Lithium Metal Foil Nano-Imprint Structure for Separator Adhesion
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Solution Overview
Problem
Conventional lithium metal secondary batteries face challenges in achieving adequate electrode-separator adhesive strength due to the use of a lithium metal foil with a flat and smooth surface, leading to issues like separation and meandering, especially when applied in next-generation batteries without a separate negative electrode active material.
Innovation Solution
A nano imprint pattern structure is formed on the surface of the lithium metal foil to enhance adhesion with the separator, allowing for physical bonding through shape deformation during the lamination process, thereby improving the adhesive strength between the negative electrode and the separator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a lithium metal foil with a flat and smooth surface is used as the negative electrode, then the energy density is improved, but the adhesive strength between the negative electrode and separator deteriorates
Solution Approach 1:
The patent applies surface texturing to the lithium metal foil negative electrode, creating micro-protrusions and micro-depressions on the surface. This curvature modification replaces the flat smooth surface with a textured surface that enables mechanical interlocking with the separator, thereby improving adhesive strength while maintaining the high energy density benefits of lithium metal foil.
2Ease of manufacture
If a lithium metal foil with a flat and smooth surface is used as the negative electrode, then the manufacturing simplicity is improved, but the assembly processability deteriorates
Solution Approach 1:
The patent implements surface texturing on the lithium metal foil negative electrode before assembly. This preliminary action of creating micro-protrusions and micro-depressions on the surface enables the electrode to form strong mechanical interlocking with the separator during assembly, thereby improving assembly processability while maintaining manufacturing simplicity through integration into the electrode preparation process.
3Stability of the object's composition
If a lithium metal foil with a flat and smooth surface is used as the negative electrode, then the material uniformity is improved, but the adhesion mechanism deteriorates
Solution Approach 1:
The patent introduces micro-scale surface texturing with protrusions and depressions on the lithium metal foil negative electrode. This curvature modification creates mechanical interlocking capability with the separator, transforming the adhesion mechanism from relying solely on electrostatic attraction to incorporating strong mechanical interlocking, thereby improving the overall adhesion mechanism while preserving material uniformity.
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 enhanced adhesive strength between the negative electrode and separator prevents bending and separation of the unit cell, improving the assembly processability and overall performance of lithium metal secondary batteries.
Implementation Method 1
a physical adhesion by the shape deformation of (the binder in) the separator that has been achieved through the rough active material surface shape of the conventional lithium ion secondary battery
Implementation Method 2
only a chemical adhesion by electrostatic attraction might be relied on
Data Source
Figure 1(a)~1(d)
Figure 2
Figure 3
AI summary
Provided is a lithium metal secondary battery ensuring electrode-separator adhesive strength and a method for fabricating the same. The lithium metal secondary battery according to the present disclosure includes a negative electrode, a separator and a positive electrode, the negative electrode including a lithium metal foil as a negative electrode material, wherein a nano imprint pattern structure is formed on a lithium metal foil surface which is a surface of the negative electrode facing the separator, and the negative electrode and the separator are adhered to each other.