TY - JOUR
T1 - Na+ Redistribution by Electrochemical Na+/K+ Exchange in Layered NaxNi2SbO6
AU - Kim, Haegyeom
AU - Kwon, Deok Hwang
AU - Kim, Jae Chul
AU - Ouyang, Bin
AU - Kim, Hyunchul
AU - Yang, Julia
AU - Ceder, Gerbrand
N1 - Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/5/26
Y1 - 2020/5/26
N2 - This work investigates the electrochemical Na+/K+ ion exchange mechanism occurring in layered Na3Ni2SbO6. Structural characterizations using X-ray diffraction and transmission electron microscopy uncover a remarkable and rich phase evolution as K is inserted in partially desodiated NaxNi2SbO6. Rather than simple addition of K to the structure, we see significant Na rearrangement, with discrete Na phases traversing the full range of Na compositions, even though the overall Na content in the sample is not changed. At any given time as much as three distinct phases can be present in the sample, consistent with thermodynamic equilibrium rules. Using DFT computations we demonstrate that this remarkable phase behavior during ion exchange is due to the repulsion between Na+ and K+ which creates distinct phases of them. Our analysis should be applicable to other ion-exchange systems where the exchanged ions are not well miscible in the host structure.
AB - This work investigates the electrochemical Na+/K+ ion exchange mechanism occurring in layered Na3Ni2SbO6. Structural characterizations using X-ray diffraction and transmission electron microscopy uncover a remarkable and rich phase evolution as K is inserted in partially desodiated NaxNi2SbO6. Rather than simple addition of K to the structure, we see significant Na rearrangement, with discrete Na phases traversing the full range of Na compositions, even though the overall Na content in the sample is not changed. At any given time as much as three distinct phases can be present in the sample, consistent with thermodynamic equilibrium rules. Using DFT computations we demonstrate that this remarkable phase behavior during ion exchange is due to the repulsion between Na+ and K+ which creates distinct phases of them. Our analysis should be applicable to other ion-exchange systems where the exchanged ions are not well miscible in the host structure.
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U2 - 10.1021/acs.chemmater.0c01152
DO - 10.1021/acs.chemmater.0c01152
M3 - Article
AN - SCOPUS:85085914132
SN - 0897-4756
VL - 32
SP - 4312
EP - 4323
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 10
ER -