LiNi<sub>0.7</sub>Mn<sub>0.3</sub>O<sub>2</sub> as a Cheap Cobalt Free Nickel Rich Cathode Material for High-Performance Li-Ion Batteries

A high-quality Lithium Nickel Manganese Oxide (LiNi 0.7 Mn 0.3 O 2 ) material is successfully synthesized via co-precipitation. The precursors for lithium rechargeable batteries have been prepared using starting materials (NiCl 2 .6H 2 O and MnSO 4 .H 2 O) with precipitating agents of oxalic acid and sodium hydroxide, Ethylene diamine tetra acetic (EDTA) and sodium hydroxide, and sodium carbonate for oxalate co-precipitation, hydroxide co-precipitation, and carbonate co-precipitation, respectively. Then, the precursors were calcined at 500°C for 5 hours, mixed with Li 2 CO 3 , and sintered at 850°C for 15 hours under oxygen. X-ray Diffraction (XRD) analysis results show that the particles obtained by oxalate co-precipitation (LiNi 0.7 Mn 0.3 O 2 -C 2 O 4 ) have higher crystallinity and more uniform particle shape than hydroxide co-precipitation and carbonate co-precipitation. The Fourier Transform Infrared (FTIR) spectroscopy characterization shows no carbonate group peak in the LiNi 0.7 Mn 0.3 O 2 -C 2 O 4 . Furthermore, electrochemical tests were analyzed by evaluating the charge/discharge curves and cycling performance. The highest specific discharge capacity of 122 mAh/g was achieved by the LiNi 0.7 Mn 0.3 O 2 -C 2 O 4 sample, which also had a low capacity loss (22.7%), retaining 89.9% of its initial specific capacity at 0.5C between 2.5 and 4.25 V after 45 cycles. Based on these results, a cheap cobalt-free cathode material is promising for a new commercialized Li-ion battery.