Facile Spray‐Drying Synthesis of Dual‐Shell Structure Si@SiO_x@Graphite/Graphene as Stable Anode for Li‐Ion Batteries

Abstract

A dual‐shell structure Si@SiOx@graphite/graphene (SGGr) is prepared by large‐scale spray‐drying. In this composite, Si nanoparticles act as the core, SiOx and graphite/graphene serve as the shell. Transmission electron microscopy (TEM) studies show that Si nanoparticles are coated with a 1–2 nm SiOx layer and embedded into the sheets of graphite/graphene. Amorphous SiOx and graphite/graphene as the production layer can prevent Si directly connecting with the electrolyte and improve the entire structural stability. In addition, nitrogen adsorption–desorption measurements indicate that the prepared SGGr has a higher Brunauer–Emmett–Teller (BET) surface area (48.4 m2 g−1) than pure Si (36.2 m2 g−1) due to the existence of mesopores and macropores, which can shorten the lithium‐ion transport pathway and provide enough void space for accommodating the volume expansion. The prepared SGGr exhibits a high reversible specific capacity of 1089.3 mAh g−1 after 400 cycles (0.16% decay per cycle), indicating that SGGr has the great potential for industrial application for lithium‐ion batteries.

Facile and Scalable Synthesis of Si@void@C Embedded in Interconnected 3D Porous Carbon Architecture for High Performance Lithium‐Ion Batteries

“…In Figure S4c (Supporting Information), three peaks located at 103.8, 103.2, and 99.1 eV in Si 2p region, are traced to silicon oxides (SiO x ) and pure Si. [ 32,33 ] The oxidation states indicate the instability of Si nanoparticles during UV illumination and hydrothermal synthesis. It's worth noting that the thin SiO x layer reacts with Li + ions, forming Li 2 O and lithium silicates to buffer the volume change and improve the cycling stability of Si yolk particles under charge/discharge process.…”

Interfacial encapsulation stress management of micron-sized porous SiO anodes for high-energy lithium-ion batteries

“…3h), three peaks at 284.8 eV, 285.7 eV and 287.9 eV correspond to C]C/C-C, C-O, and O-C-O. 33,34 The highresolution O 1s spectra of p-SiO@rGO (Fig. 3i) can be further deconvolved into C-O and Si-O at 532.5 and 533.4 eV, respectively.…”

“…Three peaks at 99.2, 101.4 and 103.3 eV are ascribed to Si-Si, Si-O-C and Si-O, respectively. 33,34 In the C 1s region of the high-resolution XPS spectra (Fig. 3h), three peaks at 284.8 eV, 285.7 eV and 287.9 eV correspond to C]C/C-C, C-O, and O-C-O.…”

Enhanced Cycle Stability of Crumpled Graphene-Encapsulated Silicon Anodes via Polydopamine Sealing

“…After this seminal work, researchers have attempted to improve upon this method by employing spray-dryers to achieve large-scale, automated production of silicon anodes based on crumpled graphene or other carbon shells. However, these works have mainly focused on the introduction of more components into the silicon core to enhance the inside conductivity or robustness of the secondary structure, such as CNTs, , SiO 2 , glucose, gelatin, sucrose, polyvinylpyrrolidone, , polyvinyl alcohol, , polyacrylic acid-carboxymethyl cellulose, and styrene-acrylonitrile, but the corresponding improvement is still limited compared to Liu’s work . To further optimize this method, a fundamental study about the effect of spray-drying parameters on the physical morphology and dimensions of GO/Si composites and the resulting battery performance is essential, although presently, few papers discuss this in detail.…”