Single-Atom-Dispersed FeNC/FeS₂ Nanocluster for High-Performance Sodium Metal Battery With Hybrid Electrochemical Behavior

Abstract

The rate capability and cycling stability of sodium metal batteries taking FeS₂ or sulfur as cathode are limited due to their low reaction kinetics and severe shuttle effect. Herein, we rationally design a novel single-atom-dispersed S₂–FeNC/FeS₂ nanocluster heterojunction embedded in carbon spheres (SFNC/FeS₂) for the electrode material of sodium metal batteries. Interestingly, during the discharging process, the Na⁺ is inserted into FeS₂ to generate Na₂S, as well as the unique electrochemical reaction between S₂–FeNC and Na⁺ to form Na₂S. Meanwhile, the FeNC can adsorb Na₂S and catalyze the conversion from Na₂S and Fe to FeS₂ or from Na₂S and FeNC to S₂–FeNC for suppressing the shuttle effect and promoting the distinct hybrid reversible electrochemical behavior, which improves performance tremendously. Notably, the SFNC/FeS₂ electrode delivers a specific capacity of 338.7 mAh g^–1 after superlong 2000 cycles at a current density of 5.0 A g^–1 and achieves a high energy density of 430.1 Wh Kg^–1 at a current density of 0.05 A g^–1. This work presents a novel approach to studying sodium metal batteries with hybrid behavior for excellent high energy density and cycling stability.

Keywords

electrochemical behavior / Fe single atom / FeS₂ / sodium metal battery / sodium sulfur battery

References

[1] Y. Chu, J. Zhang, Y. Zhang, et al., “Reconfiguring Hard Carbons With Emerging Sodium-Ion Batteries: A Perspective,” Advanced Materials 35, no. 31 (2023): 2212186.

[2] D. Mao, C. Wang, W. Li, et al., “Hollow Multishelled Structure: Synthesis Chemistry and Application,” Chemical Research in Chinese Universities 40 (2024): 346–393.

[3] J. Song, B. Xiao, Y. Lin, K. Xu, and X. Li, “Interphases in Sodium-Ion Batteries,” Advanced Energy Materials 8, no. 17 (2018): 1703082.

[4] H. Zhang, Z. Y. Gu, X. T. Wang, et al., “Electronic Confinement-Restrained MnNa· Anti-Site Defects in Sodium-Rich Phosphates Toward Multi-Electron Transfer and High Energy Efficiency,” Advanced Materials 36, no. 47 (2024): 2410797.

[5] Z. Y. Gu, J. M. Cao, K. Li, et al., “2D Exfoliation Chemistry Towards Covalent Pseudo-Layered Phosphate Framework Derived by Radical/Strain-Synergistical Process,” Angewandte Chemie 136, no. 30 (2024): e202402371.

[6] X. Wang, Y. Zhang, J. Li, H. Liu, and D. Li, “In-Situ Synthesis of Cauliflower-Like FeS₂ Grown on 3D Graphene Foam as High-Performance Electrode for Na⁺ Storage,” International Journal of Electrochemical Science 17, no. 4 (2022): 220430.

[7] M. Li, H. Zhuo, Q. Jing, et al., “Low-Temperature Performance of Na-Ion Batteries,” Carbon Energy 6, no. 10 (2024): e546.

[8] J. Zhu, A. Abdelkader, D. Demko, et al., “Electrocatalytic Assisted Performance Enhancement for the Na-S Battery in Nitrogen-Doped Carbon Nanospheres Loaded With Fe,” Molecules 25, no. 7 (2020): 1585.

[9] Y. J. Lei, H. W. Liu, Z. Yang, et al., “A Review on the Status and Challenges of Cathodes in Room-Temperature Na–S Batteries,” Advanced Functional Materials 33, no. 11 (2023): 2212600.

[10] L. Wang, T. Wang, L. Peng, et al., “The Promises, Challenges and Pathways to Room-Temperature Sodium-Sulfur Batteries,” National Science Review 9, no. 3 (2022): nwab050.

[11] L. Ma, X. Zhou, J. Sun, et al., “Synergy Mechanism of Defect Engineering in MoS₂/FeS₂/C Heterostructure for High-Performance Sodium-Ion Battery,” Journal of Energy Chemistry 82 (2023): 268–276.

[12] J. Ruan, Y. J. Lei, Y. Fan, et al., “Linearly Interlinked Fe–N_x–Fe Single Atoms Catalyze High-Rate Sodium–Sulfur Batteries,” Advanced Materials 36, no. 21 (2024): 2312207.

[13] J. Feng, C. Shi, X. Zhao, et al., “Physical Field Effects to Suppress Polysulfide Shuttling in Lithium–Sulfur Battery,” Advanced Materials 36, no. 48 (2024): 2414047.

[14] X. Yang, Z. Ran, F. Luo, Y. Li, P. Zhang, and H. Mi, “Free-Standing ZIF-8 Derived Nitrogen and Sulfur Co-Doped Porous Carbon Nanofibers Host for High Mass Loading Lithium–Sulfur Battery,” Applied Surface Science 509 (2020): 145270.

[15] X. T. Wang, Z. Y. Gu, J. M. Cao, et al., “Dual-Loop Upcycling of Spent LiFePO₄: Defect Inheritance Enables Durable and Fast-Charging Sodium-Ion Batteries,” National Science Review 12, no. 9 (2025): nwaf321.

[16] Z. Li, Y. Zhang, X. Li, et al., “Reacquainting the Electrochemical Conversion Mechanism of FeS₂ Sodium-Ion Batteries by Operando Magnetometry,” Journal of the American Chemical Society 143, no. 32 (2021): 12800–12808.

[17] T. Li, N. Zhang, B. Liu, et al., “Unlocking the Critical Role of Cations Doping in MnO₂ Cathode With Enhanced Reaction Kinetics for Aqueous Zinc Ion Batteries,” Advanced Functional Materials 35, no. 20 (2025): 2423755.

[18] T. Li, B. Liu, H. Guo, et al., “Enhanced Bifunctional Oxygen Electrocatalysis by Synergistic Active Heterostructure Design”,” Advanced Energy Materials 15, no. 35 (2025): 2502493.

[19] J. Barrio, A. Pedersen, S. C. Sarma, et al., “FeNC Oxygen Reduction Electrocatalyst With High Utilization Penta-Coordinated Sites,” Advanced Materials 35, no. 14 (2023): 2211022.

[20] R. Ma, G. Lin, Q. Ju, et al., “Edge-Sited Fe–N₄ Atomic Species Improve Oxygen Reduction Activity via Boosting O₂ Dissociation,” Applied Catalysis, B: Environmental 265 (2020): 118593.

[21] G. Cao, X. Li, R. Duan, et al., “Redistribution of D-Orbital in Fe–N₄ Active Sites Optimizing Redox Kinetics of the Sulfur Cathode,” Nano Energy 116 (2023): 108755.

[22] B. Chen, T. Wang, S. Zhao, et al., “Efficient Reversible Conversion Between MoS₂ and Mo/Na₂S Enabled by Graphene-Supported Single Atom Catalysts,” Advanced Materials 33, no. 12 (2021): 2007090.

[23] L. Yao, W. Xia, H. Zhang, et al., “In Situ Visualization of Sodium Transport and Conversion Reactions of FeS₂ Nanotubes Made by Morphology Engineering,” Nano Energy 60 (2019): 424–431.

[24] H. Chang, Y. F. Guo, X. Liu, P. F. Wang, Y. Xie, and T. F. Yi, “Dual MOF-Derived Fe/N/P-Tridoped Carbon Nanotube as High-Performance Oxygen Reduction Catalysts for Zinc-Air Batteries,” Applied Catalysis, B: Environmental 327 (2023): 122469.

[25] T. T. Wei, X. Liu, S. J. Yang, P. F. Wang, and T. F. Yi, “Regulating The Electrochemical Activity of Fe–Mn–Cu-Based Layer Oxides as Cathode Materials for High-Performance Na-Ion Battery,”,” Journal of Energy Chemistry 80 (2023): 603–613.

[26] L. Li, S. Huang, R. Cao, et al., “Optimizing Microenvironment of Asymmetric N, S-Coordinated Single-Atom Fe via Axial Fifth Coordination Toward Efficient Oxygen Electroreduction,” Small 18, no. 2 (2022): 2105387.

[27] J. Li, M. Li, N. An, et al., “Atomically Dispersed Fe Atoms Anchored on S and N-Codoped Carbon for Efficient Electrochemical Denitrification,” Proceedings of the National Academy of Sciences 118, no. 33 (2021): e2105628118.

[28] G. P. Lu, H. Shan, Y. Lin, et al., “A Fe Single Atom on N, S-Doped Carbon Catalyst for Performing N-Alkylation of Aromatic Amines Under Solvent-Free Conditions,” Journal of Materials Chemistry A 9 (2021): 25128–25135.

[29] Y. Wang, J. Wu, S. Tang, et al., “Synergistic Fe–Se Atom Pairs as Bifunctional Oxygen Electrocatalysts Boost Low-Temperature Rechargeable Zn-Air Battery,” Angewandte Chemie International Edition 62, no. 15 (2023): e202219191.

[30] Y. Zhang, Z. Zhang, Y. Zhang, et al., “Preparation of A Sulfur-Doped Graphene-Wrapped FeS₂ Microsphere Composite Material for Lithium-Ion Batteries,” Energy & Fuels 35, no. 24 (2021): 20330–20338.

[31] G. Ren, T. Tang, S. Song, et al., “Prussian Blue Analogue Derived CoS₂/FeS₂ Confined in N, S Dual-Doped Carbon Nanofibers for Sodium Storage,” ACS Applied Nano Materials 6, no. 19 (2023): 18071–18082.

[32] J. Zou, B. Wang, B. Zhu, Y. Yang, W. Han, and A. Dong, “Fe, N, S-Codoped Carbon Frameworks Derived From Nanocrystal Superlattices Towards Enhanced Oxygen Reduction Activity,” Nano Convergence 6, no. 1 (2019): 4.

[33] Q. Lin, S. Zhang, L. J. Yu, et al., “Recycle Waste Washcloth to Design Fe₃O₄/FeS₂/C Heterojunction Membrane as High-Area Capacity Freestanding Anode for Sodium-Ion Batteries,” Chemical Engineering Journal 455 (2023): 140945.

[34] L. Ma, B. Hou, H. Zhang, et al., “Regulation of MIL-88B(Fe) to Design FeS₂ Core-Shelled Hollow Sphere as High-Rate Anode for A Full Sodium-Ion Battery,” Chemical Engineering Journal 453 (2023): 139735.

[35] Y. Liu, X. Li, F. Zhang, et al., “Fe, N Co-Doped Amorphous Carbon as Efficient Electrode Materials for Fast and Stable Na/K-Storage,” Electrochimica Acta 396 (2021): 139265.

[36] C. Ma, X. Wang, J. Lan, et al., “Dynamic Multistage Coupling of FeS₂/S Enables Ultrahigh Reversible Na–S Batteries,” Advanced Functional Materials 33, no. 5 (2023): 2211821.

[37] Z. Hu, H. Cui, Y. Zhu, G. Lei, and Z. Li, “Holey Reduced Graphene Oxide Nanosheets Wrapped Hollow FeS₂@C Spheres as a High-Performance Anode Material for Sodium-Ion Batteries,” Journal of Power Sources 536 (2022): 231438.

[38] Z. Man, P. Li, D. Zhou, et al., “Two Birds With One Stone: FeS₂@C Yolk-Shell Composite for High-Performance Sodium-Ion Energy Storage and Electromagnetic Wave Absorption,” Nano Letters 20, no. 5 (2020): 3769–3777.

[39] Y. Li, D. Ye, W. Liu, et al., “Structure Adapting of Bulk FeS₂ Micron Particles and The Corresponding Anode for High Performance Sodium-Ion Batteries,” Journal of Materiomics 8 (2022): 1278–1286.

[40] Y. Huang, H. Zhao, S. Bao, Y. Yin, Y. Zhang, and J. Lu, “Hollow FeS₂ Nanospheres Encapsulated in N/S Co-Doped Carbon Nanofibers as Electrode Material for Electrochemical Energy Storage,” Journal of Alloys and Compounds 905 (2022): 164184.

[41] L. Shao, J. Hong, S. Wang, et al., “Urchin-Like FeS₂ Hierarchitectures Wrapped With N-Doped Multi-Wall Carbon Nanotubes@RGO as High-Rate Anode for Sodium Ion Batteries,” Journal of Power Sources 491 (2021): 229627.

[42] Y. Xiao, Y. Liu, B. Liu, et al., “Magnetoelectric Synergy Strategy for Superior Iron Disulfide Anode,” Inorganic Chemistry Frontiers 10, no. 5 (2023): 1671–1682.

[43] F. Liu, J. He, X. Liu, et al., “MoC Nanoclusters Anchored Ni@N-Doped Carbon Nanotubes Coated on Carbon Fiber as Three-Dimensional and Multifunctional Electrodes for Flexible Supercapacitor and Self-Heating Device,” Carbon Energy 3, no. 1 (2021): 129–141.

[44] D. Luo, Z. Zhang, G. Li, et al., “Revealing the Rapid Electrocatalytic Behavior of Ultrafine Amorphous Defective Nb₂O_5-x Nanocluster Toward Superior Li–S Performance,” ACS Nano 14, no. 4 (2020): 4849–4860.

[45] X. Pan, B. Xi, H. Lu, et al., “Molybdenum Oxynitride Atomic Nanoclusters Bonded in Nanosheets of N-Doped Carbon Hierarchical Microspheres for Efficient Sodium Storage,” Nano-Micro Letters 14 (2022): 163.

[46] H. Zhang, X. Zhou, Y. Liu, et al., “Delicate Fabrication of ZnO/ZnCo₂O₄ Heterojunction HoMSs as Anodes for Lithium-Ion Batteries With High Rate Capability,” Materials Chemistry Frontiers 6, no. 22 (2022): 3318–3328.

[47] W. D. Liu, X. Tang, J. A. Feng, et al., “Recent Advances in Vacancy Engineering for Reliable LithiumSulfur Batteries,” Rare Metals 43 (2024): 455–477.

[48] J. Feng, W. Liu, C. Shi, et al., “Enabling Fast Diffusion/Conversion Kinetics by Thiourea-Induced Wrinkled N, S Co-Doped Functional MXene for Lithium–Sulfur Battery,” Energy Storage Materials 67 (2024): 103328.

[49] S. Qi, L. Mi, K. Song, et al., “Understanding Shuttling Effect in Sodium Ion Batteries for the Solution of Capacity Fading: FeS₂ as An Example,” Journal of Physical Chemistry C 123, no. 5 (2019): 2775–2782.

[50] W. Zhang, M. Wang, H. Zhang, et al., “Binary Atomic Sites Enable a Confined Bidirectional Tandem Electrocatalytic Sulfur Conversion for Low-Temperature All-Solid-State Na–S Batteries,” Angewandte Chemie 136, no. 6 (2024): e202317776.

[51] Z. Yan, Y. Liang, J. Xiao, et al., “A High-Kinetics Sulfur Cathode With a Highly Efficient Mechanism for Superior Room-Temperature Na–S Batteries,” Advanced Materials 32, no. 8 (2020): 1906700.

[52] Y. X. Wang, B. Zhang, W. Lai, et al., “Sodium–Sulfur Batteries: Room-Temperature Sodium–Sulfur Batteries: A Comprehensive Review on Research Progress and Cell Chemistry,” Advanced Energy Materials 7, no. 24 (2017): 1770140.

[53] Y. Zhang, X. Guo, Q. Yang, et al., “Chemical and Spatial Dual-Confinement Engineering for Stable Na–S Batteries With Approximately 100% Capacity Retention,” Proceedings of the National Academy of Sciences 120, no. 48 (2023): e2314408120.

[54] X. Cai, C. Zhang, H. Ruan, et al., “Cross-Scale Decoupling Kinetic Processes in Lithium-Ion Batteries Using the Multi-Dimensional Distribution of Relaxation Time,” Advanced Science 11, no. 44 (2024): 2406934.

[55] J. Feng, C. Zhang, W. Liu, et al., “Enabling Efficient Anchoring-Conversion Interface by Fabricating Double-Layer Functionalized Separator for Suppressing Shuttle Effect,” Angewandte Chemie 136, no. 41 (2024): e202407042.

[56] L. Yue, Z. Wang, D. Wang, et al., “Aliovalent Doping Engineering Enables Multiple Modulations of FeS₂ Anodes to Achieve Fast and Durable Sodium Storage,” Journal of Materials Chemistry A 10, no. 39 (2022): 21149–21160.

[57] Y. Chen, X. Hu, B. Evanko, et al., “High-Rate FeS₂/CNT Neural Network Nanostructure Composite Anodes for Stable, High-Capacity Sodium-Ion Batteries,” Nano Energy 46 (2018): 117–127.

[58] W. Zhao, Y. Zhou, H. Zhou, et al., “Optimizing Reversible Phase-Transformation of FeS₂ Anode via Atomic-Interface Engineering Toward Fast-Charging Sodium Storage: Theoretical Predication and Experimental Validation,” Advanced Science 12, no. 2 (2025): 2411884.

RIGHTS & PERMISSIONS

2025 The Author(s). Carbon Energy published by Wenzhou University and John Wiley & Sons Australia, Ltd.