Battery Pack Insulating Separators for Short Circuit Prevention
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Solution Overview
Problem
Existing battery packs with rectangular batteries connected in series and/or parallel face challenges in efficient heat radiation and electrical insulation, leading to potential short circuits and electrolyte leaks, particularly due to exposed surfaces and safety valve locations.
Innovation Solution
A battery pack configuration using separators with electrical and heat insulating properties that cover the external cases of rectangular battery cells, excluding electrode terminals, and featuring an interconnecting structure to enclose all surfaces, including stepped region depressions for improved cooling and electrolyte absorption, preventing short circuits and leaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If separators are only sandwiched between surfaces of adjacent battery cells, then the structure is simple, but electrical insulation is insufficient and short circuits may occur
Solution Approach 1:
The separator is divided into multiple parts: a main body portion sandwiched between adjacent battery cells, and extending portions that protrude from the main body to wrap around and cover exposed regions of battery cell external cases. This segmentation allows the separator to provide both simple installation and comprehensive insulation coverage.
Solution Approach 2:
The separator extends from a two-dimensional sandwiched configuration into a three-dimensional structure by adding extending portions that wrap around battery cell surfaces. This dimensional extension enables the separator to cover not only the contact surfaces between cells but also the exposed side surfaces and edges, providing comprehensive insulation without significantly increasing complexity.
2Reliability
If entire outer surface of rectangular battery is covered, then electrical insulation is improved, but safety valve and electrode terminals cannot be accessed
Solution Approach 1:
The separator is designed with different properties in different regions: the main body provides full coverage insulation, while the extending portions are specifically shaped to wrap around and expose designated areas. This local differentiation ensures that safety valves and electrode terminals remain accessible while all other surfaces are insulated, resolving the contradiction between comprehensive coverage and operational access.
3Reliability
If resin or rubber sealing material is used at electrode base region, then insulation is provided, but degradation over time can cause electrolyte leaks
Solution Approach 1:
The separator acts as an intermediary insulating structure that covers the electrode base region and surrounding external case regions without relying on degradable sealing materials like resin or rubber. By providing insulation through the separator's extending portions that wrap around the battery cell, the design eliminates the need for separate sealing materials, thereby preventing electrolyte leaks while maintaining insulation functionality over time.
4Productivity
If rectangular batteries are placed in close disposition for higher output, then energy density is improved, but heat radiation becomes less efficient
Solution Approach 1:
The separator serves as a thermal intermediary between adjacent battery cells. While its primary function is electrical insulation, the extending portions that wrap around battery cell surfaces also create thermal barriers that facilitate heat dissipation. This allows rectangular batteries to be placed in close disposition for high energy density while the separator mediates heat management by providing thermal insulation pathways.
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 effectively prevents unintended short circuits and electrolyte leaks by ensuring comprehensive insulation and efficient cooling, enhancing the safety and reliability of the battery pack.
Implementation Method 1
separators with electrical and heat insulating properties covering the outside of each battery cell external case
Implementation Method 2
separators with electrical and heat insulating properties covering the outside of each battery cell external case
Data Source
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AI summary
In a battery pack having a plurality of battery cells 10 connected in series and/or parallel, the battery pack is provided with a plurality of battery cells 10 each encased in a rectangular external case, and a plurality of separators 20 with electrical and heat insulating properties covering the outside of each battery cell external case excluding electrode terminals 12. Each separator 20 is disposed to intervene between adjacent battery cells 10 putting the external cases of those battery cells 10 in contact with both sides of the separator 20. With the external case of each battery cell 10 covered by separators 20 while exposing electrode terminals 12, those electrode terminals 12 are connected together. As a result, excluding required regions, battery cells 10 can be enclosed and unintended events such as short circuits can be effectively prevented.