To understand the effect of heat treatment of TiO 2 modification for Ni-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode, the TiO 2 coating layer is formed on the surface of LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode by heat treatment at 500 and 600 °C. The electrochemical results show that TiO 2 -modified LiNi 0.8 Co 0.1 Mn 0.1 O 2 shows higher electrochemical performances compared to pristine sample. Among them, the TiO 2 -modified LiNi 0.8 Co 0.1 Mn 0.1 O 2 heat-treated at 500 °C delivers not only the highest initial discharge capacity of 201.3 mAh g −1 but also the extraordinary rate capability (86.4% at 6.0C). Moreover, TiO 2 -modified LiNi 0.8 Co 0.1 Mn 0.1 O 2 can effectively stabilize the cycling performance at 25 °C (79.4% after 100 cycles at 0.5C). Consequently, the TiO 2 -modified LiNi 0.8 Co 0.1 Mn 0.1 O 2 by heat treatment at 500 °C can significantly improve the electrochemical performances due to facilitating Li-ion migration, working as a protective layer and inhibiting the irreversible phase transition. KEYWORDS: heat treatment, TiO 2 modification, Ni-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 , rate capability, cycling performance

A Ni-rich layered cathode (LiNi0.8Co0.1Mn0.1O2, NCM) is a highly promising cathode material for lithium-ion batteries (LIBs).

A ZrO2-coated and Zr-doped LiNi0.8Co0.1Mn0.1O2 cathode is successfully fabricated, and its electrochemical performances are evaluated. The 0.5 wt % ZrO2-coated and Zr-doped LiNi0.8Co0.1Mn0.1O2 cathode exhibits excellent electrochemical performances compared to the pristine LiNi0.8Co0.1Mn0.1O2. The 0.5 wt % ZrO2-coated and Zr-doped LiNi0.8Co0.1Mn0.1O2 cathode shows a high discharge capacity of 220.9 mA h g–1. Moreover, it maintains a capacity retention of 76.1% after 60 cycles. Most importantly, it has extraordinary retention capacities of 76.7 and 59.1% at 4.0 and 6.0 C, respectively. This is because ZrO2 coating and Zr doping contribute to rapid Li+ conductivity and good structural stability. Thus, the LiNi0.8Co0.1Mn0.1O2 cathode with a suitable amount of ZrO2 coating and Zr doping is considered a good candidate for state-of-the-art Li-ion batteries.

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