TY - JOUR
T1 - Reversible Flat to Rippling Phase Transition in Fe Containing Layered Battery Electrode Materials
AU - Chen, Xi
AU - Hwang, Sooyeon
AU - Chisnell, Robin
AU - Wang, Yichao
AU - Wu, Fan
AU - Kim, Sooran
AU - Lynn, Jeffrey W.
AU - Su, Dong
AU - Li, Xin
N1 - Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/9/26
Y1 - 2018/9/26
N2 - Layered sodium transition metal oxides of NaTMO2 (TM = 3d transition metal) show unique capability to mix different compositions of Fe to the TM layer, a phenomenon that does not exist in LiTMO2. Here, a novel spontaneous TM layer rippling in the sodium ion battery cathode materials is reported, revealed by in situ X-ray diffraction, Cs-corrected scanning transmission electron microscopy, and density functional theory simulation, where the softening and distortion of FeO6 octahedra collectively drives the flat TM planes into rippled ones with inhomogeneous interlayer distance at high voltage. In such a rippling phase, charge and discharge of Na ions take different evolution pathways, resulting in an unusual hysteresis voltage loop. Importantly, upon discharge beyond a certain Na composition, the rippling TM layer will go back to flat, giving the reversibility of such structural evolution in the following cycles.
AB - Layered sodium transition metal oxides of NaTMO2 (TM = 3d transition metal) show unique capability to mix different compositions of Fe to the TM layer, a phenomenon that does not exist in LiTMO2. Here, a novel spontaneous TM layer rippling in the sodium ion battery cathode materials is reported, revealed by in situ X-ray diffraction, Cs-corrected scanning transmission electron microscopy, and density functional theory simulation, where the softening and distortion of FeO6 octahedra collectively drives the flat TM planes into rippled ones with inhomogeneous interlayer distance at high voltage. In such a rippling phase, charge and discharge of Na ions take different evolution pathways, resulting in an unusual hysteresis voltage loop. Importantly, upon discharge beyond a certain Na composition, the rippling TM layer will go back to flat, giving the reversibility of such structural evolution in the following cycles.
KW - Na-ion batteries
KW - novel high-voltage phases
KW - reversible hysteresis evolution
KW - rippling of layered structures
UR - http://www.scopus.com/inward/record.url?scp=85051062248&partnerID=8YFLogxK
U2 - 10.1002/adfm.201803896
DO - 10.1002/adfm.201803896
M3 - Article
AN - SCOPUS:85051062248
SN - 1616-301X
VL - 28
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 39
M1 - 1803896
ER -