Extendable Prismatic Battery Case for Overcharge Protection
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Solution Overview
Problem
Conventional prismatic rechargeable batteries face challenges in safely interrupting electric current during overcharging, which can lead to explosion or reduced lifespan due to structural limitations.
Innovation Solution
A prismatic rechargeable battery design featuring a case with a variable region that elongates along a specific direction, incorporating uncoated regions that can break to interrupt electrical coupling, and a lead member with a notch to facilitate current interruption, enhancing safety and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional prismatic battery structure is used, then the battery can be manufactured with standard design, but it cannot effectively interrupt electric current during overcharging leading to safety issues
Solution Approach 1:
The case includes an extendable region that can dynamically change its length in response to internal pressure changes during overcharging. When overcharging occurs and gas accumulates, the case extends to a second length, which triggers the uncoated region to break and interrupt the current path, providing automatic overcharge protection without complex electronic circuits
Solution Approach 2:
The invention changes the physical state of the case from rigid to extendable by incorporating an extendable region that can change length. This parameter change (length) is directly linked to the current interruption mechanism - when the case extends due to pressure, the uncoated region breaks, changing the electrical conductivity from conductive to non-conductive, thereby providing overcharge protection
2Temperature
If the case is made rigid for structural stability, then manufacturing is easier, but heat dissipation is reduced and overcharging cannot be detected
Solution Approach 1:
The case transitions from a completely rigid structure to a dynamic structure with an extendable region that can change length. This extendable region acts as a mechanical sensor that responds to internal pressure changes, enabling the battery to detect overcharging conditions and activate the current interruption mechanism while maintaining overall structural stability
3Reliability
If uncoated regions are added to enable current interruption, then overcharging protection is achieved, but manufacturing complexity increases
Solution Approach 1:
The invention extracts a specific portion of the electrode (the uncoated region) from the active material coating process. This uncoated region is intentionally left without active material coating on the current collector, creating a non-conductive or high-resistance section that serves as a built-in fuse. This simplifies the overall design by eliminating the need for separate electronic protection circuits
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 prevents overcharging by interrupting electrical current and improving heat dissipation, thereby extending battery lifespan and ensuring safety.
Implementation Method 1
a case having a case region extendable along a first direction... the case region being between the first uncoated region and the second uncoated region
Data Source
AI summary
A battery including: a case having a case region extendable along a first direction; an electrode assembly housed within the case and including a first electrode, a second electrode, and a separator between the first electrode and the second electrode, the first electrode including a first uncoated region at a first end of the electrode assembly, and the second electrode including a second uncoated region at a second end of the electrode assembly, the second end facing oppositely away from the first end, and the first uncoated region being spatially separated from the second uncoated region along the first direction; and a terminal electrically coupled to at least one of the first uncoated region or the second uncoated region, the case region being between the first uncoated region and the second uncoated region along the first direction.