Enhancing nickel-rich cathodes with dual-modified Li2MoO4/LiF layers for improved Longevity and stability

Nickel-rich ternary layered oxide (NLO), possessing a high capacity of 200 mAh/g, emerges as a promising candidate for lithium-ion battery cathodes. Nevertheless, its utility is hindered by poor structural stability and an unstable cathode solid electrolyte interphase (CEI). Through the application of self-sacrificing MoO 3-x and NH 4 F, the lithium fluoride has been utilized to generate highly thermodynamically stable and robust Li 2 MoO 4 /LiF as a Li conductor, enhancing Li diffusion kinetics and decelerating structural degradation. Moreover, the beneficial role of the Li/Ni disordered epitaxial layer , formed via lattice reconstruction, in enhancing the structural stability and surface chemical stability of NLO materials is significant. Consequently, such a “double protection” hybrid interphase grants high-nickel cathodes exceptional rate capability and long-term cycle life (up to 350 cycles at 1C with a capacity retention of 80.3 %), even operating in a broader electrochemical window without structural collapse. Moreover, the assembled full cells with a modified NCM@LMF2 cathode (1.6 mAh/cm 2 ) and graphite anode (1.9 mAh/cm 2 ) can deliver a lifespan of over 1000 cycles of use. This work presents a simple and efficient strategy to control ion transport and reactions at the cathode-electrolyte interface, which can enhance the potential for successful commercial applications of lithium-ion batteries. • A dual-modified Li 2 MoO 4 /LiF layer was applied to LiNi 0.83 Co 0.11 Mn 0.06 O 2 (NCM0.83). • The Li 2 MoO 4 /LiF layer formed from MoO 3-x , NH 4 F, and residual lithium on cathode. • The Li 2 MoO 4 /LiF layer improves ionic conductivity of NCM0.83. • The Li/Ni disordered epitaxial layer enhances the structural stabilities of NCM0.83. • The modified NCM0.83 exhibited excellent rate capability and cycling performance.