Synthesis and characterization of submicron-sized by a simple self-propagating solid-state metathesis method

摘要

Submicron-sized LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 cathode materials were synthesized using a simple self-propagating solid-state metathesis method with the help of ball milling and the following calcination. A mixture of Li(ac) centre dot 2H_2O, Ni(ac)_2 centre dot 4H_2O, Co(ac)_2 centre dot 4H_2O, Mn(ac)_2 centre dot 4H_2O (ac = acetate) and excess H_2C_2O_4 centre dot 2H_2O was used as starting material without any solvent. XRD analyses indicate that the LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 materials were formed with typical hexagonal structure. The FESEM images show that the primary particle size of the LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 materials gradually increases from about 100nm at 700 deg C to 200-500nm at 950 deg C with increasing calcination temperature. Among the synthesized materials, the LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 material calcined at 900 deg C exhibits excellent electrochemical performance. The steady discharge capacities of the material cycled at 1 C (160 mAg~(-1)) rate are at about 140mAhg~(-1) after 100 cycles in the voltage range 3-4.5 V (versus Li~+/Li) and the capacity retention is about 87 percent at the 350th cycle.