Thiol-Containing Compound for Lithium Ion Battery Dendrite Prevention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Lithium secondary batteries face internal shorts due to dendrite formation, which compromises manufacturing quality and safety, especially when copper ions are reduced and form needle-like structures that can connect the cathode and anode, leading to safety and stability issues.

Innovation Solution

Incorporating a compound with a thiol group (-SH) into the battery's unit cell, such as in the electrode or separator, to react with and capture copper ions, preventing dendrite formation and internal shorts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If copper ions are present in the battery during manufacturing, then good electrical conductivity is achieved, but dendrite formation occurs leading to internal shorts and safety issues

Engineering Contradiction:
Improvebattery safetyVSAvoiddendrite formation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

A chelating agent is introduced as an intermediary substance that binds to copper ions, preventing them from being reduced to metallic copper and forming dendrites. The chelating agent acts as a mediator between copper ions and the electrode, controlling copper ion deposition and eliminating harmful dendrite formation while maintaining electrical conductivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The chemical state of copper in the battery is changed from free copper ions that can be reduced to metallic copper, to chelated copper complexes with controlled stability. By adjusting the chelating agent concentration and selecting agents with appropriate binding strengths, the reduction potential of copper is modified, preventing dendrite formation while maintaining necessary conductivity.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If traditional battery materials are used without copper chelating agents, then manufacturing process is simple, but internal shorts occur due to dendrite formation

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoiddefect ratio
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The chelating agent is added to the battery electrolyte or coating composition before final assembly, performing preliminary binding of copper ions present in the manufacturing environment. This preliminary action prevents copper ion reduction during subsequent battery operation, eliminating dendrite formation and internal shorts without complicating the overall manufacturing process.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If copper ions are reduced at the anode surface, then electrical conductivity is maintained, but needle-like dendrite structures form causing internal shorts

Engineering Contradiction:
Improvebattery stabilityVSAvoiddendrite structure
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The chelating agent serves as an intermediary that alters the deposition mechanism of copper at the anode surface. Instead of direct reduction forming needle-like dendrites, the chelating agent mediates copper ion deposition, promoting uniform coating and preventing harmful dendritic structure formation while maintaining electrical conductivity.

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

The use of thiol-containing compounds effectively prevents dendrite growth and internal shorts, enhancing the safety and manufacturing quality of lithium ion secondary batteries by selectively reacting with copper ions, thereby maintaining battery stability and reducing defect ratios.

Implementation Method 1

a compound containing at least one thiol group (-SH) in a molecule in a unit cell of a battery

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentEP2741356B1Lithium ion secondary battery preventing internal short
Publication Date: 2018.10.03 LG CHEM LTD

AI summary

A lithium ion secondary battery including a compound containing at least one thiol group (-SH) in a molecule in a unit cell of the battery is provided. By including the compound containing thiol group (-SH) having good reactivity with copper or copper ions, the formation of dendrite through the reduction of copper ions present in the inner portion of the battery or produced during operating the battery at the surface of an anode may be prevented. The internal short between two electrodes due to the dendrite may be also prevented.