Unlocking the potential of Ni-rich LiNi0.9Co0.1O2 cathodes: a DFT investigation of performance-limiting factors

Abstract

Ni-rich layered oxides, particularly LiNi_0.9Co_0.1O₂, have garnered significant attention in the realm of high-capacity cathodes for lithium-ion batteries. Despite their promise, their commercialization is hindered by challenges related to structural instability and defect formation. This study utilizes density functional theory (DFT) to unravel the intricate structural, defect formation, and transport properties of LiNi_0.9Co_0.1O₂, thereby providing insights into the performance-limiting factors. Our findings reveal that a 10% cobalt doping while enhancing lithium mobility, is insufficient to significantly mitigate antisite defects and oxygen vacancy formation. These defects are critical in influencing the electrochemical performance and durability of the material. The study further delves into the implications of defect formation on the electrochemical characteristics, emphasizing the need for a higher concentration of cobalt doping to effectively stabilize the Ni-rich cathode. This theoretical investigation contributes to the understanding of defect behaviors in Ni-rich cathodes and paves the way for optimized material design in future high-energy-density battery technologies.