Recently working on Experimental Physics in Material Science and want to work in Theoretical Physics on fundamental properties of nature and matter-wave properties.
Designing nanostructure based robust catalyst for the electrochemical water splitting is the grea... more Designing nanostructure based robust catalyst for the electrochemical water splitting is the great task in the energy conversion field to accomplish high electrical conductivity, low overpotential and long lasting activity. Herein, the electrochemical overall water splitting is reported by using the hydrothermally synthesized binder free cobalt iron phosphate thin films on low cost stainless steel substrates as a conducting backbone for the first time. The effect of composition ratio variation of cobalt and iron was studied on the structural, compositional, morphological, and surface electronic properties by conducting various characterizations which results in amorphous hydrous cobalt iron phosphate having mesoporosity. The as synthesized cobalt iron phosphate having composition ratio (50:50 of Co:Fe) exhibits excellent electrochemical OER and HER catalytic water splitting performance. Best performing electrode exhibits smallest overpotentials of 251.9 mV and 55.5 mV for OER and HER respectively at 10 mA/cm2 current density. To split water molecule into the H2 and O2 by overall water splitting in same alkaline medium, the potential of 1.75 V was required after long duration (100 h) catalysis. Overall analysis confirms the cobalt iron phosphate thin films are outstanding and robust for the hydrogen production as clean renewable energy source.
The binder-free synthesis of nickel-cobalt phosphate electrodes grabs tremendous attention in hyb... more The binder-free synthesis of nickel-cobalt phosphate electrodes grabs tremendous attention in hybrid energy storage devices due to significant electrochemical activity based on a synergy between Ni and Co cations. So, the present work describes a facile scalable synthetic approach of potentiostatic electrodeposition (PED) for binder-free nickel-cobalt phosphate electrodes with Ni:Co variation. Alteration in Ni:Co composition leads into amorphous to crystalline structural conversion and icrospheres to nanosheets like morphological evolution of nickel-cobalt phosphate electrodes. The optimal ~1:1 (Ni:Co) composition of nickel-cobalt phosphate electrode with clustered nanoparticle-like morphology exhibits intercalation pseudocapacitive behavior and demonstrates maximum specific capacitance (capacity) of 2228 F g-1 (891 C g-1) at 1.5 A g-1 current density. Moreover, a fabricated aqueous hybrid asymmetric supercapacitor (AHAS) device delivers a high specific capacitance of 185 F g-1, having an energy density of 65.7 Wh kg-1 at 2.2 kW kg-1 power density with 97 % retention. Furthermore, the solid-state hybrid asymmetric supercapacitor (SHAS) device displays a maximum specific capacitance of 90 F g-1 with 32 Wh kg-1 energy density at 0.32 kW kg-1 power density and upholds 89 % capacitive retention. The present study establishes a scalable synthesis of binder-free nickel-cobalt phosphate electrodes as a cathode in hybrid energy storage devices for practical application.
Hydrogen production is an immediate need to replace the fossil fuels to keep environmental balanc... more Hydrogen production is an immediate need to replace the fossil fuels to keep environmental balance, and water splitting is an effective solution in presence of catalyst through oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, for the first time, we have synthesized Iron Phosphate Hydroxide (Fe 2.95 (PO 4) 2 (OH) 2) thin film electrode as a superior electrocatalyst by facile hydrothermal method using binder free approach. The crystallographic properties are studied from X-ray diffraction pattern, and Reitveld refinement analysis shows best fit with the tetragonal Lipscombite structure of Iron Phosphate Hydroxide (Fe 2.95 (PO 4) 2 (OH) 2). Flower like structure consist of agglomerated nanorods on micro and sub-micrometric spheres of Fe 2.95 (PO 4) 2 (OH) 2 exhibits lower overpotential of 281 mV at 10 mA/cm 2 current density towards OER in alkaline (1 M KOH) medium and maintains its activity after 12 h catalytic stability test. Moreover, prepared electrode shows HER with overpotential 165.7 mV at current density 10 mA/cm 2 in acidic (1 M H 3 PO 4) medium and demonstrates enhanced performance (126.4 mV overpotential) after 12 h catalytic stability. The Fe 2.95 (PO 4) 2 (OH) 2 thin film electrodes show superior performance in OER and HER, compared with its oxide counterpart (Fe 2 O 3).
In present investigation, microflowers like hydrous cobalt phosphate is prepared via a facile sin... more In present investigation, microflowers like hydrous cobalt phosphate is prepared via a facile single-step hydrothermal method on stainless steel substrate. The microflowers like morphology of hydrous cobalt phosphate thin film consists of microplates and further microplates converted to flakes, by means of a change in length, width and thickness, with urea variation. Hydrous cobalt phosphate thin film electrode demonstrates a high specific capacitance of 800 F g-1 at 2 mA cm-2 with 33.62 Wh kg-1 energy density and 3.12 kW kg-1 power density. By taking advantages of hydrous cobalt phosphate thin film (as a cathode electrode) and copper sulfide thin film (as an anode electrode), the asymmetric devices (aqueous/all-solid-state) are fabricated. Aqueous asymmetric device shows a high specific capacitance of 163 F g-1 at 2 mA cm-2 with an energy density of 58.12 Wh kg-1 and power density of 3.52 kW kg-1. Moreover, all-solid-state asymmetric supercapacitor device delivers a high specific capacitance of 70 F g-1 at 2 mA cm-2 with 24.91 Wh kg-1 energy density and 2.63 kW kg-1 power density in PVA-KOH gel electrolyte. The long-term cyclic stability (94 % after 3000 cycles) and actual practical demonstration (lightning 65 red LEDs) suggesting an industrial application of all-solid-state asymmetric device.
Hydrogen production is an immediate need to replace the fossil fuels to keep environmental balanc... more Hydrogen production is an immediate need to replace the fossil fuels to keep environmental balance, and water splitting is an effective solution in presence of catalyst through oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, for the first time, we have synthesized Iron Phosphate Hydroxide (Fe 2.95 (PO 4) 2 (OH) 2) thin film electrode as a superior electrocatalyst by facile hydrothermal method using binder free approach. The crystallographic properties are studied from X-ray diffraction pattern, and Reitveld refinement analysis shows best fit with the tetragonal Lipscombite structure of Iron Phosphate Hydroxide (Fe 2.95 (PO 4) 2 (OH) 2). Flower like structure consist of agglomerated nanorods on micro and sub-micrometric spheres of Fe 2.95 (PO 4) 2 (OH) 2 exhibits lower overpotential of 281 mV at 10 mA/cm 2 current density towards OER in alkaline (1 M KOH) medium and maintains its activity after 12 h catalytic stability test. Moreover, prepared electrode shows HER with overpotential 165.7 mV at current density 10 mA/cm 2 in acidic (1 M H 3 PO 4) medium and demonstrates enhanced performance (126.4 mV overpotential) after 12 h catalytic stability. The Fe 2.95 (PO 4) 2 (OH) 2 thin film electrodes show superior performance in OER and HER, compared with its oxide counterpart (Fe 2 O 3).
In present investigation, microflowers like hydrous cobalt phosphate is prepared via a facile sin... more In present investigation, microflowers like hydrous cobalt phosphate is prepared via a facile single-step hydrothermal method on stainless steel substrate. The microflowers like morphology of hydrous cobalt phosphate thin film consists of microplates and further microplates converted to flakes, by means of a change in length, width and thickness, with urea variation. Hydrous cobalt phosphate thin film electrode demonstrates a high specific capacitance of 800 F g-1 at 2 mA cm-2 with 33.62 Wh kg-1 energy density and 3.12 kW kg-1 power density. By taking advantages of hydrous cobalt phosphate thin film (as a cathode electrode) and copper sulfide thin film (as an anode electrode), the asymmetric devices (aqueous/all-solid-state) are fabricated. Aqueous asymmetric device shows a high specific capacitance of 163 F g-1 at 2 mA cm-2 with an energy density of 58.12 Wh kg-1 and power density of 3.52 kW kg-1. Moreover, all-solid-state asymmetric supercapacitor device delivers a high specific capacitance of 70 F g-1 at 2 mA cm-2 with 24.91 Wh kg-1 energy density and 2.63 kW kg-1 power density in PVA-KOH gel electrolyte. The long-term cyclic stability (94 % after 3000 cycles) and actual practical demonstration (lightning 65 red LEDs) suggesting an industrial application of all-solid-state asymmetric device.
As per the present energy economics and environmental status, use of renewable energy resources i... more As per the present energy economics and environmental status, use of renewable energy resources is essential. The development of solar cell technology is from the first generation silicon solar cell to the emerging fourth generation " Inorganics-inOrganic " solar cell. Various solar absorber compounds have been used for 2D solar cell manufacturing such as CdTe, Cu 2 InGaS 4 (CIGS), CIGSSe, Cu 2 ZnSnS 4 (CZTS) and CZTSSe. These compounds have more or less conversion efficiencies with some advantages and drawbacks. To overcome the drawbacks and achieve higher conversion efficiency, the efforts have been devoted. With some physical and chemical para-metric changes, researchers have got better results in the last ten years. In this review, the present research and development on the Cu 2 ZnSnS 4 thin film in the request of high efficiency solar cells is discussed. The effect of various structural and compositional change in the CZTS, different buffer layers with their interfaces, doping into the host material, partial substitution of the elements from the host, different synthesis and post treatments are thoroughly studied. In the last, the challenges regarding to improve conversion efficiency of CZTS solar cells and there future in the solar cell application are discussed.
At present world facing major problems of rapid growth of population and global economy due to th... more At present world facing major problems of rapid growth of population and global economy due to this demand for energy consumption has been considerably increased. Supercapacitor devices are emerging as one of the promising energy devices for the future energy technology. In this regards, the transition metal oxides are suitable electrode materials for pseudocapacitors due to different oxidation states and different ions. In this review article, we focused on the pure nickel oxide based materials synthesizing by various synthetic methods. Nowadays nickel oxide is emerging electrode material for energy storage application due to its thermal stability, high chemical stability, high theoretical specific capacity, low price, naturally abundant and environment friendliness. There are three important factors on which performance of supercapacitor mainly depends on namely electrochemical properties of the electrode material, electrolyte and voltage range. In this review paper, storage mechanism of supercapacitors with their types, characteristics of the electrode material, different synthesis methods of nickel oxide electrode material and different electrolyte materials have been reported.
Pure kesterite phase thin films of Cu2ZnSnS4 (CZTS) were synthesized at different substrate tempe... more Pure kesterite phase thin films of Cu2ZnSnS4 (CZTS) were synthesized at different substrate temperatures using sulphate precursors by spray pyrolysis method. The significance of synthesis temperature on the structural, morphological and optical properties has been studied. The X-ray analysis assured that synthesized CZTS thin films showing pure kesterite phase. The value of crystallite size was found maximum at the substrate temperature 400 °C. At the same temperature, microstructural properties such as dislocation density, micro-strain and stacking fault probability were found minimum. The morphological examination designates the development of porous and uniform CZTS thin films. The synthesized CZTS thin films illustrate excellent optical absorption (105 cm−1) in the visible band and the optical band gap varies in the range of 1.489 eV to 1.499 eV.
Designing nanostructure based robust catalyst for the electrochemical water splitting is the grea... more Designing nanostructure based robust catalyst for the electrochemical water splitting is the great task in the energy conversion field to accomplish high electrical conductivity, low overpotential and long lasting activity. Herein, the electrochemical overall water splitting is reported by using the hydrothermally synthesized binder free cobalt iron phosphate thin films on low cost stainless steel substrates as a conducting backbone for the first time. The effect of composition ratio variation of cobalt and iron was studied on the structural, compositional, morphological, and surface electronic properties by conducting various characterizations which results in amorphous hydrous cobalt iron phosphate having mesoporosity. The as synthesized cobalt iron phosphate having composition ratio (50:50 of Co:Fe) exhibits excellent electrochemical OER and HER catalytic water splitting performance. Best performing electrode exhibits smallest overpotentials of 251.9 mV and 55.5 mV for OER and HER respectively at 10 mA/cm2 current density. To split water molecule into the H2 and O2 by overall water splitting in same alkaline medium, the potential of 1.75 V was required after long duration (100 h) catalysis. Overall analysis confirms the cobalt iron phosphate thin films are outstanding and robust for the hydrogen production as clean renewable energy source.
The binder-free synthesis of nickel-cobalt phosphate electrodes grabs tremendous attention in hyb... more The binder-free synthesis of nickel-cobalt phosphate electrodes grabs tremendous attention in hybrid energy storage devices due to significant electrochemical activity based on a synergy between Ni and Co cations. So, the present work describes a facile scalable synthetic approach of potentiostatic electrodeposition (PED) for binder-free nickel-cobalt phosphate electrodes with Ni:Co variation. Alteration in Ni:Co composition leads into amorphous to crystalline structural conversion and icrospheres to nanosheets like morphological evolution of nickel-cobalt phosphate electrodes. The optimal ~1:1 (Ni:Co) composition of nickel-cobalt phosphate electrode with clustered nanoparticle-like morphology exhibits intercalation pseudocapacitive behavior and demonstrates maximum specific capacitance (capacity) of 2228 F g-1 (891 C g-1) at 1.5 A g-1 current density. Moreover, a fabricated aqueous hybrid asymmetric supercapacitor (AHAS) device delivers a high specific capacitance of 185 F g-1, having an energy density of 65.7 Wh kg-1 at 2.2 kW kg-1 power density with 97 % retention. Furthermore, the solid-state hybrid asymmetric supercapacitor (SHAS) device displays a maximum specific capacitance of 90 F g-1 with 32 Wh kg-1 energy density at 0.32 kW kg-1 power density and upholds 89 % capacitive retention. The present study establishes a scalable synthesis of binder-free nickel-cobalt phosphate electrodes as a cathode in hybrid energy storage devices for practical application.
Hydrogen production is an immediate need to replace the fossil fuels to keep environmental balanc... more Hydrogen production is an immediate need to replace the fossil fuels to keep environmental balance, and water splitting is an effective solution in presence of catalyst through oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, for the first time, we have synthesized Iron Phosphate Hydroxide (Fe 2.95 (PO 4) 2 (OH) 2) thin film electrode as a superior electrocatalyst by facile hydrothermal method using binder free approach. The crystallographic properties are studied from X-ray diffraction pattern, and Reitveld refinement analysis shows best fit with the tetragonal Lipscombite structure of Iron Phosphate Hydroxide (Fe 2.95 (PO 4) 2 (OH) 2). Flower like structure consist of agglomerated nanorods on micro and sub-micrometric spheres of Fe 2.95 (PO 4) 2 (OH) 2 exhibits lower overpotential of 281 mV at 10 mA/cm 2 current density towards OER in alkaline (1 M KOH) medium and maintains its activity after 12 h catalytic stability test. Moreover, prepared electrode shows HER with overpotential 165.7 mV at current density 10 mA/cm 2 in acidic (1 M H 3 PO 4) medium and demonstrates enhanced performance (126.4 mV overpotential) after 12 h catalytic stability. The Fe 2.95 (PO 4) 2 (OH) 2 thin film electrodes show superior performance in OER and HER, compared with its oxide counterpart (Fe 2 O 3).
In present investigation, microflowers like hydrous cobalt phosphate is prepared via a facile sin... more In present investigation, microflowers like hydrous cobalt phosphate is prepared via a facile single-step hydrothermal method on stainless steel substrate. The microflowers like morphology of hydrous cobalt phosphate thin film consists of microplates and further microplates converted to flakes, by means of a change in length, width and thickness, with urea variation. Hydrous cobalt phosphate thin film electrode demonstrates a high specific capacitance of 800 F g-1 at 2 mA cm-2 with 33.62 Wh kg-1 energy density and 3.12 kW kg-1 power density. By taking advantages of hydrous cobalt phosphate thin film (as a cathode electrode) and copper sulfide thin film (as an anode electrode), the asymmetric devices (aqueous/all-solid-state) are fabricated. Aqueous asymmetric device shows a high specific capacitance of 163 F g-1 at 2 mA cm-2 with an energy density of 58.12 Wh kg-1 and power density of 3.52 kW kg-1. Moreover, all-solid-state asymmetric supercapacitor device delivers a high specific capacitance of 70 F g-1 at 2 mA cm-2 with 24.91 Wh kg-1 energy density and 2.63 kW kg-1 power density in PVA-KOH gel electrolyte. The long-term cyclic stability (94 % after 3000 cycles) and actual practical demonstration (lightning 65 red LEDs) suggesting an industrial application of all-solid-state asymmetric device.
Hydrogen production is an immediate need to replace the fossil fuels to keep environmental balanc... more Hydrogen production is an immediate need to replace the fossil fuels to keep environmental balance, and water splitting is an effective solution in presence of catalyst through oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, for the first time, we have synthesized Iron Phosphate Hydroxide (Fe 2.95 (PO 4) 2 (OH) 2) thin film electrode as a superior electrocatalyst by facile hydrothermal method using binder free approach. The crystallographic properties are studied from X-ray diffraction pattern, and Reitveld refinement analysis shows best fit with the tetragonal Lipscombite structure of Iron Phosphate Hydroxide (Fe 2.95 (PO 4) 2 (OH) 2). Flower like structure consist of agglomerated nanorods on micro and sub-micrometric spheres of Fe 2.95 (PO 4) 2 (OH) 2 exhibits lower overpotential of 281 mV at 10 mA/cm 2 current density towards OER in alkaline (1 M KOH) medium and maintains its activity after 12 h catalytic stability test. Moreover, prepared electrode shows HER with overpotential 165.7 mV at current density 10 mA/cm 2 in acidic (1 M H 3 PO 4) medium and demonstrates enhanced performance (126.4 mV overpotential) after 12 h catalytic stability. The Fe 2.95 (PO 4) 2 (OH) 2 thin film electrodes show superior performance in OER and HER, compared with its oxide counterpart (Fe 2 O 3).
In present investigation, microflowers like hydrous cobalt phosphate is prepared via a facile sin... more In present investigation, microflowers like hydrous cobalt phosphate is prepared via a facile single-step hydrothermal method on stainless steel substrate. The microflowers like morphology of hydrous cobalt phosphate thin film consists of microplates and further microplates converted to flakes, by means of a change in length, width and thickness, with urea variation. Hydrous cobalt phosphate thin film electrode demonstrates a high specific capacitance of 800 F g-1 at 2 mA cm-2 with 33.62 Wh kg-1 energy density and 3.12 kW kg-1 power density. By taking advantages of hydrous cobalt phosphate thin film (as a cathode electrode) and copper sulfide thin film (as an anode electrode), the asymmetric devices (aqueous/all-solid-state) are fabricated. Aqueous asymmetric device shows a high specific capacitance of 163 F g-1 at 2 mA cm-2 with an energy density of 58.12 Wh kg-1 and power density of 3.52 kW kg-1. Moreover, all-solid-state asymmetric supercapacitor device delivers a high specific capacitance of 70 F g-1 at 2 mA cm-2 with 24.91 Wh kg-1 energy density and 2.63 kW kg-1 power density in PVA-KOH gel electrolyte. The long-term cyclic stability (94 % after 3000 cycles) and actual practical demonstration (lightning 65 red LEDs) suggesting an industrial application of all-solid-state asymmetric device.
As per the present energy economics and environmental status, use of renewable energy resources i... more As per the present energy economics and environmental status, use of renewable energy resources is essential. The development of solar cell technology is from the first generation silicon solar cell to the emerging fourth generation " Inorganics-inOrganic " solar cell. Various solar absorber compounds have been used for 2D solar cell manufacturing such as CdTe, Cu 2 InGaS 4 (CIGS), CIGSSe, Cu 2 ZnSnS 4 (CZTS) and CZTSSe. These compounds have more or less conversion efficiencies with some advantages and drawbacks. To overcome the drawbacks and achieve higher conversion efficiency, the efforts have been devoted. With some physical and chemical para-metric changes, researchers have got better results in the last ten years. In this review, the present research and development on the Cu 2 ZnSnS 4 thin film in the request of high efficiency solar cells is discussed. The effect of various structural and compositional change in the CZTS, different buffer layers with their interfaces, doping into the host material, partial substitution of the elements from the host, different synthesis and post treatments are thoroughly studied. In the last, the challenges regarding to improve conversion efficiency of CZTS solar cells and there future in the solar cell application are discussed.
At present world facing major problems of rapid growth of population and global economy due to th... more At present world facing major problems of rapid growth of population and global economy due to this demand for energy consumption has been considerably increased. Supercapacitor devices are emerging as one of the promising energy devices for the future energy technology. In this regards, the transition metal oxides are suitable electrode materials for pseudocapacitors due to different oxidation states and different ions. In this review article, we focused on the pure nickel oxide based materials synthesizing by various synthetic methods. Nowadays nickel oxide is emerging electrode material for energy storage application due to its thermal stability, high chemical stability, high theoretical specific capacity, low price, naturally abundant and environment friendliness. There are three important factors on which performance of supercapacitor mainly depends on namely electrochemical properties of the electrode material, electrolyte and voltage range. In this review paper, storage mechanism of supercapacitors with their types, characteristics of the electrode material, different synthesis methods of nickel oxide electrode material and different electrolyte materials have been reported.
Pure kesterite phase thin films of Cu2ZnSnS4 (CZTS) were synthesized at different substrate tempe... more Pure kesterite phase thin films of Cu2ZnSnS4 (CZTS) were synthesized at different substrate temperatures using sulphate precursors by spray pyrolysis method. The significance of synthesis temperature on the structural, morphological and optical properties has been studied. The X-ray analysis assured that synthesized CZTS thin films showing pure kesterite phase. The value of crystallite size was found maximum at the substrate temperature 400 °C. At the same temperature, microstructural properties such as dislocation density, micro-strain and stacking fault probability were found minimum. The morphological examination designates the development of porous and uniform CZTS thin films. The synthesized CZTS thin films illustrate excellent optical absorption (105 cm−1) in the visible band and the optical band gap varies in the range of 1.489 eV to 1.499 eV.
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Papers by Suraj khalate
Moreover, a fabricated aqueous hybrid asymmetric supercapacitor (AHAS) device delivers
a high specific capacitance of 185 F g-1, having an energy density of 65.7 Wh kg-1 at 2.2 kW
kg-1 power density with 97 % retention. Furthermore, the solid-state hybrid asymmetric
supercapacitor (SHAS) device displays a maximum specific capacitance of 90 F g-1 with 32
Wh kg-1 energy density at 0.32 kW kg-1 power density and upholds 89 % capacitive
retention. The present study establishes a scalable synthesis of binder-free nickel-cobalt
phosphate electrodes as a cathode in hybrid energy storage devices for practical application.
Hydrous cobalt phosphate thin film electrode demonstrates a high specific capacitance of 800 F g-1
at 2 mA cm-2 with 33.62 Wh kg-1 energy density and 3.12 kW kg-1 power density. By taking advantages of hydrous cobalt phosphate thin film (as a cathode electrode) and copper sulfide thin film (as an anode electrode), the asymmetric devices (aqueous/all-solid-state) are fabricated. Aqueous asymmetric device shows a high specific capacitance of 163 F g-1 at 2 mA cm-2 with an energy density of 58.12 Wh kg-1 and power density of 3.52 kW kg-1. Moreover, all-solid-state
asymmetric supercapacitor device delivers a high specific capacitance of 70 F g-1 at 2 mA cm-2 with 24.91 Wh kg-1 energy density and 2.63 kW kg-1 power density in PVA-KOH gel electrolyte. The long-term cyclic stability (94 % after 3000 cycles) and actual practical demonstration (lightning 65 red LEDs) suggesting an industrial application of all-solid-state asymmetric device.
electrode material and different electrolyte materials have been reported.
using sulphate precursors by spray pyrolysis method. The significance of synthesis temperature on the structural,
morphological and optical properties has been studied. The X-ray analysis assured that synthesized CZTS thin films showing pure kesterite phase. The value of crystallite size was found maximum at the substrate temperature 400 °C. At the same temperature, microstructural properties such as dislocation density, micro-strain and stacking fault probability
were found minimum. The morphological examination designates the development of porous and uniform CZTS thin films. The synthesized CZTS thin films illustrate excellent optical absorption (105 cm−1) in the visible band and the optical band gap varies in the range of 1.489 eV to 1.499 eV.
Moreover, a fabricated aqueous hybrid asymmetric supercapacitor (AHAS) device delivers
a high specific capacitance of 185 F g-1, having an energy density of 65.7 Wh kg-1 at 2.2 kW
kg-1 power density with 97 % retention. Furthermore, the solid-state hybrid asymmetric
supercapacitor (SHAS) device displays a maximum specific capacitance of 90 F g-1 with 32
Wh kg-1 energy density at 0.32 kW kg-1 power density and upholds 89 % capacitive
retention. The present study establishes a scalable synthesis of binder-free nickel-cobalt
phosphate electrodes as a cathode in hybrid energy storage devices for practical application.
Hydrous cobalt phosphate thin film electrode demonstrates a high specific capacitance of 800 F g-1
at 2 mA cm-2 with 33.62 Wh kg-1 energy density and 3.12 kW kg-1 power density. By taking advantages of hydrous cobalt phosphate thin film (as a cathode electrode) and copper sulfide thin film (as an anode electrode), the asymmetric devices (aqueous/all-solid-state) are fabricated. Aqueous asymmetric device shows a high specific capacitance of 163 F g-1 at 2 mA cm-2 with an energy density of 58.12 Wh kg-1 and power density of 3.52 kW kg-1. Moreover, all-solid-state
asymmetric supercapacitor device delivers a high specific capacitance of 70 F g-1 at 2 mA cm-2 with 24.91 Wh kg-1 energy density and 2.63 kW kg-1 power density in PVA-KOH gel electrolyte. The long-term cyclic stability (94 % after 3000 cycles) and actual practical demonstration (lightning 65 red LEDs) suggesting an industrial application of all-solid-state asymmetric device.
electrode material and different electrolyte materials have been reported.
using sulphate precursors by spray pyrolysis method. The significance of synthesis temperature on the structural,
morphological and optical properties has been studied. The X-ray analysis assured that synthesized CZTS thin films showing pure kesterite phase. The value of crystallite size was found maximum at the substrate temperature 400 °C. At the same temperature, microstructural properties such as dislocation density, micro-strain and stacking fault probability
were found minimum. The morphological examination designates the development of porous and uniform CZTS thin films. The synthesized CZTS thin films illustrate excellent optical absorption (105 cm−1) in the visible band and the optical band gap varies in the range of 1.489 eV to 1.499 eV.