Enhancing Lithium-Ion Battery Performance through Dual Doping in Ni-Rich Cathodes

Abstract

Doping is crucial for maintaining the long-term stability of Ni-rich layered cathodes in lithium-ion batteries. However, using a single dopant is often insufficient in achieving a stable, high-energy cathode material. In this study, we used a dual doping approach by employing Al 3+ and Nb 5+ ions to enhance the cycling stability of Li[Ni 0.92 Co 0.04 Mn 0.04 ]O 2 (NCM92) cathodes. Al 3+ doping reinforces the crystal structure, while Nb5+ doping optimizes the morphology of primary particles. This dual doping strategy not only harnesses the advantages of both dopants simultaneously, but also showcases remarkable performance improvements through synergistic effects. The resulting Li[Ni 0.905 Co 0.04 Mn 0.04 Al 0.005 Nb 0.01 ]O 2 (AlNb-NCM92) cathode, developed via dual Al and Nb doping, demonstrates remarkable stability. These findings highlight the importance of a comprehensive doping strategy that considers both crystal structure and microstructure to maximize the long-term stability of high-energy Ni-rich cathode materials.