Stacked Electrode Assembly With Ceramic Insulation Against Short Circuits
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Solution Overview
Problem
Rechargeable batteries face issues with short circuits due to differences in electrode areas, leading to potential damage such as ignition or explosion, and lithium precipitation on positive electrodes without a facing negative electrode.
Innovation Solution
The electrode assembly features a stacked configuration with positive electrodes, separators, and negative electrodes alternately stacked. The outermost positive electrode includes a substrate with an uncoated region and an active material layer, along with a ceramic layer on the opposite surface, and a functional layer between the substrate and the active material layer, which provides insulation and reduces the risk of short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the areas of positive and negative electrodes are made different to optimize battery structure, then the battery can achieve better energy density, but short circuits may occur when exposed substrate contacts active material layer of different polarity
Solution Approach 1:
The patent introduces a separator as an intermediary component between the positive and negative electrodes. This separator extends into the exposed substrate area of the outermost positive electrode, physically preventing contact between the substrate and active material layer of different polarity, thereby eliminating the short circuit risk while maintaining the different electrode area configuration for optimized energy density
Solution Approach 2:
The separator is pre-positioned to extend into the exposed substrate area before any short circuit could occur. This preliminary arrangement ensures that when the battery is assembled and operated, the separator is already in place to prevent contact between opposing polarity elements, proactively preventing the short circuit condition
2Ease of manufacture
If the outermost electrode is made as positive electrode to simplify structure, then manufacturing is easier, but lithium precipitation occurs on the positive electrode without a facing negative electrode
Solution Approach 1:
The separator acts as an intermediary that extends into the exposed substrate area of the outermost positive electrode, creating a physical barrier that prevents lithium ions from precipitating on the positive electrode surface where no negative electrode is present to accept them
Solution Approach 2:
The separator functions as a thin film structure that can extend into the exposed substrate area without adding significant structural complexity. This thin film barrier effectively prevents lithium precipitation while maintaining the simplicity of having the positive electrode as the outermost electrode
3Reliability
If functional layers and ceramic layers are added to prevent short circuits and lithium precipitation, then safety is improved, but device complexity increases
Solution Approach 1:
The separator serves multiple functions simultaneously: it prevents short circuits between electrodes of different polarity, prevents lithium precipitation on the outermost positive electrode, and maintains structural simplicity. This multi-functionality achieves improved safety without proportionally increasing device complexity
Solution Approach 2:
The patent employs composite material structures where the separator combines properties of insulation, ion permeability, and mechanical stability. This composite approach allows a single component to fulfill multiple protective roles, improving safety while minimizing the increase in device complexity
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
This configuration effectively reduces the risk of short circuits and lithium precipitation, enhancing the safety and electric characteristics of the rechargeable battery.
Implementation Method 1
the functional layer may include a material including a compound represented by Chemical Formula 1, a compound represented by [Chemical Formula 2], or a combination thereof... the resistance value (e.g., electron resistance or electrical resistance) of the functional layer may be greater than that of the substrate and the active material layer
Implementation Method 2
a ceramic layer formed on the other surface (e.g., opposite surface) of the substrate in the electrode active region
Data Source
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AI summary
An electrode assembly for a rechargeable battery according may include a stacked-type electrode assembly in which positive electrodes, separators, and negative electrodes are alternately stacked, wherein the positive electrode on an outermost side of the stacked-type electrode assembly, the positive electrode includes a substrate having an electrode uncoated region and an electrode active region, an active material layer formed on one surface of the substrate in the electrode active region, and a ceramic layer formed on the opposite surface of the substrate in the electrode active region, and the one surface is relatively adjacent to the center and faces the negative electrode.