@article {44234, title = {In situ synthesis of nitrogen- and sulfur-enriched hierarchical porous carbon for high-performance supercapacitor}, journal = {Energy \& Fuels}, volume = {32}, year = {2018}, month = {JAN}, pages = {908-915}, type = {Article}, abstract = {

In this work, we present a simple and facile method for the nitrogen (N)- and sulfur (S)- doped porous three-dimensional (3D) spongelike carbon materials via direct pyrolysis of N and S containing polymer N,N{\textquoteright}-methylene-bis-acrylamide cross-linked poly(acrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid) at varying temperatures under inert atmosphere. The obtained nitrogen- and sulfur-doped porous carbons (NSPCs) possess 3D hierarchical porous structure and contain a significantly high amount of N and S species. The concurrent incorporation of N and S successfully modified the surface properties of carbon materials and lead to enhanced capacitive performance. The presented NSPC exhibits specific capacitance of 230 F g(-1) at a current density of 1 A g(-1) and showed excellent cycling stability, depicting a promising material for energy storage devices.

}, issn = {0887-0624}, doi = {10.1021/acs.energyfuels.7b02305}, author = {Mehare, Rupali S. and Ranganath, Suresha P. and Chaturvedi, Vikash and Badiger, Manohar. V. and Shelke, Manjusha V.} } @conference {47488, title = {Impedance analysis and equivalent circuit modelling of cells subjected to sinusoidal vibration test using electrochemical impedance spectroscopy}, booktitle = { 2019 IEEE Transportation Electrification Conference (ITEC-India)}, year = {2019}, month = {DEC}, publisher = {IEEE}, organization = {IEEE}, address = {Bengaluru, India}, abstract = {Electrochemical impedance spectroscopy is a multipurpose and non-destructive characterization technique in the analysis of electrochemical power sources such as Li-ion cells. The nyquist curve obtained by EIS spectrum of the cell gives information about its overall health. Curve fitting of the EIS nyquist plots further helps in determining the Equivalent Circuit Model (ECM) for a particular cell. In this paper commercial Li-ion cells from three different chemistries; Lithium Nickel Manganese Cobalt Oxide (NMC), Lithium Cobalt Oxide (LCO) and Lithium Iron Phosphate (LFP) are subjected to sinusoidal vibration test as per testing standard mentioned in United States Advanced Battery Consortium (USABC). The EIS measurement of the test cells have been carried out before and after the vibration tests. Curve fitting is carried out on the EIS plots and ECM for the cells is obtained. The components present in ECM and their actual values are estimated from the curve fitting analysis. The magnitude of various resistances like equivalent series resistance (R s ), charge transfer resistance (R ct ) and solid electrolyte interphase resistance (R sei ) is evaluated. This technique is also used in determining the capacitances inside the cell, mainly capacitance (C sei ) due to Solid Electrolyte Interphase layer (SEI) and capacitance due to double layer (C dl ) formation at electrode surface. The resistance in the cell is found to be increased and the capacitances values are decreased after vibration test. Bode plot for the cells are analysed and the overall change in the impedance of cell due to the vibration test is investigated as well. Scanning electron microscopy technique is used on cell electrodes, after vibration test, to validate the actual damage that took place within the cell. The study reveals that the EIS can be used as a non-destructive tool to check cell health after mechanical abuse.}, doi = {10.1109/ITEC-India48457.2019.ITECINDIA2019-232}, author = {Bangal, Ojas A. and Chaturvedi, Vikash and Babu, P. K. Ajeet and Shelke, Manjusha V.} } @article {47437, title = {Ice-colloidal templated carbon host for highly efficient, dendrite free Li metal anode}, journal = {Carbon}, volume = {179}, year = {2021}, month = {JUL}, pages = {256-265}, type = {Article}, abstract = {

With its high theoretical specific capacity value, lithium metal itself would be an ideal anode material for rechargeable Li-ion batteries (LIBs). However, practical application of lithium metal is obstructed due to lithium dendrite growth during cycling leads to unstable SEI formation, volume fluctuation and safety hazard. Herein, we have developed a novel high surface area carbon network with both meso (\~{}20 nm) and micron (\~{}1{\textendash}2 μm) size porosity, via ice-colloidal templating, as a scaffold for stable lithium metal anode mitigating lithium dendrite formation. The 3D porous nitrogen doped carbon (3D PNC) network is capable of lithium deposition equivalent to 10 mAhcm-2 at 2 mAcm-2 current density with 99.96\% coulombic efficiency for 100 cycles. Moreover, 3D PNC when subjected to 3000 h of continuous plating-stripping measurements (\~{}700 cycles) depicts the coulombic efficiency of 99.84\% with no observable dendrite growth at the current density of 2 mAcm-2 and lithium intake capacity of 5 mAhcm-2. A full cell of lithium plated 3D PNC anode with LiFePO4 shows an excellently stable performance up to 50 cycles at an input current density of 50 mAg-1, with a coulombic efficiency retention of 99.73\%.

}, doi = {10.1016/j.carbon.2021.04.021}, author = {Patrike, Apurva and Kaniyamparambil, Karthika and Wahid, Malik and Chaturvedi, Vikash and Shelke, Manjusha} }