Metal-organic framework glass stabilizes high-voltage cathodes for efficient lithium-metal batteries.

Abstract

The rapid evolution of portable electronics and electric vehicles necessitates batteries with high energy density, robust cycling stability, and fast charging capabilities. High-voltage cathodes, like LiNi_0.8Co_0.1Mn_0.1O₂ (NCM-811), promise enhanced energy density but are hampered by poor stability and sluggish lithium-ion diffusion in conventional electrolytes. We introduce a metal-organic framework (MOF) liquid-infusion technique to fully integrate MOF liquid into the grain boundaries of NCM-811, creating a thoroughly coated cathode with a thin, rigid MOF Glass layer. The surface electrically non-conductive MOF Glass layer with 2.9 Å pore windows facilitating Li-ion pre-desolvation and enabling highly aggregative electrolyte formation inside the Glass channels, suppressing solvated Li-ion co-insertion and solvent decomposition. While the inner Glass layer composes of Li-ion conducting components and enhancing fast Li-ion diffusion. This functional structure effectively shields the cathode from particle cracking, CEI rupture, oxygen loss, and transition metal migration. As a result, Li | |Glass@NCM-811 cells demonstrate good rate capability and cycling stability even under high-charge rates and elevated voltages. Furthermore, we also achieve a 385 Wh kg^-1 pouch-cell (19.579 g, for pouch-cell), showcasing the practical potential of this method. This straightforward and versatile strategy can be applied to other high-voltage cathodes like Li-rich manganese oxides and LiCoO₂.