Wrinkled Metal Layer Soft Electrode for Lithium Dendrite Suppression
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Solution Overview
Problem
Lithium metal batteries face safety concerns due to lithium dendrite growth during plating and stripping, which leads to capacity decay and separator penetration, limiting their performance and stability.
Innovation Solution
A three-dimensional soft electrode is developed, comprising a soft substrate with a metal layer and a lithium layer formed on it, where the metal layer features wrinkles, allowing for stress relaxation and uniform lithium plating, reducing dendrite formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium metal is used in batteries to achieve high energy density, then energy density is improved, but lithium dendrite growth occurs leading to safety concerns and capacity decay
Solution Approach 1:
The patent employs a flexible metal layer (copper, nickel, iron, silver, platinum, or gold) with thickness of 50 nm to 1 μm that can deform and wrinkle during lithium plating and stripping cycles. This flexible metal layer accommodates the volume changes and stress of lithium deposition without fracturing, preventing dendrite penetration while maintaining high energy density lithium metal electrodes
Solution Approach 2:
The patent transitions from a traditional flat two-dimensional electrode structure to a three-dimensional architecture where the metal layer develops wrinkles and undulations. This 3D structure provides additional spatial dimensions for lithium ion accommodation, distributing plating stress more evenly and preventing localized dendrite formation while maintaining high energy density
2Ease of manufacture
If a flat metal layer is used for lithium plating, then manufacturing is simple, but lithium plating is non-uniform leading to dendrite formation
Solution Approach 1:
The patent pre-forms the metal layer with a wrinkled or undulated surface morphology before lithium plating occurs. This preliminary structural modification creates a non-flat surface that promotes uniform lithium nucleation and growth across the electrode, preventing dendrite formation while maintaining manufacturing simplicity through direct deposition on the pre-formed metal layer
Solution Approach 2:
The patent introduces curvature and wrinkles into the flat metal layer structure. These curved surfaces modify the electric field distribution and lithium ion flux during plating, promoting uniform deposition across the electrode surface. The wrinkled structure increases surface area and provides stress relief pathways, improving plating uniformity without complicating the manufacturing process
3Strength
If the metal layer is rigid to maintain structural integrity, then structural stability is improved, but stress relaxation is poor leading to dendrite growth
Solution Approach 1:
The patent uses thin metal layers (50 nm to 1 μm) that are flexible rather than rigid, allowing the metal layer to wrinkle and deform during lithium plating and stripping cycles. This flexibility enables stress relaxation that prevents dendrite formation, while the metal layer maintains sufficient structural integrity to serve as an effective current collector and barrier
Solution Approach 2:
The patent creates a dynamic metal layer structure that can change morphology during battery cycling. The metal layer transitions from a relatively flat state to a wrinkled state during lithium plating, and can partially recover during stripping. This dynamic behavior allows continuous stress relaxation and adaptation to volume changes, preventing dendrite growth while maintaining structural functionality
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 soft electrode design enhances lithium plating uniformity, reduces dendrite growth, and maintains stable cycling performance with improved Coulombic efficiency and capacity retention, addressing safety and performance issues in lithium metal batteries.
Implementation Method 1
the metal layer comprises wrinkles... allowing for stress relaxation and uniform lithium plating, reducing dendrite formation
Implementation Method 2
a lithium layer formed directly on the metal layer... forming the lithium layer on the metal layer yields uniform wrinkles in the metal layer
Data Source
AI summary
An electrode includes a soft substrate, a metal layer in direct contact with the soft substrate, and a lithium layer formed directly on the metal layer, wherein the metal layer comprises wrinkles. The wrinkles are of a substantially uniform height, and the height is in a range of 100 nm to 20 μm. The wrinkles are typically separated by a substantially uniform distance, and the distance is in a range of 100 nm to 1000 μm. The wrinkles may be one dimensional or two dimensional. Fabricating an electrode includes forming a metal layer on a soft substrate, and forming a lithium layer on the metal layer. Forming the lithium layer on the metal layer yields uniform wrinkles in the metal layer. A battery may include the electrode as described.