Multi-Layer SEI Anode Protection for Lithium Dendrite Suppression

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Lithium-ion batteries face inefficiencies and safety issues due to uneven lithium metal plating and stripping, leading to dendrite growth and inactive metallic lithium formation, which reduces cycle life and causes electrolyte depletion.

Innovation Solution

An electrochemical cell with a multi-layered artificial solid electrolyte interphase (SEI) structure comprising a porous layer over the anode and a dense layer adjacent to it, formed using inorganic or organic compounds, which stabilizes the anode and prevents direct contact with the electrolyte, thereby reducing dendrite growth and electrolyte consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If Li metal is used as anode material due to its high theoretical capacity and low electrochemical potential, then battery capacity and voltage are improved, but uneven plating and stripping occurs leading to dendrite growth and safety issues

Engineering Contradiction:

Improvebattery voltage and capacityVSAvoidsafety and cycle life

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

An artificial solid electrolyte interphase (SEI) layer is introduced as an intermediary between the Li metal anode and the electrolyte. This engineered SEI layer acts as a protective mediator that prevents direct contact between Li metal and electrolyte, thereby eliminating dendrite growth and improving safety while maintaining the high capacity and voltage benefits of Li metal anodes.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

A thin film artificial SEI layer is formed on the Li metal anode surface. This flexible thin film structure accommodates volume changes during cycling while maintaining continuous protection, preventing dendrite penetration and electrolyte decomposition, thus improving reliability without sacrificing the electrochemical performance of Li metal.

Inventive Principle:

Principle #30Flexible shells and thin films

2Reliability

If a solid electrolyte interphase (SEI) forms on Li metal surface, then protection from electrolyte reactions is achieved, but the SEI is fragile and decomposes under volume changes causing further Li metal consumption

Engineering Contradiction:

Improveprotection from electrolyte reactionsVSAvoidSEI layer stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

An artificial SEI layer is formed in advance on the Li metal anode surface before the battery begins cycling. This pre-formed protective layer is engineered to be mechanically robust and chemically stable, preventing the formation of fragile natural SEI and eliminating the cycle of decomposition and reformation that consumes Li metal and reduces stability.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the SEI reforms after decomposition, then protection is restored, but SEI thickening and electrolyte depletion occur reducing cycle life

Engineering Contradiction:

Improveprotective function restorationVSAvoidcycle life

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The artificial SEI layer converts the harmful process of continuous SEI decomposition and reformation into a beneficial stable protective barrier. By engineering a robust initial SEI layer, the system eliminates the detrimental cycle of SEI breakdown and rebuilding, preventing electrolyte depletion and extending cycle life while maintaining protective function.

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 multi-layered SEI structure enhances the cycle life and performance of lithium-ion batteries by preventing dendrite formation and maintaining electrolyte stability, reducing cell impedance and extending battery life.

Implementation Method 1

a protective layer between the anode and the electrolyte. The protective layer comprises a porous layer over the anode and a dense layer over the porous layer

Methodology Applied

Scientific EffectPhysical barrier (protective layer):

Implementation Method 2

the protective layer comprises a porous layer proximal to the anode and a dense layer adjacent to the porous layer... stabilizes the anode and prevents direct contact with the electrolyte

Methodology Applied

Scientific EffectSurface stabilization:

Data Source

PatentUS20240030501A1Electrochemical cells including anodes comprising a protective layer, and related methods

Publication Date: 2024.01.25 BATTELLE ENERGY ALLIANCE LLC

AI summary

An electrochemical cell is disclosed and comprises an electrolyte between a cathode and an anode and a protective layer between the anode and the electrolyte. The protective layer comprises a porous layer over the anode and a dense layer over the porous layer, each of the porous layer and the dense layer comprising an inorganic compound, an organic compound, or an inorganic-organic composite. Additional electrochemical cells are disclosed. Also disclosed is a method of forming an electrochemical cell.