Suppressing capacity fading and voltage decay of Ni-rich cathode material by dual-ion doping for lithium-ion batteries

Abstract

The Ni-rich cathodes are considered as the next generation candidate cathode material of lithium-ion batteries due to the high-energy–density and environmentally friendly. Unfortunately, the cathodes are up against severe structure instability at the repeated charge/discharge process, resulting in the attenuation of voltage and capacity. Herein, we proposed a novel strategy with uniform Al and Ti cations co-doping of LiNi0.8Co0.1Mn0.1O2 cathode. The modification strategy not only stabilizes the vulnerable layered structure but also mitigate voltage/capacity attenuation at different cutoff voltages. As a result, the modified cathode with trace content of Al and Ti cations co-doping can broaden the lithium ions diffusion channels, mitigate the structural collapse, and unfavorable phase transformation to some extent. Specifically, the modified sample exhibits remarkable enhanced electrochemical performance in discharge capacity and voltage retention of 76.75%, 98.78% at 1 C after 200 cycles. Even though at elevated voltage, the modified sample shows improved cycle life with a capacity retention of 70.93% after 200 cycles.