Vacancy-engineered LiMn₂O₄ embedded in dual-heteroatom-doped carbon via metal-organic framework-mediated synthesis towards longevous lithium ion battery

Spinel LiMn₂O₄ (LMO) is deemed to be a promising cathode material for commercial lithium-ion batteries (LIBs) in prospect of its cost-effectiveness, nontoxicity, fabulous rate capability, and high energy density. Nevertheless, the LMO is inevitably confronted with sluggish diffusion kinetics and drastic capacity degradation triggered by multiple issues, including Jahn-Teller distortion, Mn dissolution, and structural attenuation. Thereinto, a metal-organic framework (MOF) chemistry engineering for hierarchical micro-/nano-structural F, O-dual-doped carbon embedded oxygen vacancy enriched LiMn₂O₄ cathode (O_V-LMO@FOC) is proposed for longevous LIBs. Bestowed by experimental and theoretical implementations, systematic investigations of O_V-LMO@FOC endow that the meticulous integration of F, O-dual-doped carbon and oxygen vacancy in LMO-based cathode reconfigures the electronic structure, boosts electronic conductivity, expedites diffusion capability, facilitates energetically preferable Li⁺ adsorption, and suppresses Mn dissolution in the electrolyte, consequently achieving fabulous long-term cycling stability. As expected, the O_V-LMO@FOC behaves with compelling electrochemical performance with prosperous reversible capacity (130.2 mAh g^-1 at 0.2 C upon 200 cycles), exceptional rate capacity (93.7 mAh g^-1 even at 20 C), and pronounced long-term cyclability (112.5 mAh g^-1 after 1200 cycles with 77.6% capacity retention at 1 C). Even at the ultrahigh current density of 5 C, the O_V-LMO@FOC bears a brilliant capacity of 96.9 mAh g^-1 upon 1000 cycles with an extraordinary capacity retention of 90.7%, and maintains a discharge capacity of 70.9 mAh g^-1 upon 4000 cycles. This work envisions the MOF-chemistry in surface modification and electronic modulation engineering of high-performance cathode materials towards industrialization in automotive market.