Correlating Lithium Hydroxyl Accumulation with Capacity Retention in V2O5 Aerogel Cathodes.
V2O5 aerogels are capable of reversibly intercalating more than 5 Li(+)/V2O5 but suffer from lifetime issues due to their poor capacity retention upon cycling. We employed a range of material characterization and electrochemical techniques along with atomic pair distribution function, X-ray photoelectron spectroscopy, and density functional theory to determine the origin of the capacity fading in V2O5 aerogel cathodes. In addition to the expected vanadium redox due to intercalation, we observed LiOH species that formed upon discharge and were only partially removed after charging, resulting in an accumulation of electrochemically inactive LiOH over each cycle. Our results indicate that the tightly bound water that is necessary for maintaining the aerogel structure is also inherently responsible for the capacity fade.
Linda W
LW
Wangoh
Yiqing
Y
Huang
Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States.
Ryan L
RL
Jezorek
School of Chemistry & CRANN, Trinity College Dublin , Dublin 2, Ireland.
Aoife B
AB
Kehoe
School of Chemistry & CRANN, Trinity College Dublin , Dublin 2, Ireland.
Graeme W
GW
Watson
Fredrick
F
Omenya
Nicholas F
NF
Quackenbush
Natasha A
NA
Chernova
M Stanley
MS
Whittingham
Louis F J
LF
Piper
V2O5; X-ray photoelectron spectroscopy; aerogel; cathodes; lithium ion battery; pair distribution function