Hollow iron oxide nanoparticles for lithium-ion battery applications

July 20, 2012
Transmission electron micrograph of hollow iron oxide nanoparticles.

Novel hollow iron oxide nanoparticles with a high concentration of defects were synthesized by Center for Nanoscale Materials (CNM) facility users from Argonne's Chemical Sciences & Engineering Division and Advanced Photon Source (APS), and the University of Chicago, working collaboratively with the CNM NanoBio Interfaces Group. A new concept of electrode fabrication based on sealing nanoparticles between layers of pure carbon nanotubes was also developed. When this novel electrode was used as a cathode, the inherent iron vacancies allowed for significantly increased performance in a lithium-ion battery.

Conventional nanoparticle-based electrodes fade quickly because of poor connectivity between the nanoparticles and the current collector. The new electrodes allow for reversible lithium-ion intercalation, which resulted in high capacity and efficiency, superior rate performance, and excellent stability (no fading over more than 500 cycles). This result demonstrates that nanomaterial morphology is critical to lithium-ion battery development.

Schematic of electrode consisting of hollow iron oxide nanoparticles sealed between carbon nanotube films.

At the CNM, hollow gamma-Fe2O3 nanoparticles were synthesized with four times more cation vacancies than solid nanoparticles or bulk material. Novel electrode fabrication involved sealing the nanoparticles between layers of pure multiwalled carbon nanotubes without binders or additives. Electrochemical studies revealed high capacity (132 mAh/g at 2.5V), 99.7% Coulombic efficiency, superior rate performance (133 mAh/g at 3000 mA/g), and excellent stability. At the APS, in situ structural transformation of the nanoparticles by synchrotron X-ray absorption and diffraction techniques provided a clear understanding of lithium processes during electrochemical cycling.

Explore further: A new type of composite material with peapod structures can help improve performance of lithium-ion batteries

More information: B. Koo et al., "Hollow iron oxide nanoparticles for application in lithium ion batteries," Nano Letters,12, 2429 (2012)

Related Stories

Recommended for you

Better together: graphene-nanotube hybrid switches

August 2, 2015

Graphene has been called a wonder material, capable of performing great and unusual material acrobatics. Boron nitride nanotubes are no slackers in the materials realm either, and can be engineered for physical and biological ...

Reshaping the solar spectrum to turn light to electricity

July 28, 2015

When it comes to installing solar cells, labor cost and the cost of the land to house them constitute the bulk of the expense. The solar cells—made often of silicon or cadmium telluride—rarely cost more than 20 percent ...

Meet the high-performance single-molecule diode

July 29, 2015

A team of researchers from Berkeley Lab and Columbia University has passed a major milestone in molecular electronics with the creation of the world's highest-performance single-molecule diode. Working at Berkeley Lab's Molecular ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.