Battery (electricity)

Quantum mechanics

Engineering

Lithium (medication)

Nanoparticle

Lithium-ion battery

Electrochemistry

Materials science

Layer (electronics)

Etching (microfabrication)

Endocrinology

Power (physics)

Silicon

Chemical engineering

Physical chemistry

Nanowire

Halloysite

Physics

Nanotechnology

Composite material

Nanomaterials

Medicine

Chemistry

Electrode

Electrolyte

Optoelectronics

Electrolysis

ACS Nano

Silicon (Si) is a promising negative electrode material for lithium-ion batteries (LIBs), but the poor cycling stability hinders their practical application. Developing favorable Si nanomaterials is expected to improve their cyclability. Herein, a controllable and facile electrolysis route to prepare Si nanotubes (SNTs), Si nanowires (SNWs), and Si nanoparticles (SNPs) from halloysite clay (Al2(OH)4Si2O5·nH2O) is developed. It is found that HCl-etching temperature and electrolysis potential play key roles in controlling the morphologies of Si. After being HCl-etched at 80 or 90 °C, halloysite clay can be reduced into Si nanotubes at a suitable potential of -1.45 V or Si nanowires at a wide potential from -1.40 to -1.60 V, respectively, while Si nanoparticles can be only obtained at a more negative potential of -1.60 V without HCl-etching. The different morphologies of Si are associated with the change of reduction kinetics after HCl-etching. Besides, when serving as negative electrode materials for LIBs, Si nanotubes exhibit better Li storage performance than Si nanoparticles and Si nanowires, showing a capacity of 3044 mAh g-1 at 0.20 A g-1 and 1033 mAh g-1 after 1000 cycles at 1 A g-1. This work provides a controllable approach for the synthesis of Si nanomaterials for LIBs.

Electrochemical Synthesis of Multidimensional Nanostructured Silicon as a Negative Electrode Material for Lithium-Ion Battery