Boosting Fe Cationic Vacancies with Graphdiyne to Enhance Exceptional Pseudocapacitive Lithium Intercalation

Modulating the electronic structure of electrode materials at atomic level is the key to controlling electrodes with outstanding rate capability. On the basis of modulating the iron cationic vacancies (IV) and electronic structure of materials, we proposed the method of preparing graphdiyne/ferroferric oxide heterostructure (IV‐GDY‐FO) as anode materials. The goal is to motivate lithium‐ion batteries (LIBs) toward ultra‐high capacity, superior cyclic stability, and excellent rate performance. The graphdiyne is used as carriers to disperse Fe3O4 uniformly without agglomeration and induce high valence of Fe with reducing the energy in the system. The presence of Fe vacancy could regulate the charge distribution around vacancies and adjacent atoms, leading to facilitate electronic transportation, enlarge the lithium‐ion diffusion, and decrease Li+ diffusion barriers, and thus displaying significant pseudocapacitive process and advantageous lithium‐ion storage. The optimized electrode IV‐GDY‐FO reveals a capacity of 2084.1 mAh g−1 at 0.1 C, superior cycle stability and rate performance with a high specific capacity of 1057.4 mAh g−1 even at 10 C. Graphdiyne as anode material in Li‐ion batteries can realize effective charge transfer to induce the formation of a high number of Fe vacancies with uniform dispersion. The Fe vacancies modulate charge distribution, serve as active sites and enhance electron‐ion transportation, thereby displaying robust pseudocapacitive behavior. The Fe vacancies also reduce the diffusion energy barrier and adsorption energies, leading to a superior battery performance.