Nitrogen-Doped Carbon-Encapsulated Ordered Mesoporous SiOx as Anode for High-Performance Lithium-Ion Batteries.

Abstract

SiOx (0<x<2) has been broadly investigated as a promising anode in lithium-ion batteries (LIBs) due to its high theoretical capacity, low cost, and proper working voltage. Nevertheless, its practical application is hindered by volume expansion during the lithiation process and low electrical conductivity, resulting in rapid capacity decay. Herein, we designed a core-shell structured nitrogen-doped carbon-encapsulated ordered mesoporous SiOx composite (SiOx @NC) using 3-aminophenol-formaldehyde (3-AF) as carbon and nitrogen precursor, tetraethyl orthosilicate (TEOS) as the silica precursor, and cationic surfactant cetyltrimethylammonium bromide (C16 TAB) as the mesoporous template. The obtained composite electrode not only can effectively reduce the volume expansion, but also can effectively improve electronic conductivity and further enhance the charge and ion transfer kinetics. Benefiting from the unique structural merits, the obtained SiOx @NC-2 delivers a high reversible capacity of 602.4 mAh g-1 at 0.1 A g-1 after 100 cycles and long-term cyclability (maintain 426.1 mAh g-1 over 1000 cycles at 1 A g-1 ).