Abstract
The rapid growth of lithium-ion batteries has intensified the demand for high-performance cathode materials with improved stability and capacity retention. LiNi0.8Mn0.1Co0.1O2 (NMC 811) offers high energy density but suffers from irreversible capacity loss, cation mixing and structural instability during cycling. This study applied lanthanum (La) doping to enhance the electrochemical and structural properties of NMC 811 synthesised from recovered metal precursors. Nickel, cobalt, manganese and La were selectively leached and precipitated from spent catalysts and low-grade ores, yielding purities of 98.08% Ni, 83.61% Co, 98.66% La and 89.97% Mn, with recovery efficiencies of 93.36%, 89.28%, 90.65% and 99.53%, respectively, as determined by X-ray fluorescence. The La-doped NMC 811 (2–8 wt% % La) was prepared via a solid-state method with two-step calcination at 500 °C and 800 °C. Structural analysis by X-ray diffraction confirmed stabilisation of the layered R-3 m structure at low La content and partial transformation to rock-salt/perovskite phases at higher doping levels. The Fourier transform infrared spectroscopy verified the presence of oxalate and carbonate groups, while scanning electron microscopy micrographs showed a morphology shift from hexagonal to cubic particles with increasing La. Electrochemical testing at 0.1 C (20 mA g−1) between 2.7 and 4.3 V demonstrated that La-doped NMC 811 delivered a higher discharge capacity of 165 mAh g−1 compared to 149.05 mAh g−1 for commercial NMC 811, with stable capacity retention over 100 cycles. These findings highlight the potential of La-doped NMC 811 as a structurally stable and high-capacity cathode material for next-generation lithium-ion batteries.
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