Vacuum Core Ceramic-Carbon Electrode Layer for Thermal Runaway

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Lithium secondary batteries face safety issues due to thermal runaway phenomena, which can cause fires or explosions, especially in large devices like electric vehicles, where heat transfer between electrodes can lead to catastrophic failures.

Innovation Solution

A ceramic-carbon composite is developed, comprising a ceramic shell surrounding a hollow vacuum state portion with a carbon coating layer, which is used as a primer layer in electrodes to prevent heat transfer and enhance safety by maintaining a vacuum state and providing thermal insulation and electrical conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If thermal insulation is improved to prevent thermal runaway, then heat transfer is reduced, but electrical conductivity deteriorates

Engineering Contradiction:

Improveheat transfer preventionVSAvoidelectrical conductivity

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent employs a composite structure consisting of a ceramic shell surrounding a hollow vacuum portion, where the ceramic material provides thermal insulation properties while the vacuum core enhances heat transfer resistance. This composite design enables the electrode to simultaneously achieve thermal insulation for safety and maintain electrical conductivity through the carbon coating layer, resolving the contradiction between heat transfer prevention and electrical conductivity.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The hollow vacuum portion acts as an intermediary thermal barrier between the electrode active material and the current collector. By introducing this vacuum layer, the patent creates a mediator that blocks instantaneous heat transfer while allowing the electrode to maintain its electrical function through the conductive carbon coating, thus resolving the contradiction between thermal insulation and electrical conductivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If safety is improved by preventing thermal runaway, then heat transfer is blocked, but electrode structure complexity increases

Engineering Contradiction:

ImprovesafetyVSAvoidelectrode structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies a nested structure where the hollow vacuum portion is enclosed within the ceramic shell, forming a core-shell configuration. This nested design integrates multiple functions (thermal insulation, structural support, and safety protection) into a compact unit that can be incorporated into existing electrode architectures, minimizing the increase in overall structure complexity while achieving enhanced safety.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The ceramic shell is designed with a thin film structure that provides robust thermal insulation and mechanical strength while maintaining flexibility for integration into electrode manufacturing processes. This thin-shell approach prevents thermal runaway without requiring bulky additional components, thereby limiting the increase in electrode structure complexity.

Inventive Principle:

Principle #30Flexible shells and thin films

3Temperature

If thermal insulation is enhanced using ceramic materials, then heat transfer is prevented, but manufacturing difficulty increases

Engineering Contradiction:

Improvethermal insulationVSAvoidmanufacturing process

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The patent incorporates the hollow vacuum portion and ceramic shell structure into the electrode manufacturing process at an early stage, before the electrode active material is applied. By pre-forming the thermal insulation structure on the current collector, the patent simplifies subsequent manufacturing steps and avoids the need for complex post-processing, thereby reducing overall manufacturing difficulty despite the advanced materials used.

Inventive Principle:

Principle #10Preliminary action

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 ceramic-carbon composite effectively prevents instantaneous heat transfer between electrode active materials and current collectors, significantly improving safety by reducing the risk of thermal runaway and maintaining battery performance.

Implementation Method 1

a ceramic shell surrounding a hollow portion; and a carbon coating layer surrounding the ceramic shell, wherein the hollow portion is in a vacuum state

Methodology Applied

Scientific EffectVacuum insulation: Vacuum

Data Source

PatentEP4258389A1Carbon-ceramic composites, electrode comprising the same and secondary battery comprising the electrode

Publication Date: 2023.10.11 SK ON CO LTD

Figure 1

AI summary

The present disclosure relates to a ceramic-carbon composite including a ceramic shell surrounding a hollow portion; and a carbon coating layer surrounding the ceramic shell, wherein the hollow portion is in a vacuum state, an electrode including the ceramic-carbon composite, and a secondary battery including the electrode. The ceramic-carbon composite of the present disclosure has excellent thermal barrier effect and electrical conductivity, and thus, when used in the electrode, non-ideal heat transfer between an electrode active material and an electrode current collector is blocked to prevent a thermal runaway phenomenon, to have an effect that can significantly improve safety of the secondary battery.