Gel Polymer Electrolyte Battery Pressurization to Reduce Electrode Gaps
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Solution Overview
Problem
Lithium-ion secondary batteries with liquid electrolytes face safety issues due to volatility and ignitibility, and gel polymer electrolytes improve safety but reduce flowability, leading to performance degradation if gaps form between electrodes and separators.
Innovation Solution
A method for manufacturing gel polymer electrolyte batteries involving a pre-aging step, followed by first and second pressurization steps, and an aging step, which includes gelling an electrolyte precursor containing an organic solvent, lithium salt, and crosslinkable polymer, to reduce gaps and enhance binding between electrodes and separators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gel polymer electrolyte is used to improve safety, then safety is improved, but flowability is reduced leading to gap formation between electrode and separator
Solution Approach 1:
The patent applies preliminary action by performing a pre-aging step before the main aging process. During this pre-aging step, the gel polymer electrolyte is allowed to partially set and adapt to the battery structure, which prevents excessive flowability issues during subsequent aging while maintaining safety benefits. This preliminary preparation resolves the contradiction by preparing the electrolyte in advance to avoid gap formation.
Solution Approach 2:
The patent utilizes parameter changes by controlling temperature and time parameters during the aging process. By optimizing the aging temperature and duration, the gel polymer electrolyte achieves appropriate viscosity and flow characteristics - not too fluid to cause gaps, but not too rigid to compromise safety. This parameter optimization resolves the contradiction between safety and flowability.
2Strength
If pressurization is applied to reduce gaps between separator and electrode, then binding is improved, but excessive pressure may deform components
Solution Approach 1:
The patent applies periodic action by implementing pressurization in distinct stages rather than continuously. Pressurization is applied during specific steps (pre-aging and aging) with controlled duration and intensity, allowing the battery components to adapt gradually. This staged approach ensures adequate binding between separator and electrode while preventing deformation from excessive or prolonged pressure.
Solution Approach 2:
The patent utilizes dynamics by making the pressurization process adaptable and controllable. The pressure parameters are optimized based on the specific battery configuration and aging stage, allowing dynamic adjustment of pressing force. This dynamic approach ensures sufficient binding strength is achieved without applying excessive pressure that could deform components.
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 method results in batteries with reduced gaps, improved shape stability, increased initial capacity, reduced resistance, and enhanced safety characteristics, including high-temperature and overcharge safety, while maintaining physical property stability and processing efficiency.
Implementation Method 1
injecting an electrolyte precursor thereto, and gelling the electrolyte precursor to form a gel polymer electrolyte
Implementation Method 2
a first pressurization step of pressurizing the product of (S1)... a second pressurization step of pressurizing the product of (S4), wherein step (S5) is carried out under a pressure higher than that of step (S2)
Data Source
AI summary
A method for manufacturing a gel polymer electrolyte battery, the method comprising two steps of pressurization carried out before and after a formation step, is provided. The method provides a gel polymer electrolyte battery having a small gap between a separator and an electrode, high binding force, reduced thickness, improved shape stability and stiffness, and thus provides the gel polymer electrolyte battery having increased initial capacity, reduced initial resistance, and improved characteristics, such as cycle characteristics, high-temperature safety, overcharge safety and penetration safety.