Improving Electrochemical Performance of Ni-rich Cathode Using Atomic Layer Deposition with Particle by Particle Coating Method

Atomic layer deposition (ALD) enhances the stability of cathode materials via surface modification. Previous studies have demonstrated that an Ni-rich cathode, such as LiNi0.8Co0.1Mn0.1O2, is a promising candidate owing to its high capacity, but is limited by poor cycle stability. In this study, to enhance the stability of the Ni-rich cathode, synthesized LiNi0.8Co0.1Mn0.1O2 was coated with Al2O3 using ALD. Thus, the surface-modified cathode exhibited enhanced stability by protecting the interface from Ni–O formation during the cycling process. The coated LiNi0.8Co0.1Mn0.1O2 exhibited a capacity of 176 mAh g−1 at 1 C and retained up to 72% of the initial capacity after 100 cycles within a range of 2.8–4.3 V (vs Li/Li+). In contrast, pristine LiNi0.8Co0.1Mn0.1O2 presented only 58% of capacity retention after 100 cycles with an initial capacity of 173 mAh g−1. Improved cyclability may be a result of the ALD coating, which physically protects the electrode by modifying the interface, and prevents degradation by resisting side reactions that result in capacity decay. The electrochemical impedance spectra and structural and morphological analysis performed using electron microscopy and X-ray techniques establish the surface enhancement resulting from the aforementioned strategy. Keywords: Lithium Ion Battery, Ni-rich Cathode, Capacity Fading, Atomic Layer Deposition, Coating