摘要
Silica(SiO_(2)),with its high theoretical capacity and abundance,holds great potential as anode material for lithium-ion batteries(LIBs).However,its practical application is hindered by inherently low conductivity and significant volume change during cycling.In this work,we present a simple yet effective strategy to address these challenges by homogeneously binding high-density,ultra-small SiO_(2) nanoparticles within a carbon nanosheet framework(denoted as SiO_(2)@CNS).In this design,densely packed sufficiently-small SiO_(2) nanoparticles(about 6 nm)ensure high electrochemical reactivity,while the conductive and flexible CNS matrix facilitates rapid ion/electron transfer and buffers volume changes during cycling.As a result,the SiO_(2)@CNS anode delivers a remarkable capacity of 607.3 mA·h/g after 200 cycles at 0.1 A/g,superior rate capability(407.4 mA·h/g at 2 A/g)and outstanding durability,retaining 93.1%of its capacity after 2000 cycles at 1 A/g.In-situ transmission electron microscopy and ex-situ microscopic and spectroscopic analyses reveal moderate volume variation and exceptional structural stability during cycling,supported by the formation of a robust solid-electrolyte interphase that underpins its long-lasting performance.Full cells paired with commercial LiFePO_(4) cathode exhibit outstanding rate and cycling performance.This work provides valuable insights into developing highly-efficient SiO_(2)-based anodes for high-performance LIBs.
基金
supported by the National Natural Science Foundation of China(Grants Nos.52122211,92472104,52072323)
the Frontier Exploration Projects of Longmen Laboratory(Grant No.LMQYTSKT008)
the Shenzhen Technical Plan Project(No.JCYJ20220818101003008).
