Enhancement of electrochemical performance of Li[Li0.2Mn0.54Ni0.13Co0.13]O2 by surface modification with Li4Ti5O12

Li[Li0.2Mn0.54Ni0.13Co0.13]O2 was prepared using a coprecipitation method and modified with Li4Ti5O12. The sample coated with 3 wt% Li4Ti5O12 exhibited the best cyclability and mean coulombic efficiency in the voltage range of 2.0-4.75 V. These improvements are attributed to the effective Li4Ti5O12 coating layer, which stabilizes the host structure, protects the electrode surface from electrolyte attack, and prevents the formation of a thick passive film on the electrode surface. The initial irreversible capacity loss was eliminated by blending with 10 wt% Li4Ti5O12, in the larger potential window of 1.5-4.75 V. It was confirmed that the irreversible capacity loss decreased with increasing Li4Ti5O12 content; this is because Li4Ti5O12 offers a larger number of available sites for insertion of extracted lithium.