Highly Stable Three Lithium Insertion in Thin V2O5 Shells on Vertically Aligned Carbon Nanofiber Arrays for Ultrahigh‐Capacity Lithium Ion Battery Cathodes
Abstract
Here the authors demonstrate an approach to achieving stable 3 Li+ insertion into vanadium pentoxide (V2O5) by implementing a 3D core–shell structure consisting of coaxial V2O5 shells sputter‐coated on vertically aligned carbon nanofiber cores. The hydrated amorphous microporous structure in the “as‐deposited” V2O5 shells and the particulated nanocrystalline V2O5 structure formed by thermal annealing are compared. The former provides remarkably high capacities of 360 and 547 mAh g−1 in the voltage range of 4.0–2.0 and 4.0–1.5 V, respectively, far exceeding values in current oxide‐based lithium ion battery cathodes and even the corresponding theoretical values of 294 mAh g−1 for 2 Li+/V2O5 insertion and 441 mAh g−1 for 3 Li+/V2O5 insertion into crystalline V2O5 materials. This is attributed to the additional reactions with the hydrated amorphous structure. After 100 cycles of 3 Li+/V2O5 insertion/extraction at 0.20 A g−1 (≈C/3), ≈84% of the initial capacity is retained. After thermal annealing, the core–shell structure presents a capacity of 294 and 390 mAh g−1, matching well with the theoretical values for 2 and 3 Li+/V2O5 insertion. The annealed sample shows further improved stability, with a remarkable capacity retention of ≈100% and ≈88% for 100 cycles of 2 and 3 Li+/V2O5 insertion/extraction.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 13, 2016
- Source ID
- 10.1002/admi.201600824
Entities
People
- Emery Brown
- Gaind P. Pandey
- Jagaran Acharya
- Judy Z. Wu
- Jun Li
Organizations
- Army Research Office
- Kansas State University
- National Aeronautics and Space Administration
- National Science Foundation
- University of Kansas