An effective approach to reaching the theoretical capacity of a low-cost and environmentally friendly Na4Fe3(PO4)2(P2O7) cathode for Na-ion batteries
Само за регистроване кориснике
2024
Аутори
Gezović, AleksandraMilović, Miloš
Bajuk-Bogdanović, Danica
Grudić, Veselinka
Dominko, Robert
Mentus, Slavko
Vujković, Milica J.
Метаподаци
Приказ свих података о документуАпстракт
M4Fe3(PO4)2(P2O7) specific family has appeared as a new class of polyanionic compounds for sodium-ion batteries, capable of offering a higher operating voltage than individual phosphates and pyrophosphates. The study addresses the issue of Na4Fe3(PO4)2P2O7 (NFPP) sol-gel synthesis when both phosphates and pyrophosphates act as reactants, leading to successful production of NFPP under controlled synthesis conditions, capable of reaching the theoretical capacity. Spontaneous citric-assisted sol-gel reaction, between PO43− and P2O72− units occurring at pH of 3 (which follows NFPP stoichiometry), leads to the formation of pyrophosphate (Na2FeP2O7, NFP) with a certain amount of the mixed phase. Fe-oxalate coordination is dominant at low pH while the citric acid protonation suppresses direct Fe-citric complexation. pH adjustment to a neutral value changes the complexation and reaction pathway, allowing direct Fe(II)-citric coordination and subsequent oxidation. The exchange of Fe-oxalate wit...h the soluble ferric ammonium citrate complex happens under neutral pH and therefore leads to the formation of NFPP as the dominant phase, liberated from NFP. Furthermore, a series of samples, developed by varying citric-to-Fe molar ratio and controlling pH, served as a platform to identify and solve problems regarding the unambiguous FTIR assignment of the polyanionic NFP/NFPP mixture. FTIR and CV methods are proposed as assisting tools for XRD to identify NFP admixture. Finally, and most importantly, NFPP phase formed under neutral pH has a higher sodiation/desodiation capacity than NFPP/NFP heterostructure, reaching a theoretical value at a rather high current of 1 A g−1, which has not been attained in the literature.
Кључне речи:
Na4Fe3(PO4)2(P2O7) / Na2FeP2O7 secondary phase / sol-gel synthesis / Na-ion batteriesИзвор:
Electrochimica Acta, 2024, 476, 143718-Издавач:
- Elsevier BV
Финансирање / пројекти:
- NATO Science for Peace and Security Programme, G5836-SUPERCAR
- Министарство науке, технолошког развоја и иновација Републике Србије, институционално финансирање - 200175 (Институт техничких наука САНУ, Београд) (RS-MESTD-inst-2020-200175)
- Министарство науке, технолошког развоја и иновација Републике Србије, институционално финансирање - 200146 (Универзитет у Београду, Факултет за физичку хемију) (RS-MESTD-inst-2020-200146)
- Ministry of Science and Technological Development Montenegro for the "Scholarship for Doctoral Research in Montenegro"
- Serbian Academy of Sciences and Arts, project F-190
Институција/група
Институт техничких наука САНУ / Institute of Technical Sciences of SASAGezović, A., Milović, M., Bajuk-Bogdanović, D., Grudić, V., Dominko, R., Mentus, S.,& Vujković, M. J.. (2024). An effective approach to reaching the theoretical capacity of a low-cost and environmentally friendly Na4Fe3(PO4)2(P2O7) cathode for Na-ion batteries. in Electrochimica Acta Elsevier BV., 476, 143718. https://doi.org/10.1016/j.electacta.2023.143718 https://hdl.handle.net/21.15107/rcub_dais_16379
Gezović A, Milović M, Bajuk-Bogdanović D, Grudić V, Dominko R, Mentus S, Vujković MJ. An effective approach to reaching the theoretical capacity of a low-cost and environmentally friendly Na4Fe3(PO4)2(P2O7) cathode for Na-ion batteries. in Electrochimica Acta. 2024;476:143718. doi:10.1016/j.electacta.2023.143718 https://hdl.handle.net/21.15107/rcub_dais_16379 .
Gezović, Aleksandra, Milović, Miloš, Bajuk-Bogdanović, Danica, Grudić, Veselinka, Dominko, Robert, Mentus, Slavko, Vujković, Milica J., "An effective approach to reaching the theoretical capacity of a low-cost and environmentally friendly Na4Fe3(PO4)2(P2O7) cathode for Na-ion batteries" in Electrochimica Acta, 476 (2024):143718, https://doi.org/10.1016/j.electacta.2023.143718 ., https://hdl.handle.net/21.15107/rcub_dais_16379 .