Electrolytic Formation of Crystalline Silicon/Germanium Alloy Nanotubes and Hollow Particles with Enhanced Lithium‐Storage Properties

Abstract

Crystalline silicon(Si)/germanium(Ge) alloy nanotubes and hollowp articles are synthesized for the first time through ao ne-pot electrolytic process.T he morphology of these alloy structures can be easily tailored from nanotubes to hollowp articles by varying the overpotential during the electro-reduction reaction. The continuous solid diffusion governed by the nanoscale Kirkendall effect results in the formation of inner void in the alloy particles.Benefitting from the compositional and structural advantages,t hese SiGe alloy nanotubes exhibit muche nhanced lithium-storage performance compared with the individual solid Si and Ge nanowires as the anode material for lithium-ion batteries.

Facile electrosynthesis of silicon carbide nanowires from silica/carbon precursors in molten salt

“…3c and d ), which is the characteristic of SiC 12 . The previous studies 25 – 39 generally proved that high-purity metals/alloys/composites powders can be prepared in molten CaCl 2 from their oxides precursors. In this work, high-purity SiO 2 /C powders were used as precursors, therefore, based on the experimental results (Figs 2c and 3 ), it is reasonable to believe that the synthesized SiC NWs possess relatively high purity, only a small amount of residual carbon coexists in the product (Fig.…”

“…This distinct reaction mechanism may lead to the formation of homogenous SiC NWs. Actually, the reaction mechanism in molten salt is usually distinct due to the molten salt electrolyte can provide the microgravity field during the synthesis process, which can contribute to the formation of some special structures, such as nanowire/nanotube and hollow particle 39 . It should be noted that the proposed reaction mechanism may only be used as general guidelines for understanding the reaction mechanism of the electrosynthesis process.…”

“…Recently, the molten salt electroreduction process has been intensively investigated for the facile production of micro/nanostructured metals/alloys/composites powders 25 – 39 . In particular, the electroreduction process in molten salt can directly convert solid metal oxides into micro/nanostructured metals/alloys powders and consumes only electrons as reductant 27 , 28 .…”

“…In particular, the electroreduction process in molten salt can directly convert solid metal oxides into micro/nanostructured metals/alloys powders and consumes only electrons as reductant 27 , 28 . These innovative previous studies 25 – 39 offer an attractive promising strategy for the facile electrosynthesis of micro/nanostructured metal carbides in molten salt. In addition, it has been proved that the distinctive dissolution-electrodeposition mechanism for silica in molten salt (silica → silicate ions → silicon) can contribute to the formation of Si nanowire structure 34 – 38 .…”

Synthesis and Investigation of CuGeO3 Nanowires as Anode Materials for Advanced Sodium-Ion Batteries

“…3c , the CGO nanowires delivered an initial charge capacity of up to 306.7 mAh g −1 and an initial CE of 61.74% at a constant current density of 50 mA g −1 . The high capacity loss in the initial cycle could be attributed to the formation of SEI layer on the active material surface and other irreversible reaction, which is a common feature of nanostructured anodes [ 33 , 34 ]. Furthermore, the charge capacity rapidly decayed to 205 mAh g −1 at 10th cycle and slowly decreased to 171 mAh g −1 at 60th (only 0.68 mAh g −1 capacity loss for per cycle from the 10th to 60th cycle).…”