Work

Regulation of gradient pores and heteroatom-doped sites in carbonaceous cathodes for promoting Zn-ion storage capability

Year: 2025

Type: article

Abstract: Carbonaceous cathodes with numerous heteroatom-doped active sites and accessible pore structures can effectively boost the charge storage capacity and energy density of carbon-based aqueous zinc-ion capacitors (AZICs). In this study, N/P-doped gradient porous carbon (GCNP) is constructed to increase the Zn ion storage capacity, owing to the abundant N, P, and O heteroatom active sites and unique gradient-pore structure. The gradient porous structure (micropores and mesopores of approximately 1.19 and 2.67 nm) of the GCNP 2 -1 cathode provides rapid ion/electron pathways, promoting Zn ion diffusion and transfer behaviors. Density functional theory calculation reveals that the incorporated N and P functional groups effectively regulate the charge density distribution in gradient porous (micro-mesoporous) carbonaceous structure, thereby enhancing Zn ion adsorption. Consequently, GCNP 2 -1 based AZICs deliver capacities of 218.1 and 112.3 mAh g −1 at 0.2 and 10 A g −1 . Moreover, the GCNP 2 -1 based AZICs exhibit 70.5 % capacity retention after 30,000 cycles at 10 A g −1 , and excellent energy density with 200.1 and 49.4 Wh kg −1 at 0.159 and 31.2 kW kg −1 . This work provides an effective strategy for designing N/P-doped gradient porous carbon cathodes, highlighting the potential for superior Zn ion capacity cathode materials in practical AZICs applications.

Source: Journal of Power Sources

DOI: 10.1016/j.jpowsour.2025.237072