Shaikshavali Petnikota | Swedish University of Agricultural Sciences (original) (raw)

Papers by Shaikshavali Petnikota

Sustainable Energy & Fuels

We report herein wet-jet milling produced graphene (GWJM) as a high performing aluminium battery ... more We report herein wet-jet milling produced graphene (GWJM) as a high performing aluminium battery (AB) cathode material.

Figure S11. SEM images of bare 304 SS. Figure S12. XRD patterns of a-VOx films deposited under di... more Figure S11. SEM images of bare 304 SS. Figure S12. XRD patterns of a-VOx films deposited under different pO2 conditions in comparison with 304 SS. Figure S13. GC profiles of a-VOx-13Pa (a, b) and a-VOx-30Pa (c, d) at 0.1 C. Figure S14. Li-ion battery CV profile of bare 304 SS at 0.1 mV s−1. Figure S15. Li-ion battery CV (a and c) at 0.1 mV s−1 and GC at 0.1 C profiles of crystalline V2O5 (b and d). Figure S16. Na-ion battery CV profiles about 10 cycles of a-VOx films at 0.1 mV s−1 after 100th GC cycling. (DOCX 1728 kb)

Electrochem, 2021

Metal–organic frameworks (MOFs) have found a potential application in various domains such as gas... more Metal–organic frameworks (MOFs) have found a potential application in various domains such as gas storage/separation, drug delivery, catalysis, etc. Recently, they have found considerable attention for energy storage applications such as Li- and Na-ion batteries. However, the development of MOFs is plagued by their limited energy density that arises from high molecular weight and low volumetric density. The choice of ligand plays a crucial role in determining the performance of the MOFs. Here, we report a nickel-based one-dimensional metal-organic framework, NiC4H2O4, built from bidentate fumarate ligands for anode application in Li-ion batteries. The material was obtained by a simple chimie douce precipitation method using nickel acetate and fumaric acid. Moreover, a composite material of the MOF with reduced graphene oxide (rGO) was prepared to enhance the lithium storage performance as the rGO can enhance the electronic conductivity. Electrochemical lithium storage in the framewo...

Journal of The Electrochemical Society, 2020

Journal of Energy Storage, 2021

Abstract Highly crystalline few-layered graphene (hcFLG) is synthesized using microwave exfoliati... more Abstract Highly crystalline few-layered graphene (hcFLG) is synthesized using microwave exfoliation of in-house prepared graphene oxide. When hcFLG is tested as an anode material in a Li-ion coin cell, it showed unique lithiation electrochemistry. Cyclic voltammetry (CV), structural and electrochemical impedance spectroscopic analyses of hcFLG showed enhanced surface lithiation above 0.3 V and in-situ exfoliation of hcFLG responsible for excellent storage capacity of hCFLG. Below 0.3 V, the CV data before and after long-term cycling showed a unique Li-staging phenomenon and confirmed that diffusion-controlled lithiation is responsible for stable capacity. hcFLG delivered reversible specific capacities as high as 400 and 330 mAh/g at current rates of 0.1 and 1 C, respectively. hcFLG also exhibited an excellent rate capability by showing a reversible specific capacity of 215 mAh/g at a very high current rate of 10 C. At the end of long-term cycling (i.e., 1175 cycles), hcFLG displayed a significant increase in specific capacity from 330 to 555 mAh/g and 200 to 365 mAh/g at current rates of 1.0 and 2.0 C, respectively, attributed to a safe in-situ exfoliation. The performance of hcFLG is far superior to the commercial graphite and other materials of the same class. hcFLG is best suited for emerging battery technologies like ‘All Graphene Battery”.

New Journal of Chemistry, 2019

Composites such as MgO/few-layered graphene can be used as electrode materials in supercapacitors... more Composites such as MgO/few-layered graphene can be used as electrode materials in supercapacitors with aqueous electrolytes but not non-aqueous electrolytes.

Nanoscale Research Letters, 2018

Herein, we report additive-and binder-free pristine amorphous vanadium oxide (a-VOx) for Li-and N... more Herein, we report additive-and binder-free pristine amorphous vanadium oxide (a-VOx) for Li-and Na-ion battery application. Thin films of a-VOx with a thickness of about 650 nm are grown onto stainless steel substrate from crystalline V 2 O 5 target using pulsed laser deposition (PLD) technique. Under varying oxygen partial pressure (pO 2) environment of 0, 6, 13 and 30 Pa, films bear O/V atomic ratios 0.76, 2.13, 2.25 and 2.0, respectively. The films deposited at 6-30 Pa have a more atomic percentage of V 5+ than that of V 4+ with a tendency of later state increased as pO 2 rises. Amorphous VOx films obtained at moderate pO 2 levels are found superior to other counterparts for cathode application in Li-and Na-ion batteries with reversible capacities as high as 300 and 164 mAh g −1 at 0.1 C current rate, respectively. At the end of the 100th cycle, 90% capacity retention is noticed in both cases. The observed cycling trend suggests that more is the (V 5+) stoichiometric nature of a-VOx better is the electrochemistry.

The Journal of Physical Chemistry C, 2017

Graphenothermal reduction mechanism of Fe2O3 by graphene oxide (GO) is elucidated through careful... more Graphenothermal reduction mechanism of Fe2O3 by graphene oxide (GO) is elucidated through careful experimental analysis. The degree of oxidation (DO) of GO plays a key role in controlling the reduction of Fe2O3 by GO. GO with low DO follows a conventional three stage reaction path i.e., ′2 + 2 3 → / 3 4 () → / () → / ()′ (where EG is exfoliated reduced graphene oxide) at temperatures 650 and 750 °C to reduce Fe2O3. Whereas the GO with higher DO transforms rapidly and ceases the reduction at Stage I i.e., with the formation of EG/Fe3O4 at 650 °C. It is also found that slow thermal treatment of GO continues the reduction to Stage II and further to Stage III depending on time of heating and temperature. EG/Fe3O4 (synthesized at 550 °C-5 h) by using GO with low DO showed superior cycling performance as an anode of Li-ion battery than its counterpart prepared (at 650 °C-5 h) from GO with high DO owing to good contacts between EG and

Electrochimica Acta, 2017

RSC Advances, 2016

Easy solid state synthesis of Co2Mo3O8/reduced graphene oxide composite which exhibited a very hi... more Easy solid state synthesis of Co2Mo3O8/reduced graphene oxide composite which exhibited a very high specific capacity (∼954 mA h g−1) when tested as an anode material in lithium ion batteries.

ACS Applied Materials & Interfaces, 2016

MoO 2 ' composites are synthesized by a simple solid state 'Graphenothermal Reduction' method. Gr... more MoO 2 ' composites are synthesized by a simple solid state 'Graphenothermal Reduction' method. Graphene Oxide (GO) is used as a reducing agent to reduce MoO 3 and as a source for EG. The formation of different submicron sized morphologies such as spheres, rods, flowers, etc., of monoclinic MoO 2 on EG surfaces

Electrochimica Acta, 2015

Abstract A simple solid state ‘graphenothermal’ reduction reaction is used to obtain few layered ... more Abstract A simple solid state ‘graphenothermal’ reduction reaction is used to obtain few layered graphene (FLG)–complex metal oxide (A 2 Mo 3 O 8 , A = Co, Mn and Zn) composites. Carbons of the exfoliating GO are used as an aid to reduce metal precursors to A 2 Mo 3 O 8 . As-synthesized composites are used as anode materials in Li ion batteries. In 0.005-3 V potential window and at 60 mA/g current density, FLG–Co 2 Mo 3 O 8 , FLG–Mn 2 Mo 3 O 8 and FLG–Zn 2 Mo 3 O 8 composites exhibit high reversible capacities of 785, 495 and 630 mAh/g respectively, even at the end of 50 th cycle. The composites show far better cycling performance and rate capability than Mo-metal cluster compound. Amongst the three composites, FLG–Co 2 Mo 3 O 8 shows excellent capacity retention (∼87%) and Coulombic efficiency (∼98%). Cyclic voltammetry shows that: (i) redox couples of A 2 Mo 3 O 8 and (ii) electrochemical adsorption and desorption by FLG in the composites are responsible for Li storage and release.

ACS Sustainable Chemistry & Engineering, 2015

Exfoliated graphene oxide (EG)/manganese(II) oxide (MnO) composite powder is synthesized by simpl... more Exfoliated graphene oxide (EG)/manganese(II) oxide (MnO) composite powder is synthesized by simple solid state graphenothermal reduction process. Structural, chemical, and morphological studies confirm the formation of EG/MnO composite in which cubic MnO crystallites are found to anchor onto EG surfaces. The as-synthesized EG/MnO composite is constituted with 65 and 35 wt % of MnO and EG, respectively. The EG/MnO composite exhibits a specific surface area of ∼82 m2 g–1 and an average pore size of ∼12 nm. As an anode in lithium-ion batteries, the EG/MnO composite shows a high reversible capacity of 936 mAh g–1 at a current rate of 75 mA g–1. Capacity retention of ∼84% (784 mAh g–1) is observed even at the 100th cycle which corresponds to a Coulombic efficiency of ∼99%. Cyclic voltammetry studies on the composite show that Li storage is owing to reversible conversion reactions of MnO and electrochemical absorption/desorption by EG. Electrochemical impedance spectroscopy studies clearly show easy lithiation ...

Journal of Power Sources, 2015

h i g h l i g h t s g r a p h i c a l a b s t r a c t EG/FeO composites were prepared by grapheno... more h i g h l i g h t s g r a p h i c a l a b s t r a c t EG/FeO composites were prepared by graphenothermal reduction method. EG/FeO composites were characterized by variety of techniques. EG/FeO showed excellent capacity of 730 mAh g À1 with 85% capacity retention. Comparative electrochemical performance of Fe 2 O 3 and Fe 3 O 4 are discussed.

Proceedings of the 14th Asian Conference on Solid State Ionics (ACSSI 2014)(1AGSSEA), 2014

ACS Applied Materials & Interfaces, 2015

Combustion of magnesium in dry ice and a simple subsequent acid treatment step resulted in MgO de... more Combustion of magnesium in dry ice and a simple subsequent acid treatment step resulted in MgO decorated few-layered graphene (FLG) composite that has a specific surface area of 393 m 2 /g and an average pore volume of 0.9 cm 3 /g. As an anode material in Li-ion batteries the composite exhibited high reversible capacity and excellent cyclic performance despite of high first cycle irreversible capacity loss. Reversible capacity as high as 1052 mAh/g was measured during the first cycle. Even at the end of 60 th cycle, more than 83% of the capacity

Journal of Solid State Electrochemistry, 2013

Few-layered graphene (FLG) with specific surface area of only~8.2 m 2 g −1 was synthesized from g... more Few-layered graphene (FLG) with specific surface area of only~8.2 m 2 g −1 was synthesized from graphene oxide (GO) using microwave-assisted exfoliation. GO was prepared using modified Hummers method. Few-layered nature of the exfoliated material was confirmed by electron microscopy, X-ray and electron diffraction, and Raman spectroscopy. Coin cells were fabricated using FLG as an anode and lithium metal as a counter electrode. The cells were tested using cyclic voltammetry and galvanostatic cycling techniques. FLG showed reversible capacity values of~400 and 250 mAh g −1 at current rates of 0.1 and 1 C, respectively. Columbic efficiency was more than 98 % while cycle to cycle capacity fading was less than 2 %. Maximum discharge or charging capacity was below 0.3 V, a preferable characteristic for achieving ideal anodic behavior.