Rights statement: This is the peer reviewed version of the following article: Rinaldi, A., Wijaya, O. and Hoster, H. E. (2016), Lithium-Oxygen Cells: An Analytical Model to Explain the Key Features in the Discharge Voltage Profiles. ChemElectroChem. Accepted Author Manuscript. doi:10.1002/celc.201600184 which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/celc.201600184/abstract This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
Accepted author manuscript, 546 KB, PDF document
Available under license: CC BY-NC: Creative Commons Attribution-NonCommercial 4.0 International License
Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Lithium-oxygen cells
T2 - an analytical model to explain the key features in the discharge voltage profiles
AU - Rinaldi, Ali
AU - Wijaya, Olivia
AU - Hoster, Harry Ernst
N1 - This is the peer reviewed version of the following article: Rinaldi, A., Wijaya, O. and Hoster, H. E. (2016), Lithium-Oxygen Cells: An Analytical Model to Explain the Key Features in the Discharge Voltage Profiles. ChemElectroChem. Accepted Author Manuscript. doi:10.1002/celc.201600184 which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/celc.201600184/abstract This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
PY - 2016/11
Y1 - 2016/11
N2 - Sodium-oxygen Lithium-oxygen (Li-O2) cells are popular due to their potentially high energy density. A characteristic fingerprint of a given cell is the voltage profile during constant-current discharge. We suggest that the typical initial dip and the following increase of the voltage result from a temporary increase and slow decrease in the concentration of dissolved superoxide, respectively, feeding into the Nernst equation. The steady-state superoxide concentration decreases as the surface area of the solid precipitation product (Li2O2) increases. Importantly, these products bury the electrochemically active carbon surface. Assuming that the electrochemical step only occurs on bare carbon, the Tafel equation provides an expression for the increasing overpotential as a result of the shrinking effective electrode area. This boils the discharge voltage profile down to the sum of two logarithms, grasping all relevant features in recorded discharge voltage profiles.
AB - Sodium-oxygen Lithium-oxygen (Li-O2) cells are popular due to their potentially high energy density. A characteristic fingerprint of a given cell is the voltage profile during constant-current discharge. We suggest that the typical initial dip and the following increase of the voltage result from a temporary increase and slow decrease in the concentration of dissolved superoxide, respectively, feeding into the Nernst equation. The steady-state superoxide concentration decreases as the surface area of the solid precipitation product (Li2O2) increases. Importantly, these products bury the electrochemically active carbon surface. Assuming that the electrochemical step only occurs on bare carbon, the Tafel equation provides an expression for the increasing overpotential as a result of the shrinking effective electrode area. This boils the discharge voltage profile down to the sum of two logarithms, grasping all relevant features in recorded discharge voltage profiles.
KW - batteries
KW - discharge voltage profiles
KW - EC mechanism
KW - Li–O 2 cells
KW - modelling
U2 - 10.1002/celc.201600184
DO - 10.1002/celc.201600184
M3 - Journal article
VL - 3
SP - 1944
EP - 1950
JO - ChemElectroChem
JF - ChemElectroChem
SN - 2196-0216
IS - 11
ER -