Electrode separator with piezoelectric layer for in-stack pressure sensing and dendrite cleaning
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Solution Overview
Problem
Current battery technologies lack efficient in-stack pressure sensing and effective dendrite cleaning mechanisms, leading to potential short circuits and reduced battery performance in electric vehicles.
Innovation Solution
Incorporation of a piezoelectric layer within the electrode separator assembly in lithium-class battery cells, which senses pressure changes and generates electrical signals for real-time monitoring, and applies localized vibrations to break dendrite growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a piezoelectric layer is integrated into the electrode separator assembly, then in-stack pressure sensing capability is improved, but device complexity increases
Solution Approach 1:
The patent integrates the piezoelectric layer directly into the electrode separator assembly, merging the pressure sensing function with the existing separator structure. This allows the separator to simultaneously perform its traditional function of preventing electrode contact and the new function of sensing stack pressure through the piezoelectric material's response to compression.
Solution Approach 2:
The electrode separator assembly is designed to perform multiple functions: it maintains electrical insulation between electrodes, allows ion transport through its porous structure, and simultaneously provides pressure sensing capability through the integrated piezoelectric layer that generates electrical signals in response to stack compression.
2Loss of information
If piezoelectric layer is added for pressure sensing, then real-time monitoring capability is improved, but manufacturing complexity increases
Solution Approach 1:
The piezoelectric layer is incorporated into the separator assembly during the manufacturing process, allowing the sensing capability to be built in beforehand. This eliminates the need for separate installation of pressure sensors after battery assembly, simplifying the overall manufacturing workflow despite the added complexity of the piezoelectric material itself.
3Reliability
If piezoelectric layer is used for dendrite cleaning, then battery reliability is improved, but energy consumption increases
Solution Approach 1:
The piezoelectric layer is actuated with an alternating current signal that causes it to vibrate mechanically. These vibrations are transmitted to the electrode surfaces, physically disrupting and removing dendrite formations that would otherwise grow and cause short circuits, thereby maintaining battery reliability.
Solution Approach 2:
The dendrite cleaning function is implemented through periodic application of alternating current signals to the piezoelectric layer. Rather than continuous operation, the periodic actuation creates vibration cycles that effectively dislodge dendrites while minimizing unnecessary energy consumption during periods when cleaning is not required.
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
Enhances battery performance by simplifying design, reducing pack size and costs, increasing driving range, and improving fuel economy through effective pressure sensing and dendrite prevention.
Implementation Method 1
Expansion or bowing of the electrodes causes deformation of the piezoelectric (piezo) layer; this, in turn, causes the release of an electrical charge from the shifting crystalline structure within the piezo material.
Implementation Method 2
a modulated voltage may be passed through the piezo layer to generate a localized harmonic vibration of sufficient amplitude/frequency to break dendrite growth off of the electrodes.
Data Source
AI summary
Presented are electrochemical devices with in-stack pressure sensors, methods for making/using such devices, and battery cells with electrode stacks having an electrode separator assembly with a piezoelectric layer for in-stack pressure sensing and dendrite cleaning. An electrochemical device, such as a lithium-class secondary battery cell for example, includes a device housing with an ion-conducting electrolyte located inside the device housing. A stack of working electrodes is also located inside the device housing, in electrochemical contact with the electrolyte. At least one electrode separator assembly is located inside the device housing, interposed between a neighboring pair of the working electrodes. The electrode separator assembly includes a pair of separator layers that transmit therethrough the ions of the electrolyte, and a piezoelectric layer that is interposed between the two separator layers. The piezoelectric layer outputs an electrical signal in response to deformation of one or both of the neighboring working electrodes.