Doctoral Dissertations

Keywords and Phrases

Cathode; Crystallography; Li-ion Battery; Na-ion Battery; Solid-state; Synthesis

Abstract

"A number of new materials have been discovered through exploratory synthesis with the aim to be studied as the positive electrode (cathode) in Li-ion and Na-ion batteries. The focus has been set on the ease of synthesis, cost and availability of active ingredients in the battery, and decent cycle-life performance through a combination of iron and several polyanionic ligands. An emphasis has been placed also on phosphite (HPO32-) as a polyanionic ligand, mainly due to the fact that it has not been studied seriously before as a polyanion for cathode materials. The concept of mixed polyanions, for example, boro-phosphate and phosphate-nitrates were also explored. In each case the material was first made and purified via different synthetic strategies, and the crystal structure, which dominantly controls the performance of the materials, has been extensively studied through Single-Crystal X-ray Diffraction (SCXRD) or synchrotron-based Powder X-ray Diffraction (PXRD). This investigation yielded four new compositions, namely Li3Fe2(HPO3)3Cl, LiFe(HPO3)2, Li0.8Fe(H2O)2B[P2O8]·H2O and AFePO4NO3 (A = NH4/Li, K). Furthermore, for each material the electrochemical performance for insertion of Li+ ion has been studied by means of various electrochemical techniques to reveal the nature of alkali ion insertion. In addition Na-ion intercalation has been studied for boro-phosphate and AFePO4NO3. Additionally a novel synthesis procedure has been reported for tavorite LiFePO4F1-x(OH)x, where 0≤ x ≤1, an important class of cathode materials. The results obtained clearly demonstrate the importance of crystal structure on the cathode performance through structural and compositional effects. Moreover these findings may contribute to the energy storage community by providing insight into the solid-state science of electrode material synthesis and proposing new alternative compositions based on sustainable materials"--Abstract, page iv.

Advisor(s)

Choudhury, Amitava

Committee Member(s)

Nath, Manashi
Leventis, Nicholas
Stavropoulos, Pericles
Liang, Xinhua

Department(s)

Chemistry

Degree Name

Ph. D. in Chemistry

Sponsor(s)

Missouri University of Science and Technology. Materials Research Center
University of Missouri Research Board
Energy Research and Development Center

Comments

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.

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2016

Journal article titles appearing in thesis/dissertation

  • Phosphorous acid route synthesis of iron tavorite phases, LiFePO4(OH)xF1-x [0d x d1] and comparative study of their electrochemical activities
  • Li3Fe2(HPO3)3Cl: an electroactive iron phosphite as a new polyanionic cathode material for Li-ion battery
  • Phosphite as polyanion-based cathode for Li-ion battery: Synthesis, structure and electrochemistry of LiFe(HPO3)2
  • Iron borophosphate as potential cathode for lithium- and sodium-ion batteries
  • Combined theoretical and experimental approach to the discovery of electrochemically active mixed polyanionic phosphatonitrates, AFePO4NO3 (A = NH4/Li, K)

Pagination

xiv, 186 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2016 Hooman Yaghoobnejad Asl, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Subject Headings

Lithium ion batteriesStorage batteriesCrystallography

Thesis Number

T 11061

Electronic OCLC #

974710352

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Included in

Chemistry Commons

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