Oxygen Vacancy-Driven Lattice Modulation in Zn2P2O7: A Novel Anode Enabling Accelerated Kinetics and Long Cycling Stability for Sodium-Ion Batteries

Lattice defect-induced tuning of the chemical bonding environment is a promising strategy to enhance the performance of electrode materials. The deliberate introduction of oxygen vacancies (OVs) has demonstrated remarkable efficacy in boosting electronic conductivity and ion diffusion kinetics, while the resultant chemical bond engineering optimizes the bonding environment, thereby enhancing structural stability and electrochemical reversibility. This study pioneers a dual-modification strategy involving OVs -induced C-P bonds formation in the Zn 2 P 2 O 7 structure. Through systematic electrochemical characterization complemented by density functional theory (DFT) calculations, the synergistic mechanism between OVs-mediated electron structure modulation and C-P bonds reinforcement is elucidated. As a novel anode material for sodium-ion batteries, the engineered Zn 2 P 2 O 7−x @C composite exhibits substantially enhanced rate capability (316.6 mAh g −1 at 0.05 A g −1 ) and cycling stability (171.3 mAh g −1 after 1000 cycles at 1 A g −1 ), in stark contrast to the rapid performance degradation observed in pristine Zn 2 P 2 O 7 . Furthermore, the extension of this strategy to lithium-ion battery systems further validates the universal effectiveness of this defect/chemical bonding synergy strategy in improving alkali metal ions storage, demonstrating its broad applicability across various energy storage platforms.