The microwave annealing approach produces a Co-free, Ni-rich layered oxide cathode with the composition LiNi_0.9Fe_0.05Al_0.05O₂ in substantially less time (2 h) than conventional annealing (24 h). The cathode provides better rate capability and cycle stability than its conventionally annealed equivalent, resulting in improved Li-ion battery performance.

Abstract

The growing demand for high-energy density Ni-rich cathode materials, driven by the rise in lithium-ion batteries for electric vehicles and electronics necessitates fast, efficient production methods. Traditional methods for Ni-rich cathodes are energy-intensive, taking up to 24 hours, which increases costs and CO₂ emissions. In contrast, this study introduces a Co-free Ni-rich layered oxide cathode (LiNi_0.9Fe_0.05Al_0.05O₂ (NFA)) synthesis using a rapid microwave heating technique. This method takes just 2.5 hours, including heating and dwell time, while consuming minimal electricity. The microwave-annealed cathodes exhibits a well-ordered layered structure with fewer defects compared to those produced by traditional calcination (21 h). Furthermore, these cathodes display superior discharge capacities across all C-rates (e. g. 157 mAh g⁻¹ at 1 C-rate and 129 mAh g⁻¹ at 10 C-rate) and retain 78.1 % specific capacity after 100 cycles at high current density (1 C-rate). This study paves the way for the rapid, energy-efficient synthesis of high-performance cathode materials for advanced lithium-ion batteries.