceramic electrolyte.

Inventive Principle:

Principle #30Flexible shells and thin films

3Quantity of substance

If a liquid electrolyte is used in a lithium secondary battery, then discharge capacity and energy density are high, but the risk of electrolyte leakage, fires, and explosions increases

Engineering Contradiction:

Improvedischarge capacityVSAvoidelectrolyte leakage and fire risk

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The electrolyte is transformed from liquid phase to solid phase, representing a fundamental parameter change in its physical state. This phase change eliminates the harmful properties associated with liquid electrolytes (leakage, fire, explosion risks) while the solid electrolyte is engineered to maintain high ion conductivity that preserves discharge capacity and energy density performance.

Inventive Principle:

Principle #35Parameter changes

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 decreases interfacial resistance and suppresses capacity decrease in all-solid-state batteries, enabling stable and efficient charge and discharge cycles.

Implementation Method 1

a solid electrolyte layer and first and second internal electrodes stacked with the solid electrolyte layer interposed therebetween

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Implementation Method 2

applying a material capable of intercalating and de-intercalating lithium ions into a positive electrode and a negative electrode

Methodology Applied

Scientific EffectIntercalation: Absorption (physical)

Data Source

PatentUS20230343957A1All-solid-state battery

Publication Date: 2023.10.26 SAMSUNG ELECTRO MECHANICS CO LTD

AI summary

An all-solid-state battery includes an electrode assembly including a solid electrolyte layer and first and second internal electrodes stacked with the solid electrolyte layer interposed therebetween, a first external electrode connected to the first internal electrode, and a second external electrode connected to the second internal electrode. The first internal electrode and the second internal electrode include the same active material, and the active material includes a compound having an olivine-type crystal structure.