Cross-linked Compound Particle for Battery Electrolyte

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Solution Overview

Problem

Lithium secondary batteries face challenges with uniform electrolyte impregnation due to uncured crosslinking agents, leading to increased viscosity and decreased battery performance.

Innovation Solution

A cross-linked compound particle comprising a monomer as the core and a thermoplastic resin film as the shell, with a polymerization initiator, which can be included in the electrolyte or coated on the electrodes, to enhance electrolyte solution impregnation and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a thermally polymerizable crosslinking agent is used to manufacture directly-crosslinked polymer batteries, then manufacturing process simplicity is improved, but electrolyte impregnation uniformity deteriorates due to increased viscosity

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidelectrolyte impregnation uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The crosslinking agent is divided into segmented compound particles with a core-shell structure. The core contains the crosslinking agent monomer and polymerization initiator, while the shell contains a material that disappears at a predetermined temperature. This segmentation allows the crosslinking agent to be uniformly distributed in the electrolyte without increasing viscosity, as the particles remain discrete until thermal curing activates them in situ.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The compound particles are prepared in advance with the crosslinking agent monomer and polymerization initiator already positioned in the core, and the temperature-disappearing material already forming the shell. This preliminary preparation allows uniform distribution before curing, and the shell material disappears at a predetermined temperature to enable subsequent electrolyte impregnation without viscosity issues.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If crosslinking agent remains uncured in the electrolyte, then manufacturing flexibility is improved, but battery performance deteriorates due to difficulty in achieving uniform impregnation

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidbattery performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The polymerization initiator in the core is designed to be activated by specific parameters such as temperature, light, or other external stimuli. This allows the crosslinking agent to remain in monomer form during manufacturing (maintaining flexibility), and only polymerize when the activation parameter is applied, at which point uniform impregnation is achieved and battery performance is ensured.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If conventional lithium ion battery methods are used, then electrolyte impregnation is achieved, but safety deteriorates due to liquid electrolyte leakage risk

Engineering Contradiction:
Improveelectrolyte impregnationVSAvoidelectrolyte leakage risk
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent employs a phase transition approach where the crosslinking occurs thermally in situ within the battery structure. The polymerization initiator is activated by temperature, causing the monomer to polymerize and form a crosslinked gel structure that retains the electrolyte, thereby transitioning from a liquid electrolyte system to a gel polymer battery system that prevents leakage while maintaining manufacturing feasibility.

Inventive Principle:
Principle #36Phase transitions

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 compound particle improves battery performance by ensuring uniform electrolyte distribution and preventing core material deterioration, resulting in enhanced lifespan and high-temperature storage characteristics.

Implementation Method 1

a cross-linked compound particle comprising a monomer and a polymerization initiator, as a core

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Implementation Method 2

a film including a material disappeared at predetermined temperature as the shell

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentUS10217983B2Cross-linked compound particle and secondary battery including the same
Publication Date: 2019.02.26 LG ENERGY SOLUTION LTD

AI summary

Disclosed are a cross-linked compound particle and a secondary battery including the same. More particularly, a compound particle which includes a monomer and a polymerization initiator, as a core and a film including a material disappeared at predetermined temperature as a shell is provided.