Periodic Reporting for period 1 - ENHANCER (Engineering Hybrid Metal Nitrides/Carbon-Atom Wire Novel Materials for high-performance Electrochemical Energy Storage)
Reporting period: 2022-09-01 to 2024-08-31
Due to the limited resources in crude oil and global energy demand, the energy production using renewable sources and the advancement in electrochemical energy storage devices has received significant attention. For the electrochemical energy storage devices (e.g. supercapacitors, and battery), electrode materials plays a major role and hence design of suitable electrode materials with admirable properties such as high surface area, electrochemical stability, and electrical conductivity became necessary. Among the electrochemical energy storage devices, supercapacitor provides high power density and hence being utilized for high-power applications such as rapid start, and breaking systems. On the other hand, battery with high energy density is quite popular for the hybrid electric vehicles, mobiles, laptops etc. However, both the devices can not be used as stand alone since supercapacitor has lower energy density than the battery and battery has poor power density. Thus they are the commentary devices used for energy storage and deliver. However, supercapacitor came to the spotlight to store and deliver the charges for on chip devices or internet of things application. Considering supercapacitor device, depending on the charge storage mechanism, the electrode materials are categorized into electric double layer capacitor (EDLC) and pseudocapacitor. EDLC, mostly carbon based materials, stored the charge through double layer formation at the electrode/electrolyte interface, and hence designing highly porous carbon structures with excellent electrical and thermal conductivity has gained the attention. Thanks to the charge-storage mechanism that the EDLC provides excellent electrochemical stability and power density. On the other hand, as pseudocapactive materials stored the charge via Faradaic redox reactions at the interface, they provides around 10-100 times higher charge storage capacitance but shows poor cycle stability. However, there is huge scope to design novel nanostructures by cost-effective and sustainable approach. Hence the current research focus on fusing this two types of materials to improve the energy storage performances further. With this motivation, the current ENHANCER project was focused on designing highly porous carbon nanostructures and the composite with pseudocapacitive materials and studying their structure-property relationships to exploit them for supercapacitor application.
Since ENHANCER was focused on the development of carbon-based electrode materials to enhance the energy storage performance, the electrode materials such as carbon nanofoam, metal oxynitride nanofoams, carbon/metal oxynitride composite nanofoams were synthesized by pulsed laser deposition techniques. The morphology and structural properties of nanofoams were tuned by optimizing parameters in pulsed laser deposition such as deposition time, deposition pressure, laser energy, background gases. In order to improve the structural properties, post treatments were also carried out. The morphology and structural properties were investigated by scanning electron microscope, Energy dispersive X-ray spectroscopy, Raman spectroscopy, contact angle measurements, X-ray photoelectron spectroscopy etc. The charge storage performance for supercapacitor application were examined by both the three-electrode and two-electrode configuration via cyclic voltammetry, charge-discharge test and electrochemical impedance spectroscopy in various aqueous electrolytes. In this project, binder-free pristine and functionalized amorphous carbon nanofoams electrodes were synthesized, formed by backward ablated species and ablated species propagates frontside, using pulsed laser deposition in single production run. It has been shown that ballistic aggregated carbon nanofoams, formed by highly reactive ablated plasma species, outperformed in terms of electrochemical charge-storage properties than the nanofoam deposited conventionally. Moreover, carbon/metal oxynitride porous composite was synthesized by a unique synthesis strategy by ablating graphite and metal nitride targets at same time with single laser using pulsed laser deposition. By tuning the ablation spot, it has been shown that one can control the elemental compositional ratio to obtain better charge-storage performance. Beside the nanofoam designed by pulsed laser deposition, sp-carbon/polymer composite was prepared by drop-coating technique and air-brush spray coating techniques. The morphology and structure of fabricated electrode materials were investigated and finally showed the supercapacitor performance of those electrode in aqueous electrolytes.
Apart from my own research, I also contributed in many collaborative researches such as metal oxides for wastewater applications, Au nanoparticles coated TiO2 nanotube arrays for surface enhanced Raman spectroscopic applications etc.
Apart from my own research, I also contributed in many collaborative researches such as metal oxides for wastewater applications, Au nanoparticles coated TiO2 nanotube arrays for surface enhanced Raman spectroscopic applications etc.
The successful outcomes of ENHANCER are manyfold as listed below:
1. Till now, pulsed laser deposition is extensively used conventionally to prepare the materials in the frontside of plasma plume and some reports on the off-axis deposition. Here, for the first time, I showed that one can deposit the materials in the target side in addition to the conventional deposition. Eventually, target-side deposited materials showed better charge-storage performance as a supercapacitor electrode than the conventionally deposited materials on the front side of plasma plume. Later, the carbon nanofoams were modified by improving their structure and wettability, and the modified nanofoams exhibited much higher charge-storage capacitance and energy density compared to their as-grown nanofoam counterpart.
2. Pulsed laser deposition is also well known technique to deposit the composite using the composite target ablation or ablating several targets by multiple lasers, which is costly, time consuming and energy consuming. In the project, I demonstrated that one can deposit the composite by placing one smaller size target on the bigger target and ablating the species from the both target with a single laser.
3. I also explored another carbon structure called carbyne. Despite the excellent properties, poor stability under harsh environment is one of major drawbacks of this materials to be used for desirable application. In this project, I showed excellent electrochemical stability of carbyne by wrapping polymer and the composite exhibited higher charge storage performance of many studied electrode materials reported till now.
4. In collaboration, I contributed in surface enhanced Raman spectroscopic measurements to detect analytes such as Rhodamine6G using Au coated TiO2 nanotubes. I also contributed in the structure-morphology characterizations of magnetic nanoparticles for dye adsorptions for potential use in wastewater treatment. Last but not least, I contributed on the theoretical simulation on the thermal management of lithium ion battery.
1. Till now, pulsed laser deposition is extensively used conventionally to prepare the materials in the frontside of plasma plume and some reports on the off-axis deposition. Here, for the first time, I showed that one can deposit the materials in the target side in addition to the conventional deposition. Eventually, target-side deposited materials showed better charge-storage performance as a supercapacitor electrode than the conventionally deposited materials on the front side of plasma plume. Later, the carbon nanofoams were modified by improving their structure and wettability, and the modified nanofoams exhibited much higher charge-storage capacitance and energy density compared to their as-grown nanofoam counterpart.
2. Pulsed laser deposition is also well known technique to deposit the composite using the composite target ablation or ablating several targets by multiple lasers, which is costly, time consuming and energy consuming. In the project, I demonstrated that one can deposit the composite by placing one smaller size target on the bigger target and ablating the species from the both target with a single laser.
3. I also explored another carbon structure called carbyne. Despite the excellent properties, poor stability under harsh environment is one of major drawbacks of this materials to be used for desirable application. In this project, I showed excellent electrochemical stability of carbyne by wrapping polymer and the composite exhibited higher charge storage performance of many studied electrode materials reported till now.
4. In collaboration, I contributed in surface enhanced Raman spectroscopic measurements to detect analytes such as Rhodamine6G using Au coated TiO2 nanotubes. I also contributed in the structure-morphology characterizations of magnetic nanoparticles for dye adsorptions for potential use in wastewater treatment. Last but not least, I contributed on the theoretical simulation on the thermal management of lithium ion battery.