Synergistically Enhanced Electrochemical Properties of LiNi0.5Co0.2Mn0.3O2 by the Co-Modification of Ti and Na.

The layered material of nickel cobalt manganese oxide lithium oxide is one of the most promising lithium-ion battery (LIBs) materials, with the characteristics of high capacity and high density. However, most nickel-rich layered oxides have the phenomenon of cation mixing and the phenomenon that the layered structure changes to the spinel structure during the cycle, which results in poor capacity and cycle performance under high cut-off voltage. Herein, we modified LiNi 0. 5 Co 0. 2 Mn 0. 3 O2 with Ti and Na co-doping to observe the changes in the specific capacity, cycle performance and crystal structure of the material. Ti and Na co-doped LiNi 0. 5 Co 0. 2 Mn 0. 3 O2 has the most obvious effect on increasing the discharge specific capacity and improving the cycle performance. In sthe voltage range of 3–4.5 V, its discharge specific capacity reaches 183.5 mAh/gat 0.5C, and the capacity retention rate after 100 cycles is 81.96%, and its discharge specific capacity reaches 164.2 mAh/g at 1C and after 100 cycles Capacity retention rate is 80.93%. The introduction of Ti and Na plays an important role in improving the cation mixing phenomenon and improving the stability of the crystal structure. The NCM523 capacity and cycling efficiency of Ti and Na co-doping pair are the best, which is attributed to the co-doping of Ti and Na, increases the Li layer spacing, stabilizes the crystal structure, and effectively prevents the collapse of crystal lamellar structure in the process of cycling. [ABSTRACT FROM AUTHOR]