Simplified Spray Pyrolysis Synthesis Enabling a Novel Dual-Doping Strategy for Ultrahigh-Rate Ni-Rich Cathode...

Elemental doping has been extensively explored to address key challenges associated with Ni-rich cathode material, such as Li/Ni cation mixing and anisotropic lattice strain, which hinder rapid Li⁺ transport and accelerate mechanical degradation. However, single-atom dopants typically improve only limited aspects of structural and electrochemical performance. In this study, we introduce a rational Zr─Ti co-doping strategy via spray pyrolysis, in which Ti⁴⁺ selectively modulates the local transition-metal environment and the Ni oxidation state, while Zr⁴⁺ strengthens the Ni-rich lattice through robust Zr─O bonding. This synergistic doping suppresses detrimental phase transitions, stabilizes the oxygen sublattice, and mitigates microcrack formation, without aggravating Li/Ni disorder. To ensure homogeneous dopant incorporation, a spray pyrolysis approach utilizing Li-containing precursor droplets was employed. This method offers uniform elemental distribution, simplified synthesis, and a reduced environmental footprint compared with conventional co-precipitation techniques. As a result, Zr─Ti co-doped Ni-rich NCA microspheres (LiNi_0.85Co_0.10Al_0.04Zr_0.007Ti_0.003O₂) synthesized via short-time, low-temperature calcination, exhibit excellent high-rate capability (161 mA h g^-1 at 10C). This work demonstrates that integrating dual-dopant chemistry with a scalable spray pyrolysis process offers a promising pathway to concurrently enhance rate performance and structural integrity, providing a generalizable framework for the next generation of Ni-rich cathode materials.