Samhita Pappu | Indian institute of Technology,Hyderabad (original) (raw)
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Papers by Samhita Pappu
Journal of The Electrochemical Society, Apr 1, 2023
Carbon fiber (CF)-based freestanding intermetallic Ni-Sn alloy is prepared by a facile one-pot el... more Carbon fiber (CF)-based freestanding intermetallic Ni-Sn alloy is prepared by a facile one-pot electrodeposition method and used as an anode in lithium-ion batteries (LIB) and sodium-ion batteries (SIB). Unique fern leaves-like morphology with nanotubular channels of the Sn-rich deposit of Ni-Sn@CF diminishes the challenges of large volume changes with maximum capacity utilization from Sn. Furthermore, the electro-inactive Ni phase and conductive carbon fiber backbone provide mechanical flexibility and prevent particle agglomeration during alloying/de-alloying. Electrochemistry reveals that the deposit in LIB exhibits superior C-rate performance and long-term cycling stability with an initial capacity of 984 mAh g−1 at 500 mA g−1 current density and 580 mAh g−1 capacity at the end of 500 cycles. Besides, it delivers 220 mAh g−1 capacity at 150 mAh g−1 with 77% capacity retention over 300 cycles in SIBs. This work enlightens the metal current collector-free carbon fibre-based 3D electrode designing approach toward high-performance Li-ion and Na-ion storage capability.
Energy & Fuels, Oct 21, 2022
Global challenges, Oct 1, 2022
Batteries & supercaps, Aug 4, 2020
Nanostructured transition metal oxide synthesis possessing high energy density and stability is d... more Nanostructured transition metal oxide synthesis possessing high energy density and stability is desirable for supercapacitors. Herein, we synthesize three‐dimensional NiCo2O4 (NCO) nanosheets with oxygen vacancies induced by sustainable and environmentally benign electrodeposition assisted chemical reduction process. Oxygen vacancies increase the conductivity, adsorptivity, and the active surface area, thereby enhancing the charge storage capabilities. The binder‐free NCO delivers the highest specific capacitance (Csp) of 2065 F g−1 at 1 A g−1, retaining 89.30 % of its initial value at 10 A g−1 after 10,000 continuous charge‐discharge (CD) cycles. An asymmetric supercapacitor (ASC) fabricated shows remarkable electrochemical properties with high energy density (Emax) of 28.6 Wh kg−1 and power density (Pmax) of 7.5 kW kg−1. The assembled ASC reports exceptional cyclic retention of 90.6 % for 10,000 CD cycles with practical demonstration. The approach used herein is suitable for eco‐friendly supercapacitor electrode fabrication with large scale manufacturing capability and less capital investment.
ChemElectroChem, Jun 1, 2022
Lead‐carbon hybrid ultracapacitors (Pb−C HUC) have become apparent as a way out of the sulfation ... more Lead‐carbon hybrid ultracapacitors (Pb−C HUC) have become apparent as a way out of the sulfation issue of lead‐acid batteries, simultaneously enhancing the system‘s power density and cycle life. In this work, exfoliated graphene oxides (EGO) were synthesized by the electrochemical exfoliation method followed by chemical activation and carbonization at 600 °C (AEGO‐600). The composite electrode delivered 800 F g−1 capacitance at 1 A g−1. The Pb−C HUC fabricated using AEGO‐600 anode and PbO2 cathode can achieve capacitance of 325 F g−1 at 10 A g−1 and retain 71 % capacitance after 15000 charge‐discharge cycles in the voltage range of 2.3–0.8 V. The highly stable capacitance was due to the formation of layered carbons in AEGO‐600 that enhanced the favorable electrolyte ion assessment to maximum active sites. Owing to the facile, cost‐effective synthesis approach and better charge storage behavior, the activated‐exfoliated graphene oxides thus produced could be suitable candidates for future hybrid ultracapacitor systems.
Journal of The Electrochemical Society
Carbon fiber (CF)-based freestanding intermetallic Ni-Sn alloy is prepared by a facile one-pot el... more Carbon fiber (CF)-based freestanding intermetallic Ni-Sn alloy is prepared by a facile one-pot electrodeposition method and used as an anode in lithium-ion batteries (LIB) and sodium-ion batteries (SIB). Unique fern leaves-like morphology with nanotubular channels of the Sn-rich deposit of Ni-Sn@CF diminishes the challenges of large volume changes with maximum capacity utilization from Sn. Furthermore, the electro-inactive Ni phase and conductive carbon fiber backbone provide mechanical flexibility and prevent particle agglomeration during alloying/de-alloying. Electrochemistry reveals that the deposit in LIB exhibits superior C-rate performance and long-term cycling stability with an initial capacity of 984 mAh g−1 at 500 mA g−1 current density and 580 mAh g−1 capacity at the end of 500 cycles. Besides, it delivers 220 mAh g−1 capacity at 150 mAh g−1 with 77% capacity retention over 300 cycles in SIBs. This work enlightens the metal current collector-free carbon fibre-based 3D elec...
Global challenges, Aug 9, 2022
The Li‐ion hybrid capacitor (LIHC) system explores the possibility of achieving both high energy ... more The Li‐ion hybrid capacitor (LIHC) system explores the possibility of achieving both high energy and power density in a single energy storage system with an intercalation anode and capacitive cathode. However, to achieve a high power and energy‐based system, the properties of the cathode electrode material are vital. Here, bio‐waste plant stem‐derived activated porous carbon is explored as a cathode for LIHC application. A specific surface area of 1826 m2 g−1, enhanced degree of crystallinity, and graphitization results for porous carbon from activation by potassium hydroxide. When employed as supercapacitor material, the device exhibits good rate capability, energy, and power attributes with a specific capacitance of 116 F g−1 (1 A g−1). Simultaneously when tested for LIHC application the formulated device shows good capacity retention for 2500 cycles with a high energy density of 125 Wh kg−1 at a power density of 69 W kg−1. The work demonstrates unique, cost‐effective strategy to develop a crystalline high surface area carbon from any such bio‐waste sources to be employed as potential electrodes for energy storage applications.
Journal of Energy Storage
Reference Module in Earth Systems and Environmental Sciences
Journal of The Electrochemical Society, Apr 1, 2023
Carbon fiber (CF)-based freestanding intermetallic Ni-Sn alloy is prepared by a facile one-pot el... more Carbon fiber (CF)-based freestanding intermetallic Ni-Sn alloy is prepared by a facile one-pot electrodeposition method and used as an anode in lithium-ion batteries (LIB) and sodium-ion batteries (SIB). Unique fern leaves-like morphology with nanotubular channels of the Sn-rich deposit of Ni-Sn@CF diminishes the challenges of large volume changes with maximum capacity utilization from Sn. Furthermore, the electro-inactive Ni phase and conductive carbon fiber backbone provide mechanical flexibility and prevent particle agglomeration during alloying/de-alloying. Electrochemistry reveals that the deposit in LIB exhibits superior C-rate performance and long-term cycling stability with an initial capacity of 984 mAh g−1 at 500 mA g−1 current density and 580 mAh g−1 capacity at the end of 500 cycles. Besides, it delivers 220 mAh g−1 capacity at 150 mAh g−1 with 77% capacity retention over 300 cycles in SIBs. This work enlightens the metal current collector-free carbon fibre-based 3D electrode designing approach toward high-performance Li-ion and Na-ion storage capability.
Energy & Fuels, Oct 21, 2022
Global challenges, Oct 1, 2022
Batteries & supercaps, Aug 4, 2020
Nanostructured transition metal oxide synthesis possessing high energy density and stability is d... more Nanostructured transition metal oxide synthesis possessing high energy density and stability is desirable for supercapacitors. Herein, we synthesize three‐dimensional NiCo2O4 (NCO) nanosheets with oxygen vacancies induced by sustainable and environmentally benign electrodeposition assisted chemical reduction process. Oxygen vacancies increase the conductivity, adsorptivity, and the active surface area, thereby enhancing the charge storage capabilities. The binder‐free NCO delivers the highest specific capacitance (Csp) of 2065 F g−1 at 1 A g−1, retaining 89.30 % of its initial value at 10 A g−1 after 10,000 continuous charge‐discharge (CD) cycles. An asymmetric supercapacitor (ASC) fabricated shows remarkable electrochemical properties with high energy density (Emax) of 28.6 Wh kg−1 and power density (Pmax) of 7.5 kW kg−1. The assembled ASC reports exceptional cyclic retention of 90.6 % for 10,000 CD cycles with practical demonstration. The approach used herein is suitable for eco‐friendly supercapacitor electrode fabrication with large scale manufacturing capability and less capital investment.
ChemElectroChem, Jun 1, 2022
Lead‐carbon hybrid ultracapacitors (Pb−C HUC) have become apparent as a way out of the sulfation ... more Lead‐carbon hybrid ultracapacitors (Pb−C HUC) have become apparent as a way out of the sulfation issue of lead‐acid batteries, simultaneously enhancing the system‘s power density and cycle life. In this work, exfoliated graphene oxides (EGO) were synthesized by the electrochemical exfoliation method followed by chemical activation and carbonization at 600 °C (AEGO‐600). The composite electrode delivered 800 F g−1 capacitance at 1 A g−1. The Pb−C HUC fabricated using AEGO‐600 anode and PbO2 cathode can achieve capacitance of 325 F g−1 at 10 A g−1 and retain 71 % capacitance after 15000 charge‐discharge cycles in the voltage range of 2.3–0.8 V. The highly stable capacitance was due to the formation of layered carbons in AEGO‐600 that enhanced the favorable electrolyte ion assessment to maximum active sites. Owing to the facile, cost‐effective synthesis approach and better charge storage behavior, the activated‐exfoliated graphene oxides thus produced could be suitable candidates for future hybrid ultracapacitor systems.
Journal of The Electrochemical Society
Carbon fiber (CF)-based freestanding intermetallic Ni-Sn alloy is prepared by a facile one-pot el... more Carbon fiber (CF)-based freestanding intermetallic Ni-Sn alloy is prepared by a facile one-pot electrodeposition method and used as an anode in lithium-ion batteries (LIB) and sodium-ion batteries (SIB). Unique fern leaves-like morphology with nanotubular channels of the Sn-rich deposit of Ni-Sn@CF diminishes the challenges of large volume changes with maximum capacity utilization from Sn. Furthermore, the electro-inactive Ni phase and conductive carbon fiber backbone provide mechanical flexibility and prevent particle agglomeration during alloying/de-alloying. Electrochemistry reveals that the deposit in LIB exhibits superior C-rate performance and long-term cycling stability with an initial capacity of 984 mAh g−1 at 500 mA g−1 current density and 580 mAh g−1 capacity at the end of 500 cycles. Besides, it delivers 220 mAh g−1 capacity at 150 mAh g−1 with 77% capacity retention over 300 cycles in SIBs. This work enlightens the metal current collector-free carbon fibre-based 3D elec...
Global challenges, Aug 9, 2022
The Li‐ion hybrid capacitor (LIHC) system explores the possibility of achieving both high energy ... more The Li‐ion hybrid capacitor (LIHC) system explores the possibility of achieving both high energy and power density in a single energy storage system with an intercalation anode and capacitive cathode. However, to achieve a high power and energy‐based system, the properties of the cathode electrode material are vital. Here, bio‐waste plant stem‐derived activated porous carbon is explored as a cathode for LIHC application. A specific surface area of 1826 m2 g−1, enhanced degree of crystallinity, and graphitization results for porous carbon from activation by potassium hydroxide. When employed as supercapacitor material, the device exhibits good rate capability, energy, and power attributes with a specific capacitance of 116 F g−1 (1 A g−1). Simultaneously when tested for LIHC application the formulated device shows good capacity retention for 2500 cycles with a high energy density of 125 Wh kg−1 at a power density of 69 W kg−1. The work demonstrates unique, cost‐effective strategy to develop a crystalline high surface area carbon from any such bio‐waste sources to be employed as potential electrodes for energy storage applications.
Journal of Energy Storage
Reference Module in Earth Systems and Environmental Sciences