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Valorization of coal fly ash for the synthesis of lithium nickel-cobalt-aluminum-iron oxide (NCAF) cathode material Yudha, Cornelius Satria; Rahmawati, Aleida Dwi; Sumarti, Ragil; Muzayanha, Soraya Ulfa; Lestari, Annisa Puji; Arinawati, Meidiana
International Journal of Renewable Energy Development Vol 14, No 2 (2025): March 2025
Publisher : Center of Biomass & Renewable Energy (CBIORE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61435/ijred.2025.60829

Abstract

This study demonstrates a novel approach to high-performance cathode materials by utilizing coal fly ash as a source of Al and Fe dopants for nickel-rich layered oxides. LiNixCoyAlzFe(1-x-y-z)O2 (NCAF) materials were synthesized through a combined hydrometallurgical-solid state route, incorporating fly-ash waste-derived Al/Fe hydroxides (AFH) at various concentrations during the lithiation process. The characteristics of NCAF precursors, AFH and Ni0.8Co0.2C2O4, were thoroughly investigated. Structural analysis confirms the successful formation of single-phase materials with α-NaFeO2 structure (R-3m) up to 5% AFH content, exhibiting changes in the level of order, lattice parameters, and unit cell volume. Surface area characteristics show a transition from 38.747 m²/g to 6.52 m²/g with increasing AFH content, approaching the ideal surface area. The compositional evolution from LiNi0.8Co0.2O2 to LiNi0.66Co0.16Al0.08Fe0.10O2 maintains uniform atomic distribution. In the full-cell configuration with graphite anodes (N/P ratio: 1.2-1.3), NCAF with 5% AFH demonstrates enhanced electrochemical performance (~155 mAh/g), attributed to synergistic effects of Al-induced structural stabilization and Fe-contributed redox activity. This approach establishes a pathway for simple and low-cost battery material development while addressing industrial waste utilization.
Safer and Sustainable Co-precipitation Synthesis of NCA (LiNi0.80Co0.15Al0.05O2) Cathodes: Eliminating Ammonia in Favor of NaOH for pH Control Nisa, Shofirul Sholikhatun; Arinawati, Meidiana; Yudha, Cornelius Satria; Nurohmah, Anisa Raditya
JKPK (Jurnal Kimia dan Pendidikan Kimia) Vol 10, No 3 (2025): JKPK (Jurnal Kimia dan Pendidikan Kimia)
Publisher : Program Studi Pendidikan Kimia FKIP Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/jkpk.v10i3.108184

Abstract

Developing safer and more sustainable synthesis routes for lithium ion battery cathodes is important for both environmental practice and laboratory education. This study reports an ammonia free oxalate coprecipitation route to synthesize LiNi0.80Co0.15Al0.05O2 (NCA), in which ammonia as the usual pH controller was fully replaced by sodium hydroxide (NaOH). NaOH dosage was varied at 20 g, 40 g, 60 g, and 80 g to control precipitation, precursor quality, and the properties of the final cathode after calcination and sintering. X ray diffraction confirmed formation of a layered α NaFeO2 type structure with R3m symmetry for all samples without detectable secondary phases. The 40 g NaOH condition showed the best structural ordering, reflected by a relatively high I(003)/I(104) intensity ratio associated with reduced cation mixing. Fourier transform infrared spectra verified oxalate ligand decomposition during thermal treatment and the appearance of metal oxygen lattice vibrations consistent with NCA formation. Scanning electron microscopy revealed that the 40 g NaOH sample produced more uniform particles with a narrower size distribution than other variants. Based on these results, the 40 g NaOH sample was selected for electrochemical evaluation and delivered an initial discharge capacity of about 110 mAh/g at 0.1 C in a full cell configuration. Overall, NaOH is demonstrated as an effective and safer substitute for ammonia in oxalate coprecipitation, enabling greener NCA synthesis protocols for research and teaching.