Riveted Separator-Collector Laminate for Lithium Dendrite Suppression
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Solution Overview
Problem
Conventional lithium-ion batteries face safety issues and performance limitations due to lithium dendrite formation, which can lead to short circuits and fires, and require external pressure to suppress dendrite growth, making them costly and hindering battery pack design optimization.
Innovation Solution
A riveting laminate separator-foil-separator structure is designed for anode-free cells, featuring a perforated anode current collector with a compliant polymer layer that provides inwardly directed pressure to confine lithium plating and prevent dendrite growth, eliminating the need for external pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external pressure is applied to suppress lithium dendrite growth, then safety is improved, but device complexity and cost increase
Solution Approach 1:
The battery cell structure itself generates the necessary compression force through its own components. The separator with elastic modulus between 0.1-10 MPa and the electrode assembly work together to provide self-compression that suppresses lithium dendrite growth, eliminating the need for external pressure application systems.
Solution Approach 2:
The separator acts as an intermediary element that provides both mechanical compression and physical separation functions. By selecting materials with specific elastic moduli (0.1-10 MPa), the separator mediates between the electrode assembly and the need for dendrite suppression, converting structural elements into active compression providers.
2Reliability
If external pressure is used to prevent dendrite formation, then reliability is improved, but manufacturing cost increases
Solution Approach 1:
The battery cell structure itself generates the necessary compression force through its own components. The separator with elastic modulus between 0.1-10 MPa and the electrode assembly work together to provide self-compression that suppresses lithium dendrite growth, eliminating the need for external pressure application systems.
3Ease of manufacture
If conventional electrode structure is used, then manufacturing is simpler, but lithium dendrite formation occurs leading to safety issues
Solution Approach 1:
The invention changes the mechanical parameter (elastic modulus) of the separator to be between 0.1-10 MPa, which is significantly softer than conventional separators. This parameter change enables the separator to provide continuous compression on the anode, preventing lithium dendrite formation while maintaining a simple manufacturing process.
Solution Approach 2:
The invention uses composite material structure combining a soft separator (0.1-10 MPa elastic modulus) with electrode assembly to create a system that provides both structural support and active compression. This composite approach prevents lithium dendrite formation without complicating the manufacturing process.
4Reliability
If uniform pressure environment is created, then lithium dendrite formation is suppressed, but structural complexity increases
Solution Approach 1:
The invention merges the separator and electrode assembly into an integrated structure where the soft separator is in direct contact with the anode. This merging eliminates the need for separate pressure application mechanisms, as the combined structure naturally provides uniform compression throughout the cell during assembly.
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 structure effectively suppresses lithium dendrite formation, enhancing safety and cycle life while allowing for a more compact and cost-effective battery design by generating internal pressure, thus improving energy density and extending the range of electric vehicles.
Implementation Method 1
The structure may provide the anode free cell with a compliant characteristic that imparts an inwardly directed pressure to confine lithium plating during a charge cycle of the anode-free cell
Implementation Method 2
a ceramic layer disposed between the base separator film and the polymer layer
Data Source
AI summary
An anode-free cell that includes a cathode and a separator-collector-separator structure. The separator-collector-separator structure includes a perforated anode current collector, and a polymer layer contiguously disposed on both surfaces of the perforated anode current collector through perforations in the perforated anode current collector. The polymer layer is a binder.