scholarly journals Porous MnO2/ carbon Hybrid Material with Improved Electrochemical Performance

2021 ◽  
Vol 59 (9) ◽  
pp. 670-676
Author(s):  
Venugopal Nulu

In this work, MnO2 nanoparticles were embedded in a carbon matrix as a porous composite, fabricated using a simple chemical route followed by low-temperature annealing, with activated carbon (AC) as the carbon source in the composite preparation. The porous MnO2/carbon structures contained some selective nanoparticles coated with carbon. The structural feature was identified by transmission electron microscopy (TEM). The surface area and pore size distribution of the materials were investigated by N2 adsorption/desorption isotherms, and demonstrated a high surface area of about 80 m2 g-1. AC is a readily available carbon source that can easily form a composite with MnO2 nanoparticles, forming a distinctive porous morphology. When employed as an anode material for lithium-ion batteries (LIB), the composite electrode demonstrated high specific capacities with an initial discharge capacity of 2500 mAh g-1 and maintained about 1391 mAh g-1 after fifty cycles. It also demonstrated excellent high rate performance, delivering more than 500 mAh g-1 of specific capacity at 3000 mA g-1, which is a higher capacity than a conventional graphite anode. Overall, the MnO2/ carbon composite electrode delivered superior anode performance, which was attributed to the improved surface area of the carbon hybridized MnO2 nanoparticles. The porous composite has benefits for lithium storage performance.

2016 ◽  
Vol 4 (24) ◽  
pp. 9593-9599 ◽  
Author(s):  
Gaihua Li ◽  
Hao Yang ◽  
Fengcai Li ◽  
Jia Du ◽  
Wei Shi ◽  
...  

Utilizing the adsorption properties of MOFs, a nanostructured NiP2@C was successfully synthesized, which exhibited enhanced capability for lithium storage in terms of both the reversible specific capacity and high-rate performance.


2019 ◽  
Vol 31 (8) ◽  
pp. 1709-1718
Author(s):  
T. Veldevi ◽  
K. Thileep Kumar ◽  
R.A. Kalaivani ◽  
S. Raghu ◽  
A.M. Shanmugharaj

Hierarchical nanostructured graphene–manganese dioxide nanowire (G-MnO2-NW) composites have been prepared by hydrothermal synthesis route using water/1-decanol as the medium. Synthesized materials were analyzed using various characterization tools to corroborate their chemical compositions, structure/morphology and surface area. Electrochemical measurements of the synthesized G-MnO2-NW electrode materials delivered the highest specific capacity (255 Fg-1), high rate capability and improved cycling stability at 0.5 Ag–1 in 1M sodium sulfate solution and this fact may be attributed to its high surface area and porosity. Moreover, synthesized G-MnO2-NW electrodes displayed better energy and power density, when compared to the MnO2-NW based electrodes.


2010 ◽  
Vol 20 (11) ◽  
pp. 2092 ◽  
Author(s):  
Shu-Lei Chou ◽  
Jia-Zhao Wang ◽  
David Wexler ◽  
Konstantin Konstantinov ◽  
Chao Zhong ◽  
...  

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 996 ◽  
Author(s):  
Jiang ◽  
Yan ◽  
Du ◽  
Kang ◽  
Du ◽  
...  

The spherical-graphite/Fe3O4 composite has been successfully fabricated by a simple two-step synthesis strategy. The oxygenous functional groups between spherical-graphite and Fe3O4 benefit the loading of hollow Fe3O4 nanospheres. All of the composites as anodes for half cells show higher lithium storage capacities and better rate performances in comparison with spherical-graphite. The composite containing 39 wt% of hollow Fe3O4 nanospheres exhibits a high reversible capacity of 806 mAh g−1 up to 200 cycles at 0.5 A g−1. When cycled at a higher current density of 2 A g−1, a high charge capacity of 510 mAh g−1 can be sustained, even after 1000 long cycles. Meanwhile, its electrochemical performance for full cells was investigated. When matching with LiCoO2 cathode, its specific capacity can remain at 137 mAh g−1 after 100 cycles. The outstanding lithium storage performance of the spherical-graphite/Fe3O4 composite may depend on the surface modification of high capacity hollow Fe3O4 nanospheres. This work indicates that the spherical-graphite/Fe3O4 composite is one kind of prospective anode material in future energy storage fields.


MRS Advances ◽  
2018 ◽  
Vol 3 (60) ◽  
pp. 3495-3500 ◽  
Author(s):  
Yiqun Yang ◽  
Kayla Strong ◽  
Gaind P. Pandey ◽  
Lamartine Meda

ABSTRACTVanadium Pentoxide (V2O5) has been identified as a potential cathode material owning to its high specific capacity, theoretically, 441 mAh g-1 for 3Li+ ions insertion/extraction. However, the intrinsic drawbacks of V2O5, i.e. structural instability and poor electronic and ionic conductivity, greatly inhibit its application as a cathode. Here, we report a cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal reaction to synthesize V2O5 nanoclusters. Unique aggregated fiber structure was obtained after annealing. To achieve a porous structure and increase the conductivity, nitrogen-doped Graphene (NG) suspended in ethylene glycol was added to the reaction mixture. The obtained spherical V2O5 nanoparticles and NG sheets were randomly dispersed in the matrix of the V2O5 spheres. As a cathode material for lithium-ion batteries, the V2O5/NG hybrids demonstrate better rate performance compared to the bundle-like V2O5 fibers, delivering higher specific capacity of ∼ 300 and 150 mAh g-1 at a rate of C/10 and 5C, respectively. The enhanced performance in lithium storage are attributed to the synergistic effect of the nanostructured V2O5/NG composites.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1672
Author(s):  
Shih-Chieh Hsu ◽  
Tzu-Ten Huang ◽  
Yen-Ju Wu ◽  
Cheng-Zhang Lu ◽  
Huei Chu Weng ◽  
...  

Carbon-coated Li4Ti5O12 (LTO) has been prepared using polyimide (PI) as a carbon source via the thermal imidization of polyamic acid (PAA) followed by a carbonization process. In this study, the PI with different structures based on pyromellitic dianhydride (PMDA), 4,4′-oxydianiline (ODA), and p-phenylenediamine (p-PDA) moieties have been synthesized. The effect of the PI structure on the electrochemical performance of the carbon-coated LTO has been investigated. The results indicate that the molecular arrangement of PI can be improved when the rigid p-PDA units are introduced into the PI backbone. The carbons derived from the p-PDA-based PI show a more regular graphite structure with fewer defects and higher conductivity. As a result, the carbon-coated LTO exhibits a better rate performance with a discharge capacity of 137.5 mAh/g at 20 C, which is almost 1.5 times larger than that of bare LTO (94.4 mAh/g).


2017 ◽  
Vol 5 (44) ◽  
pp. 23221-23227 ◽  
Author(s):  
Hao Wang ◽  
Ziliang Chen ◽  
Yang Liu ◽  
Hongbin Xu ◽  
Licheng Cao ◽  
...  

Hybrid nanocomposites constructed from starfish-like ZnxCo1−xS rooted in porous carbon and strongly coupled carbon nanotubes have been rationally designed and they exhibit excellent lithium-storage performance.


Nanoscale ◽  
2014 ◽  
Vol 6 (17) ◽  
pp. 10243-10254 ◽  
Author(s):  
Uttam Kumar Sen ◽  
Priya Johari ◽  
Sohini Basu ◽  
Chandrani Nayak ◽  
Sagar Mitra

Experimental evidence and theoretical correlation of the formation of elemental sulphur during the discharge process of MoS2, a high rate lithium ion battery anode.


2018 ◽  
Vol 47 (41) ◽  
pp. 14540-14548 ◽  
Author(s):  
Peng Huang ◽  
Ming Zhao ◽  
Bo Jin ◽  
Huan Li ◽  
Zhi Zhu ◽  
...  

With the depletion of fossil energy and rapid development of electronic equipment, the commercial lithium-ion batteries (LIBs) do not meet the current energy demand.


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