TY - JOUR
T1 - Factors Defining the Intercalation Electrochemistry of CaFe2O4-Type Manganese Oxides
AU - Nolis, Gene
AU - Gallardo-Amores, José M.
AU - Serrano-Sevillano, Jon
AU - Jahrman, Evan
AU - Yoo, Hyun Deog
AU - Hu, Linhua
AU - Hancock, Justin C.
AU - Bolotnikov, Jannie
AU - Kim, Soojeong
AU - Freeland, John W.
AU - Liu, Yi Sheng
AU - Poeppelmeier, Kenneth R.
AU - Seidler, Gerald T.
AU - Guo, Jinghua
AU - Alario-Franco, Miguel A.
AU - Casas-Cabanas, Montse
AU - Morán, Emilio
AU - Cabana, Jordi
N1 - Funding Information:
This work was led by the Joint Center for Energy Storage Research (JCESR), which is financially supported by the U.S. Department of Energy (DOE). Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02-06CH11357. This research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231. H.D.Y. was supported by the National Research Foundation (NRF-2018R1C1B6004808 and NRF-2018R1A5A1025594) of the Korean Ministry of Science and ICT.
Funding Information:
This work was led by the Joint Center for Energy Storage Research (JCESR), which is financially supported by the U.S. Department of Energy (DOE). Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02-06CH11357. This research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231. H.D.Y. was supported by the National Research Foundation (NRF-2018R1C1B6004808 and NRF-2018R1A5A1025594) of the Korean Ministry of Science and ICT. A eulogy praising the life of E.M. was written by his close friend, M.A.A.-F., and is available in both Spanish ( https://www.ucm.es/labcoap/file/emilio-semblanza-ma-alario-2?ver ) and English ( https://www.ucm.es/labcoap/file/a-biographical-sketch-for-emilio-maaf-1?ver ).
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/10/13
Y1 - 2020/10/13
N2 - Oxides with the CaFe2O4-type structure have been predicted as being suitable hosts for reactions of intercalation of light cations such as Li and Mg because of their favorable cationic diffusion. Although Li has been shown to intercalate into the Mn2O4 variant, the key structure property correlations determining function are not fully ascertained. This basic information is needed before attempting the intercalation of divalent cations, which face comparably higher migration barriers. For this purpose, the electrode function of CaFe2O4-type Li0.8Mn2O4 was compared for materials made by a direct high-pressure route or through cation exchange from NaMn2O4. X-ray diffraction and absorption spectroscopy revealed that, despite having largely the same bulk structure, the presence of surface defects blocked Li+ transfer in Li0.8Mn2O4 made at high pressure. These defects were not present in the cation-exchanged material, which resulted in highly reversible Li intercalation with very fast kinetics in micrometric crystals. Delithiated electrodes from the cation-exchange synthesis were subsequently reduced in an ionic liquid electrolyte containing Mg2+. The process induced topotactic changes in the bulk, strongly suggesting the existence of intercalation, but it is accompanied by severe reactivity with the electrolyte that impedes reversibility. This study uncovers that defects affect the fundamentals of cation intercalation in this novel class of materials. The ability of the cation-exchanged material to conduct fast reactions with Li is consistent with calculated activation energy barriers and creates promise for their use as Mg hosts, provided that novel electrolytes enhanced stability at high potential can be realized.
AB - Oxides with the CaFe2O4-type structure have been predicted as being suitable hosts for reactions of intercalation of light cations such as Li and Mg because of their favorable cationic diffusion. Although Li has been shown to intercalate into the Mn2O4 variant, the key structure property correlations determining function are not fully ascertained. This basic information is needed before attempting the intercalation of divalent cations, which face comparably higher migration barriers. For this purpose, the electrode function of CaFe2O4-type Li0.8Mn2O4 was compared for materials made by a direct high-pressure route or through cation exchange from NaMn2O4. X-ray diffraction and absorption spectroscopy revealed that, despite having largely the same bulk structure, the presence of surface defects blocked Li+ transfer in Li0.8Mn2O4 made at high pressure. These defects were not present in the cation-exchanged material, which resulted in highly reversible Li intercalation with very fast kinetics in micrometric crystals. Delithiated electrodes from the cation-exchange synthesis were subsequently reduced in an ionic liquid electrolyte containing Mg2+. The process induced topotactic changes in the bulk, strongly suggesting the existence of intercalation, but it is accompanied by severe reactivity with the electrolyte that impedes reversibility. This study uncovers that defects affect the fundamentals of cation intercalation in this novel class of materials. The ability of the cation-exchanged material to conduct fast reactions with Li is consistent with calculated activation energy barriers and creates promise for their use as Mg hosts, provided that novel electrolytes enhanced stability at high potential can be realized.
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U2 - 10.1021/acs.chemmater.0c01858
DO - 10.1021/acs.chemmater.0c01858
M3 - Article
AN - SCOPUS:85095781692
SN - 0897-4756
VL - 32
SP - 8203
EP - 8215
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 19
ER -