Separator Coating with Ceramic and Polymer Particles

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current separators for high-energy batteries face challenges such as mechanical instability, high internal resistance, limited thermal stability, and safety concerns due to melting at elevated temperatures, leading to potential short-circuits and explosions.

Innovation Solution

A separator with a substrate and voids containing an electrically nonconductive coating of oxide particles adhesively bonded to the substrate, incorporating polymer particles in addition to oxide particles like Al2O3, ZrO2, and SiO2, which enhances flexibility, stability, and safety by preventing ion flow at high temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separator uses a thin porous structure to reduce internal resistance and increase ion permeability, then electrochemical performance is improved, but mechanical strength and handling stability deteriorate

Engineering Contradiction:
Improveelectrochemical performanceVSAvoidmechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The separator combines a porous base structure with ceramic coating particles to create a composite material that maintains the porosity needed for ion transport while the ceramic particles provide enhanced mechanical strength and thermal stability, resolving the contradiction between thin porous structure requirements and mechanical strength needs

Inventive Principle:
Principle #40Composite materials

2Reliability

If a separator uses organic polymer materials to achieve flexibility and ion conductivity, then electrochemical performance is improved, but thermal stability deteriorates due to melting at elevated temperatures

Engineering Contradiction:
Improveion conductivityVSAvoidthermal stability
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The separator combines organic polymer base material with inorganic ceramic coating particles to create a composite structure where the polymer provides flexibility and ion conductivity while the ceramic coating layer provides thermal stability and prevents melting at elevated temperatures

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The ceramic coating is applied as a porous layer that maintains ion transport pathways while providing thermal stability, allowing the separator to retain ion conductivity benefits of porous structures while gaining thermal resistance

Inventive Principle:
Principle #31Porous materials

3Temperature

If a separator uses inorganic ceramic materials to achieve thermal stability, then safety is improved, but flexibility and handling properties deteriorate

Engineering Contradiction:
Improvethermal stabilityVSAvoidflexibility
Core Design Contradiction:
TemperatureVSEase of operation

Solution Approach 1:

The separator uses a composite structure where the flexible organic polymer base provides flexibility and handling properties while the ceramic particles embedded in the coating provide thermal stability, allowing both properties to coexist

Inventive Principle:
Principle #40Composite materials

4Reliability

If a separator uses a dense coating structure to prevent short-circuits, then safety is improved, but ion permeability deteriorates

Engineering Contradiction:
Improveshort-circuit preventionVSAvoidion permeability
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The ceramic coating is designed with a porous structure that provides physical barrier properties to prevent direct electrode contact and short-circuits while maintaining open pathways for ion transport, thus achieving both safety and ion permeability

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 separator exhibits improved handling properties, increased flexibility, and enhanced safety features, including reduced ceramic dust during cutting and increased tolerance to bending, while maintaining electrochemical performance comparable to prior art separators.

Implementation Method 1

a separator with a substrate and voids containing an electrically nonconductive coating of oxide particles adhesively bonded to the substrate

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Implementation Method 2

incorporating polymer particles in addition to oxide particles like Al2O3, ZrO2, and SiO2, which enhances flexibility, stability, and safety by preventing ion flow at high temperatures

Methodology Applied
Scientific EffectThermal shutdown: Melting

Data Source

PatentUS10044015B2Separator with improved ease of handling
Publication Date: 2018.08.07 EVONIK OPERATIONS GMBH

AI summary

Robust separator which has, on a substrate and in the voids of the substrate, which comprises fibers of an electrically nonconductive material, an electrically nonconductive coating comprising oxide particles which are adhesively bonded to one another and to the substrate by an inorganic adhesive and comprise at least one oxide selected from Al2O3, ZrO2 and SiO2, polymer particles also being present in the ceramic coating in addition to the oxide particles of Al2O3, ZrO2 and/or SiO2. These separators have particularly good handling properties since they are mechanically very stable.