Segmented Current Collector Layout for Battery Thermal Runaway
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Solution Overview
Problem
Thermal runaway in electrochemical cells, particularly lithium ion cells, poses safety hazards due to high reactivity and can lead to fires and explosions, with existing solutions like insulating materials compromising energy and power density.
Innovation Solution
A segmented current collector design with dividers and a fuse section that directs electron flow to prevent direct paths to short circuit points, reducing short circuit current and temperature increase without adding mass.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulating materials are added to prevent thermal runaway, then safety is improved, but energy density and power density deteriorate
Solution Approach 1:
The current collector is divided into multiple segments separated by insulating dividers, creating multiple electron flow paths. This segmentation provides thermal runaway protection through the fuse section while avoiding the need to add bulk insulating materials that would reduce energy density. The dividers are integrated into the current collector structure itself, maintaining compact design.
Solution Approach 2:
The fuse section acts as an intermediary element between the connection region and electrode region. It provides thermal protection by melting at a specific temperature to interrupt electron flow during thermal runaway events, without requiring additional insulating materials in the cell structure.
2Reliability
If a continuous current collector is used, then electrical conductivity is improved, but thermal runaway protection deteriorates
Solution Approach 1:
The current collector is segmented into multiple regions separated by insulating dividers, creating multiple electron flow paths. This segmentation limits short circuit current by forcing electrons to travel longer, more resistive paths while still maintaining adequate electrical conductivity for normal operation through the fuse section.
Solution Approach 2:
Different regions of the current collector have different properties: the connection region and electrode region maintain high conductivity for normal operation, while the fuse section is designed with specific melting characteristics for thermal protection. The dividers provide localized insulation to create electron flow paths without compromising overall conductivity.
3Reliability
If the current collector is segmented with dividers, then thermal runaway prevention is improved, but device complexity increases
Solution Approach 1:
The insulating dividers are merged with the current collector structure, and the fuse section is integrated as part of the current collector. This combining of functions reduces the number of separate components and simplifies manufacturing while maintaining thermal runaway protection capabilities.
Solution Approach 2:
The current collector serves multiple functions: it collects electrons during normal operation, provides thermal runaway protection through the fuse section, and guides electron flow through the segmented structure. The dividers simultaneously provide insulation and define electron flow paths, reducing the need for separate protective components.
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 segmented current collector design effectively limits temperature rise and prevents thermal runaway, enhancing safety and maintaining energy and power density by redirecting electron flow and using a fuse section to isolate the connection region at high temperatures.
Implementation Method 1
the thin strip of conductive material melts at a melting temperature and substantially prevent electron movement between the electrode region and the connection region
Implementation Method 2
The plurality of electron flow paths direct the flow of electrons between the electrode region and the connection region
Data Source
AI summary
Embodiments described herein relate to electrochemical cells with one or more current collectors divided into segments, and methods of producing the same. A current collector divided into segments comprises a substantially planar conductive material including a connection region and an electrode region. The electrode region includes one or more dividers defining a plurality of electron flow paths. The plurality of electron flow paths direct the flow of electrons from the electrode region to the connection region. In some embodiments, the current collector includes a fuse section disposed between the electrode region and the connection region. In some embodiments, the fuse section can include a thin strip of conductive material, such that the thin strip of conductive material melts at a melting temperature and substantially prevent electron movement between the electrode region and the connection region.