One-pot spray pyrolysis synthesis strategies of lithium-rich manganese-based oxide-spinel composite microspheres as advanced cathode materials for lithium-ion batteries

Abstract

A scalable and sustainable route to high-energy lithium-rich manganese-based oxide (LRM) cathodes remains elusive due to complex multi-step syntheses, extensive wastewater generation, and cobalt dependence. Here we report, for the first time, a one-pot spray pyrolysis strategy that directly synthesizes layered-spinel composite LRM microspheres with controlled phase evolution and highly stable electrochemical performance. During the rapid droplet-to-particle conversion, intrinsic lithium volatilization and in-situ CO and H2 generation from polystyrene nanobeads synergistically drive lithium deficiency–induced cation migration and oxygen-vacancy formation, promoting uniform nucleation of high-voltage spinel domains within a Li-rich layered matrix. Synchrotron 3D STXM tomography (∼90 nm) and ptychographic nanotomography (14.87 nm) reveal a densified active framework, well-connected internal void network, and homogeneous transition-metal distribution, enabling shortened Li-ion diffusion pathways and reduced tortuosity. The optimized composite (synthesized at 1000 °C) exhibits high initial Coulombic efficiency (95.1%), excellent cycling retention of 88.2% after 200 cycles, and superior high-rate capability up to 10 C, outperforming both low-temperature layered and high-temperature spinel-dominated counterparts. © 2026 Elsevier B.V.