Crosslinked Polymer Electrolyte for High-Temperature Li-Ion Strength

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Solution Overview

Problem

Existing polymer electrolytes in lithium ion secondary batteries face challenges in achieving high ionic conductivity while maintaining strength, especially at high temperatures, and are prone to short circuits under impact.

Innovation Solution

A polymer electrolyte with a three-dimensional crosslinked structure containing terminal-free chains and an anion and cationic group with a nitrogen-containing aromatic structure, which enhances ionic conductivity and impact resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a polymer gel or linear polymer electrolyte is used, then ionic conductivity is improved, but strength at high temperatures and impact resistance deteriorate

Engineering Contradiction:
Improveionic conductivityVSAvoidstrength at high temperatures and impact resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies composite materials by combining polymer (1) with specific functional groups ( formulas (2)-(4) ) to create a polymer electrolyte that achieves both high ionic conductivity and mechanical strength. The composite structure integrates multiple functional components working synergistically to resolve the contradiction between conductivity and strength.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by introducing specific functional groups at localized positions within the polymer structure. The polymer contains specific structural units (formulas (2)-(4)) at controlled ratios (formula (1) at 90-99 mass%, formulas (2)-(4) at 1-10 mass%), creating local regions with enhanced ionic conductivity while maintaining overall structural integrity and strength.

Inventive Principle:
Principle #3Local quality

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 polymer electrolyte maintains high ionic conductivity and strength even at high temperatures, reducing the risk of short circuits and improving battery performance.

Implementation Method 1

charging and discharging are performed by the movement of ions between the electrodes through the electrolyte

Methodology Applied
Scientific EffectIonic conduction: Conduction (electrical)

Implementation Method 2

a polymer electrolyte having a volume swelling ratio of 40% to 120%, as measured by a methyl ethyl ketone immersion method

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP4641589A1Polymer electrolyte and secondary battery
Publication Date: 2025.10.29 CANON KK
  • EP4641589A1 patent drawingFigure 1
  • EP4641589A1 patent drawingFigure 2
  • EP4641589A1 patent drawingFigure 3

AI summary

Provided is a polymer electrolyte that is not susceptible to any decrease in strength even in a high temperature range and has high ion conductivity at room temperature and lower temperatures even without relying on a liquid electrolyte. This polymer electrolyte contains a polymer that has a specific polyether structure having a free end, a crosslinked structure produced using a specific polyether, and a specific ammonium cationic group, the polymer electrolyte furthermore containing a lithium salt, and the volume swelling ratio of the polymer electrolyte being 40-120% as determined by a methyl ethyl ketone immersion method.