Unlocking High‐Performance Na‐CO 2 Batteries via a d‐p Orbital Hybridization Descriptor for Rational Catalyst Design

Abstract Metal‐based catalysts show great promise for efficient Na‐CO 2 batteries. However, the absence of a universal principle that connects catalytic properties to battery performance has impeded rational catalyst design. To bridge this gap, we propose a descriptor based on d‐p orbital hybridization. Focusing on sodium oxalate (Na 2 C 2 O 4 ), a key discharge product with faster decomposition kinetics than carbonates, we systematically investigate the hybridization between metal d‐band centers and oxygen p‐orbitals, revealing the mechanism governing the formation/decomposition for Na 2 C 2 O 4 . By constructing electronic structure‐based theoretical descriptors, we enable efficient prediction and rational design of catalyst performance. The Pd‐based catalyst designed using the d‐p orbital hybridization descriptor screening strategy enables a battery that achieves a cycling stability of 1800 h with retained energy efficiency of 85.5% and a low overpotential of 0.49 V. The strong correlation between the descriptor and the Gibbs free energy (ΔG) of the rate‐determining reaction step confirms its predictive accuracy. This work establishes d‐p orbital hybridization as a descriptor for controlling discharge products, guiding the design of high‐energy‐density Na‐CO 2 batteries.