Rechargeable Battery Pressure-Deformable Plate Safety Mechanism
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Solution Overview
Problem
High-output rechargeable batteries, particularly prismatic batteries, face challenges in preventing explosions due to excessive heat or internal pressure increases, as existing safety mechanisms like chemical cells with valves and temperature switches can be delayed in response and are complex in structure.
Innovation Solution
A rechargeable battery design featuring a pressure-deformable plate with a notch that short-circuits the electrodes and provides venting, made of conductive material, which deforms to contact a tab and break at increased pressure, preventing explosion and combustion without additional vent holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complicated safety mechanism comprising a valve, piston, spring and breakable spacer element is used, then gas explosion can be prevented, but the device structure becomes complex
Solution Approach 1:
The patent combines multiple safety functions (pressure relief, short-circuit protection, and explosion prevention) into a single integrated deformable plate structure. The plate simultaneously acts as a pressure-sensitive element, electrical conductor, and mechanical barrier, eliminating the need for separate valve, piston, spring, and spacer components while maintaining comprehensive safety protection.
Solution Approach 2:
The deformable plate performs multiple functions: it serves as a pressure sensor that triggers short-circuit at moderate pressure increases, acts as an electrical conductor to short-circuit electrodes, and functions as a mechanical barrier to prevent explosion. This multi-functional design replaces several specialized components with one universal safety element.
2Reliability
If a temperature switch formed of a bimetal is used, then short-circuit protection is provided, but the response is delayed due to temperature distribution time
Solution Approach 1:
The patent replaces the thermal-mechanical bimetal temperature switch with a pressure-sensitive deformable plate system. Instead of waiting for temperature changes to propagate through the battery and cause bimetal deformation, the system responds immediately to pressure increases caused by gas generation, providing faster safety intervention before thermal runaway occurs.
Solution Approach 2:
The deformable plate is positioned and configured in advance to detect pressure changes from gas generation. When gas begins to form during overcharge or malfunction, the pressure increase immediately deforms the plate to create a short-circuit, preventing further dangerous conditions before temperature can rise to dangerous levels.
3Object-generated harmful factors
If additional vent holes are provided in the cap plate, then gas can be discharged, but the structure becomes more complex and electrolyte combustion risk increases
Solution Approach 1:
The patent converts the harmful effect of internal pressure buildup into a useful safety mechanism. The pressure from gas generation that would normally be dangerous is instead used to deform the plate and trigger the short-circuit protection, while the plate's deformation path and notch provide controlled gas release without requiring additional vent holes, thus eliminating electrolyte combustion risk.
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 short-circuits the electrodes and vents gas to prevent explosions, maintaining a stable contact state and preventing electrolyte combustion, while allowing heat emission to prevent excessive heat accumulation, thus enhancing safety and simplifying the structure.
Implementation Method 1
The pressure-deformable plate is adapted to be deformed to short-circuit the first electrode and the second electrode when excessive heat is generated inside the rechargeable battery or internal pressure is increased
Implementation Method 2
the notch of the pressure-deformable plate is broken when the pressure is further increased so as to prevent explosion of the rechargeable battery
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A rechargeable battery according to an exemplary embodiment of the present invention includes an electrode assembly, a case in which the electrode assembly is installed, and a cap assembly. The electrode assembly includes a first electrode, a second electrode, and a separator disposed between the first and second electrodes, and the cap assembly is combined to the case. The cap assembly includes a short tab that is electrically connected to the first electrode and an deformable plate that is electrically connected to the second electrode and includes a notch so as to be opened according to increase of pressure. The deformable plate is deformed according to the increase of pressure and thus electrically contacts the short circuit tab.