Electrochemical characterization of high-performance LiNi0.8Co0.2O2 cathode materials for rechargeable lithium batteries

The cathode material, LiNi0.8Co0.2O2 was synthesized by acid dissolution method using lithium carbonate, nickel hydroxide (carbonate), cobalt hydroxide (carbonate) as insoluble starting materials, and acrylic acid, which acts as an organic acid as well as a chelating agent. Structural and chemical characterization of the spray-dried xerogel precursor was performed through its compositional and thermogravimetric analysis (TGA), which shows that the xerogel can be expressed as Li[MA]3, where M is the transition metal atom. The electrochemical performance of the synthesized powder was tested manufacturing the coin-type cells with lithium metal as an anode material. With the voltage range of 3.0-4.2V, the capacity retentions after 50 cycles were 98.6 and 94.5%, respectively, for the powders calcined at 800 deg C for 15 and 20h. At the rate capability test, discharge capacity ratio between 3.0 and 0.5C rate is about 91-84% till 60 cycles.