Nanoporous Battery Separator Coating for Metal Ion Blocking

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Solution Overview

Problem

Existing lithium battery manufacturing processes are slow, complex, and expensive, and they pose safety risks due to metal fragments and metal ion migration, particularly with transition metals like manganese, nickel, and cobalt, which reduce battery cycle life.

Innovation Solution

A battery stack manufacturing process using a reusable substrate with a nanoporous separator coated with an anionic compound to inhibit metal ion migration, combined with a safety shutdown layer and edge reinforcement, allowing for faster, less expensive production and improved safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If existing manufacturing processes are used to produce lithium batteries, then batteries can be manufactured, but the manufacturing process is slow, complex and expensive

Engineering Contradiction:
Improvemanufacturing speedVSAvoidmanufacturing process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention divides the battery structure into modular components (separator layers with integrated protective coatings, electrode assemblies with current collectors) that can be manufactured independently and then assembled. This segmentation allows for specialized manufacturing equipment for each component type, improving overall productivity while reducing process complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The separator layer is designed to perform multiple functions simultaneously: it acts as a physical barrier between electrodes, provides thermal shutdown protection, and includes protective coatings that prevent metal ion migration. This multi-functionality reduces the number of separate components needed, simplifying the manufacturing process while maintaining high productivity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Strength

If metal substrates are used in battery manufacturing, then structural support is provided, but metal fragments can be embedded into the separator causing short circuits

Engineering Contradiction:
Improvestructural supportVSAvoidshort circuit risk
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention replaces permanent metal substrates with disposable metal foil layers that are intentionally designed to dissolve or decompose under specific conditions. These thin metal foils provide necessary structural support during assembly but are sacrificed to prevent long-term reliability issues from metal fragment embedding, as they break down before causing short circuits.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The separator includes pre-applied protective coatings that act as a barrier against metal ion migration and fragment embedding. These coatings are applied beforehand to the separator surface, creating a protective cushion that prevents harmful interactions between metal components and the separator, thereby eliminating short circuit risks before they can occur.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Ease of manufacture

If transition metals like manganese are used in the cathode, then battery cost is reduced, but metal ions migrate through the separator reducing battery cycle life

Engineering Contradiction:
Improvebattery costVSAvoidbattery cycle life
Core Design Contradiction:
Ease of manufactureVSDuration of action of stationary object

Solution Approach 1:

The invention introduces protective coatings on the separator as an intermediary layer between the transition metal cathode and the separator bulk. These coatings selectively block metal ion migration while maintaining ionic conductivity for lithium ions, allowing the use of cost-effective transition metals like manganese without compromising battery cycle life. The intermediary coating thus enables both low cost and long duration performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The separator utilizes a porous structure with controlled pore sizes and distributions that allow lithium ion transport while physically restricting larger transition metal ions. The porous material provides selective permeability based on ion size, enabling the use of inexpensive transition metal cathodes while preventing their ions from migrating through the separator, thus maintaining both cost-effectiveness and extended battery cycle life.

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 process enables cost-effective, high-speed production of lithium batteries with enhanced safety by preventing metal ion diffusion and reducing the risk of short circuits, thereby extending battery cycle life and improving manufacturing efficiency.

Implementation Method 1

the separator includes an anionic compound that inhibits migration of metal ions from the cathode to the anode

Methodology Applied
Scientific EffectIon repulsion/attraction: Ion Repulsion/Attraction

Implementation Method 2

enables cost-effective, high-speed production of lithium batteries with enhanced safety by preventing metal ion diffusion

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP4283700B1Nanoporous separators for batteries and related manufacturing methods
Publication Date: 2025.08.27 LG ENERGY SOLUTION LTD
  • EP4283700B1 patent drawingFigure 1
  • EP4283700B1 patent drawingFigure 2
  • EP4283700B1 patent drawingFigure 3

AI summary

Provided is a lithium battery, wherein the battery comprises an anode, a cathode, wherein the cathode comprises one or more transition metals, an electrolyte, and a porous separator interposed between the cathode and anode, wherein the separator comprises an anionic compound. Also provided are methods of manufacturing such batteries.