Lithium Ion Battery Solid Electrolyte Layer Segmentation
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Solution Overview
Problem
Existing lithium ion secondary batteries with a single active material layer structure are prone to short circuits due to continuous active material between the positive and negative current collectors, leading to high impedance and reliability issues.
Innovation Solution
A lithium ion secondary battery with a laminated structure featuring a solid electrolyte layer with a discontinuous active material between the positive and negative current collectors, utilizing a volume ratio of 65:35 or less for the solid electrolyte to active material, and sintering at 500° C. to 600° C. to prevent reaction products and maintain low impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single active material layer structure is used, then the production process is simplified and manufacturing cost is reduced, but short circuits occur due to continuous active material between positive and negative current collectors
Solution Approach 1:
The active material layer is segmented into discontinuous regions separated by solid electrolyte portions, preventing continuous conductive paths between positive and negative current collectors while maintaining electrochemical functionality. This segmentation resolves the short circuit issue without requiring complete structural redesign.
Solution Approach 2:
The solid electrolyte serves as an intermediary substance that both enables ionic conduction between electrodes and provides electrical insulation to prevent electron conduction (short circuits). This dual role of the solid electrolyte allows the single-layer structure to function reliably.
2Use of energy by moving object
If continuous active material is used between current collectors, then electrochemical activity is maximized, but impedance increases and short circuits occur
Solution Approach 1:
Different regions of the active material layer are given different local qualities: active material portions provide electrochemical activity while solid electrolyte portions provide ionic conduction and electrical insulation. This local differentiation allows simultaneous optimization of electrochemical performance and impedance control.
3Reliability
If high volume ratio of solid electrolyte to active material is used, then short circuit prevention is improved, but manufacturing precision requirements increase
Solution Approach 1:
The invention specifies a quantitative parameter range (volume ratio of solid electrolyte to active material of 65:35 or less) that balances short circuit prevention with manufacturing feasibility. This parameter specification provides clear manufacturing targets while ensuring reliable short circuit prevention.
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 solution prevents short circuits, reduces interface resistance, and enhances battery reliability and capacity, allowing for a simpler production process with reduced structural defects and improved yield.
Implementation Method 1
a solid electrolyte layer including an active material in a matrix made of solid electrolyte
Implementation Method 2
sintering at 500° C. to 600° C. to prevent reaction products
Data Source
AI summary
Disclosed is a lithium ion secondary battery that has a simple structure, is easily produced, and wherein short circuits do not arise. The lithium ion secondary battery comprises an active material being contained in a matrix comprising a laminated body that includes a positive current collector and a negative current collector which are laminated on each other via a solid electrolyte layer, the solid electrolyte layer includes an active material in a matrix made of solid electrolyte, and a ratio of the volume of the solid electrolyte and the volume of the active material being 90:10-65:35. Also, the active material may also be contained in a matrix of a conductive substance of the positive current collector and/or the negative current collector.