Keywords and Phrases
Cathode; Crystallography; Li-ion Battery; Na-ion Battery; Solid-state; Synthesis
"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.
Ph. D. in Chemistry
Missouri University of Science and Technology. Materials Research Center
University of Missouri Research Board
Energy Research and Development Center
Missouri University of Science and Technology
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)
xiv, 186 pages
© 2016 Hooman Yaghoobnejad Asl, All rights reserved.
Dissertation - Open Access
Library of Congress Subject Headings
Lithium ion batteries
Electronic OCLC #
Yaghoobnejad Asl, Hooman, "New polyanion-based cathode materials for alkali-ion batteries" (2016). Doctoral Dissertations. 2550.