Enhanced electrochemical properties of Li1·2Ni0·13Co0·13Mn0·54O2 coated with Al2O3 nano-film

The pristine Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 and Al 2 O 3 -coated Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 with R-3m space group were successfully synthesized by wet chemical method . The TEM shows that the Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 is coated by a dense Al 2 O 3 nano-film with the thickness of 5–10 nm. When used as a cathode material for lithium-ion battery, the Al 2 O 3- coated Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 exhibits much enhanced rate performance and cyclic stability in comparison with those of Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 . It possesses a discharge specific capacity of 245.7, 148.3 and 129.6 mAh g −1 at 0.1, 2 and 4 C, respectively. And 71.4% of its initial discharge capacity is also remained after 50 cycles at the rate of 1 C. The improved electrochemical performance could be the result of the Al 2 O 3 coating on the surface that can avoid the direct contact between the cathode and the electrolyte. It can also stabilize the basic structure of Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 during the delithium/intercalation process.