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Multicomponent transition metal oxides are among the most successful lithium-ion battery cathode materials, and many previous reports have described the sensitivity of final electrochemical performance of the active materials to the detailed composition and processing. Coprecipitation of a precursor template is a popular, scalable route to synthesize these transition metal oxide cathode materials because of the homogeneous mixing of the transition metals within the particles, and the morphology control provided by the precursors. However, the deviation of the precursor composition from feed conditions is a challenge that has generally not been reported in previous studies. Using a target final material of the high voltage spinel LiMn 1.5 Ni 0.5 O 4 as an example, we show in this study that the compositional deviation caused by coprecipitation can be significant under certain conditions, impacting the calcined final material structure and electrochemical properties. The study herein provides insights into the role of solution equilibrium and rate of precipitation of the transition metals during precipitate formation on precursor, and thus final active material, composition. Such knowledge is necessary to rationally predict and tune multicomponent battery precursor compositions synthesized via coprecipitation with high levels of accuracy.
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This content will become publicly available on February 18, 2027
Structural and Morphological Control of Spherical NFM333 Precursors for Na-Ion Batteries: A Comparative Study of Ammonia- and Citrate-Based Coprecipitation Routes
Morphology control is a key design parameter for sodium-ion layered oxide cathodes, yet achieving uniform precursors with balanced stoichiometry is more challenging than in lithium-ion systems due to the broader range of transition-metal chemistries involved. These complexities highlight the need for systematic comparisons of coprecipitation routes tailored to sodium-ion compositions. Here, we examine how ammonia- and citrate-based coprecipitation methods shape the morphology and composition of equimolar Ni–Fe–Mn hydroxide and oxyhydroxide precursors. We investigate how pH, ligand concentration, and temperature jointly influence precipitation onset, particle shape, and metal incorporation. In the ammonia system, precipitation proceeds readily between pH 10.5–11.5, with pH ≈ 11.0 yielding the most uniform morphology and target Ni:Fe:Mn ≈ 1:1:1 stoichiometry. Higher ammonia levels improve morphology but above ∼1.0 M begin to delay Ni incorporation and introduce phase separation. In contrast, the citrate system shows delayed precipitation (threshold pH ≈ 11.8) but forms dense granular microspheres with narrow size distributions across 0.1–0.6 M citrate, with Fe enrichment emerging at higher ligand concentrations. X-ray diffraction revealsβ-Ni(OH)2-type hydroxides for ammonia-derived precursors andδ-FeOOH-type oxyhydroxides for citrate-derived ones. Together, these results provide practical guidance for tailoring precursor morphology and composition in Fe- and Mn-rich sodium-ion cathode materials.
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- Award ID(s):
- 2325464
- PAR ID:
- 10666431
- Publisher / Repository:
- IOP
- Date Published:
- Journal Name:
- Journal of The Electrochemical Society
- Volume:
- 173
- Issue:
- 4
- ISSN:
- 0013-4651
- Page Range / eLocation ID:
- 040506
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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