Power Storage Cell Fuse Layout Against Vibration Reconnection
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Solution Overview
Problem
Existing power storage cells with fuse portions can recombine after being disconnected due to vibration, posing a risk of circuit re-establishment even after an overcurrent event.
Innovation Solution
Incorporating thermal expansion and contraction members within the cell case to apply external forces or redistribute self-weight, thereby promoting and maintaining the disconnection of the fuse portion, preventing recombination during vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal expansion member is added to prevent fuse recombination, then disconnection stability is improved, but device complexity increases
Solution Approach 1:
The thermal expansion member serves multiple functions: it acts as a spacer maintaining distance between the top wall and electrode assembly, provides thermal response to overcurrent conditions, and applies pressing force to prevent fuse recombination. This multi-functionality reduces the need for additional separate components.
Solution Approach 2:
The patent changes the physical state of the thermal expansion member from a relaxed state to an expanded state in response to temperature increase. This parameter change (volume expansion) automatically generates the necessary pressing force without requiring additional actuators or control mechanisms.
2Reliability
If distance between top wall and electrode assembly is increased to prevent recombination, then fuse portion disconnection stability is improved, but cell case volume increases
Solution Approach 1:
The patent employs a dynamic distance adjustment mechanism where the thermal expansion member adjusts the spacing between the top wall and electrode assembly based on temperature conditions. During normal operation, the distance is minimized to save space; during overcurrent events, the distance increases automatically as the member expands.
Solution Approach 2:
The thermal expansion member is pre-positioned in a compressed state between the top wall and electrode assembly. When temperature rises, it expands to create the necessary distance and pressing force, eliminating the need for permanent spacing structures that would increase cell volume.
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
Effectively inhibits the recombination of the fuse portion by increasing the distance between components and utilizing self-weight to maintain disconnection, ensuring the circuit remains interrupted.
Implementation Method 1
The thermal expansion member exhibits positive thermal expansion. When an overcurrent flows in the cell case, a temperature in the cell case can be increased. The thermal expansion member can be expanded to cause the thermal expansion member to press the electrode assembly.
Implementation Method 2
The thermal contraction member exhibits negative thermal expansion. When an overcurrent flows in the cell case, a temperature in the cell case can be increased. The thermal contraction member is contracted to cause the electrode assembly to lose its support from the thermal contraction member.
Data Source
AI summary
A power storage cell includes a cell case and an electrode assembly. The cell case houses the electrode assembly. The cell case includes a top wall, a peripheral wall, and a bottom wall. The top wall faces the bottom wall. The peripheral wall connects the top wall and the bottom wall. The top wall is provided with an electrode terminal. A current path that electrically connects the electrode terminal and the electrode assembly is formed in the cell case. The current path includes a fuse portion. The power storage cell further includes at least one of a thermal expansion member and a thermal contraction member. The thermal expansion member is disposed between the top wall and the electrode assembly. The thermal contraction member is disposed between the electrode assembly and at least one of the peripheral wall and the bottom wall. The thermal contraction member supports the electrode assembly.