Lithium Metal Battery Protective Layer Dendrite Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Lithium metal segregation between the negative electrode current collector and the solid electrolyte layer in lithium metal secondary batteries leads to dendrite growth, cracking of the solid electrolyte, and delamination of the negative electrode, reducing the battery's durability.

Innovation Solution

Incorporating a protective layer with a metal capable of alloying with lithium, such as antimony, bismuth, or tin, on the negative electrode current collector, which has a volumetric capacity density of 1000 mAh/L or more, to prevent lithium dendrite growth and enhance durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lithium metal secondary battery uses a conventional negative electrode structure without a protective layer, then the battery structure is simple, but lithium metal segregates between the negative electrode current collector and solid electrolyte layer causing dendrite growth and reducing durability

Engineering Contradiction:

Improvebattery durabilityVSAvoidnegative electrode structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A protective layer is formed on the negative electrode current collector before lithium metal deposition occurs. This protective layer pre-prevents lithium metal segregation and dendrite growth by providing a controlled interface between the current collector and solid electrolyte, eliminating the need for complex post-processing or redesign of the battery structure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The protective layer acts as an intermediary between the negative electrode current collector and the solid electrolyte layer. It mediates the interaction between these components by controlling lithium metal deposition and preventing direct contact that would cause segregation and dendrite formation, thereby improving durability without complicating the overall battery design.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the protective layer has high volumetric capacity density (1000 mAh/L or more), then lithium metal deposition is controlled effectively preventing dendrite growth, but the protective layer occupies more volume reducing battery energy density

Engineering Contradiction:

Improvedendrite prevention capabilityVSAvoidbattery energy density

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The protective layer is designed with specific volumetric capacity density parameters (1000 mAh/L or more) to optimize its function. By controlling the thickness and composition of the protective layer, it achieves sufficient lithium metal deposition control and dendrite prevention while minimizing volume occupation, thus balancing reliability and energy density.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If lithium metal segregates during charging, then the battery can be charged, but lithium dendrites grow causing solid electrolyte cracking and current collector delamination

Engineering Contradiction:

Improvecharging capabilityVSAvoidstructural integrity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The protective layer is designed to counteract lithium metal segregation before it occurs during charging. By providing a controlled deposition surface, it prevents the harmful segregation process that leads to dendrite growth, solid electrolyte cracking, and current collector delamination, allowing charging to proceed safely without compromising structural integrity.

Inventive Principle:

Principle #9Preliminary anti-action

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 protective layer effectively prevents lithium dendrite formation, maintains the integrity of the solid electrolyte, and improves the overall durability of the lithium metal secondary battery by ensuring the lithium metal is deposited correctly, thereby maintaining capacity and reducing resistance over cycles.

Implementation Method 1

the protective layer including a metal capable of being alloyed with lithium

Methodology Applied

Scientific EffectAlloying:

Data Source

PatentUS20230075536A1Lithium metal secondary battery

Publication Date: 2023.03.09 HONDA MOTOR CO LTD

AI summary

There is provided a lithium metal secondary battery including a positive electrode, a negative electrode, and a solid electrolyte layer between the positive electrode and the negative electrode, the negative electrode including a negative electrode current collector and a protective layer, and the protective layer including a metal capable of being alloyed with lithium and having a volumetric capacity density of 1000 mAh/L or more.