Abstract

The development of high-power cathode materials is critical for meeting the growing demand for high-rate performance in lithium-ion batteries (LIBs) used in portable electronics, electric vehicles, and grid storage. In this work, an ultra high-rate-performance LiFePO₄ (LFP) cathode material is synthesized through a synergistic strategy combining Ni²⁺-ion doping, uniform carbon coating, and particle size reduction. Structural analysis by XRD confirms the orthorhombic phase of LFP, while FE-SEM images reveal pulverized particles in the 1-10 μm, and HR-TEM confirms homogeneous carbon coating. Rietveld refinement shows that Ni²⁺ doping reduces cell volume and lattice parameters, altering the Li-ion local environment, as further supported by density functional theory calculations. XPS analysis confirms the presence of Fe exclusively in the Fe²⁺ state. Electrochemical performance demonstrated outstanding performance with a high discharge capacity of 171mAh g⁻¹ at C/5 rate, remarkable rate capability of 136 mAh g⁻¹ at 10C with a flat 3.3 V plateau, and over 80 % capacity retention after 200 cycles at 5C. The exceptional performance is attributed to reduced particle size, improved electrode kinetics from Ni²⁺ doping, and an enhanced Li-ion transport. These findings position Ni-LFP/C as a promising high-power cathode material for next generation LIB applications for high-power LIB applications.