High rate performance of Lithium-ion batteries with Co-free LiNiO2 cathode

Co-free LiNiO2 (H-LNO) nanoparticles were synthesized by the urea-based hydrothermal synthesis in the presence of sodium dodecyl sulfate as an anionic surfactant, followed by a high-temperature calcination process with a lithium source. Compared to the LiNiO2 samples prepared via the co-precipitation method (C-LNO), the H-LNO samples exhibited superior electrochemical properties, such as charge/discharge capacity, rate capability, and cycle performance. Electrochemical tests showed that the H-LNO cathode reached an ultra-high initial discharge capacity of 211.9 mAh/g at 0.1C and maintained a capacity of 131.9 mAh/g at 5C, approximately twice greater than that of the C-LNO cathode. The H-LNO sample retained 77.33 % of its capacity, which is higher than that for the C-LNO sample (65.84 %) after 50 cycles at 0.5C. These results were attributed to the combined effect of the high Li+ diffusion coefficient and low charge transfer resistance, suggesting that the H-LNO powder is beneficial for practical applications in Li-ion batteries.