High rate capability and cyclic stability of hierarchically porous Tin oxide (IV)–carbon nanofibers as anode in lithium ion batteries

Abstract

Tin oxide-carbon composite porous nanofibres exhibiting superior electrochemical performance as lithium ion battery (LIB) anode have been prepared using electrospinning technique. Surface morphology and structural characterizations of the composite material is carried out by techniques such as XRD, FESEM, HR-TEM, XPS, TGA and Raman spectroscopy. FESEM and TEM studies reveal that nanofibers have a uniform diameter of 150-180 nm and contain highly porous outer wall. The carbon content is limited to *10% in the nanofibers as shown by the TGA and EDAX which does not fade the high capacity of SnO 2 . These nanofibers delivered a higher discharge capacity of 722 mAh/g even after 100 cycles at high rate of 1C. The excellent electrochemical performance can be ascribed to the synergy effect of small amount of carbon in the composite and the hierarchically porous structure which accommodate large volume changes associated with Li-ion insertion-desertion. The porous nano-architecture would also provide a short diffusion path for Li ? ions in addition to facilitating high flux of electrolyte percolation through micropores. The electrochemical performance of composite material has also been tested at 60°C at a higher rate of 2C and 5C. Post cycling FESEM analysis shows no volumetric and morphology changes in porous nanofibers after completing rate capability at high rate of 10C.

A Convenient Synthesis Route for Co3O4 Hollow Microspheres and Their Application as a High Performing Anode in Li-Ion Batteries

“…The superior performance is due to their morphology that provides sufficient buffer space to accommodate volume changes during lithium insertion–deinsertion. 21,40,44,55,62,63 In addition, the high surface area and the hierarchical porous network structure render a short path length for lithium diffusion during insertion/extraction enabling high rate performance. 49,55,64−73…”

Template assisted synthesis of Sn@C microspheres and SnO2@C micro bowls as anode for Li‐Ion batteries

“…During first cycle, cathodic peak observed at 0.76 V is related to the reduction of metal oxide (SnO 2 ) to metal (Sn) and to the formation of SEI as described in (Equation (1)). 5,9,10,32,[47][48][49][50] SnO…”

“…11,26,31,46,[51][52][53][54] During the first anodic scan, four oxidation peaks were observed at 0.50 and 0.64 V, which corresponds to extraction of lithium ions from Li x Sn alloys. 1,32,55 The peaks at 1.26 and 1.84 V corresponds to the partial reversible reaction of Equation (1). 32,54,[56][57][58] For subsequent second cathodic cycle, five peaks are observed.…”

“…1,32,55 The peaks at 1.26 and 1.84 V corresponds to the partial reversible reaction of Equation (1). 32,54,[56][57][58] For subsequent second cathodic cycle, five peaks are observed. The peak observed at 1.3 V originate from the electrolyte decomposition, 26 0.92 V formation of solid electrolyte interface (SEI) layer on the surface of active material, 32,51 0.62 V assigned tin oxide reduction to metallic tin (SnO 2 to Sn).…”

“…13,21,26 To prevent this, often a supporting matrix (carbon matrix) is used for improving the mechanical stability especially for hollow nanostructures to prevent pulverization during cycling. 21 Considering the above aspects, various hierarchical nanostructured SnO 2 materials have been developed recently such as, SnO 2 @carbon core-shell structures, 21 SnO 2 nanospheres, 23 SnO 2 @polypyrrole nanotubes, 26 SnO 2 nanoparticles on cross-stacked carbon nanotube sheets, 27 SnO 2 nanotubes embedded on carbon, 28 SnO 2 nanosheets on graphene, 29 graphene wrapped SnO 2 nanotubes, 30 carbon-coated SnO 2 nanocolloids, 31 hierarchically porous SnO 2 carbon nanofibers, 32 SnO 2 /C coaxial hollow nanospheres, 33 hollow core-shell SnO 2 -carbon fiber, 34 bowl-like SnO 2 @Carbon hollow particles, 35 double-shelled SnO 2 yolk-shell. 36 Herein, we report for the first time synthesis of Sn@C microspheres and SnO 2 @C composite micro-bowls by phloroglucinol−formaldehyde (P-F) gel method.…”