Investigation of effect of Ball-Milling an‎d Calcination parameters on the synthesis an‎d electrochemical performace of NCM cathode material prepared from spent Li-ion batteries

9/14/2025 12:00:00 AM

Lithium-ion batteries, due to their high energy density, suitable lifespan, an‎d excellent performance, are widely used in electronics, electric vehicles, an‎d energy storage systems. With increasing deman‎d, sustainable recycling of their valuable materials has become crucial. In this study, spent NCM523 cathodes were regenerated using high-energy ball milling (HEBM) an‎d high-temperature calcination, with the effects of precursor type, milling time, an‎d calcination temperature on structure an‎d electrochemical performance systematically investigated. Regarding precursor effects, NCM Oxide/Li Carbonate formed a well-ordered layered structure with minimal cation mixing an‎d high crystallinity, outperforming other synthesis routes. These properties are critical for enhancing NCM cathode electrochemical performance. Conversely, oxalate-based precursors, due to multi-stage decomposition, gas release, an‎d potential lithium loss, produced irregular, porous structures with high cation mixing, rendering them unsuitable for electrochemical applications. The HEBM process, by repeatedly crushing particles an‎d increasing surface energy, reduced particle size an‎d improved structural properties. However, milling beyond 20 hours caused agglomeration, increasing the average particle size (D50) an‎d reducing size distribution uniformity. XRD results showed that the 20-hour milled sample, with the highest lattice order, lowest cation mixing, finer particle size, an‎d minimal agglomeration, exhibited the best structural an‎d microstructural properties, making it the optimal choice for further experiments. Calcination of NCM samples post-HEBM improved crystallinity, reduced cation mixing, an‎d optimized the layered structure. The sample calcined at 750°C achieved the best balance of lattice order, particle size, specific surface area, an‎d electrochemical stability. At 800°C, despite increased surface area, lithium evaporation reduced specific capacity. At 850°C, excessive grain growth an‎d reduced porosity further degraded performance. Electrochemical tests (rate capability, cycling) an‎d XPS analysis confirmed the superiority of the 750°C sample, with higher specific capacity, lower polarization, better reversibility, an‎d an optimal surface chemical structure.

بازيافت مستقيم ماده كاتدي , NCM 523 , آسياب گلوله‌اي با انرژي بالا , كلسيناسيون

Direct recycling of cathode material , NCM 523 , igh-energy ball milling , calcination

Arta Sokhan Pajooh

Dr. Masoudpanah