BROWSE
Detail
Journal Article
[Zn1K2]Fe3(PO4)2(P2O7) as a Zn2+/K+ dual-ion cathode with enhanced diffusion kinetics and structural stability for aqueous zinc-ion batteries
Cited 1 time in 
Share 
Share
- Authors
- Sunha Hwang, Hyunji Kwoen, Jihoe Lee, Bonyoung Ku, Jinho Ahn, Hoseok Lee, Lahyeon Jang, Hyeong Jun Kook, Hyungsub Kim, Dong Ok Shin, Jongsoon Kim
- Issue Date
- 2025-10
- Citation
- Energy Storage Materials, v.82, pp.1-11
- ISSN
- 2405-8297
- Publisher
- Elsevier
- Language
- English
- Type
- Journal Article
- Abstract
- Aqueous zinc-ion batteries (AZIBs) have gained attention as safe and cost-effective alternatives to conventional lithium-ion batteries. However, their practical performance is often hindered by sluggish Zn2+ diffusion, primarily due to the large hydrated ionic radius and strong electrostatic interactions. To address this, we present a polyanion-based cathode material, [Zn
1 K2 ]Fe3 (PO4 )2 (P2 O7 ), that enables a reversible dual-ion intercalation mechanism involving both Zn2+ and K+. Compared to Zn2+, monovalent K+ interacts more weakly with the PO4 /P2 O7 framework and desolvates more readily at the electrolyte–cathode interface, enabling the Zn2+/K+ dual-ion system to achieve faster kinetics than the Zn2+-only system. This leads to significantly enhanced power capability and structural reversibility under the AZIB system. The discharge capacity of [Zn1 K2 ]Fe3 (PO4 )2 (P2 O7 ) is 100.4 mAh g-1 at C/5 (1C = 100 mA g-1), corresponding to de/intercalation of 2 mol K+ and 0.5 mol Zn2+. Even at 5C, it maintains a capacity of 70 mAh g-1, outperforming the Zn2+-only analogue Zn2 Fe3 (PO4 )2 (P2 O7 ) (55 mAh g-1). Galvanostatic intermittent titration technique measurements further confirm the enhanced ionic diffusion kinetics enabled by the Zn2+/K+ dual-ion system. Moreover, the capacity retention of [Zn1 K2 ]Fe3 (PO4 )2 (P2 O7 ) is 84.6 % after 100 cycles, while Zn2 Fe3 (PO4 )2 (P2 O7 ) deliver only 56.1 %. Advanced structural analyses reveal highly reversible lattice evolution during cycling, supporting the proposed dual-ion storage mechanism.
- KSP Keywords
- Cathode interface, Cathode materials, Electrostatic interaction, Galvanostatic intermittent titration technique(GITT), Ion storage, Ionic diffusion, Ionic radius, Lattice evolution, Lithium-ion batteries(LIBs), Storage mechanism, Structural analyses