Laser‐Assisted Fabrication of Pseudohexagonal Phase Niobium Pentoxide Nanopillars for Lithium Ion Battery Anodes

Abstract

Herein, we report a convenient route to fabricate pseudohexagonal phase niobium pentoxide (TT-Nb 2 O 5 ) nanopillars via combination of laser ablation in liquids (LAL) and hydrothermal treatment without using any organic surfactants or stabilizers. The morphology and structure of the assynthesized samples are investigated through scanning and transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Such nanopillars exhibit excel-lent lithium storage properties, including high reversible capacity, good rate capability, and excellent cycle stability (81% capacity retention after 1000 cycles) at a rate of 5 C in the potential range of 1.0 to 3.0 V, which is higher than other previously reported Nb 2 O 5 -based electrode. The synergistic effects from the nanopillar morphology, high electronic conductivity and stable structure promise potential applications in high-security and high-rate capability Li-ion batteries. Scheme 1. Schematic of the synthesis of TT-Nb 2 O 5 nanopillars.

Highly [001]-oriented N-doped orthorhombic Nb2O5 microflowers with intercalation pseudocapacitance for lithium-ion storage

“…In the first cycle, the reduction/oxidation peaks can be attributed to the redox couples of Nb 5+ /Nb 4+ and Nb 4+ /Nb 3+ . 44–46 During the intercalation/deintercalation processes, x mol of Li + ions can be inserted/extracted into/from 1 mol Nb 2 O 5 (Nb 2 O 5 + x Li + + x e − → Li x Nb 2 O 5 , 0 < x < 2), and accordingly, Nb 2 O 5 has a maximum theoretical capacity of 201.6 mA h g −1 , as x is 2. The subsequent two cycles exhibit excellent repetition, confirming the good reversibility of N-Nb 2 O 5 for Li + storage.…”

“…S5 † that the rate capacity of the N-Nb 2 O 5 anode is also comparable to those of some other reported niobium oxide-based anodes, especially at high current density. 31,45,[50][51][52][53][54] The rate capacity of the anode is decided by the kinetics of electron transfer, which is investigated using electrochemical impedance spectroscopy (EIS) (Fig. 6b).…”

“…The initial three cyclic voltammetry (CV) curves of N-Nb 2 O 5 are shown in Fig.S4. † In the first cycle, the reduction/oxidation peaks can be attributed to the redox couples of Nb 5+ /Nb 4+ and Nb 4+ /Nb 3+ [44][45][46]. During the intercalation/deintercalation processes, x mol of Li + ions can be inserted/extracted into/from 1 mol Nb2 O 5 (Nb 2 O 5 + xLi + + xe − → Li x Nb 2 O 5 , 0 < x < 2), and accordingly, Nb 2 O 5 has a maximum theoretical capacity of 201.6 mA h g −1 , as x is 2.…”

Amorphization of Pseudocapacitive T−Nb2O5 Accelerates Lithium Diffusivity as Revealed Using Tunable Isomorphic Architectures

“…Surface‐limited kinetics are possible when the overall rate is not limited by diffusive processes and there is an absence of a crystallographic phase changes upon intercalation [22–26] . Numerous nanoscale niobia structures have been reported with an emphasis on individual performance metrics [27–74] . A few investigations have approached the relationship between nanostructure and T‐Nb 2 O 5 performance using computational models, [75] advanced electrochemical techniques, [76] tunable nanotubes, [77] and core‐shell particles [78,79] without experimentally isolating the rate‐limiting process(es).…”

Laser ablation in air and its application in catalytic water splitting and Li-ion battery

“…In another example (Huang et al, 2015), CdSe nanowire arrays were fabricated with the aid of oleic acid and tri-n-octylphosphine. Some energy materials have been prepared by LAL, such as niobium pentoxide for Li-ion battery (Liang et al, 2020) or silver stacking faults for hydrogen evolution (Li et al, 2019b). Also, Wang et al reviewed the recent applications of LAL on functional micro-supercapacitors (Wang et al, 2021b).…”