Ag-coated one-dimensional orthorhombic Nb2O5 fibers as high performance electrodes for lithium storage

Abstract

In the recent times, pseudocapacitive electrode materials have received great attention due to their considerable capability in storing ions at relatively fast charging rates. Among various candidates, niobium (V) pentoxide (Nb2O5) has gained much attraction for lithium-ion batteries (LIBs) due to its insertion/extraction reaction with Li, safe redox potential, and considerably good capacity (about 200 mA hg(-1)). Nevertheless, low conductivity of Nb2O5 has so far prevented its use as a viable electrode material for LIBs. In this study, we have successfully coated silver (Ag) nanoparticles (NPs) on the surface of one-dimensional orthorhombic Nb2O5 fiber (1D T-Nb2O5) using simple electrospinning processing. Ag NPs coated Nb2O5 fibers (Ag-1D T-Nb2O5) provided faster electron pathways, resulting in much improved capacity at a given current density with superior rate capabilities compared with pristine 1D T-Nb2O5. In addition, 1D T-Nb2O5 was more suitable for coating Ag NPs compared with T-Nb2O5 NPs, where its structural integrity was maintained even after cycling. As a result, effective coating of conductive Ag NPs on the 1D T-Nb2O5 resulted in excellent cycle retention characteristics (179.7 mAhg(-1) after 500 cycles at 500 mAg(-1)) as well as superior rate capabilities (103.6 mAhg(-1) at a current density of 5000 mAg(-1)). (c) 2018 Elsevier Ltd. All rights reserved.