A Top‐Down Strategy toward SnSb In‐Plane Nanoconfined 3D N‐Doped Porous Graphene Composite Microspheres for High Performance Na‐Ion Battery Anode

Abstract

Engineering of 3D graphene/metal composites with ultrasmall sized metal and robust metal-graphene interfacial interaction for energy storage application is still a challenge and rarely reported. In this work, a facile top-down strategy is developed for the preparation of SnSb-in-plane nanoconfined 3D N-doped porous graphene networks for sodium ion battery anodes, which are composed of several tens of interconnected empty N-graphene boxes in-plane firmly embedded with ultrasmall SnSb nanocrystals. The all-around encapsulation (plane-to-plane contact) architecture that provides a large interface between N-graphene and SnSb nanocrystal not only effectively enhances the electron conductivity and structural integrity of the overall electrode, but also offers excess interfacial sodium storage, thus leading to much enhanced high-rate sodium storage capacity and stability, which has been proven by both experimental results and first-principles simulations. Moreover, this top-down strategy can enable new paths to the low-cost and high-yield synthesis of 3D graphene/metal composites for applications in energy-related fields and beyond.

Heterocarbides Reinforced Electrochemical Energy Storage

“…As the scan rate increases, it is observed that the peak intensities of the tested samples increase simultaneously, with a quick signal feedback to the increased scan rate, and all samples show well‐preserved CV shapes. As the discharge and charge reaction rates are highly dependent on the ion diffusion process, the Li + diffusion coefficients ( D Li+ ) were compared based on the Randles–Sevcik equation (Equation ) …”

“…C is the concentration of Li + . Since all tested electrodes and cells were fabricated by the same procedure, the Randles–Sevcik equation to calculate Li + diffusion coefficient could be simplified as Equation in which, k is considered to be a constant in lithium‐ion batteries, and the Li + diffusion coefficient could be redefined as kD 1/2 , which could be obtained from the linear relationship between the peak current ( i p : A*/B*/C*) and the square root of the scan rates (ν 1/2 ). As clearly seen, the Li + diffusion process of MoC‐nws has been proved to be more efficient than that of Mo 2 C‐nws.…”

In Situ Construction of Multibuffer Structure 3D CoSn@SnOx/CoOx@C Anode Material for Ultralong Life Lithium Storage

“…As shown from the HRTEM in Figure d,e, a multishell structure is clearly observed from a monodisperse alloy particle. Specifically, in the outermost layer, a uniform thin graphitized carbon layer was observed, which is derived from the catalytic effect of CoSn alloy nanoparticles to the surrounding carbon . For the middle layer, a uniform amorphous oxide layer with a thickness of ≈2 nm is shown, combined with the X‐ray photoelectron spectroscopy (XPS) analysis, it can be identified as Sn x O/Co x O, which may form during the process of alloying and carbonization of citric acid.…”

“…It is noteworthy that a suitable carbon structure is crucial to the stability of alloy/carbon anode. 3D porous carbon with excellent mechanical flexibility, abundant void, large specific surface area (SSA), outstanding thermal stability, and superior electronic conductivity is a recommendable support for constructing alloy/carbon material and has been widely investigated as electrode for lithium‐ion batteries . To obtain a 3D porous structure, some common methods such as the hard template method and soft template method have been attempted.…”

Elucidating the origin of superior electrochemical cycling performance: new insights on sodiation–desodiation mechanism of SnSb from operando spectroscopy

“…7 In their very recent study Qin et al demonstrate that via embedding SnSb nanocrystalls in a graphene scaffold the capacity can be stabilized over thousands of cycles. 8 Such outstanding electrochemical performance make SnSb one of the most promising negative electrode materials for NIB. The remarkable cycle life of SnSb vs. Na, which exceeds by far the one observed vs. Li for the same electrode, comes as a surprise considering the huge volume expansion (226%) expected for the reaction of SnSb with ≈4.9 Na.…”