Stabilizing lattice oxygen and interface chemistry of Ni-rich and Co-poor cathodes for high-energy lithium-ion batteries

Abstract

Development of Ni-rich and Co-poor cathodes (Ni ≥ 80%, Co ≤ 5%) is indispensable for the next-generation lithium-ion batteries (LIBs) owing to the serious impact of scarce resources and fragile supply chain of cobalt, but they suffer from a more prominent lattice oxygen emission with serious Li/Ni intermixing as well as worsening crystal and interface structure. Herein, CeO_2−x-coated LiNi_0.9Co_0.045Mn_0.045Al_0.01O₂ has been demonstrated to stabilize lattice oxygen by the well-dispersed Al–O bonds and the reversible oxygen-storage protective layer. The in situ DEMS and ex situ spectral analyses verified the negligible O₂ and CO₂ emission, even charging to 4.4 V, and the formation of stable cathode–electrolyte interfacial membrane. The as-obtained cathode exhibited a reversible specific capacity as high as 223 mA h g⁻¹ at 0.1C and 140 mA h g⁻¹ even at 10C with 96.7% capacity retention at 1C after 100 cycles in a coin-type half-cell. About 90.1% capacity retention could still be obtained at 1C in a pouch-type full-cell after 300 cycles. This work provides a viable cathode for durable LIBs by stabilizing the lattice oxygen of Ni-rich and Co-poor cathodes.