Anode-Free Lithium Secondary Battery With Protective Layers

Solution Overview

Problem

Lithium metal batteries face challenges due to the reactivity of lithium with water and oxygen, leading to surface oxide layer formation, which decreases electrical conductivity and battery lifetime, and the complexity of the assembly process.

Innovation Solution

A negative electrode free battery structure is developed, where a lithium metal layer is formed on a negative electrode current collector using lithium ions from the positive electrode after assembly, with a series of protective layers to prevent lithium dendrite growth and surface oxide formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If lithium metal is used as negative electrode material to achieve high capacity, then energy density is improved, but surface oxide layer formation occurs due to reactivity with atmosphere

Engineering Contradiction:

Improveenergy densityVSAvoidsurface oxide layer formation

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by pre-coating the lithium metal surface with protective layers (LiF, Al2O3, or SiO2) before battery assembly. This preliminary protective coating prevents oxidation during assembly and initial charging cycles, allowing the lithium metal to maintain its high reactivity properties while being protected from harmful atmospheric exposure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates an inert environment by using protective coating layers that act as barriers between the reactive lithium metal and the atmospheric environment. These coatings (particularly LiF and Al2O3) provide chemical inertness, effectively isolating the lithium metal from oxygen and moisture during assembly and operation.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

2Object-affected harmful factors

If vacuum deposition process is used to improve lithium reactivity, then surface oxide layer formation is partially reduced, but assembly process complexity increases

Engineering Contradiction:

Improvesurface oxide layerVSAvoidassembly process

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-coating the lithium metal surface with protective layers (LiF, Al2O3, or SiO2) before battery assembly. This preliminary protective coating prevents oxidation during assembly and initial charging cycles, allowing the lithium metal to maintain its high reactivity properties while being protected from harmful atmospheric exposure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses composite materials by combining lithium metal with protective coating layers (LiF, Al2O3, or SiO2) to create a composite negative electrode structure. This composite approach integrates the high capacity of lithium metal with the protective and conductive properties of the coating materials, achieving both performance and stability.

Inventive Principle:

Principle #40Composite materials

3Manufacturing precision

If lithium metal layer is formed after assembly to suppress oxide formation, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:

Improveoxide layer suppressionVSAvoidbattery structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-coating the lithium metal surface with protective layers (LiF, Al2O3, or SiO2) before battery assembly. This preliminary protective coating prevents oxidation during assembly and initial charging cycles, allowing the lithium metal to maintain its high reactivity properties while being protected from harmful atmospheric exposure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses intermediary materials by introducing protective coating layers (LiF, Al2O3, or SiO2) as intermediary substances between the lithium metal and the atmospheric environment. These intermediary layers facilitate the coexistence of reactive lithium metal with the external environment during assembly and operation.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This approach suppresses surface oxide layer formation, enhances cycle lifetime, and prevents lithium dendrite growth, resulting in improved battery performance and stability.

Implementation Method 1

lithium ions migrate from the positive electrode after charging to form a lithium metal layer on the negative electrode current collector

Methodology Applied

Scientific EffectIon migration: Electrophoresis

Implementation Method 2

a first protective layer is formed on a negative electrode current collector, a second protective layer is formed on the first protective layer, and a third protective layer is formed inside and on one surface of the second protective layer

Methodology Applied

Scientific EffectPhysical barrier protection: Physical Containment

Implementation Method 3

by consecutively forming first to third protective layers on a negative electrode current collector, preventing a decrease in the battery lifetime caused by lithium dendrite generated during battery charge and discharge

Methodology Applied

Scientific EffectPhysical constraint: Physical Containment

Data Source

PatentUS12191498B2Lithium secondary battery

Publication Date: 2025.01.07 LG ENERGY SOLUTION LTD

AI summary

A lithium secondary battery comprising a positive electrode, a negative electrode, a lithium metal layer, and an electrolyte disposed between the positive electrode and the negative electrode. The negative electrode comprises a first protective layer formed on a negative electrode current collector, a second protective layer formed on the first protective layer opposite the negative electrode current collector, and a third protective layer formed inside and on one surface of the second protective layer opposite the first protective layer, and wherein the lithium metal layer is formed between the negative electrode current collector and the first protective layer in the negative electrode when lithium ions migrate from the positive electrode after charging.