Functionalized Battery Separator for Lithium Dendrite Breakdown

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Solution Overview

Problem

Lithium dendrites form during high current charging in rechargeable Li metal battery cells, leading to short circuits and reduced cycling performance due to penetration through the separator.

Innovation Solution

A functionalized separator with an active solid coating layer and protective layer that reacts with and breaks down lithium dendrites, enhancing mechanical strength and preventing short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional separator is used, then the battery cell can operate, but lithium dendrites penetrate through the separator causing short circuits and reduced cycling performance

Engineering Contradiction:

Improvecycling performanceVSAvoidlithium dendrite penetration

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies the 'Blessing in disguise' principle by coating the separator with active solid particles that react with lithium dendrites. Instead of merely blocking dendrites passively, the reactive coating converts the harmful dendrite growth into a beneficial chemical reaction that eliminates the dendrites and prevents short circuits, thereby improving cycling performance and reliability.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent employs composite materials by combining the separator with an active solid coating layer containing reactive particles. This composite structure integrates the mechanical separation function of the separator with the chemical reactivity of the coating, creating a multi-functional barrier that both physically blocks and chemically neutralizes lithium dendrites.

Inventive Principle:

Principle #40Composite materials

2Productivity

If high current charging is applied, then charging speed increases, but lithium dendrites form and penetrate the separator

Engineering Contradiction:

Improvecharging speedVSAvoidlithium dendrite formation

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The reactive solid coating converts the harmful effect of high current-induced dendrite formation into a beneficial chemical reaction. The coating actively reacts with and breaks down dendrites as they form during high current charging, enabling fast charging without the usual penalty of dendrite penetration and short circuits.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent applies 'Preliminary anti-action' by pre-coating the separator with reactive solid particles before battery operation. This preliminary protective layer is already in place to counteract and neutralize dendrite formation as it occurs during high current charging, preventing the harmful effects before they can compromise battery performance.

Inventive Principle:

Principle #9Preliminary anti-action

3Reliability

If the separator is made thicker to prevent dendrite penetration, then short circuit risk decreases, but battery cell volume increases

Engineering Contradiction:

Improveshort circuit preventionVSAvoidbattery cell volume

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent changes the functional parameters of the separator by adding a reactive coating layer rather than simply increasing the bulk thickness. This parameter change allows the separator to maintain its original thin dimensions while gaining enhanced dendrite-blocking capability through the chemical reactivity of the coating, thus preventing short circuits without increasing battery volume.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Instead of using increased thickness as a passive mechanical barrier, the patent converts the separator into an active protective element through reactive coating. This approach achieves superior short circuit prevention at thinner dimensions by chemically neutralizing dendrites, thereby reducing battery volume while improving reliability.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 functionalized separator reduces the likelihood of short circuits and improves cycling performance by reacting with lithium dendrites, thereby stabilizing the battery cell under high current density.

Implementation Method 1

The first active solid coating layer comprises active solid particles that react with lithium

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentUS20250349909A1Battery cell including functionalized separator

Publication Date: 2025.11.13 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A battery cell includes C cathode electrodes, A anode electrodes, and S separators, where C, A, and S are integers greater than zero. Each of the S separators includes a separator layer, a first active solid coating layer arranged on the separator layer, and a protective layer.