Epitaxial Nucleation of NaxFeFe(CN)6@rGO with Improved Lattice Regularity as Ultrahigh-Rate Cathode for Sodium-Ion Batteries

作者：Tang, Yun; Wang, Lei; Hu, Jianwei; Chen, Manlin; Zhou, Min^*; Wang, Kangli; Jiang, Kai^*

来源：Advanced Energy Materials, 2024.

DOI：10.1002/aenm.202303015

• epitaxial nucleation
• graphene oxides
• high-power cathodes
• prussian blue analogues
• sodium-ion batteries

Although Prussian blue analogues are the promising candidate cathode materials for the Na-ion batteries for the grid storage due to 3D open-framework structure and large interstitial "A" sites, high content of defects in the crystals obtained in the conventional strategy severely impede Na+ migration, leading to an unsatisfactory power density. Here a novel epitaxial nucleation-assisted controlled crystallization approach to eliminate the structural defects of NaFeHCF crystals is reported. Due to their limited lattice misfit of only 4.87% (< 5%) between the graphene and NaFeHCF as well as the electronegativity of the functional groups (& horbar;COOH, & horbar;OH, & horbar;CH(O)CH & horbar;), GO can act as the nucleation and subsequent epitaxial growth platform of NaFeHCF, which results in a unique one-corner-cut cubic nano-crystals morphologies with much decreased contents of defects (0.08 per formula unit). This enhanced lattice regularity significantly enhanced the speedy diffusion of Na cations (by 5 times) in the nanocrystals, resulting in the unprecedented rate capability of 96.8 mAh g(-1) at an ultra-high rate of 9 A g(-1) (39 s, 23228 W kg(-1)), which is far exceeding that of any previously reported PBA-based cathodes to the knowledge, authenticating its superiority as a candidate for high-power sodium-ion batteries for the reliable grid energy storage.

• 单位
  华中科技大学