An Overall Understanding of Sodium Storage Behaviors in Hard Carbons by an “Adsorption‐Intercalation/Filling” Hybrid Mechanism

Abstract Hard carbon has the potential to serve as a high‐capacity anode material for sodium‐ion batteries (SIBs), however, its Na + storage mechanism, particularly on the low potential plateau, remains controversial. To overcome this issue, two types of hard carbons with different microstructures are employed and the relationship between the microstructures and Na + storage behaviors is evaluated. By the combination of operando X‐ray diffraction, ex situ Raman spectroscopy, NMR, and theoretical calculation, it is found that the sodium storage capacities of the hard carbons in the low potential plateau region contain the concurrent contributions from both interlayer intercalation and micropores filling, and…