Current Collector Conduction Barriers for Battery Safety
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Solution Overview
Problem
Battery safety is compromised due to physical damage leading to thermal runaway conditions, as existing designs fail to effectively control harmful effects of mechanical abuse, such as penetration or short circuits, which can result in fire or explosion.
Innovation Solution
A battery electrode assembly with a current collector featuring conduction barrier regions that change from a conductive state to a safety state upon a short-threatening event, reducing electrical conductivity and limiting capacity discharge to prevent thermal runaway, achieved through physical deformation of the current collector and strategic design of isolation subregions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the current collector maintains high electrical conductivity throughout, then normal battery operation is enabled, but thermal runaway risk increases during mechanical abuse
Solution Approach 1:
The current collector is divided into multiple isolation subregions separated by conduction barrier regions. During normal operation, these barrier regions conduct electricity. During mechanical abuse, the barriers fracture to electrically isolate subregions, preventing thermal runaway propagation while maintaining normal conductivity when intact.
Solution Approach 2:
The conduction barrier regions transition dynamically between two states: a conductive state during normal operation that enables battery function, and a non-conductive state during mechanical abuse that prevents thermal runaway. This dynamic property allows the same structure to serve opposing functions under different conditions.
2Object-affected harmful factors
If conduction barrier regions are designed to fracture during mechanical deformation, then thermal runaway is prevented, but normal electrical conductivity is reduced
Solution Approach 1:
The conduction barrier regions are designed with specific geometric parameters (thin bridges, narrow connections) that allow them to maintain conductivity under normal stress conditions but fracture when subjected to mechanical abuse forces. The parameter design enables the transition from conductive to non-conductive state based on applied stress levels.
3Strength
If the battery is designed with fracture-resistant current collector, then mechanical durability is improved, but thermal runaway protection is reduced
Solution Approach 1:
The current collector has non-uniform local properties: the conduction barrier regions are designed with localized weak points (thin bridges, narrow connections) that are intentionally made fracture-prone, while the rest of the current collector maintains high mechanical strength. This local quality differentiation enables thermal runaway protection without compromising overall mechanical durability.
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 limits current flow and heat generation, preventing thermal runaway and allowing the battery to function partially even after mechanical damage, while maintaining normal operation by disconnecting anode or cathode pieces electrically, thus reducing the risk of fire or explosion.
Implementation Method 1
The conduction barrier regions can be changed from the conductive state to the safety state by physical deformation of at least a portion of the current collector
Implementation Method 2
The area of the isolation subregion can be selected to limit the battery capacity that can be discharged through the isolation subregions to less than the capacity which causes sufficient Joule heating to initiate thermal runaway of a fully charged battery
Data Source
AI summary
A battery electrode assembly includes a current collector with conduction barrier regions having a conductive state in which electrical conductivity through the conduction barrier region is permitted, and a safety state in which electrical conductivity through the conduction barrier regions is reduced. The conduction barrier regions change from the conductive state to the safety state when the current collector receives a short-threatening event. An electrode material can be connected to the current collector. The conduction barrier regions can define electrical isolation subregions. A battery is also disclosed, and methods for making the electrode assembly, methods for making a battery, and methods for operating a battery.