WS2 Nanosheet Loaded Silicon-Oxycarbide Electrode for Sodium and Potassium Batteries

Abstract

Transition metal dichalcogenides (TMDs) such as the WS2 have been widely studied as potential electrode materials for lithium-ion batteries (LIB) owing to TMDs’ layered morphology and reversible conversion reaction with the alkali metals between 0 to 2 V (v/s Li/Li+) potentials. However, works involving TMD materials as electrodes for sodium- (NIBs) and potassium-ion batteries (KIBs) are relatively few, mainly due to poor electrode performance arising from significant volume changes and pulverization by the larger size alkali-metal ions. Here, we show that Na+ and K+ cyclability in WS2 TMD is improved by introducing WS2 nanosheets in a chemically and mechanically robust matrix comprising precursor-derived ceramic (PDC) silicon oxycarbide (SiOC) material. The WS2/SiOC composite in fibermat morphology was achieved via electrospinning followed by thermolysis of a polymer solution consisting of a polysiloxane (precursor to SiOC) dispersed with exfoliated WS2 nanosheets. The composite electrode was successfully tested in Na-ion and K-ion half-cells as a working electrode, which rendered the first cycle charge capacity of 474.88 mAh g−1 and 218.91 mAh g−1, respectively. The synergistic effect of the composite electrode leads to higher capacity and improved coulombic efficiency compared to the neat WS2 and neat SiOC materials in these cells.

Addressing Irreversibility and Structural Distortion in WS2 Inorganic Fullerene-Like Nanoparticles: Effects of Voltage Cutoff Experiments in Beyond Li+-Ion Storage Applications

“…The height of the anodic peak (1.5 V) in the negative current axis for the 0.01–1.5 V KIB cell was pronounced, indicating more electrons are transferred due to partial reactions than the complete reaction of the 0.01–2.5 V cell, thereby indirectly affirming the initial hypothesis of this study that a high voltage cutoff extends protection of the WS 2 IF structure. This technique could be explored with a combination of composite structure formation to realize the full potential of voltage cutoff experiments since some composite structure formation techniques have been shown to enhance the capacity and stabilize the electrochemistry of TMD-based nanomaterials. , …”

“…This technique could be explored with a combination of composite structure formation to realize the full potential of voltage cutoff experiments since some composite structure formation techniques have been shown to enhance the capacity and stabilize the electrochemistry of TMD-based nanomaterials. 58 , 59 …”

Cu9S5-nanowire-pinned-WS2 sheets on hollow cubic carbon for synergistic promotion in K-ion battery performance

“…The second and third cycles overlap well, indicating a gradual stabilization of the electrochemical reaction. [45][46][47] To determine the reasons for the differences in the electrochemical performance of the three electrodes, the capacityvoltage curves of the three electrodes at different current densities were analyzed, as shown in Fig. 5(d-f).…”

State-of-art progress and perspectives on alloy-type anode materials for potassium-ion batteries

“…Silicon oxycarbide has also been investigated for PIBs both theoretically and experimentally; however, their electrochemical performances are far from satisfactory. 64,65 To the best of our knowledge, the reported specific capacities of Si anodes for PIBs are far from the theoretical values owing to the lack of experimental data. Much more attention should be paid to the alloying mechanism of Si in PIBs as well as the structural design to improve its electrochemical performance.…”

“…Silicon oxycarbide has also been investigated for PIBs both theoretically and experimentally; however, their electrochemical performances are far from satisfactory. 64,65…”