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Silicon has demonstrated inordinate potential as anode material for next-generation lithium-ion batteries due to its high theoretical specific capacity. Nevertheless, the structural dilapidation during the lithiation/delithiation process has restricted its large-scope application. To conquer these challenges, we design a novel reduced graphene oxide (rGO)-coated Si@SiO x @β-Bi 2 O 3 /Bi composite by a facile one-pot method. The Bi 2 O 3 shell chiefly guarantees the structural integrity of Si-core during cyclings and synergizes with Bi nanodots to expediting Li+/e− transport kinetics. rGO mainly acts as the carrier to attaining the twofold goals of ameliorating the electronic conductivity and cushioning the stress from volume expansion. Therefore, the novel rGO-coated Si@SiO x @β-Bi 2 O 3 /Bi composite exhibits a high specific capacity of 1784 mAh g−1 at 1 A g−1 after 200 cycles and a good cycling stability of 1007 mAh g−1 at a high rate of 4 A g−1. [Display omitted] [ABSTRACT FROM AUTHOR]

Silicon is one of the most promising candidates for anode materials of lithium-ion batteries, due to its high theoretical capacity and low working voltage, etc. Nonetheless, silicon has huge volume change during the lithiation/delithiation, resulting in poor cycle performance. Herein, novel double-shell-structured Si@Al 2 O 3 @C nanoparticles are prepared to obtain stable electrochemical performance. The improved performance can be attributed to novel double-shell structure, which greatly improves the conductivity of material, stabilizes solid-electrolyte interface (SEI) film, and releases the expansion stress of silicon. Si@Al 2 O 3 @C nanoparticles deliver a specific capacity of 1316.1 mAh g−1 at 1 A g−1 after 100 cycles, and the average discharge capacity of Si@Al 2 O 3 @C nanoparticles at 4 A g−1 still remains 781.6 mAh g−1. Additionally, the initial Coulombic efficiency (ICE) of material is as high as 82.9%. This work offers a significant method to further enhance the performance of lithium-ion batteries. [Display omitted] • For lithium-ion batteries, double-shell-structured Si@Al 2 O 3 @C anode is reported for the first time. • The double-shell structure can improve conductivity, stabilize SEI film, and release the expansion pressure of silicon. • Si@Al 2 O 3 @C nanoparticles show a high ICE of 82.9% and a reversible capacity of 1316.1 mAh g−1 at 1 A g−1 after 100 cycles. • Simple two-step synthesis. [ABSTRACT FROM AUTHOR]