Self-sacrificed synthesis of carbon-coated SiO_x nanowires for high capacity lithium ion battery anodes

Abstract

Carbon-coated SiOx nanowires are synthesized through a novel self-sacrificed method and applied for high-performance LIB anodes.

Preparation of a Si/SiO2–Ordered‐Mesoporous‐Carbon Nanocomposite as an Anode for High‐Performance Lithium‐Ion and Sodium‐Ion Batteries

“…Meanwhile, Li 4 SiO 4 and LiO 2 were irreversibly formed during lithiation process, which consume much lithium and thus cause irreversible capacity loss to some extent. Fortunately, the generation of these oxides could act as buffer to accommodate the agglomeration the volume expansion caused by Si particles, in favor of the cycle ability of the electrode . The lithiation reaction of the Si/SiO 2 –OMC composite could be described by Equations . …”

“…Additionally, according to the XPS semi‐quantitative state analysis, it showed that the Si 4+ / Si molar ratio is about 0.86:1, indicating the SiO 2 / Si mass ratio is about 1.84:1. The broad C 1s spectrum (Figure c) can be fitted into three peaks at 284.7, 285.8, and 287 eV, which can be assigned to the C−C, C−O, and C=O bonds, respectively …”

“…Firstly, the carbon matrix contributes to providing good electronic conductivity of the electrode, preventing agglomeration of SiO x , and suppressing volume expansions of the active Si during cycling . Secondly, SiO 2 not only severs as a buffering layer to confine the volume change, but also plays a bonding role to enhance the interfacial adhesion between Si nanoparticles and the carbon matrix . In the case of the Si/SiC–OMC sample, SiC can be considered as a structural reinforcement backbone to couple with Si.…”

Pressure‐Induced Vapor Synthesis of Carbon‐Encapsulated SiOx/C Composite Spheres with Optimized Composition for Long‐Life, High‐Rate, and High‐Areal‐Capacity Lithium‐Ion Battery Anodes

“…By growing vertical graphene nanosheets on the surface of SiO, the areal capacity of 1.40 mAh cm −2 was achieved after 100 cycles at 0.32 A g −1 . By coating carbon layers on the surface of SiO x nanowires, the areal capacity of 1.27 mAh cm −2 was achieved after 100 cycles at 0.1 A g −1 . The areal capacity of 3.22 mAh cm −2 obtained here after 100 cycles is higher than those of all the SiO x ‐based anodes reported previously at a similar cycling number (Table S4, Supporting Information), indicating that the carbon‐encapsulated SiO x /C spheres are highly promising for practical applications.…”

Metal–Organic Frameworks‐Derived Mesoporous Si/SiOx@NC Nanospheres as a Long‐Lifespan Anode Material for Lithium‐Ion Batteries

“…Recently, Si‐based materials have been recognized as a promising material for anodes, owing to its high theoretical capacity (≈3579 mAh g −1 , almost ten times higher than that of graphite 372 mAh g −1 ), abundant resources, and moderate working potential . However, some inherent disadvantages such as massive volume variation upon cycling and poor electrical conductivity can easily result in structural failure and inferior electrochemical performance by a formation of new solid electrolyte interface (SEI) film . These issues greatly hinder the practical application of Si as an anode material in LIBs.…”