Dual-Case Secondary Battery for Visible Swelling Indication
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Solution Overview
Problem
Conventional secondary batteries lack a method to clearly observe and assess the swelling phenomenon with the naked eye, which is indicative of electrolyte decomposition and side reactions.
Innovation Solution
A secondary battery design featuring a first and second battery case with different colors and grooves in the second case, allowing the second case to rupture and expose the first case during expansion, enabling visual confirmation of swelling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a wound type separator is used to improve flexibility and fit, then the battery can accommodate volume changes during charging/discharging, but the manufacturing complexity increases due to the need for precise formation processes
Solution Approach 1:
The separator is pre-formed with a wound configuration and pre-assembled with electrodes before being installed in the battery housing. This preliminary formation allows the separator to be ready to accommodate volume changes from the start, eliminating the need for complex in-situ formation processes during battery assembly.
Solution Approach 2:
The separator is divided into multiple layers with different functions: a base separator layer for ion conduction and additional wound-type structural layers for volume accommodation. This segmentation allows each layer to specialize in specific functions, simplifying the overall formation process while maintaining adaptability.
2Adaptability or versatility
If the battery case is designed to accommodate volume changes, then the battery can expand and contract during charging/discharging, but the space utilization and energy density decrease
Solution Approach 1:
The battery components (electrodes, separator, electrolyte) are nested in a compact wound configuration that allows for controlled expansion in specific directions. The nested structure maximizes space utilization while providing room for volume changes during operation, thereby maintaining high energy density alongside adaptability.
3Reliability
If gel electrolyte is used to improve safety and prevent leakage, then the battery becomes safer and maintenance-free, but the internal resistance increases and low-temperature performance deteriorates
Solution Approach 1:
The electrolyte system uses a composite structure combining gel electrolyte with conductive additives and porous support materials. This composite approach maintains the safety and leakage prevention benefits of gel electrolyte while reducing internal resistance through the conductive components, thereby improving energy efficiency without sacrificing reliability.
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
Enables easy visual detection of battery expansion and the degree of swelling by exposing the first case with a different color, maintaining battery performance through the intact first case.
Implementation Method 1
When a secondary battery using a silicon-synthetic graphite composite anode active material is charged, lithium ions are preferentially intercalated into the silicon portion rather than the synthetic graphite portion
Implementation Method 2
a silicon-synthetic graphite composite anode active material in which silicon particles to which an aluminum oxide coating is applied are mixed and dispersed
Data Source
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AI summary
A secondary battery according to one embodiment of the present disclosure includes an electrode assembly; a first battery case that houses the electrode assembly; and a second battery case that houses the first battery, wherein the second battery case is formed to have a different color from that of the first battery case.