Key Takeaways & Executive Findings
- •• The ZTO-G-C nanofibers exhibit high reversible capacity (230.82 mA·h/g after 100 cycles) and excellent rate capability (184.78 mA·h/g at 1 A/g) as KIB anodes. • The synergistic integration of amorphous SnO2, ZnO, and graphene within a porous carbon matrix enhances structural stability and charge transport, mitigating volume expansion during K+ intercalation. • The pseudocapacitive contribution from the porous carbon substrate significantly boosts the overall potassium storage capacity. • This work provides a facile electrospinning strategy for designing high-performance anodes for next-generation potassium-ion batteries.
Abstract
Potassium-ion batteries (KIBs) are rising as a noteworthy contender to lithium-ion batteries (LIBs), particularly for large-scale applications, driven by the natural abundance and cost-effectiveness of potassium resource. Yet, lacking anodes which can reversibly accommodate the larger K+ currently poses a critical development hurdle, highlighting an urgent need for innovative solutions. Herein, porous ZnO-SnO2-graphene-carbon (ZTO-G-C) nanofibers are presented, featuring amorphous SnO2 and ZnO nanoparticles homogeneously dispersed within a carbon matrix, with the strategic graphene incorporation for enhanced performance. Employing an adjustable and straightforward electrospinning method, the nanofibers were crafted to achieve a stable fibrous architecture. When evaluated as KIB anodes, the ZTO-G-C nanofibers demonstrated remarkable cycling stability (retaining 230.82 mA·h/g over 100 cycles at 100 mA/g), and rate capability (184.78 mA·h/g at 1 A/g). This outstanding performance is due to the synergistic interaction among all active components, collectively enhancing the structural stability against volume expansion during K+ intercalation, facilitating efficient charge transport, and delivering exceptional cyclability, capacity, and rate performance. Moreover, the intrinsic pseudocapacitive behavior stemming from the porous carbon substrate of ZTO-G-C further boosts its overall K-storage capacity. It is anticipated that the insights gained from this study offer fresh perspectives for developing next-generation high-performance KIB anodes.
1. Introduction
In recent years, pursuing sustainable and renewable energy sources has gained unprecedented momentum, driven by concerns over environmental degradation and the exhaustion of fossil fuel reserves [1−3]. Among various energy storage technologies, potassium-ion batteries (KIBs) have emerged as a viable substitute for lithium-ion batteries (LIBs), attributed to their abundant raw materials, low cost, and similar electrochemical properties to lithium [4−6]. Moreover, the relatively weak Lewis acidity and low desolvation energy of K+ in specific liquid electrolytes, exemplified by blends of ethylene carbonate (EC) and diethyl carbonate (DEC), are conducive to swift charge transportation and insertion processes [7, 8].
However, the larger radius of K+ (1.38 Å (K+) > 0.76 Å (Li+)) introduces distinct obstacles for keeping electrode stability [9], including the structural collapse in the active material, detachment from the current collector, and suboptimal electrical contact, thus hindering the long-term performance and durability. Against this background, the development of high-performance anodes for KIBs, capable of well hosting and reversibly storing K+ during cycling, maintains a meaningful and ongoing endeavor.
Carbon-based materials, renowned for their exceptional stability and cost-effectiveness, stand out as promising candidates in the field of KIBs. At the forefront of KIB anode research, representative carbonaceous materials characterized with varied morphologies like carbon nanosphere [10], nanosheet [11], nanocage [12], nanoflower [13], reduced graphene oxide [14], along with diverse classifications including hard carbon [15], soft carbon [16], composites of hard and soft carbon [17] and graphite [18], have been thoroughly explored. Great efforts continued to be dedicated to refining the carbonaceous anodes to elevate their potassium storage capabilities. In recent strides, composites integrating a carbon-based matrix with metal oxide nanoparticles (such as SnO2) have garnered significant attention as potential anode materials for KIBs [19−21]. These composites leverage the high theoretical capacity of metal oxides for storing K+ through conversion and alloying reactions, which in turn boosts the energy density. The carbon matrix acts as a conductive scaffold, ensuring efficient electron transport and maintaining structural integrity, especially important for active materials like SnO2, which can undergo substantial volume changes during cycling.
Loading authentic research manuscript (Pages 1–5)...
HUANG Zhao, YANG Yuan-wen, LI Zhao-hui, CHEN Ling-jiao, SHI Wei, ZHANG Ming (2025). Boosting K+ storage capacity in carbon nanofibers: A synergistic strategy involving amorphous SnO2, ZnO integration, and graphene decoration. Journal of Central South University. https://doi.org/10.1007/s11771-025-6099-8
Research & Educational Purpose Only:The translations, structured abstracts, analytical annotations, and data reports provided by SinoTechIntel are intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoTechIntel claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What are the key materials used in the ZTO-G-C nanofibers?
The ZTO-G-C nanofibers are composed of amorphous SnO2 and ZnO nanoparticles uniformly dispersed in a carbon matrix, with graphene incorporated to enhance performance.
How were the ZTO-G-C nanofibers synthesized?
The nanofibers were fabricated using an adjustable and straightforward electrospinning method, which allowed for a stable fibrous architecture.
What electrochemical performance did the ZTO-G-C nanofibers exhibit?
The nanofibers showed a high reversible capacity of 230.82 mA·h/g after 100 cycles at 100 mA/g and a rate capability of 184.78 mA·h/g at 1 A/g.
Why is the synergistic strategy effective for potassium storage?
The synergy among amorphous SnO2, ZnO, and graphene enhances structural stability against volume expansion, facilitates charge transport, and contributes to pseudocapacitive behavior, collectively boosting potassium storage capacity.
What is the significance of this study for KIB development?
This study provides a novel approach to designing high-performance anodes for potassium-ion batteries, addressing the critical challenge of accommodating larger K+ ions and offering insights for next-generation energy storage.
Related Technical Papers & Translations
Direct Repair of the Crystal Structure and Coating Surface of Spent LiFePO4 Materials Enables Superfast Li-Ion Migration
The rapid accumulation of spent LiFePO4 (LFP) cathodes from retired lithium-ion batteries necessitates the development of effective and environmental-friendly recycling strategies. In this context, direct regeneration has emerged as a promising approach for reclaiming LFP cathode materials, offering a streamlined pathway to restore their electrochemical functionality. We report an integrated regeneration protocol that simultaneously repairs the degraded crystal structure and reconstructs the damaged carbon coating in spent LFP. The regenerated cathode material had superfast lithium-ion diffusion kinetics and a stable cathode–electrolyte interface, giving a remarkable rate capability with specific capacities of 122 mAh g−1 at 5C and 106 mAh g−1 at 10C (1C = 170 mA g−1). It also maintained capacities of 110.7 mAh g−1 (5C) and 84.1 mAh g−1 (10C) after 400 cycles. It could be used in harsh environments and could be stably cycled at subzero temperatures (−10 and −20 °C) and in solid-state electrolyte batteries. Life cycle assessment combined with economic evaluation using the EverBatt model reveals that this direct regeneration approach has high economic and environmental benefits.
Oxide Semiconductor for Advanced Memory Architectures: Atomic Layer Deposition, Key Requirement and Challenges
Oxide semiconductors (OSs), introduced by the Hosono group in the early 2000s, have evolved from display backplane materials to promising candidates for advanced memory and logic devices. The exceptionally low leakage current of OSs and compatibility with three-dimensional (3D) architectures have recently sparked renewed interest in their use in semiconductor applications. This review begins by exploring the unique material properties of OSs, which fundamentally originate from their distinct electronic band structure. Subsequently, we focus on atomic layer deposition (ALD), a core technique for growing excellent OS films, covering both basic and advanced processes compatible with 3D scaling. The basic surface reaction mechanisms—adsorption and reaction—and their roles in film growth are introduced. Furthermore, material design strategies, such as cation selection, crystallinity control, anion doping, and heterostructure engineering, are discussed. We also highlight challenges in memory applications, including contact resistance, hydrogen instability, and lack of p-type materials, and discuss the feasibility of ALD-grown OSs as potential solutions. Lastly, we provide an outlook on the role of ALD-grown OSs in memory technologies. This review bridges material fundamentals and device-level requirements, offering a comprehensive perspective on the potential of ALD-driven OSs for next-generation semiconductor memory devices.
Laser powder bed fusion of biodegradable Zn-4Cu alloy: Processing, microstructure and properties
Zn's natural degradability and biocompatibility make it a promising candidate for implants, however, its mechanical properties remain insufficient for bone applications. In this study, the performance of Zn was enhanced by developing Zn-Cu alloys via laser powder bed fusion (LPBF). Optimal LPBF parameters for forming stable tracks were achieved by adjusting laser power and scanning speed. Under optimized conditions of 100 W and 100 mm/s, high-density (99.58%) Zn-Cu alloys with improved hardness (68.2HV) and yield strength (160 MPa) were achieved. These improvements are attributed to solid solution strengthening, segregation strengthening, and grain refinement. The Zn-Cu alloys also demonstrated favorable degradation behavior, with a rate of 0.16 mm/year. This degradation is primarily driven by micro-galvanic corrosion between the CuZn5 phase and Zn matrix, along with refined grains and increased grain boundary density. This work demonstrates a viable strategy for fabricating Zn-based implants with enhanced structural integrity and mechanical performance via LPBF.