Electrochemically Reduced Graphene Electrodes for Binder-Free Energy Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrodes in power storage devices face challenges in achieving high conductivity, charge and discharge capacity per unit weight or volume, and durability due to limitations in active material weight and binder swelling issues.
Innovation Solution
Graphene is formed through electrochemical reduction using electric energy, forming a layer of graphene oxide on a conductive layer and applying a potential to reduce it to graphene, which is then integrated into the electrode structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrodes include conductive additives and binders to achieve conductivity and structural integrity, then the electrode can maintain structural stability, but the weight of active material per unit weight decreases and charge and discharge capacity per unit weight decreases
Solution Approach 1:
The invention changes the physical and chemical parameters of the electrode by replacing conventional binders with graphene coating. The graphene layer provides both mechanical integrity and electrical conductivity, fundamentally altering the electrode's compositional parameters to eliminate the need for separate conductive additives and binders.
Solution Approach 2:
The invention creates a composite structure where graphene coats the active material particles, forming a core-shell type composite. This composite material simultaneously provides structural stability, electrical conductivity, and high active material content, resolving the contradiction between structural requirements and active material weight.
2Strength
If conventional electrodes use binders to maintain structural integrity, then the electrode can withstand mechanical stress, but the binder swells upon contact with electrolyte causing electrode deformation and reduced durability
Solution Approach 1:
The invention extracts and removes the binder component from the electrode structure entirely. By replacing the binder with a graphene coating on active material particles, the harmful swelling effect is eliminated while maintaining necessary mechanical integrity through the graphene network.
Solution Approach 2:
The invention replaces the conventional binder (which has limited lifespan due to swelling and degradation) with graphene, a stable and durable material that does not swell in electrolyte, thereby significantly improving electrode durability and lifespan.
3Power
If conventional electrodes include conductive additives to achieve sufficient conductivity, then the electrode can conduct electricity effectively, but the weight and volume occupied by non-active materials increases
Solution Approach 1:
The invention merges the functions of binders and conductive additives into a single graphene coating layer. This multi-functional integration eliminates the need for separate conductive additives, maximizing active material content while maintaining effective electrical conductivity through the graphene network.
Solution Approach 2:
The invention changes the conductivity mechanism by replacing conventional conductive additives (carbon black, metal powders) with graphene, which provides superior electrical conductivity per unit weight. This parameter change in conductivity efficiency allows for minimal non-active material while achieving effective conductivity.
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 resulting graphene exhibits higher conductivity and stability, enhancing the charge and discharge capacity, reliability, and durability of power storage devices.
Implementation Method 1
a method for forming graphene, which includes the steps of forming a layer including graphene oxide over a first conductive layer; and supplying a potential at which a reduction reaction of the graphene oxide occurs to the first conductive layer in an electrolyte in which the first conductive layer as a working electrode and a second conductive layer as a counter electrode are immersed
Data Source
AI summary
The formation method of graphene includes the steps of forming a layer including graphene oxide over a first conductive layer; and supplying a potential at which the reduction reaction of the graphene oxide occurs to the first conductive layer in an electrolyte where the first conductive layer as a working electrode and a second conductive layer with a as a counter electrode are immersed. A manufacturing method of a power storage device including at least a positive electrode, a negative electrode, an electrolyte, and a separator includes a step of forming graphene for an active material layer of one of or both the positive electrode and the negative electrode by the formation method.