Weakened Interfacial Hybridization Unlocks High-Capacity Operation of Commercial Spinel Cathodes.

Abstract

Despite significant progress in cathode and electrolyte design, interfacial degradation continues to limit the practical capacity of high-energy secondary batteries. Here, we introduce a thermodynamics-guided strategy to modulate the interfacial hybridization by aligning the electronic band structures of the cathode and electrolyte. As a proof of concept, we construct a weakly hybridized inner Helmholtz plane (IHP) layer on commercial LiNi_0.5Mn_1.5O₄ (LNMO), and unlock an unprecedented practical specific capacity of 333.0 mA h g^-1 and a specific energy of 1097.0 Wh kg^-1, far exceeding the conventional operational thresholds (<150 mA h g^-1). Theoretical calculations and in/ex situ spectroscopic investigations reveal that attenuated hybridization between the cathode and electrolyte anions/solvents suppresses transition metal dissolution and mitigates structural degradation during extended deep cycling. Implemented in commercial Al-coated electrodes, our approach enables stable long-term cycling at 300 mA g^-1 with 212.5 mA h g^-1 specific capacity retained after 300 cycles. These findings establish interfacial hybridization modulation as a universal and scalable design principle for overcoming intrinsic capacity limitations, offering a viable pathway toward practical high-energy-density, long-life lithium-ion batteries.