Supercapacitor electrodes for enhanced energy storage
The Department of Physics is happy to announce that Prof Ranjit Thapa and his PhD Scholar Mr Samadhan Kapse have published a paper titled “Supercapacitor electrodes based on quasi-one-dimensional van der Waals TiS3 nanosheets: experimental findings and theoretical validation” in the Nature indexed journal ‘Applied Physics Letters’ having an impact factor of 3.79. The Paper is published in collaboration with Abhinandan Patra and Chandra Sekhar Rout from Jain University and Dattatray J Late from Amity University.
Abstract of the Research
To cease the ever-increasing energy demand, additional enthusiastic focus has been given to generate more sustainable energy from alternative renewable sources. The storage of these energies for future usage solely depends on the energy storage devices. A diversity of electrode materials based on two-dimensional (2D) transition metals and their derivatives have enticed the whole world owing to their tunable properties. Transition metal trichalcogenides (TMTCs- MX3 type) is the emergent class of 2D materials that gathered a lot of interest because of their quasi-one-dimensional anisotropic properties with the van der Waals force of attraction in between the layers. Herein, TiS3 being an MX3-type of material is preferred as the electrode for supercapacitor application with detailed experimental investigations and theoretical validation. The highest capacitance attained for TiS3 is found to be 235 F/g (105 C/g) at 5 mV/s with a battery type of charge storage mechanism. The asymmetric device is fabricated using Ti3C2Tx MXene nanosheets as negative electrode and a brilliant 91 % of capacitance retention is accomplished with an extensive potential window of 1.5 V. The investigational discoveries are substantiated by theoretical simulation in terms of the quantum capacitance assessment and charge storage mechanisms.
About the Research
In this work, a battery type TMTC material i.e., TiS3 has been synthesized and characterized by different analytical techniques such as Raman spectroscopy, FESEM and TEM to gain information on its structural and morphological aspects. The electrochemical performance was found to be promising by considering its good energy storage performance. High capacitance of 235 F/g (105 C/g) at 5 mV/s was achieved and the asymmetric supercapacitor devices disclosed outstanding cycling stability of 91 % over 6000 GCD cycles. In addition, the theoretical simulations also validated the experimental findings through the evaluation of the quantum capacitance. The higher conductivity, abundant electrochemical active sites, swift faradic redox kinetics and well-connected pathway for ion transfer characteristics pave the way for TiS3 to emerge as an eminent material for energy storage application in the long run.
Social Implications
Energy storage devices come into picture whenever there is a prerequisite of storing renewable energy. Among the numerous energy storage devices, batteries and ultracapacitors have acquired more popularity in nanotechnology and optoelectronics field. The high stability, accuracy, swift functionality, power density and reversibility are the key factors that have positioned ultracapacitors at the forefront of all energy storage devices. On the contrary, the low energy density and high cost of supercapacitor electrodes try to put them in the back seat of the wheels of the energy industry. Henceforth, in recent times the development of supercapattery (abbreviated for supercapacitor and battery) types of materials has become a way out which tie the aces like high specific power of supercapacitors with the high energy density of batteries. These materials exhibit capacitive or battery type behaviour on the basis of materials properties, electrolytic ions, design of the electrochemical cell. Due to these advantages and superior energy storage performance, the demand for this kind of material is growing.
Theoretical quantum capacitance is an important parameter to investigate the supercapacitor performance of low dimensional materials such as electrodes. This approach is highly cost-effective for the rapid screening of various materials for supercapacitor applications.
- Published in Departmental News, News, Physics News, Research News
Optimising the anaerobic digestion process
Publishing a paper in the second-best journal in the discipline of Environmental Engineering and having an impact factor of 9.7 is obviously a significant achievement. The Department of Environmental Science is elated to inform you that the paper, “Dynamic Simulation and Optimization of Anaerobic Digestion Processes using MATLAB” has been published by Dr Karthik Rajendran, Assistant Professor of Environmental Science, and his PhD student, Mr Prabhakaran G in ‘Bioresource Technology’ journal.
Abstract of the research
Time series-based modelling provides a fundamental understanding of process fluctuations in an anaerobic digestion process. However, such models are scarce in literature. In this work, a dynamic model was developed based on modified Hill’s model using MATLAB, which can predict biomethane production with time series. This model can predict the biomethane production for both batch and continuous processes, across substrates and at diverse conditions such as total solids, loading rate, and days of operation. The deviation between the literature and the developed model was less than ±7.6%, which shows the accuracy and robustness of this model. Moreover, statistical analysis showed there was no significant difference between literature and simulation, verifying the null hypothesis. Finding a steady and optimized loading rate was necessary from an industrial perspective, which usually requires extensive experimental data. With the developed model, a stable and optimal methane yield generating loading rate could be identified at minimal input.
About the research
Anaerobic Digestion (AD) is a natural process that converts organic waste into biogas, in the absence of oxygen, which can be used as cooking fuel or for electricity generation. Biogas generation depends on various operational parameters of the AD processes like temperature, organic loading rate, and pH. For example, the speed of a car depends on various parameters like mileage per litre, type of fuel (petrol or diesel), engine power, type of gear, and road type. The optimum speed of a car can be defined by the manufacturer. Likewise, the optimum biogas/ biomethane can be calculated by computer simulations. If the loading rate is increased, the biogas yield increases up to a particular time and then decreases due to overloading like human bodies (eating a large amount of food may strain or cause failure of the digestive system), then the biogas plant will be a failure.
Optimising the loading rate through experiment was not easy, as multiple trials were necessary and it will take a longer time and high cost. In this work, the researchers did the optimisation based on the loading rate over the time period. The loading rate was optimised to maximum methane production, which also showed the region of stability from an operational perspective.
Practical implementations of the research
The practical implications of this work are, to use it in real-time operations of an AD plant and in research laboratories to estimate the best region of operation in terms of loading rate and yield. This work shows that longer days of operation could optimise better loading rates or could help in reaching a steady-state condition in real-time biogas plants.
Future research plans
Real-time biogas plants are deficient in the availability of data to do the computer simulation by using the mathematical model. To overcome this problem, researchers are planning to do Artificial Intelligence (Machine learning)- based biogas prediction by data-driven techniques. It will reduce the complexity with higher accuracy. In future, the machine learning model will integrate with real-time bioreactor for self-diagnosis and better decision making.
- Published in Departmental News, ENVS News, News, Research News
Do you think CSIR-JRF is a tough nut to crack? Persistence is the key
“Believe you can and you’re halfway there.” – Theodore Roosevelt
Jesni M Jacob, currently doing research under Dr Mahesh Kumar Ravva narrates her journey to achieving CSIR-JRF All India Rank of 65 through persistent efforts.
I’m working in the field of computational chemistry on designing and developing organic molecules for OLED applications. Securing an AIR of 65 in the CSIR JRF in Chemical Science June 2021 exam is a dream come true moment for me.
In 2019, I completed my post-graduate studies at Madras Christian College, Chennai. The four-year-long journey from zero to JRF AIR 65 was of hard work, patience, sleepless nights, sacrifices and even frustrated moments. It was challenging to remain motivated after multiple unsuccessful attempts. But I wasn’t ready to give up hope. I believed in myself and dreamed big with faith in God Almighty.
My previous attempts didn’t provide me with any hope of continuing my preparation because my marks were consistently far below the cutoffs. That made me realise one thing: without coaching and ample guidance, qualifying for CSIR JRF is a toiling task for an average student. But I learned that with strong passion, proper dedication, and right strategies of do’s and don’ts, any aspiring student can pass the exam with flying colours.
After each attempt, I learned from my mistakes and tried to optimise my strategies. One should never try to cover the entire syllabus and be bothered about it. I analysed the unit-wise weightage and narrowed it down to a few important topics that I found exciting and comfortable.
- Choose topics carefully and focus solely on mastering them.
- Try to stick to and rely on reliable standard textbooks as much as possible.
- The SRMAP library provided me with excellent access to a wide range of standard texts.
The JRF aspirants should try to solve previous years’ questions from standard exams (CSIR, GATE, IISc, etc.) and note new concepts or approaches every day. Enjoy and prepare short notes with a lot of scribbling and highlighting in various colours. Notes should be concise and simple to revise later. But don’t spend too much time making notes.
I made time for exam preparation along with my work and research activities. I’m grateful to my family, teachers, and especially my guide- Dr Mahesh Kumar Ravva, for their constant support and encouragement. He gave me a safe space to express my desire to ace the exam and my anxieties about it. Dr Mahesh always listened to my concerns and helped me to gain clarity on my thoughts. He always encouraged me to dream big and shared his perspectives and lessons from his life experiences. He is a great mentor, motivator, and teacher to me.
- Published in Blog, Chemistry-news, Departmental News, News, Research, Students Achievements
Presenting our first doctorate holder: Dr Vasavi Dutt
The university revels in its monumental achievement of bringing out the maiden doctorate degree holder, Dr Vasavi Dutt, within four years of its inception. Dr Vasavi Dutt enrolled as a PhD scholar in the Department of Chemistry, under the supervision of Dr Nimai Mishra, Assistant Professor, in 2018. She received the academic honour for her research thesis titled “Improvement of Photoluminescence and Achieving the Stabilization of Cesium Lead Halide Perovskite Nanocrystals for Light-emitting Applications”. Dr Vasavi has been an extremely diligent student and she mustered up immense courage to bring her research to closure even during the testing times of the pandemic.
In the words of Dr Nimai Mishra, “It was a great privilege for me to supervise Ms Vasavi, (correct me Dr Vasavi now) as my first PhD student. She joined my research lab in July 2018 when there was no lab at all, and we started our work at Chemistry BTech Lab”. Dr Mishra was gleaming with pride as he spoke more about his scholar, “During these three and a half years, I had relentless scientific discussions with Vasavi which enriched both of us. Her attitude towards research was remarkable, whenever I gave her a research problem, she used to come up with a detailed outline of how to go ahead with the project”. He also praised her for all her accomplishments which include the publication of 13 research papers, filing of 3 patents and winning the best poster in national & internal conferences.
Dr Vasavi also shared her happiness for having received the mentorship of Dr Mishra, “Working in Dr Nimai Mishra’s lab was a great experience. I had the opportunity to engage and initiate multiple research topics and collaborations. He has always encouraged me to explore new fields to broaden perspectives and bring together new ideas”. She also expressed her gratitude to him for being a welcoming and approachable mentor. “I’m eternally thankful to Dr Mishra for his friendship, empathy, and moreover, for his great sense of humour”. She currently resides in the US with her family. Now that she has successfully completed her PhD, soon she would start looking for a job or rather pursue a post-doctoral fellowship in America.
Dr Vasavi was out of words to thank the university for facilitating and bringing the best in technology and infrastructure for advanced research. “I can never thank my university enough for extending a hospitable environment and nutritious food for all the doctorate students”, she further mentioned. The university serves as a promised land for thousands of research aspirants like her to head towards their dream of making unfeigned contributions to academia.
- Published in Chemistry-news, Departmental News, News, Students Achievements