Wound Li-Ion Battery Separator for Impact Short-Circuit Suppression
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Solution Overview
Problem
Existing non-aqueous electrolyte secondary batteries do not adequately address internal shorts due to external impacts in both full and non-full charge states.
Innovation Solution
A non-aqueous electrolyte secondary battery design featuring a wound-type electrode assembly with a positive electrode and a separator having normal and plastically deformed regions, where the separator is stretched during winding to enhance puncture strength and suppress internal shorts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coating layer is formed on the diaphragm to prevent resin aggregate adhesion, then battery reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent changes the chemical composition parameters of the coating layer by incorporating specific inorganic particles (such as alumina, silica, or boehmite) with controlled particle sizes (0.1-10 μm) and surface treatments. This parameter modification enables the coating to provide anti-adhesion properties without requiring complex multi-layer structures, thus improving battery reliability while maintaining manufacturing feasibility.
Solution Approach 2:
The patent creates a composite coating structure by combining organic binder resins with inorganic particles. This composite approach provides both the adhesion benefits of organic materials and the anti-adhesion properties of inorganic particles, achieving reliable battery performance through a single integrated coating layer rather than multiple separate layers.
2Manufacturing precision
If solvent type is restricted in coating formation to ensure quality, then coating quality is improved, but ease of manufacture deteriorates
Solution Approach 1:
The patent modifies the solvent selection criteria by specifying particular solvent types (such as esters, carboxylic acids, or their mixers) with controlled boiling points and polarity. This parameter-based approach ensures consistent coating quality through controlled solvent evaporation rates while maintaining ease of manufacture by using commonly available industrial solvents rather than requiring specialized chemical compounds.
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 battery withstands external impacts in both full and non-full charge states, effectively preventing internal shorts through the use of a separator with varying puncture strengths and deformability.
Implementation Method 1
a coating layer formed from a binder resin and inorganic particles
Implementation Method 2
non-aqueous electrolyte secondary battery which uses a non-aqueous electrolyte solution
Data Source
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AI summary
The purpose of the present disclosure is to provide a non-aqueous electrolyte secondary battery capable of suppressing an internal short circuit of a battery due to an external impact in both a fully charged state and a non-fully charged state. The non-aqueous electrolyte secondary battery according to one embodiment of the present disclosure is characterized by: comprising a wound electrode body in which a positive electrode and a negative electrode are wound thereon via a separator, and a battery case that houses the electrode body; the positive electrode having a positive electrode current collector and a positive electrode mixture layer formed on at least one surface of the positive electrode current collector; and the separator having a normal part and a plastically deformed part having a higher puncture strength than the normal part.