Influence of precursor selection on the structural integrity and electrochemical performance of α-NaMnO2 cathode

Doğan E., Whba R., Canbay C. A., Arshad M., ŞAHİNBAY S., ALTIN S.

Journal of the American Ceramic Society, cilt.108, sa.12, 2025 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 108 Sayı: 12
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1111/jace.70217
  • Dergi Adı: Journal of the American Ceramic Society
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Periodicals Index Online, Aerospace Database, Applied Science & Technology Source, Art Source, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Computer & Applied Sciences, EBSCO Education Source, INSPEC, Metadex, Civil Engineering Abstracts
  • Anahtar Kelimeler: cathode materials, ex situ analysis, full-cell performance, hard carbon, presodiated, α-NaMnO2
  • İnönü Üniversitesi Adresli: Evet

Özet

In this study, the α-NaMnO2 phase was successfully synthesized using three different combinations of starting materials: Na2O2/Mn2O3, Na2O2/MnO2, and Na2CO3/Mn2O3. A one-step heat treatment at 900°C for 5 h under air with quenching was applied. X-ray diffraction analysis confirmed the formation of pure α-NaMnO2 phase in all three samples, with only slight variations in lattice parameters. Elemental and oxidation state analyses were conducted using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy with energy-dispersive X-ray spectroscopy, and inductively coupled plasma measurements. XPS results revealed noticeable differences in Mn ion valence states, suggesting variations in oxygen stoichiometry and the presence of oxygen-excess structures. Electrochemical evaluations were performed in both half-cell and full-cell configurations. The samples exhibited distinct performance characteristics, with capacity fade over 100 cycles at C/3 between 1.5 and 4.3 V measured at 83.6%, 73.9%, and 83.1%, respectively. These differences correlated with the average oxidation state of Mn and O content. Full-cells, paired with presodiated commercial hard carbon anodes, showed the highest capacity for the Na2O2/MnO2 system and the best retention for the Na2CO3/Mn2O3 sample. Overall, this work demonstrates how even small variations in starting materials can significantly influence the structural and electrochemical behavior of α-NaMnO2.