TY  - JOUR
U1  - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed)
A1  - Hall, Florian
A1  - Touzri, Jonas
A1  - Wußler, Sabine
A1  - Buqa, Hilmi
A1  - Bessler, Wolfgang G.
T1  - Experimental Investigation of the Thermal and Cycling Behavior of a Lithium Titanate-based Lithium-ion Pouch Cell
JF  - Journal of Energy Storage
N2  - Lithium-ion pouch cells with lithium titanate (Li4Ti5O12, LTO) anode and lithium nickel cobalt aluminum oxide (LiNi0.8Co0.15Al0.05O2, NCA) cathode were investigated experimentally with respect to their electrical (0.1C…4C), thermal (5 °C…50 °C) and long-time cycling behavior. The 16 Ah cell exhibits an asymmetric charge/discharge behavior which leads to a strong capacity-rate effect, as well as a significantly temperature-dependent capacity (0.37 Ah ∙ K−1) which expresses as additional high-temperature feature in the differential voltage plot. The cell was cycled for 10,000 cycles inbetween the nominal voltage limits (1.7–2.7 V) with a symmetric 4C constant-current charge/discharge protocol, corresponding to approx. 3400 equivalent full cycles. A small (0.192 mΩ/1000 cycles) but continuous increase of internal resistance was observed. Using electrochemical impedance spectroscopy (EIS), this could be identified to be caused by the NCA cathode, while the LTO anode showed only minor changes during cycling. The temperature-corrected capacity during 4C cycling exhibited a decrease of 1.28%/1000 cycles. The 1C discharge capacity faded by only 4.0% for CC discharge and 2.3% for CCCV discharge after 10,000 cycles. The cell thus exhibits very good internal-resistance stability and excellent capacity retention even under harsh (4C continuous) cycling, demonstrating the excellent stability of LTO as anode material.
Y1  - 2018
SN  - 2352-152X
SS  - 2352-152X
U6  - https://dx.doi.org/10.1016/j.est.2018.02.012
DO  - https://dx.doi.org/10.1016/j.est.2018.02.012
VL  - 17
SP  - 109
EP  - 117
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
U1  - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed)
A1  - Hall, Florian
A1  - Wußler, Sabine
A1  - Buqa, Hilmi
A1  - Bessler, Wolfgang G.
T1  - Asymmetry of Discharge/Charge Curves of Lithium-Ion Battery Intercalation Electrodes
JF  - The Journal of Physical Chemistry C
N2  - Nickel cobalt aluminum oxide (NCA) based lithium-ion battery electrodes exhibit a distinct asymmetry in discharge/charge behavior towards high bulk stoichiometry (low state of charge). We show that basic electrochemical relationships, that is, the Nernst equation and the Butler-Volmer equation, are able to reproduce this behavior when a two-step reaction mechanism is assumed. The two-step mechanism consists of (1) lithium-ion adsorption from the electrolyte onto the active material particle surface under electron transfer, and (2) intercalation of surface-adsorbed lithium atoms into the bulk material. The asymmetry of experimental half-cell data of an NCA electrode cycled at 0.1 C-rate can be quantitatively reproduced with this simple model. The model parameters show two alternative solutions, predicting either a saturated (highly-covered) or a depleted surface for high bulk lithiation.
KW  - Lithium-Ionen-Akkumulator
KW  - Aufladung
Y1  - 2016
SN  - 1932-7455 (Online)
SS  - 1932-7455 (Online)
SN  - 1932-7447 (Print)
SS  - 1932-7447 (Print)
U6  - https://dx.doi.org/10.1021/acs.jpcc.6b07949
DO  - https://dx.doi.org/10.1021/acs.jpcc.6b07949
VL  - 120
IS  - 41
SP  - 23407
EP  - 23414
ER  - 
TY  - CHAP
U1  - Konferenzveröffentlichung
A1  - Hall, Florian
A1  - Wußler, Sabine
A1  - Buqa, Hilmi
A1  - Bessler, Wolfgang G.
T1  - Thermal and cycling behavior of an LTO/NCA lithium-ion pouch cell
T2  - 14th Symposium on Fuel Cell and Battery Modelling and Experimental Validation (ModVal 14), Karlsruhe, Germany (03/2017), Book of Abstracts
Y1  - 2017
UR  - http://www.modval14.kit.edu/downloads/Updated_BookOfAbstracts.pdf
SP  - 117
S1  - 1
CY  - Karlsruhe
ER  -