Improving Lithium‐Ion Half‐/Full‐Cell Performance of WO₃‐Protected SnO₂ Core‐Shell Nanoarchitectures

Abstract

Anodes derived from SnO2 offer a greater specific capacity comparative to graphitic carbon in lithium‐ion batteries (LIBs); hence, it is imperative to find a simple but effective approach for the fabrication of SnO2. The intelligent surfacing of transition metal oxides is one of the favorite strategies to dramatically boost cycling efficiency, and currently most work is primarily aimed at coating and/or compositing with carbon‐based materials. Such coating materials, however, face major challenges, including tedious processing and low capacity. This study successfully reports a new and simple WO3 coating to produce a core‐shell structure on the surface of SnO2. The empty space permitted natural expansion for the SnO2 nanostructures, retaining a higher specific capacity for over 100 cycles that did not appear in the pristine SnO2 without WO3 shell. Using WO3‐protected SnO2 nanoparticles as anode, a coin half‐cell battery was designed with Li‐foil as counter‐electrode. Furthermore, the anode was paired with commercial LiFePO4 as cathode for a coin‐type full cell and tested for lithium storage performance. The WO3 shell proved to be an effective and strong enhancer for both current rate and specific capacity of SnO2 nanoarchitectures; additionally, an enhancement of cyclic stability was achieved. The findings demonstrate that the WO3 can be used for the improvement of cyclic characteristics of other metal oxide materials as a new coating material.

ZnFe2O4@WO3–X/Polypyrrole: An Efficient Ternary Photocatalytic System for Energy and Environmental Application

“…Among them, the bands at 717 and 811 cm −1 correspond to stretching and bending modes such as W−O stretching, W−O bending, and O−W−O deformation motion, respectively, while the peaks at a lower frequency explain the bending modes of O−W−O with a bridging oxygen atom. 33,34 Moreover, similar types of Raman modes were obtained for the WO 3 specimen with a slight shifting in the band position, as provided in Figure S7a. More interestingly, the appearance of an additional band at 440 cm −1 for WO 3−X in comparison to neat WO 3 indicates the presence of defective oxygen species, which plays a vital role in the charge separation and transfer mechanism.…”

Engineering an oxygen-vacancy-mediated step-scheme charge carrier dynamic coupling WO3−X/ZnFe2O4 heterojunction for robust photo-Fenton-driven levofloxacin detoxification

“…The band at the lower frequency explains the breathing mode of O-W-O with bridged O-atoms, while the bands at the higher frequency correspond to breathing and stretching modes such as W-O breathing, W-O stretching, and O-W-O deformations, respectively. 30,31 Moreover, the occurrence of a supplementary Raman signal at 440 cm À1 for WO 3ÀX specifies the formation of OVs that plays an important part in photo-exciton splitting and transmission mechanisms. 31 The OVs in WO 3 were formed only after the thermal treatment.…”

Core‐Shell Engineered WO3 Architectures: Recent Advances from Design to Applications

“…These structures comprising internal voids are useful in applications that require gas diffusion, volume changes, or trapping pollutants due to their inherently high surface area. Use cases include gas sensing, [ 33 ] energy storage and conversion, [ 34 ] and photocatalytic water remediation. [ 35 ] However, the lack of an internal core could be a disadvantage for energy storage applications.…”

“…[ 53 ] Core SnO 2 nanostructures, which were prepared via co‐precipitation, were observed inside the WO 3 shell. [ 34 ] The relatively high conductivity of WO 3 aided in relieving the volume expansion and facilitating unidirectional electron transport, thus enhancing the cyclability of SnO 2 ( Figure a,b). WO 3 contributes to the prevention of capacity loss, as natural expansion can occur in empty space, thus retaining the specific capacity for >100 cycles.…”

“…Schematic representations of Li-ion insertion/extraction a) without andb) with a WO 3 shell coating the SnO 2 core. Reproduced with permission [34]. Copyright 2021, Willey.…”