Integrated Ceramic Separator Structure for Short-Circuit-Resistant Cells

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Solution Overview

Problem

Existing electrochemical cells face challenges in maintaining structural integrity and preventing short circuits due to differential expansion and contraction of electrode materials, particularly with polyolefin separators that can shrink and expose electrodes, leading to increased risk of shorting and lithium plating.

Innovation Solution

Incorporating an integrated ceramic separator with a non-planar interlocking region between electrode layers, which includes interpenetrating fingers to maintain mechanical stability and reduce interfacial resistance, combined with a polyolefin separator for thermal shutoff, thereby enhancing cell safety and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polyolefin separators are used, then thermal shutoff function is provided, but separator shrinkage occurs leading to exposed electrodes and increased short circuit risk

Engineering Contradiction:

Improveshort circuit preventionVSAvoidseparator dimensional stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent uses a composite separator structure combining polyolefin material (providing thermal shutoff) with a ceramic coating layer (providing dimensional stability). This composite approach allows the separator to maintain its shape at elevated temperatures while still providing thermal shutdown functionality, resolving the contradiction between reliability and compositional stability.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent modifies the physical and chemical parameters of the separator by applying a ceramic coating that changes the thermal expansion characteristics and mechanical properties of the separator. This parameter change prevents shrinkage-induced electrode exposure while preserving the thermal shutoff mechanism.

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If ceramic separator is used, then mechanical integrity and dimensional stability are improved, but interfacial resistance between electrode and separator increases

Engineering Contradiction:

Improveseparator dimensional stabilityVSAvoidinterfacial resistance

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent applies local quality modification by creating a graded interface between the ceramic coating and the polyolefin substrate, with different regions having different properties. The ceramic layer provides dimensional stability while the transition zone maintains good interfacial contact, reducing resistance while preserving stability.

Inventive Principle:

Principle #3Local quality

3Device complexity

If integrated separator design is used, then manufacturing complexity is reduced, but manufacturing precision requirements increase

Engineering Contradiction:

Improveseparator structure complexityVSAvoidcoating uniformity and thickness control

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent employs a porous ceramic coating structure that can be formed through controlled deposition processes. The porous nature allows for tolerance in thickness variations while maintaining functional performance, reducing the stringency of manufacturing precision requirements for the integrated separator structure.

Inventive Principle:

Principle #31Porous 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

The integrated ceramic separator design improves mechanical integrity, reduces interfacial resistance, prevents short circuits, and maintains ion mobility, while also providing a thermal shutoff mechanism, resulting in a more stable and efficient electrochemical cell.

Implementation Method 1

a first interlocking region is formed between the one or more first active material layers and the first separator layer; wherein the first interlocking region comprises a non-planar interpenetration of first fingers of the one or more first active material layers and second fingers of the first integrated separator layer

Methodology Applied

Scientific EffectInterlocking: Mechanical Fastener

Implementation Method 2

combined with a polyolefin separator for thermal shutoff, thereby enhancing cell safety and performance

Methodology Applied

Scientific EffectThermal shutoff: Melting

Implementation Method 3

maintains ion mobility, while also providing a thermal shutoff mechanism

Methodology Applied

Scientific EffectIon transport: Porosity

Data Source

PatentUS20250219099A1Electrochemical cell with integrated ceramic separator

Publication Date: 2025.07.03 ENPOWER INC

AI summary

An electrochemical cell including a positive electrode (e.g., a cathode) and a negative electrode (e.g., an anode), at least one of which includes an integrated ceramic separator. An integrated ceramic separator may include a plurality of ceramic particles. In some examples, an interlocking region may be disposed between the integrated ceramic separator layer and a corresponding electrode layer, the region including a non-planar boundary between the two layers. In some examples, the electrochemical cell includes a polyolefin separator disposed between the positive electrode and the negative electrode. In some examples, both the positive electrode and the negative electrode include an integrated ceramic separator. In these examples, the positive electrode and the negative electrode may be calendered together such that the integrated separator layers merge and become indistinguishable from each other.