• Home
  • Anomalous capacity increase at high-rates in lithium-ion battery anodes based on silicon-coated vertically aligned carbon nanofibers

Anomalous capacity increase at high-rates in lithium-ion battery anodes based on silicon-coated vertically aligned carbon nanofibers

Journal of Power Sources 276, 73, 2015

ABSTRACT

This study reports of a multi-scale hierarchical lithium-ion battery (LIB) anode that shows a surprising increase in storage capacity at higher current rates from ∼3C to ∼8C. The anode, composed of forest-like vertically aligned carbon nanofibers coaxially coated with Si shells, is shown to obtain a storage capacity of 3000–3500 mAh (gSi)−1 and greater than 99% coulombic efficiency at a 1C (or C/1) rate, leading to remarkable stability over 500 charge–discharge cycles. In contrast to other studies, this hierarchical LIB anode shows superior high-rate capability where the capacity decreased by less than 7% from ∼C/8 to ∼3C rates and, more importantly, increased by a few percent from ∼3C to ∼8C rates, displaying a new phenomenon that becomes more evident after going through long cycles. Electron microscopy, Raman, and electrochemical impedance spectroscopy reveal that the electrode structure remains stable during long cycling and that this enhanced property is likely associated with the combination of the unique nanocolumnar microstructure of the Si coating and the vertical core–shell architecture. It reveals an exciting potential to develop high-performance lithium-ion batteries.

File

wuj.pdf

Authors: 
Steven A. Klankowski, Gaind P. Pandey, Brett A. Cruden, Jianwei Liu*, Judy Wu*, Ronald A. Rojeski, Jun Li *KU Authors

Department Communications

Colloquia         Seminars         Public Events         AAL

MARAC2017

NEWSLETTERS

Department            Alumni

VIDEOS

Mr. Bob Show              Colloquia

Alumni Remembrances          Public Lectures

Departmental Calendar

Paper of the Week
Mr. Bob T-Shirts: Lab Support
Home to 50+ departments, centers, and programs, the School of the Arts, and the School of Public Affairs and Administration
KU offers courses in 40 languages
No. 1 ranking in city management and urban policy —U.S. News and World Report
One of 34 U.S. public institutions in the prestigious Association of American Universities
44 nationally ranked graduate programs.
—U.S. News & World Report
KU Today
An @ugresearchKU Award can jump start an idea for a business. Just ask Jack Figgs-Hoard and #BeAJayhawk . (CC)… https://t.co/bVFziNjuwM


Social Media

Find us on Facebook