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

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Interfacial degradation limits practical capacity in high-energy secondary batteries.
• Optimizing cathode and electrolyte interfaces is crucial for battery performance.

Purpose of the Study:

• To introduce a thermodynamics-guided strategy to modulate interfacial hybridization.
• To enhance the electronic band alignment between cathode and electrolyte.

Main Methods:

• Constructed a weakly hybridized inner Helmholtz plane (IHP) layer on LiNi0.5Mn1.5O4 (LNMO) cathode.
• Utilized theoretical calculations and in/ex situ spectroscopic investigations.
• Implemented the approach in commercial Al-coated electrodes.

Main Results:

• Achieved unprecedented practical specific capacity (333.0 mA h g⁻¹) and specific energy (1097.0 Wh kg⁻¹).
• Demonstrated suppressed transition metal dissolution and mitigated structural degradation.
• Enabled stable long-term cycling with 212.5 mA h g⁻¹ capacity retained after 300 cycles at 300 mA g⁻¹.

Conclusions:

• Interfacial hybridization modulation is a universal design principle for overcoming capacity limitations.
• The strategy offers a viable pathway toward practical high-energy-density, long-life lithium-ion batteries.