Piezoelectric Battery Structure for SEI Growth Suppression
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Solution Overview
Problem
The formation of a solid-electrolyte interphase (SEI) layer on electrodes in lithium-ion and lithium metal batteries leads to capacity fade due to lithium loss, which is not effectively addressed by current technologies.
Innovation Solution
Incorporating a structure comprising a piezoelectric material within the electrochemical cell that generates a local electric field to regulate ion transport and reduce SEI formation, improving capacity and cycle life by controlling the SEI growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a solid-electrolyte interphase layer forms on the anode during charging, then the anode is protected against solvent decomposition, but the SEI layer thickens over time leading to capacity fade and lithium loss
Solution Approach 1:
A piezoelectric layer is introduced as an intermediary component between the anode and electrolyte. This layer generates a local electric field through piezoelectric effect when subjected to mechanical stress from electrode expansion/contraction, which actively regulates ion transport and suppresses SEI formation at the anode surface, thereby reducing lithium loss while maintaining protection against solvent decomposition
Solution Approach 2:
The piezoelectric layer dynamically changes the local electric field parameters at the anode surface through mechanical stress-induced piezoelectric effect. The generated electric field modifies the ion transport conditions and reaction potential at the SEI interface, transforming the passive SEI formation process into an actively regulated process that prevents excessive thickening and lithium loss
2Reliability
If the SEI layer grows thicker over time, then continued protection is maintained, but capacity fade occurs due to competition with reversible lithium intercalation
Solution Approach 1:
The piezoelectric layer acts as a mediator that actively regulates ion transport through the SEI interface. By generating a local electric field in response to electrode mechanical stress, it ensures protected ion transport while preventing the competitive consumption of lithium that causes capacity fade, thus maintaining both protection and productivity
3Duration of action of stationary object
If piezoelectric material is added to the electrochemical cell, then SEI formation is reduced and cycle life is improved, but device complexity increases
Solution Approach 1:
The piezoelectric component is implemented as a thin film or coating layer that can be integrated into the existing battery structure. This flexible implementation minimizes structural complexity while effectively delivering the piezoelectric effect to reduce SEI formation and extend cycle life
Solution Approach 2:
The piezoelectric layer serves multiple functions simultaneously: it generates protective electric fields during charging, regulates ion transport, reduces SEI formation, and maintains structural integrity. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity
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 introduction of a piezoelectric structure enhances the capacity and energy performance of electrochemical cells by reducing SEI formation, leading to longer cycle life and improved efficiency.
Implementation Method 1
The structure (e.g., a layer or a film) comprising a piezoelectric material can generate a local electric field across its thickness as a result of an externally applied pressure or force
Implementation Method 2
The generated local electric field regulates ion transport, reaction potential or double layer structure at and near the SEI interface between active material and electrolyte
Data Source
AI summary
A system and method are disclosed that can improve the capacity, energy and cycle life of an electrochemical cell by using a structure comprising a piezoelectric material. In one form, the electrochemical cell comprises: an anode having a solid-electrolyte interphase layer formed thereon; a cathode; an electrolyte, wherein at least a portion of the electrolyte is located between the anode and cathode; and a structure comprising a piezoelectric material, the structure contacting at least a portion of the solid-electrolyte interphase layer of the anode. In another form, the electrochemical cell comprises: an anode having a solid-electrolyte interphase layer formed thereon; a cathode; an electrolyte, wherein at least a portion of the electrolyte is located between the anode and cathode; and a structure comprising units distributed in a matrix, the units comprising a piezoelectric material, the structure contacting at least a portion of the solid-electrolyte interphase layer of the anode.