Facile synthesis and electrochemical properties of LiNi0.8Co0.15Al0.05O2 with enlarged exposed active planes for Li-ion batteries

Abstract

Because enlarged exposed active planes facilitate the improvement of the rate capability of layered cathode material by providing more points for Li+ intercalation/de-intercalation, LiNi0.8Co0.15Al0.05O2 layered cathode material with enlarged exposed {010} active planes is desirable. In this article, micro-sized LiNi0.8Co0.15Al0.05O2 particles possessing enlarged exposed {010} active planes have been synthesized using Ni0.842Co0.158(OH)2 precursor prepared by an improved co-precipitation method. As-prepared LiNi0.8Co0.15Al0.05O2 demonstrates a good rate capability. The reversible capacity is 103 mAh g−1 at 10 °C, which is explained by the enhanced Li+ diffusion coefficient detected by CV and GITT measurements and reduced charge transfer resistance calculated by EIS tests. Moreover, the as-prepared LiNi0.8Co0.15Al0.05O2 also displays a good cycling stability. The capacity retention after 100 cycles at 0.2 °C is 85%. This good cycling stability can be ascribed to the porous structure of LiNi0.8Co0.15Al0.05O2 which provides a buffer area for volume expansion of the primary particles during cycling.