Accommodation of Two-Dimensional SiO_x in a Point-to-Plane Conductive Network Composed of Graphene and Nitrogen-Doped Carbon for Robust Lithium Storage

Abstract

Silicon oxides (SiO x ) are one of the most promising anode materials for next-generation lithium-ion batteries owing to their abundant reserve and low lost and high reversible capacity. However, the practical application of SiO x is still hindered by their intrinsically low conductivity and huge volume change. In this regard, we design a novel anode material in which sheet-like SiO x nanosheets are encapsulated in a unique point-to-plane conductive network composed of graphene flakes and nitrogen-doped carbon spheres. This unique composite structure demonstrates high specific capacity (867.7 mAh g–1 at 0.1 A g–1), superior rate performance, and stable cycle life. The electrode delivers a superior reversible discharge capacity of 595.8 mAh g–1 after 200 cycles at 1.0 A g–1 and 287.5 mAh g–1 after 500 cycles at 5.0 A g–1. This work may shed light on the rational design of SiO x -based anode materials for next-generation high-performance lithium-ion batteries.

Facile Synthesis of 2D SiOx‐3D Si Hybrid Anode Materials by Ca Modification Effect for Enhanced Lithium Storage Performance

“…As shown in Figure a, the optimized HSiBM@C electrode shows a better rate performance, which maintains a specific capacity of 469 mAh g −1 at the current density of 7.14 A g −1 , demonstrating an outstanding rate capacity. Compared with other works reported about SiO x nanosheets, [ 34,39,42–45 ] the HSiBM@C anode possesses the advantage of high capacity and fast charge/discharge ability (Figure 5b). The long‐term cycling of the optimized HSiBM@C electrode at 1.79 A g −1 was also performed to test the cycling stability at high current density.…”

Preparation of porous silicon composite anode material coated with open pore polymethyl acrylate and its electrochemical performance as a carbon source

“…This can be attributed to silicon's low electronic conductivity, ranging from 10 À5 to 10 À3 S m À1 . 38 Higher silicon content accentuates this impedance effect. Nonetheless, the PSi@C electrode, compared to the pure PSi electrode, reduces both R f and R ct due to the carbon layer coating, enhancing its conductivity.…”

Enabling Uniform and Stable Lithium‐Ion Diffusion at the Ultrathin Artificial Solid‐Electrolyte Interface in Siloxene Anodes

“…Primordially, the Zintl phase CaSi 2 , which exhibits a densely packed layered structure (Figure S1, Supporting Information), was pretreated in 2 m NaOH aqueous solution to remove the residual crystalline silicon. [ 22 ] X‐ray diffraction (XRD) pattern demonstrates that the typical crystalline silicon peak at 28° completely disappeared after alkali washing, compared with that before washing (Figure S2, Supporting Information). Later, the pretreated Zintl phase CaSi 2 was etched in cold concentrated HCl solution under an inert atmosphere to remove the Ca ions from Zintl phase CaSi 2 via a topotactic reaction.…”