1 research outputs found
Dual Core–Shell Structured Si@SiO<sub><i>x</i></sub>@C Nanocomposite Synthesized via a One-Step Pyrolysis Method as a Highly Stable Anode Material for Lithium-Ion Batteries
Silicon (Si) has been regarded as
a promising high-capacity anode material for developing advanced lithium-ion
batteries (LIBs), but the practical application of Si anodes is still
unsuccessful mainly due to the insufficient cyclability. To deal with
this issue, we propose a new route to construct a dual core–shell
structured Si@SiO<sub><i>x</i></sub>@C nanocomposite by
direct pyrolysis of polyÂ(methyl methacrylate) (PMMA) polymer on the
surface of Si nanoparticles. Since the PMMA polymers can be chemically
bonded on the nano-Si surface through the interaction between ester
group and Si surface group, and thermally decomposed in the subsequent
pyrolysis process with their alkyl chains converted to carbon and
the residue oxygen recombining with Si to form SiO<sub><i>x</i></sub>, the dual core–shell structure can be conveniently
formed in a one-step procedure. Benefiting from the strong buffering
effect of the SiO<sub><i>x</i></sub> interlayer and the
efficient blocking action of dense outer carbon layer in preventing
electrolyte permeation, the obtained nanocomposite demonstrates a
high capacity of 1972 mA h g<sup>–1</sup>, a stable cycling
performance with a capacity retention of >1030 mA h g<sup>–1</sup> over 500 cycles, and particularly a superiorly high Coulombic efficiency
of >99.5% upon extended cycling, exhibiting a great promise for
practical uses. More importantly, the synthetic method proposed in
this work is facile and low cost, making it more suitable for large-scale
production of high capacity anode for advanced LIBs