Prismatic Battery Collector Design for Energy Density
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Solution Overview
Problem
Prismatic secondary batteries used in EVs and PHEVs face challenges in increasing energy density due to space requirements for exposed electrode core body portions and complex collector structures, which hinder higher capacity and reliability.
Innovation Solution
A prismatic secondary battery design with positive and negative electrode tab portions disposed at the end of the electrode body on the sealing plate side, incorporating a pressure-sensitive current breaking mechanism and collector connections between the tab portions and large-area side walls, which reduces non-electricity generating space and enhances energy density and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wound positive electrode core body exposed portion and wound negative electrode core body exposed portion are disposed at edge portions, then current collection is improved, but spaces are required in the battery case which hinders energy density increase
Solution Approach 1:
The patent changes the spatial arrangement by moving from edge portion disposition to end portion disposition of the electrode core body exposed portions. This dimensional repositioning allows the exposed portions to be located at the terminal end of the wound electrode body, eliminating the need for separate spaces in the battery case and enabling higher energy density while maintaining current collection functionality.
Solution Approach 2:
The patent merges the functions of the positive and negative electrode exposed portions by disposing them at the same end portion of the wound electrode body. This consolidation eliminates the need for separate spaces that would otherwise be required for each exposed portion, thereby increasing energy density without compromising current collection.
2Quantity of substance
If positive electrode core body exposed portion and negative electrode core body exposed portion are disposed at one end portion, then energy density is improved, but collector structure becomes more complex
Solution Approach 1:
The patent segments the collector structure into a collector body portion and a collector connection portion. The collector body portion is disposed on the electrode body side of the deformation plate, while the collector connection is disposed between the current breaking mechanism and the large-area side walls. This segmentation simplifies the overall structure by clearly defining functional zones and reducing complexity.
Solution Approach 2:
The patent introduces a deformation plate as an intermediary component that seals the opening portion of the conductive member. The collector body portion is disposed on the electrode body side of this deformation plate, which acts as a mediator between the electrode body and the collector structure, simplifying the overall arrangement.
3Quantity of substance
If collector connection is disposed between current breaking mechanism and large-area side walls, then space utilization is improved, but manufacturing complexity increases
Solution Approach 1:
The patent specifies precise positioning parameters for the collector connection, placing it between the current breaking mechanism and the large-area side walls of the battery case. This parameter-based positioning optimizes space utilization while maintaining manufacturability through clear geometric definitions.
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 design achieves higher energy density and larger battery capacity while preventing overcharging through the pressure-sensitive mechanism, resulting in a more reliable battery pack.
Implementation Method 1
the conductive path between the positive electrode plate and the positive electrode terminal or in a conductive path between the negative electrode plate and the negative electrode terminal is disconnected upon breakage of a fragile portion caused by deformation of the deformation plate deforming when a pressure inside the battery is equivalent to or above a predetermined value
Data Source
AI summary
An electrode body including positive electrode plate and negative electrode plate includes a positive electrode tab portion at an end portion on the sealing plate side. The positive electrode plate is electrically connected to a positive electrode collector including a collector body portion and a collector connection. A pressure-sensitive current breaking mechanism includes a conductive member including an opening portion on an electrode body side, a deformation plate that seals the opening portion, and a collector body portion that is disposed on the electrode body side of the deformation plate and that is connected to the deformation plate. The collector connection is disposed between the current breaking mechanism and one of the large-area side walls of the prismatic outer package, and the positive electrode tab portion is connected to the collector connection.