Nitrogen-Doped Porous Graphene Supercapacitor Electrode via NO Gas Pyrolysis
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Solution Overview
Problem
There is a lack of a simple and efficient production method for nitrogen-doping porous graphene, which limits the development of high-performance supercapacitors with improved energy and power density.
Innovation Solution
A one-step method involving rapid temperature increase and continuous injection of nitric oxide (NO) gas is used to produce nitrogen-doping porous graphene, which is then integrated into activated carbon electrodes for supercapacitors, utilizing an organic electrolyte with specific solvents and ions to enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional production methods (direct synthesis or post synthesis treatment) are used to create nitrogen-doping graphene, then nitrogen doping can be achieved, but the production process becomes complex and inefficient
Solution Approach 1:
The patent combines nitrogen doping and porous structure formation into a single simultaneous process using nitric oxide gas treatment during thermal processing. This merges what were previously separate steps (nitrogen introduction and pore creation) into one integrated operation, reducing process complexity while achieving both nitrogen doping and porous structure formation effectively
Solution Approach 2:
The nitric oxide gas treatment serves multiple functions simultaneously: it introduces nitrogen atoms into the graphene lattice, creates porous structures through gas evolution, and modifies the electronic properties. This multi-functional approach eliminates the need for separate treatment steps for each modification, streamlining the production process
2Manufacturing precision
If multiple treatment steps are used to achieve nitrogen doping and porous structure, then the desired material properties can be obtained, but the production time and energy consumption increase
Solution Approach 1:
The patent combines nitrogen doping and porous structure formation into a single simultaneous process using nitric oxide gas treatment during thermal processing. This merges what were previously separate steps (nitrogen introduction and pore creation) into one integrated operation, reducing process complexity while achieving both nitrogen doping and porous structure formation effectively
Solution Approach 2:
The method uses nitric oxide gas that inherently contains both nitrogen for doping and oxygen for creating porous structures through decomposition. This preliminary preparation of the gas reagent allows both modifications to occur simultaneously during a single thermal treatment step, eliminating the need for sequential processing
3Reliability
If conventional nitrogen doping methods are used, then graphene conductivity can be improved, but residual functional groups remain that complicate further processing
Solution Approach 1:
The patent controls the thermal processing parameters (temperature, gas flow rate, treatment time) to optimize nitrogen incorporation while minimizing residual functional groups. By adjusting these parameters, the process achieves effective nitrogen doping for improved conductivity while reducing unwanted residual groups that would complicate further processing
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 improved energy density (21 Wh/Kg) and power density (31 kW/Kg), while simplifying the production process and reducing residual functional groups.
Implementation Method 1
the carbon atoms in the graphene lattice are replaced by nitrogen atoms or functional group with nitrogen, the nitrogen atom and carbon lattice of the graphene in sp2 mixed track may share electron pairs to make chemical bond
Implementation Method 2
by fast increasing temperature and continuously injecting nitric oxide (NO) gas to make nitrogen-doping porous graphene by one step
Implementation Method 3
Since the nitrogen atom has a characteristics of strong electronic negativity, it influences neighboring carbon atoms to cause chemical characteristics change of the graphene
Implementation Method 4
the activated material is applied to the conductive substrate by a scraper to deposing on the conductive substrate
Data Source
AI summary
In this patent, a high energy and power density supercapacitor was invented. A coin cell with supercapacitor includes a spring lamination, a working electrode, a counter electrode, a separator, and an Organic electrolyte. The working and counter electrodes were Activated carbon/N-doping porous graphene/binder coated on Aluminum substrate. The separator was from Nippon Kodoshi Corporation. The Organic electrolyte was 1M TEABF4/PC. The method of producing N-doping porous graphene included the following steps: Step 1: Graphite oxide (GO) was transferred into the furnace. Step 2: Inject 50 c.c./min gas flow of Nitrous oxides for one hour. Step 3: Intensify 40 Celsius degrees/min to 900 Celsius degrees and after holding for one hour, lower the temperature naturally to the room temperature, it can be prepared into N-doping porous graphene. In this patent, the capacitance of the supercapacitor is 122 F/g and the power density is 31 kW/Kg.