Pressure-Triggered Inner Pouch for Electrolyte Replenishment in Cells
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Solution Overview
Problem
Existing lithium secondary batteries face reduced lifespan and increased resistance due to electrolyte depletion during charging and discharging, with existing methods for replenishing electrolyte complicating manufacturing and risking exposure of electrodes to air.
Innovation Solution
A pouch-shaped battery cell design featuring an inner pouch with a penetration member, including a piezoelectric element and electroactive polymer (EAP) pin, that discharges electrolyte when pressure increases, allowing replenishment without disassembling the cell.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the battery cell is disassembled to add electrolytic solution, then electrolyte replenishment is possible, but the electrode may be exposed to air and sealing becomes difficult
Solution Approach 1:
The patent implements an inner pouch containing electrolytic solution nested within the battery case. This nested structure allows the electrolyte to be supplied to the electrode assembly without disassembling the battery cell, thereby preventing electrode exposure to air while enabling electrolyte replenishment. The inner pouch acts as a contained reservoir that can release electrolyte through a penetration member when needed.
2Quantity of substance
If a pressure transmission medium is disposed between electrode layers to discharge electrolytic solution, then electrolyte replenishment is enabled, but battery capacity is reduced
Solution Approach 1:
The patent relocates the electrolyte storage function from the space between electrode layers (2D/3D internal space) to an inner pouch structure positioned in the peripheral space of the battery case. This dimensional repositioning allows electrolyte storage without occupying active battery volume, thus maintaining battery capacity while enabling electrolyte replenishment functionality.
3Quantity of substance
If an air cap is provided at the inner wall to store electrolytic solution, then electrolyte replenishment is possible, but the manufacturing process becomes complicated
Solution Approach 1:
The patent merges the electrolyte storage function with the existing battery case structure by implementing an inner pouch that is integrated into the battery case periphery. This unified structure combines the battery case and electrolyte reservoir into a single manufacturing unit, simplifying the manufacturing process compared to separately installing an air cap, while still enabling electrolyte replenishment when needed.
4Ease of operation
If the air cap is easily broken to discharge electrolytic solution, then electrolyte can be discharged, but the electrolyte may be discharged before depletion due to external impact
Solution Approach 1:
The patent changes the activation parameter from external impact (mechanical force) to internal pressure (electrochemical pressure). The penetration member is designed to respond to pressure changes within the battery case that occur during normal operation, allowing electrolyte discharge based on operational conditions rather than external impacts. This prevents premature discharge while enabling timely replenishment.
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 design maintains battery performance by replenishing electrolyte automatically, minimizing thickness increase and preventing resistance growth, thus extending the battery's cycle life.
Implementation Method 1
a penetration member configured to penetrate the inner pouch in order to discharge the electrolytic solution for replenishment, wherein the penetration member is configured to be deformed to discharge the electrolytic solution for replenishment received in the inner pouch when a pressure in the battery case increases
Implementation Method 2
a penetration member configured to penetrate the inner pouch in order to discharge the electrolytic solution for replenishment, wherein the penetration member is configured to be deformed to discharge the electrolytic solution for replenishment received in the inner pouch when a pressure in the battery case increases
Implementation Method 3
the penetration member is configured to be deformed to discharge the electrolytic solution for replenishment received in the inner pouch when a pressure in the battery case increases
Data Source
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AI summary
The present invention relates to a pouch-shaped battery cell configured such that an electrolytic solution depleted during charging and discharging of the pouch-shaped battery cell is replenished, whereby lifespan characteristics of the pouch-shaped battery cell are improved, wherein the pouch-shaped battery cell includes a battery case made of a laminate sheet, an electrode assembly received in the battery case, an inner pouch located on the outer surface of the electrode assembly, the inner pouch having an electrolytic solution for replenishment received therein, and a penetration member configured to penetrate the inner pouch in order to discharge the electrolytic solution for replenishment, wherein the penetration member is deformed to discharge the electrolytic solution for replenishment received in the inner pouch when pressure in the battery case increases.