Collective use of deep eutectic solvent for one-pot synthesis of ternary Sn/SnO₂@C electrode for supercapacitor

Thorat, Gaurav M.,Jadhav, Harsharaj S.,Chung, Wook-Jin,Seo, Jeong Gil Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.732 No.-

<P><B>Abstract</B></P> <P>Scalable and simple preparation of metal/metal oxide-carbon composite with high specific surface areas and designated properties are essential for their large scale practical applications. In view of this, we report an ecofriendly deep eutect solvents (DESs) assisted synthesis of Sn/SnO<SUB>2</SUB>@C hybrid composite. Herein, we have investigated the crucial role of DESs which collectively acts as solvent-precursor-reactant system offering an interesting and exciting physicochemical properties and alternative for the conventional solution-based synthesis methods. TEM images reveal that the massive Sn/SnO<SUB>2</SUB> nanoparticles with average size of 15–20 nm, are uniformly confined in highly layered porous carbon sheets leading to the carbonaceous composite with large surface area of 500 m<SUP>2</SUP>/g after thermal treatment. It is noteworthy that the excellent electrochemical performance of Sn/SnO<SUB>2</SUB>@C hybrid composite for supercapacitor electrode material (109.70 mAh/g at 1.42 mA/cm<SUP>2</SUP> and almost 100% capacitance retention for 5000 cycles) can be attributed to the higher surface area and synergic properties of Sn and SnO<SUB>2</SUB>. Nevertheless, the carbon matrix with a low degree of graphitization can establishes a good electrical contact and also prevents the detachment of nanoparticles during the course of long-term electrochemical reactions. In addition, selection of less toxic component is possible by virtue of compositional versatility of DESs. Thus the use of DESs can bring froth the twin benefits of solvent-precursor-reactant system and cost effective eco-friendly synthesis route which can be applicable for the synthesis of various metal/metal oxide-carbon composites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Simple one-pot synthesis of hybrid Sn/SnO<SUB>2</SUB>@C using Deep eutectic solvent (DESs). </LI> <LI> DESs collectively act as solvent-precursor –reactant system. </LI> <LI> The composites exhibit the high surface area value (∼500 m<SUP>2</SUP>/g). </LI> <LI> Almost no capacitance loss up to 5000 cycles at 2 A/g. </LI> <LI> The presence of both Sn & SnO<SUB>2</SUB> is the key for superior electrochemical performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Bi-functionality of mesostructured MnCo₂O₄ microspheres for supercapacitor and methanol electro-oxidation

Thorat, Gaurav M.,Jadhav, Harsharaj S.,Seo, Jeong Gil Elsevier 2017 CERAMICS INTERNATIONAL Vol.43 No.2

<P><B>Abstract</B></P> <P>In this work, we describe the synthesis of hierarchically mesoporous MnCo<SUB>2</SUB>O<SUB>4</SUB> microspheres via a urea-assisted co-precipitation method, followed by a post-annealing treatment in air. The stoichiometric amount of urea serves as a self-template to favor the self-assembly of hierarchically well-organized, 3D interconnected precursor carbonate microspheres under optimized reaction conditions. An electrode fabricated from micro/nano-structured MnCo<SUB>2</SUB>O<SUB>4</SUB> delivers an excellent multi-functional electrochemical performance when used in supercapacitors and methanol electro-oxidations. The electrode exhibits a high specific capacitance of 1857F/g at a 5mV/s scan rate, and 97% capacitance retention after 5000 cycles. Also, as an electro-catalyst for methanol oxidation, it maintains an optimum current density up to 95A/g. The superior electrochemical performance might be attributed to its three-dimensional interconnected porous architecture, which offers a rapid ion/electron transfer, and structural stability. The synthesis method adopted in the present study is simple, controllable, and easy to carry out at a production scale. Furthermore, the superior electrochemical performance of the as-obtained MnCo<SUB>2</SUB>O<SUB>4</SUB> microspheres renders them a potential candidate for various energy applications.</P>

Crosslinked Poly(acrylicacid) as a Self-healing Polymer Binder based on Reversible Radical Chemistry for Si anode

장원석,( Gaurav M. Thorat ),김상욱,강유미,김태현 한국공업화학회 2022 한국공업화학회 연구논문 초록집 Vol.2022 No.1

Lambda Carrageenan as a Novel Polysaccharide Binder for Si anode in Lithium Ion Battery

장원석,( Gaurav M. Thorat ),김상욱,강유미,김태현 한국공업화학회 2022 한국공업화학회 연구논문 초록집 Vol.2022 No.1

Mesoporous Mn₂O₃/reduced graphene oxide (rGO) composite with enhanced electrochemical performance for Li-ion battery

Jadhav, Harsharaj S.,Thorat, Gaurav M.,Kale, Bharat B.,Seo, Jeong Gil Royal Society of Chemistry 2017 Dalton Transactions Vol. No.

<▼1><P>Transition metal oxides are the most promising candidates in low-cost and eco-friendly energy storage/conversion applications.</P></▼1><▼2><P>Transition metal oxides are the most promising candidates in low-cost and eco-friendly energy storage/conversion applications. Herein, bare Mn2O3 and a Mn2O3/reduced graphene oxide (rGO) composite have been synthesized by a facile chemical co-precipitation and subsequent annealing procedure. The synthesized Mn2O3/rGO composite exhibits a porous microcube structure formed with several interconnected particles. The porous Mn2O3/rGO composite, with high surface area and increased conductivity, facilited the charge transfer to enhance the overall electrochemical performance when applied as an anode material in Li-ion batteries. The porous Mn2O3/rGO composite exhibits a highly reversible lithium storage capacity of 1015 mA h g<SUP>−1</SUP> at a rate of 0.5 C (230 mA g<SUP>−1</SUP>) during 130 cycles with excellent cycling stability and rate capability. The superior electrochemical performance results mainly due to the combined effect of rGO and Mn2O3, which offers high conductivity, faster Li<SUP>+</SUP> ion transfer, and enhanced structural stability. The material synthesis strategy presented in this study is simple, cost-effective and scalable, which can open new avenues for large-scale applications of composites of graphene and other transition metal oxides.</P></▼2>

Mesoporous CuCo2O4 as multi-functional electrode for Li-ion battery and supercapacitors

( Harsharaj Jadhav ),서정길,( Gaurav M Thorat ) 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0

Efficient energy storage and its economic use are central to the development of modern communication. Lithium ion batteries (LIBs) and supercapacitors can offer higher power densities with longer cycle life. Transition metal oxides based materials showed synergistic improvements in chemical activity and stability. CuCo2O4 have been widely used as a promising electrode material for LIBs and supercapacitors. In present study hierarchical mesoporous CuCo2O4 deposited directly on conducting substrate. The important properties of electrode material such as morphology, surface area, porosity desirable for its high performance. The desirable electrochemical performance of CuCo2O4, indicates it is promising candidates as electrode material for LIB and supercapacitors. **This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (No. 2009-0093816).

Hierarchical free-standing networks of MnCo2S4 as efficient Electrocatalyst for oxygen evolution reaction

Harsharaj S. Jadhav,ROY ANIMESH,Gaurav M. Thorat,정욱진,서정길 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.71 No.-

The development of highly efficient, stable and cost-effective electrocatalyst for oxygen evolutionreaction (OER) is critical. Herein, we report growth of MnCo2S4 flakes on SS-mesh using two-stepstrategy, and used as an efficient, highly active and stable electrocatalyst for OER under alkalinecondition. The free-standing electrocatalyst delivers exceptional stability of 100 h and activity for OERwith overpotential of 290 mV at a current density of 10 mA cm 2 in 1 M KOH. The enhancedelectrocatalytic performance was supported experimentally by electrochemical impedance spectra andmeasurement of the electrochemically active surface area. The high electrochemical active surface areaand electrical conductivity of MnCo2S4 flakes played an essential role in their high electrocatalyticperformance.

Hierarchical free-standing networks of MnCo₂S₄ as efficient Electrocatalyst for oxygen evolution reaction

Jadhav, Harsharaj S.,Roy, Animesh,Thorat, Gaurav M.,Chung, Wook-Jin,Seo, Jeong Gil Elsevier 2019 Journal of industrial and engineering chemistry Vol.71 No.-

<P><B>Abstract</B></P> <P>The development of highly efficient, stable and cost-effective electrocatalyst for oxygen evolution reaction (OER) is critical. Herein, we report growth of MnCo<SUB>2</SUB>S<SUB>4</SUB> flakes on SS-mesh using two-step strategy, and used as an efficient, highly active and stable electrocatalyst for OER under alkaline condition. The free-standing electrocatalyst delivers exceptional stability of 100h and activity for OER with overpotential of 290mV at a current density of 10mAcm<SUP>−2</SUP> in 1M KOH. The enhanced electrocatalytic performance was supported experimentally by electrochemical impedance spectra and measurement of the electrochemically active surface area. The high electrochemical active surface area and electrical conductivity of MnCo<SUB>2</SUB>S<SUB>4</SUB> flakes played an essential role in their high electrocatalytic performance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> MnCo<SUB>2</SUB>S<SUB>4</SUB> have been synthesized by electrodeposition followed by sulfidation. </LI> <LI> Electrocatalyst exhibits overpotential of 290mV at a 10mA/cm<SUP>2</SUP> current density. </LI> <LI> Large ECSA with plenty active sites deliver exceptional stability of 100h. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The free-standing electrocatalyst demonstrates superior activity over that of a oxide catalyst, with the need of an overpotential of 290mV to drive a geometrical catalytic current density of 10mAcm<SUP>−2</SUP> in 1M KOH, which is superior to earlier report of MnCo<SUB>2</SUB>S<SUB>4</SUB>.</P> <P>[DISPLAY OMISSION]</P>