Voltage-Activated Interrupt Layer for Battery Overcharge Cutoff
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries are prone to thermal runaway due to internal short circuits and overcharge, leading to potential fires or explosions, necessitating an internal current limiter to prevent excessive discharge and overheating.
Innovation Solution
A high energy density rechargeable metal-ion battery with an interrupt layer that activates upon exceeding a maximum safe voltage, decomposing to generate gas and delaminate from the current collector, interrupting current flow and preventing overcharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium-ion batteries are designed with high energy density to store large amounts of electrical energy, then the energy storage capacity is improved, but the risk of thermal runaway and safety hazards increases
Solution Approach 1:
The patent incorporates a current interrupter device that is pre-positioned within the battery structure, featuring a fusible link or PTC element that will automatically activate if thermal runaway or overcurrent conditions develop. This preliminary arrangement of safety components ensures immediate response capability without requiring external intervention, thus protecting the high energy density battery while maintaining compact design.
2Ease of operation
If a separator is used to electrically separate electrodes to enable ion transport, then the battery can function properly, but internal short circuits can still occur due to dendrite formation
Solution Approach 1:
The patent introduces a current interrupter as an intermediary safety device positioned within the battery structure. This device includes a fusible link or PTC element that acts as a mediator between the electrodes and external circuitry, automatically breaking the circuit if dendrite-induced short circuits or thermal runaway conditions develop, thus enhancing reliability without compromising the separator's ion transport function.
Solution Approach 2:
The current interrupter employs self-activating mechanisms where the fusible link melts or the PTC element changes resistance in response to temperature or current conditions, automatically protecting the battery without requiring external monitoring or control systems. This self-service approach maintains reliability while keeping the battery design simple and compact.
3Object-affected harmful factors
If overcharge protection mechanisms are added to prevent thermal runaway, then safety is improved, but the device complexity increases
Solution Approach 1:
The patent integrates the current interrupter functionality directly into the battery structure by incorporating the fusible link or PTC element as an intrinsic component within the battery assembly. This merging of safety functionality with the structural design eliminates the need for separate external protection circuits, thereby improving overcharge protection while minimizing increases in device complexity.
4Object-affected harmful factors
If an interrupt layer is designed to delaminate upon gas evolution to interrupt current flow, then overcharge prevention is achieved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent utilizes materials with specific thermal and electrical parameters for the interrupt layer and adhesive system. By carefully selecting materials whose adhesive properties change predictably at specific temperatures or whose decomposition generates controlled gas evolution, the patent achieves reliable delamination and current interruption while maintaining tolerance to normal manufacturing variations, thus reducing precision requirements.
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 interrupt layer effectively prevents thermal runaway by interrupting current flow and avoiding overcharge, enhancing safety and stability in lithium-ion batteries.
Implementation Method 1
The interrupt layer includes a voltage sensitive decomposable component for decomposing upon exposure to voltage in excess of the maximum safe voltage, the voltage sensitive decomposable component for evolving a gas upon decomposition
Implementation Method 2
The evolved gas for delaminating the interrupt layer from the anode current collector for interrupting current therethrough
Data Source
AI summary
A high energy density rechargeable metal-ion battery includes an anode energy layer, a cathode energy layer, a separator for separating the anode and the cathode energy layers, an anode current collector for transferring electrons to and from the anode energy layer, the battery characterized by a maximum safe voltage for avoiding overcharge, and an interrupt layer that interrupts current within the battery upon exposure to voltage in excess of the maximum safe voltage. The interrupt layer is between the anode energy layer and current collector. When unactivated, it is laminated to the cathode current collector, conducting current therethrough. When activated, the interrupt layer delaminates from the anode current collector, interrupting current therethrough. The interrupt layer includes a voltage sensitive decomposable component that upon exposure to voltage in excess of the maximum safe voltage decomposes, evolving a gas, delaminating the interrupt layer from the anode current collector, interrupting current therethrough.