Pouch Battery Unidirectional Terminal Structure for Heat and Space
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Solution Overview
Problem
Pouch-shaped secondary batteries face reduced lifespan due to heat generated from electrode leads and nonuniform use of active materials during charging and discharging, and require more space for packing, leading to reduced energy density.
Innovation Solution
A pouch-shaped secondary battery structure is developed where bidirectional electrode terminals are converted to unidirectional terminals by orienting electrode tabs in one direction, using a unidirectional structure with a coating layer made of high electrical insulation materials, and incorporating a metal layer or substrate to improve heat dissipation and insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If bidirectional electrode terminals are used, then space utilization is improved and energy density is increased, but heat generation from electrode leads increases and lifespan is reduced
Solution Approach 1:
The patent extracts and removes the electrode leads from the bidirectional terminal configuration, converting to a unidirectional terminal structure where only one electrode lead is required. This elimination of unnecessary electrode leads directly reduces heat generation and improves cell lifespan while maintaining space utilization through optimized tab placement.
Solution Approach 2:
The patent changes the terminal configuration parameter from bidirectional to unidirectional, fundamentally altering the electrical connection architecture. This parameter change reduces the number of electrode leads from two to one, thereby reducing resistive heating and improving reliability while maintaining or enhancing energy density through better space utilization.
2Reliability
If unidirectional electrode terminals are used, then lifespan is improved by reducing heat generation, but space requirement increases and energy density is reduced
Solution Approach 1:
The patent repositions the electrode tabs from opposite sides (bidirectional) to the same side (unidirectional) of the electrode assembly, utilizing the two-dimensional space of the electrode assembly more efficiently. This dimensional reconfiguration allows for better space utilization in the battery pack while maintaining the lifespan benefits of reduced heat generation from fewer electrode leads.
Solution Approach 2:
The patent performs preliminary optimization of the electrode tab placement and collector design to maximize space utilization in the unidirectional configuration. By carefully designing the tab positions and collector geometry before assembly, the patent achieves high energy density despite the unidirectional terminal structure, preventing the typical space penalty associated with such configurations.
3Volume of moving object
If bidirectional electrode terminals are used, then space utilization is improved, but nonuniform use of active materials occurs and stability is reduced
Solution Approach 1:
The patent applies local quality optimization by strategically positioning the single electrode tab and collector to ensure uniform current distribution across the electrode active material. The collector design and tab placement are locally optimized to prevent current concentration at specific regions, thereby achieving uniform active material utilization and enhanced stability while maintaining compact space utilization.
Solution Approach 2:
The patent replaces the mechanical bidirectional terminal structure with a unidirectional structure that inherently provides more uniform current distribution. This structural substitution eliminates the asymmetry and current concentration issues associated with bidirectional terminals, thereby improving the uniformity of active material usage and overall cell stability.
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 enhances the stability and energy density of the battery by reducing heat-related issues and optimizing space usage, while maintaining the characteristics of a bidirectional cell in a unidirectional cell assembly.
Implementation Method 1
using a unidirectional structure with a coating layer made of high electrical insulation materials
Implementation Method 2
incorporating a metal layer or substrate to improve heat dissipation and insulation
Data Source
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AI summary
Disclosed herein is a pouch-shaped secondary battery configured to have a structure in which a unit cell, including an electrode assembly constituted by a positive electrode and a negative electrode, stacked in the state in which a separator is interposed between the positive electrode and the negative electrode, electrode tabs, and electrode leads, or a cell assembly, including two or more stacked unit cells, is mounted in a pouch-shaped case, wherein the pouch-shaped secondary battery includes a unidirectional structure in which electrode terminals oriented in two directions are changed to electrode terminals oriented in one direction. In the case in which a battery pack is constituted using a bidirectional cell, a large space is required, whereby the energy density of the battery pack is reduced. The disclosed pouch-shaped secondary battery has the effect of solving the above problem. The lifespan of a unidirectional cell is reduced due to heat generated from electrode leads and due to nonuniform use of active materials in the cell at the time of charging and discharging the cell. The disclosed pouch-shaped secondary battery has the effect of solving the above problem.