Characterization of CNT-MnO2 nanocomposite by electrophoretic deposition as potential electrode for supercapacitor

At a Glance

Metadata	Details
Publication Date	2016-01-01
Journal	AIP conference proceedings
Authors	Alfin Darari, Hafidh Rahman Ardiansah, Arifin Arifin, Nurmanita Rismaningsih, Andini Novia Ningrum
Institutions	Diponegoro University
Citations	6
Analysis	Full AI Review Included

Technical Documentation and Analysis: Diamond Materials for High-Performance Supercapacitors

Executive Summary

This research characterizes a CNT-MnO₂ nanocomposite fabricated via Electrophoretic Deposition (EPD) for high-potential supercapacitor electrodes. The findings demonstrate a promising, scalable route for energy storage material synthesis, highlighting the critical role of carbon phases and material morphology in electrochemical performance.

Synthesis Achievement: Successful fabrication of homogeneous CNT-MnO₂ thin films on stainless steel (SS) foil using cost-effective Electrophoretic Deposition (EPD).
Optimal Composition: FTIR analysis identified the optimal composite ratio as CNT:MnO₂ 75:25 for transition vibration bonding integrity.
Crystalline Structure: XRD analysis confirmed the presence of both Graphite Carbon (2θ = 26.63°) and the highly valuable Diamond Carbon phase (2θ = 43.97°) in the composite material.
Material Morphology: The resulting nanocomposite featured a crystal size ranging from 40 nm to 52.3 nm and a thin film coating thickness of approximately 800 nm.
High Performance: The prototype double-layer supercapacitor achieved a specific capacitance of 7.86 F/g, significantly exceeding the typical market standard for similar capacitors (<2 F).
Application Potential: The material is identified as highly promising for high-capacity, fast-charge energy storage devices applicable in electric vehicles, energy converters, and advanced electronics.

Technical Specifications

Parameter	Value	Unit	Context
Optimal CNT:MnO₂ Ratio	75:25	Ratio	Based on FTIR bonding analysis
Achieved Specific Capacitance	7.86	F/g	Measured via Electrochemical Impedance Spectroscopy (EIS)
Crystalline Size (Average)	52.3	nm	Calculated using Scherrer formula
Coating Thickness	~800	nm	Observed via SEM (Figure 8.a)
CNT Synthesis Method	Spray Pyrolysis	N/A	Using Ferrocene/Benzene mixture
CNT Synthesis Temperature	900	°C	Quartz tube furnace
CNT Purification/Calcination	80	°C	Oven temperature for 1 hour
EPD Applied Voltage	50	Volts	Power supply setting for deposition
EPD Applied Current	5	A	Power supply setting for deposition
EPD Power	250	Watts	Calculated EPD power
Primary XRD Peak (Graphite C)	26.63	° (2θ)	Highest intensity peak
Secondary XRD Peak (Diamond C)	43.97	° (2θ)	Characteristic of diamond carbon type
Mn-O Bond Vibration	979.84, 509.21	cm^-1	Observed in 25% CNT/MnO₂ sample

Key Methodologies

The study utilized a multi-stage approach for synthesizing and characterizing the CNT-MnO₂ nanocomposite electrode material:

CNT Synthesis:
- Method: Spray pyrolysis using 0.6 g of Ferrocene mixed with 10 mL of Benzene.
- Conditions: Spraying into a quartz tube placed in a furnace at 900 °C.
CNT Purification and Preparation:
- Sieving: Raw CNT powder sieved at 175 mesh.
- Reflux: Washing using 65% HNO₃ acid (50 mL) and refluxing for 7 hours.
- Calcination: Dried and calcined in a furnace at 80 °C for 1 hour.
MnO₂ Synthesis:
- Method: Nano MnO₂ prepared via the sol-gel method using KMnO₄.
Nanocomposite Preparation:
- Mixture: CNT and MnO₂ powders were mixed to test three specific ratios: 25:75, 50:50, and the optimal 75:25.
- Electrolyte: Nanocomposite powder was mixed in Na₂SO₄ solution and sonicated before deposition.
Electrophoretic Deposition (EPD):
- Setup: Aluminum foil (Alufoil) and Stainless Steel foil (SS foil) plates used as electrodes (anode/cathode).
- Parameters: Power supply set to 50 V, 5 A, and 250 W to deposit the CNT-MnO₂ thin film onto the substrate.
Characterization:
- Morphology: SEM analysis confirmed the coating thickness (~800 nm) and crystal size (40-50 nm).
- Bonding: FTIR spectroscopy used to confirm Mn-O vibrational bonding and determine the optimal ratio.
- Crystallinity: XRD analysis identified carbon phases (Graphite and Diamond) and was used with the Scherrer formula to calculate average crystal size.

6CCVD Solutions & Capabilities: Diamond for Supercapacitors and Electrochemistry

The detection of the Diamond Carbon type (2θ = 43.97°) in the highly promising CNT-MnO₂ nanocomposite provides a direct engineering pathway toward utilizing superior, stable diamond materials for next-generation energy storage. 6CCVD specializes in the highest quality MPCVD diamond, providing materials that offer electrochemical performance far exceeding traditional carbon or metal oxide composites.

Applicable Materials for Advanced Electrochemical Systems

For researchers and engineers looking to replicate or significantly extend the stability and efficiency of this supercapacitor design, 6CCVD strongly recommends Boron-Doped Diamond (BDD). BDD is the premier electrode material for electrochemistry due to its unique properties:

6CCVD Material Recommendation	Material Properties & Application	Relevance to Research
Boron-Doped Polycrystalline Diamond (BDD PCD)	Wide solvent potential window, low double-layer capacitance, extreme corrosion resistance. Ideal for high-stability, high-power supercapacitors and electroanalysis.	Directly replaces the conductive carbon matrix (CNT) with a highly stable, superior electrochemical carbon, eliminating degradation issues common in nanotubes.
Thin Film Single Crystal Diamond (SCD)	Exceptional thermal conductivity, ideal insulator/substrate for heterogeneous deposition (like MnO₂).	Can serve as an ultra-high stability substrate for depositing active materials, critical for high-temperature or high-current operation.
Custom MPCVD Polycrystalline Diamond (PCD)	Available up to 125mm in size and up to 500 µm thick.	Provides the large-area stability required for scalable energy storage prototypes and industrial applications like electric car components.

Customization Potential

The research used thin films (800 nm) on conductive foils. 6CCVD provides the specialized material engineering services necessary to transition this research into robust, high-performance devices:

Precise Thickness Control: 6CCVD delivers SCD and PCD layers with thickness control from 0.1 µm up to 500 µm, allowing precise tuning of active electrode layer geometry, crucial for optimizing specific capacitance.
Custom Substrate Integration: While the paper used SS foil, 6CCVD can supply SCD or PCD films bonded to various non-diamond substrates (silicon, ceramics) or provide free-standing wafers up to 125mm diameter.
Advanced Metalization Services: The reliable construction of a supercapacitor requires robust current collectors and contacts. 6CCVD provides in-house deposition of metals, including Au, Pt, Ti, and Cu, perfectly suited for creating low-resistance contacts required for fast-charge/discharge supercapacitors.
High-Quality Polishing: For applications requiring precise interfaces, 6CCVD offers unmatched polishing services, achieving roughness as low as Ra < 1 nm (SCD) and Ra < 5 nm (PCD) across inch-sized wafers.

Engineering Support

6CCVD’s in-house team of PhD material scientists and engineers specializes in diamond film growth and post-processing, providing expert consultation for advanced electrochemical projects:

Material Selection: Assistance in selecting the optimal boron doping level and diamond morphology (PCD vs. SCD) to maximize the operational potential window and stability for supercapacitor applications.
Process Integration: Support for integrating active material coatings (such as MnO₂) onto BDD surfaces, ensuring high adhesion and optimal electrochemical interface.
Global Logistics: Utilizing our global shipping network (DDU default, DDP available), 6CCVD ensures rapid and secure delivery of custom diamond solutions worldwide.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Energy crisis that occured in Indonesia suggests that energy supply could not offset the high rate request and needs an electric energy saving device which can save high voltage, safety, and unlimited lifetime. The weakness of batteries is durable but has a low power density while the capacitor has a high power density but it doesn’t durable. The renewal of this study is CNT-MnO2 thin film fabrication method using electrophoretic deposition. Electrophoretic deposition is a newest method to deposited CNT using power supply with cheap, and make a good result. The result of FTIR analysis showed that the best CNT-MnO2 composition is 75:25 and C-C bond is detected in fingerprint area. The result is electrode thin film homogen and characterized by X-ray diffraction (XRD) peaks 2θ=26,63° is characterization of graphite, and 2θ=43,97° is characterization of diamond Carbon type and measured by Scherrer formula results 52,3 nm material average size .EIS test results its capacitance about 7,86 F. from the data it can be concluded that CNT-MnO2 potential electrode very promising for further study and has a potential to be a high capacitance, and fast charge supercapacitor which can be applied for electronic devices, energy converter, even electric car.

Tech Support

Original Source

DOI: https://doi.org/10.1063/1.4945466