TY  - JOUR
AU  - Windmüller, Anna
AU  - Bridges, Craig A.
AU  - Tsai, Chih-Long
AU  - Lobe, Sandra
AU  - Dellen, Christian
AU  - Veith, Gabriel M.
AU  - Finsterbusch, Martin
AU  - Uhlenbruck, Sven
AU  - Guillon, Olivier
TI  - Impact of Fluorination on Phase Stability, Crystal Chemistry, and Capacity of LiCoMnO 4 High Voltage Spinels
JO  - ACS applied energy materials
VL  - 1
IS  - 2
SN  - 2574-0962
CY  - Washington, DC
PB  - ACS Publications
M1  - FZJ-2020-02419
SP  - 715 - 724
PY  - 2018
AB  - Fluorinated LiCoMnO4−yFy (y = 0, 0.05, 0.1) spinel electrodes, electrochemically active at 5−5.3 V versus Li/Li+, show enhanced phase purity and enhanced capacity with increasing y. We disclose the impact of fluorination on the phase purity and reversible capacity of LiCoMnO4 via joint Rietveld refinement of neutron and synchrotron powder diffraction data, combined with micro-Raman spectroscopy. It is found that fluorination stabilizes the spinel phase and hinders precipitation of Li2MnO3 as a secondary phase, which controls the cation distribution on tetrahedral and octahedral sites in spinel. That is to say, for higher fluorine content the cobalt occupancy at the tetrahedral site in spinel decreases, and the lithium occupancy increases. Accordingly, the number of lithium sites that are available for electrochemical extraction and insertion of lithium ions is raised so that the capacity isincreased. Further investigation of the lithium ion diffusion by means of cyclic voltammetry at different scan rates and the application of the Randles−Sevcik equation were carried out to investigate the extent of capacity enhancement due to faster lithium ion diffusion in the high voltage region.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000458705100061
DO  - DOI:10.1021/acsaem.7b00186
UR  - https://juser.fz-juelich.de/record/877718
ER  -