Papers by Vengadesh Krishna M
Triblock copolymer P(VdCl.), LiClO 4 salt and tetrahydrofuran (THF) were purchased from Sigma-Ald... more Triblock copolymer P(VdCl.), LiClO 4 salt and tetrahydrofuran (THF) were purchased from Sigma-Aldrich. Appropriate amount of P(VdCl.) and LiClO 4 is dissolved in THF solvent at room temperature and stirred continuously. A homogeneous viscous liquid is obtained after continuous stirring for 4 days. The homogeneous liquid is transferred into petri dish and left undisturbed for evaporation. Finally, solid polymer electrolytes of composition 60 wt%
Macromolecular Chemistry and Physics, Jun 11, 2023
This paper deals with development and characterization of the solid biopolymer electrolyte using ... more This paper deals with development and characterization of the solid biopolymer electrolyte using Sodium alginate as the host biopolymer and magnesium perchlorate used as a doping salt. Membranes are prepared via solution casting technique. Several characterization techniques, such as X‐ray and diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, AC impedance spectroscopy, linear sweep voltammetry, and transference number measurement are performed to characterize the prepared biopolymer membrane. The highest ionic conductivity 2.41 × 10−3 S cm−1 is observed for prepared solid biopolymer electrolyte contains 40:60 m wt% of NaAlg:Mg(ClO4)2. The electrochemical stability of highest ion conducting biopolymer membrane is observed at 3.62 V. A primary magnesium battery is constructed using the highest ionic conducting biopolymer membrane and the open circuit voltage of the fabricated magnesium battery is found to be 2.0 V.
Polymer Bulletin, Mar 29, 2021
A new class of environmental friendly bio-based electrolytes has been synthesized from natural tr... more A new class of environmental friendly bio-based electrolytes has been synthesized from natural tree gum of Moringa oleifera by solution casting technique. An ionic salt of ammonium nitrate (NH4NO3) of varying compositions from 0.2 to 0.6 wt % has been used as an additive to optimize the ionic conductivity of Moringa gum (MG) based biopolymer membranes. X-ray diffractograms affirm the enhancement in amorphous nature of the membranes with the addition of salt, and the high degree of amorphous nature is exhibited by the composition of MG (1 g) with 0.5 wt % NH4NO3. Complex formation between MG and salt has been studied by Fourier transform infra-red (FTIR). Thermal behavioural study by differential scanning calorimetry (DSC) authenticates the flexibility of the prepared MG-based membrane with NH4NO3 by low glass transition temperature. The obtained solid polymer electrolyte MG (1 g) with 0.5 wt % NH4NO3 achieved an ionic conductivity as high as 2.66 × 10−3 S cm−1 at room temperature and the high ionic transference number of 0.98 is observed for the same. Primary proton cell has been fabricated with the optimum conducting polymer membrane (with a configuration Zn: ZnSO4.7H2O:C|| MG :0.5 wt % NH4NO3 Membrane || PbO2: V2O5 ) exhibits an open cell potential of 2.19 V and 1.88 V when shunted through the load resistance of 100 KΩ. Natural tree gum of Moringa oleifera as an electrolyte in the primary proton cell has provided a considerable open cell potential of 2.19 V which authenticates the utility of MG as a successful electrolytic material.
Journal of Materials Science: Materials in Electronics, May 27, 2022
Polymer Science: Peer Review Journal
Triblock copolymer P(VdCl.), LiClO 4 salt and tetrahydrofuran (THF) were purchased from Sigma-Ald... more Triblock copolymer P(VdCl.), LiClO 4 salt and tetrahydrofuran (THF) were purchased from Sigma-Aldrich. Appropriate amount of P(VdCl.) and LiClO 4 is dissolved in THF solvent at room temperature and stirred continuously. A homogeneous viscous liquid is obtained after continuous stirring for 4 days. The homogeneous liquid is transferred into petri dish and left undisturbed for evaporation. Finally, solid polymer electrolytes of composition 60 wt%
Ionics
In this present work, a proton-conducting solid biopolymer electrolyte membrane that consists of ... more In this present work, a proton-conducting solid biopolymer electrolyte membrane that consists of sodium alginate (SA) incorporated with ammonium formate (NH4HCO2) has been prepared by solution casting technique. Using the highest proton-conducting membrane, electrochemical devices like battery and fuel cell have been constructed. Graphene quantum dot has been used as an additive to highest conducting polymer electrolyte (30 M.wt%SA:70 M.wt%NH4HCO2). The prepared membranes (SA:NH4HCO2) were subjected to various characterization techniques such as XRD, FTIR, DSC, Ac impedance technique, and LSV. On increasing salt concentration, XRD analysis shows that amorphous nature increases. Highest amorphous nature has been found for 30 M.wt%SA:70 M.wt%NH4HCO2. The complex formation between SA and NH4HCO2 has been confirmed by FTIR measurements. The glass transition temperature, Tg, has been measured using DSC (differential scanning calorimetry). 30 M.wt%SA:70 M.wt%NH4HCO2 membrane shows a highest ionic conductivity value of 2.77 × 10−3 S cm−1. The addition of 1.25 ml GQD into the 30 M.wt%SA:70 M.wt%NH4HCO2 biopolymer electrolyte membrane has improved the value of ionic conductivity to 2.01 × 10−2 S cm−1. Transference number analysis reveals that the conductivity is mainly due to the ions in the polymer electrolyte (Wagner’s polarization method). LSV technique is used to measure the electrochemical stability of the biopolymer electrolyte membrane which resulted with 1.90 V (without GQD) and 2.08 V (with GQD). Battery constructed with highest ionic conducting membrane shows an open circuit voltage of 1.77 V (without GQD) and 1.79 V (with GQD). A fuel cell has been constructed using highest conducting biopolymer electrolyte membrane and the open circuit voltages of 707 mV (without GQD) and 778 mV (with GQD) have been measured.
Polymer Bulletin
A new class of environmental friendly bio-based electrolytes has been synthesized from natural tr... more A new class of environmental friendly bio-based electrolytes has been synthesized from natural tree gum of Moringa oleifera by solution casting technique. An ionic salt of ammonium nitrate (NH4NO3) of varying compositions from 0.2 to 0.6 wt % has been used as an additive to optimize the ionic conductivity of Moringa gum (MG) based biopolymer membranes. X-ray diffractograms affirm the enhancement in amorphous nature of the membranes with the addition of salt, and the high degree of amorphous nature is exhibited by the composition of MG (1 g) with 0.5 wt % NH4NO3. Complex formation between MG and salt has been studied by Fourier transform infra-red (FTIR). Thermal behavioural study by differential scanning calorimetry (DSC) authenticates the flexibility of the prepared MG-based membrane with NH4NO3 by low glass transition temperature. The obtained solid polymer electrolyte MG (1 g) with 0.5 wt % NH4NO3 achieved an ionic conductivity as high as 2.66 × 10−3 S cm−1 at room temperature and the high ionic transference number of 0.98 is observed for the same. Primary proton cell has been fabricated with the optimum conducting polymer membrane (with a configuration Zn: ZnSO4.7H2O:C|| MG :0.5 wt % NH4NO3 Membrane || PbO2: V2O5 ) exhibits an open cell potential of 2.19 V and 1.88 V when shunted through the load resistance of 100 KΩ. Natural tree gum of Moringa oleifera as an electrolyte in the primary proton cell has provided a considerable open cell potential of 2.19 V which authenticates the utility of MG as a successful electrolytic material.
Journal of Polymer Research
Journal of Materials Science: Materials in Electronics
Journal of Materials Science
The development of a sustainable ion-conducting solid electrolyte is an intense area of research ... more The development of a sustainable ion-conducting solid electrolyte is an intense area of research because of its potential application in all-solid-state batteries. In the present work, ion-conducting electrolyte membranes based on water-soluble biopolymer sodium alginate and sodium perchlorate (NaClO4) are prepared and analyzed. The complexation between NaClO4 and the sodium alginate biopolymer is well established by Fourier transform infrared spectroscopy (FTIR) analysis. The inclusion and the impact of NaClO4 concentration producing changes in the crystalline/amorphous nature of the membrane is recognized by the X-ray diffraction (XRD) technique. The thermal analysis by differential scanning calorimetry (DSC) reveals the changes in glass transition temperature (Tg) for various sodium alginate/NaClO4 compositions. The membrane with 60 wt% NaClO4:40 wt% sodium alginate exhibits maximum ion conductivity of 2.291 × 10–3 S cm−1 at room temperature possessing a transference number of 0.96 and a potential window of 3.4 V. An all-solid-state primary battery has been constructed which is found to manifest an open-circuit potential of 3.14 V. The present investigation is very appropriate and promising for utilizing the prepared biopolymer membranes for the application of the sodium-ion battery.
Ionics, 2021
Based on the biopolymer Gellan gum with ammonium thiocyanate (NH4SCN) salt, solid electrolyte has... more Based on the biopolymer Gellan gum with ammonium thiocyanate (NH4SCN) salt, solid electrolyte has been prepared with distilled water as solvent, using solution casting technique. The prepared solid electrolytes are subjected to various characterization techniques such as XRD, FTIR, DSC, and Ac impedance technique. Amorphous/crystalline nature of biopolymer membrane is studied by XRD. The polymer–salt complex formation has been studied by FTIR technique. Biopolymer membrane of 1 g Gellan gum with 1.1 M wt% of NH4SCN exhibits very high amorphous nature with a high proton conductivity of 1.41 × 10−2 S/cm and a glass transition temperature (Tg) of 42.98 °C. Using the highest ionic conducting biopolymer electrolyte, proton battery and fuel cell have been fabricated and their performance is studied. Proton battery constructed shows the open circuit voltage of 1.62 V. A single fuel cell constructed using the highest conducting membrane gives the voltage of 580 mV.
Ionics, 2022
A solid-state biopolymer electrolyte was prepared from the biomaterial Corn Silk Extract (CSE) by... more A solid-state biopolymer electrolyte was prepared from the biomaterial Corn Silk Extract (CSE) by blending with polyvinyl alcohol and different concentration of MgCl2 by opting solution casting technique. The maximum ionic conductivity of 1.74 × 10−5 Scm−1 for the blend pure biopolymer (0.9 g CSE + 1 g PVA) and 1.28 × 10−3 Scm−1 for the biopolymer electrolyte was obtained from the AC Impedance analysis. The obtained biopolymer electrolyte is characterized by Fourier transform infrared spectroscopy to look into the complex formation of the biopolymer blend and the salt. The maximum amorphous nature has been observed for 0.9 g CSE + 1 g PVA + 0.45wt% MgCl2 by the XRD technique. Glass transition temperature of the biopolymer electrolyte was found by the differential scanning calorimetry (DSC) process. The electrochemical potential window of the biopolymer electrolyte with maximum conductivity is obtained as 2.65 V in linear sweep voltammetry (LSV). The transference number is calculated from Wagner’s and Evan’s polarization techniques. A primary Mg-ion battery is constructed with an open-circuit voltage of 1.95 V at room temperature.
Eco-Friendly, non-toxic and biodegradable natural biopolymer electrolyte, Gellan Gum with Magnesi... more Eco-Friendly, non-toxic and biodegradable natural biopolymer electrolyte, Gellan Gum with Magnesium Chloride has been prepared by solution casting technique. The prepared biopolymer electrolyte has been characterized by XRD, FTIR, DSC and AC impedance analysis techniques. XRD study is used to analyze amorphous nature/crystalline nature of the polymer electrolyte. Complex formation between Gellan Gum and magnesium chloride salt has been studied by FTIR technique. The glass transition temperature (Tg) of the polymer electrolytes are obtained by DSC measurement. The highest ionic conductivity 2.91×10− 2 Scm− 1 has been obtained for electrolyte of 1.0 g Gellan Gum with 0.5 M.wt% MgCl2 from AC impedance analysis at room temperature. Transference number 0.97 has been obtained by Wagner’s polarization method for high conducting sample. The Mg2+ cationic transport number 0.35 has been found by Evan’s method for high conducting sample. Magnesium ion conducting battery has been constructed us...
Journal of Solid State Electrochemistry, 2021
Herein, solid biopolymer electrolyte membranes based on sodium alginate are prepared and investig... more Herein, solid biopolymer electrolyte membranes based on sodium alginate are prepared and investigated for their application in sodium-ion batteries. Various concentrations of sodium thiocyanate (NaSCN) are introduced into the matrix of sodium alginate biopolymer. Solution cast route is the method opted to prepare the electrolyte membrane. The complex formation between sodium alginate and NaSCN has been confirmed with the help of X-ray diffraction (XRD) analysis and Fourier transform infrared spectroscopy (FTIR). On increasing NaSCN concentration, the semi-crystalline nature of the sodium alginate gets abated thus elevating the amorphous domain of the electrolyte membrane. Information about the glass transition temperature (Tg) is acquired from differential scanning calorimetry (DSC). Decrement in the Tg upon NaSCN addition favors the segmental motion of the polymer chain. The biopolymer host material (30 wt%) can accommodate large amounts of NaSCN salt (70 wt%) exhibiting ionic conductivity of 1.22 × 10−2 S cm−1. The transference number measurement with Wagner’s DC polarization method is found to be 0.96 (near unity) which confirms ions are the governing charge carriers. The linear sweep voltammetry (LSV) technique that measures the potential window for the biopolymer electrolyte membrane is 2.7 V, representing it as a potential applicant for electrochemical energy storage devices. An all-solid-state sodium-ion battery is assembled with a high ion–conducting biopolymer electrolyte membrane that displays an open cell potential of 2.87 V. The results highlight the possibilities of sodium ion–conducting solid biopolymer electrolytes to extend their hands in a safe sodium-ion battery.
Ionics, 2020
Energy crisis and environmental pollution are the major problems faced by all the people at prese... more Energy crisis and environmental pollution are the major problems faced by all the people at present time. It is time to switch over to biopolymer electrolyte-based batteries instead of synthetic due to its high cost and not being environmentally green. Biopolymer membranes have been prepared using 1 g K-carrageenan with different molar mass percentages of LiNO 3 by solution casting technique using double-distilled water as a solvent. Prepared biopolymer electrolyte membranes are characterized by XRD, FTIR, DSC, and AC impedance techniques. XRD confirms the amorphous nature of the biopolymer membranes. FTIR reveals the complexation formed between 1 g K-carrageenan and LiNO 3. It has been found from DSC analysis that glass transition temperature of the biopolymer membrane 1 g K-carrageenan with LiNO 3 decreases due to the addition of salt compared to the pure biopolymer 1 g K-carrageenan. Biopolymer membrane 1 g K-carrageenan with 0.65 wt% of LiNO 3 has got the highest ionic conductivity of 1.89 × 10 −3 S cm −1. Transference number analysis has been done by Wagner's polarization method and Bruce and Vincent method. Electrochemical stability has been studied by linear sweep voltammetry. The highest conducting biopolymer membrane (1 g K-carrageenan with 0.65 wt% of LiNO 3) is electrochemically stable up to 3.2 V. Lithium ion conducting battery has been constructed using the highest conducting biopolymer membrane and its performance has been analyzed.
Ionics, 2022
Bio-based solid polymer electrolytes are synthesized and characterized for the application of sod... more Bio-based solid polymer electrolytes are synthesized and characterized for the application of sodium-ion conducting batteries. Biopolymer tamarind seed polysaccharide (TSP) has been chosen as the host polymer and ionic dopant of sodium perchlorate (NaClO4) in various compositions (0.5 g to 0.9 g) added to the host polymer as a source of charge carriers. Simple solution casting technique is utilized for the synthesis of solid biopolymer electrolyte membranes. X-ray diffraction analysis has been used to analyze the nature (crystalline/amorphous) of prepared biopolymer membranes. The complex formation between the host biopolymer and sodium perchlorate has been examined with the help of FTIR spectroscopy analysis. Glass transition temperatures (Tg) of the membranes are observed using differential scanning calorimetry (DSC). Ionic conductivities of the membranes are determined from the Ac impedance technique. Among the prepared biopolymer electrolytes, 1 g TSP with 0.8 g of NaClO4 exhibits the optimum ionic conductivity of 1.70 × 10−3 S cm−1. Electrochemical stability window for the optimum conducting biopolymer electrolyte is found to be 3.24 V by linear sweep voltammetry (LSV). The open-circuit cell potential of 3.15 V is observed by fabricating primary sodium battery using the highest conducting biopolymer electrolyte (1 g TSP: 0.8 g NaClO4).
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Papers by Vengadesh Krishna M