Porous Ceramic Battery Separator for Dendrite-Blocking Fast Charging

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Solution Overview

Problem

Lithium ion batteries face safety concerns due to lithium deposition during high charge rates, leading to thermal events and explosions, and existing separators fail to effectively block dendrites and maintain mechanical integrity at high temperatures.

Innovation Solution

Development of a porous, microporous battery separator filled with an ionic conductive medium, which is mechanically strong, non-reactive, and blocks metal dendrite growth, allowing high charge rates without lithium deposition, using ceramic coatings and specific porosity and tortuosity values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If carbonaceous materials are used as anode materials to achieve high energy density, then energy density is improved, but lithium deposition occurs at high charge rates causing safety risks

Engineering Contradiction:

Improveenergy densityVSAvoidsafety

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

A porous coating layer comprising metal oxide particles (such as aluminum oxide, magnesium oxide, calcium oxide, or silicon oxide) is applied to the anode surface. This coating acts as an intermediary between the carbonaceous anode material and the electrolyte, preventing direct harmful interactions while allowing ionic transport. The coating layer specifically prevents lithium deposition and dendrite formation during high charge rates, thereby maintaining safety without compromising the high energy density benefits of carbonaceous materials.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If charge rate is increased to improve productivity, then charging speed is improved, but lithium deposition and polarization increase causing safety concerns

Engineering Contradiction:

Improvecharging speedVSAvoidsafety

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The porous coating layer serves as a protective intermediary that enables high charge rates without lithium deposition. The coating's porous structure allows efficient ionic transport while its metal oxide particles prevent lithium metal formation, thus permitting high productivity charging without compromising safety.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The coating layer is designed with a porous structure that facilitates rapid ionic transport during high charge rates. The porosity allows electrolyte penetration and lithium ion diffusion while the metal oxide particles within the porous matrix prevent lithium deposition, enabling both high charging speed and safety.

Inventive Principle:

Principle #31Porous materials

3Reliability

If separator properties are enhanced to block dendrites and prevent melting, then safety is improved, but separator complexity increases

Engineering Contradiction:

ImprovesafetyVSAvoidseparator complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The separator is constructed as a composite material combining a polyolefin base matrix with dispersed ceramic particles (such as aluminum oxide, magnesium oxide, calcium oxide, or silicon oxide). This composite structure provides both the melt-blocking capability of ceramics at high temperatures and the mechanical integrity of polyolefin, while the ceramic particles also actively block dendrite penetration. This composite approach achieves enhanced safety without requiring overly complex multi-layer structures.

Inventive Principle:

Principle #40Composite 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 improved separator enables safe lithium ion batteries to operate at charge rates up to 5.0 C without lithium deposition, enhancing battery life and safety by preventing dendrite formation and maintaining mechanical strength.

Implementation Method 1

The porous separator absorbs liquid electrolyte

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Implementation Method 2

blocks metal dendrite growth

Methodology Applied

Scientific EffectPhysical barrier: Physical Containment

Implementation Method 3

is an electronic insulator under any conditions

Methodology Applied

Scientific EffectElectronic insulation: Electrical Resistance

Implementation Method 4

has a mechanical strength equal to or greater than steel

Methodology Applied

Scientific EffectComposite material reinforcement: Composite Materials

Data Source

PatentUS12603321B2Battery separators, electrodes, cells, lithium batteries and related methods

Publication Date: 2026.04.14 CELGARD LLC

AI summary

An improved battery separator and an energy cell comprising the improved battery separator are provided. The improved battery separator comprises a porous membrane having at least one of the following properties when wet with electrolyte: has no or low volume; has no or low mass; soaks as much liquid electrolyte as possible; blocks or removes any harmful substances in the electrolyte; never melts at any high temperature; does not react with the cathode or the anode under any conditions; has a mechanical strength equal to or greater than steel; is an electronic insulator under any conditions; and blocks metal dendrite growth.