Graphene Supercapacitor Current Collector Manufacturing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional supercapacitors face challenges in maximizing capacity for unit volume due to the thickness and density of metal layers used as current collectors, which limits their application in devices requiring high energy density, such as wearable electronics and drones.
Innovation Solution
The method involves forming graphene current collectors and electrodes in a multi-layer structure, where the metal layers are removed through compression and heat treatment, resulting in a thinner current collector that enhances unit volume capacity and increases interfacial adhesion between the electrode and current collector, thereby improving cycle life and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal layer (aluminum or copper) is used as a current collector in conventional supercapacitors, then the current collector provides good electrical conductivity and structural support, but the thickness and high density of the metal layer decrease the capacity for unit volume
Solution Approach 1:
The patent changes the material parameter from metal to graphene, fundamentally altering the physical properties of the current collector. Graphene's two-dimensional structure and exceptional electrical conductivity provide the necessary reliability while its atomic thickness dramatically reduces volume occupation, resolving the contradiction between conductivity and volume efficiency.
Solution Approach 2:
The patent employs a temporary metal layer that serves as a sacrificial substrate during manufacturing. This metal layer is intentionally designed to be removed after graphene formation, as it fulfills its purpose only during the fabrication process. This approach enables the use of graphene's superior properties in the final product while maintaining manufacturing feasibility.
2Ease of manufacture
If a metal layer is used as a current collector, then the manufacturing process is straightforward with metal deposition, but the metal layer occupies excessive volume and reduces energy density
Solution Approach 1:
The patent performs the metal layer deposition as a preliminary action that enables subsequent graphene growth through CVD. The metal layer serves as a temporary catalyst and substrate that is removed after serving its manufacturing purpose. This preliminary action facilitates the creation of the high-energy-density graphene structure without permanently occupying volume.
Solution Approach 2:
The patent discards the metal layer after it has served its manufacturing function. The metal is removed through etching or other removal processes after graphene is successfully formed on the substrate. This discarding approach eliminates the volume occupation of metal while maintaining the ease of manufacturing graphene through established CVD processes on metal substrates.
3Strength
If a thicker current collector is used to ensure mechanical strength and handling, then the structural integrity is improved, but the capacity for unit volume decreases
Solution Approach 1:
The patent creates a composite structure where graphene is combined with a supporting substrate or framework. This composite approach provides the necessary mechanical strength for handling while maintaining the ultra-thin profile of graphene. The supporting structure bears the mechanical load, allowing graphene to function at its full volumetric efficiency without compromising structural integrity.
Solution Approach 2:
The patent utilizes graphene's inherent flexibility and two-dimensional film structure to provide mechanical strength without thickness. Graphene's exceptional strength-to-thickness ratio allows it to function as an ultra-thin yet mechanically robust current collector, eliminating the need for thick metal layers and maximizing capacity for unit volume.
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
This approach results in a supercapacitor with increased capacity for unit volume, easier manufacturing by removing unnecessary metal layers, and enhanced reliability and life span due to improved adhesion between the graphene current collector and electrode.
Implementation Method 1
The third stacked layer is compressed to remove the first and second metal layers
Implementation Method 2
unnecessary metal layer in the supercapacitor is removed easily via compressing and heat treatment
Data Source
AI summary
In a method for manufacturing a supercapacitor, a first graphene current collector, a first electrode and a first separating layer are sequentially formed on a first metal layer, to form a first stacked layer. A second graphene current collector and a second electrode are sequentially formed on a second metal layer, to form a second stacked layer. The second electrode of the second stacked layer is formed on the first separating layer of the first stacked layer, to form a third stacked layer. The third stacked layer is compressed to remove the first and second metal layers, to form a unit stacked layer. The unit stacked layer and a second separating layer or an insulating layer are alternately formed.