Search

This paper presents a novel approach for optimizing potassium-ion battery electrode materials. By employing a pre-bonding technique, we have effectively combined the strengths of hard carbon's rapid potassium-ion adsorption and graphite's extensive potassium storage. The resulting pre-bonded carbon (PBC) composite exhibits remarkable electrochemical performance with exceptional stability. Electrochemical characterizations, along with SEM, Raman, XRD, and macroscopic observations, provide insights into PBC's advantages. PBC's structural integrity, maintained even after extended cycling, highlights its capacity to protect the graphite structure from damage. This buffering effect is especially significant under high current conditions. Furthermore, the pre-bonding process enables PBC to store potassium effectively, ensuring a high energy density for the negative electrode material. In contrast, samples mixed without pre-bonding exhibit poor adhesion between hard carbon and graphite, leading to graphite breakage and reduced electrochemical performance. PBC's simplicity of implementation and compatibility with existing production systems make it a valuable addition to potassium-ion battery development, particularly in large-scale energy storage applications. The findings underscore the significance of pre-bonding as a promising technique to optimize potassium-ion battery electrode materials. [ABSTRACT FROM AUTHOR]

Nanoscale Sn-based alloy materials are high-performance anode materials for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), however, the insertion and extraction of Li+/Na+ during the charging and discharging process can lead to dramatic expansion of the electrode volume as well as collapse and crushing of the structure. Therefore, we successfully synthesized a new mesoporous Sn/SnO 2 -Ni@C composite anode material. Mesoporous Sn/SnO 2 -Ni@C has excellent electrochemical properties and can reach large reversible capacities after 200 cycles at 0.2 A g −1 (LIBs: 1020.7 mAh g −1, SIBs: 342.6 mAh g −1) as well as remarkable stability after 1000 cycles at 1.0 A g −1 (LIBs: 864.6 mAh g −1, SIBs: 219.3 mAh g −1). In addition, mesoporous Sn/SnO 2 -Ni@C also has outstanding rate performance (LIBs: 564.6 mAh g −1 at 5.0 A g −1, SIBs: 212.5 mAh g −1 at 1.0 A g −1). In particular, the unique mesoporous structure not only provides additional transport channels for Li+/Na+ and electrons, but also enables the electrode material to be fully immersed in the electrolyte. Meanwhile, the synergistic effect between Sn/SnO 2 -Ni alloy can prevent shuttle effect and alleviate volume expansion, the presence of Ni can prevent the coarsening of Sn. Thus, mesoporous Sn/SnO 2 -Ni@C has fast kinetics and is a promising anode material for LIBs/SIBs. [Display omitted] [ABSTRACT FROM AUTHOR]

As a promising lithium‐ion battery anode materials, silicon suboxides (SiOx) exhibit elusive microstructure with atomic‐scale disproportionation which reveals a strong relation to performance. Generally, the structure of SiOx could be tuned via high‐temperature treatment. In this work, disproportionated SiOx are prepared to systematically discuss the internal relationship among microstructure, physicochemical properties and electrochemical performance. After annealing, amorphous SiO2 and nanocrystalline Si appear, and the SiO2 accumulating on the surface results in large resistance and low Li‐ion diffusivity, which leads to large overpotential and poor performance. If mechanical milling is employed followed by annealing, the SiO2 layer can be crushed, SiOx and Si with electrochemical activity are uncovered. Further research on the SiOx with diverse degrees of disproportionation indicates that proper amount of Si and SiO2 determines the optimal electrochemical performance. This result gives an in‐depth understanding and probable guidance to the modification investigation of SiOx anode for Li‐ion batteries. [ABSTRACT FROM AUTHOR]

Potassium-ion batteries (PIBs) are considered alternatives to lithium-ion batteries because of their comparatively cheaper manufacturing costs and lower potential (2.936 V compared to standard hydrogen electrodes). However, their large ionic radii and unstable structures hindered their satisfactory electrochemical performance. In this study, F–Sn/SnO x @C, a novel porous layered composite material, was prepared using NaCl as a template for in situ etching to obtain a promising negative electrode material for PIBs. The significant specific surface area of the composite material and the uniform embedding of tin nanoparticles within the layered porous carbon shell, contributed to its excellent potassium intercalation/deintercalation performance. Fluorine doping enhanced electron transfer, prevented nanoparticle aggregation, and improved electrolyte penetration and potassium ion migration. The PIBs prepared from this electrode showed high potassium storage capacity, outstanding cycle stability (retaining 263 mAh g−1 after 200 cycles at 100 mA g−1), and remarkable rate capability (505.6, 288.4, 193.5, 134.1, and 83.3 mAh g−1 at 0.1, 0.2, 0.3, 0.5, and 1.0 A g−1, respectively). These results provide a straightforward solution for improving the electrochemical performance of PIBs. [ABSTRACT FROM AUTHOR]

Material Nano-genesis has gradually obtained more technical feedback and support in the study of lithium batteries, but problems such as volume expansion still need in-depth study. In this paper, SnO 2 –TiO 2 –CNS ternary composites were prepared by hydrothermal method and ball milling. Depending on the layered structure, the SnO 2 –TiO 2 nanoparticles are uniformly attached to carbon nanosheets. It is noteworthy that the volume variation of SnO 2 was alleviated by mixed TiO 2 and CNS, thus generating a wider space to move around for the lithium ion during the conduction process. The STC was tested for 100 cycles at 0.2 Ag-1 and the capacity was achieved 1046.1 mAhg−1. At 1.0 Ag-1, the capacity of STC can attain 1443.3 mAhg−1 after 1000 cycles. Then, the SEM image of the recovered electrode material was measured, and it was observed that the SnO 2 –TiO 2 –CNS composite remained stable. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bimetallic alloy nanoparticles enhance the cycling stability during K intercalation/de-intercalation process. • A novel preparation of PIB anode via a scalable bimetallic alloy nanoparticles and carbonization. • The doped N and O elements increase the contact sites between the electrode materials and electrolyte. • The composite material has bimetallic alloy active site and conductive carbon frame. Metal-organic frameworks (MOFs) have great potential as anode materials for potassium-ion batteries (PIBs) due to their hierarchical porous structures, large number of reaction sites, and adjustable chemistry. However, the larger size of potassium ions adversely impacts the electrochemical performance and specific capacity. Therefore, it is imperative to develop novel electrode materials featuring distinctive structures for PIBs. This study achieved bimetal introduction by adding Ammonium ferric citrate during ZIF-67 growth. The resulting metal–organic skeleton of the bimetallic alloy nanoparticle (FeCo@PAZ-C) exhibits a core–shell structure and adorned with numerous microspheres on its surface, thereby offering an abundance of active sites for K+ storage. This architecture effectively reduces the diffusion path length for potassium ions and enhances electron transport pathways, ultimately contributing to improved performance. At 100 mA g−1 and after 500 cycles, the FeCo@PAZ-C electrode material demonstrated a stable specific capacity of 328 mAh/g with 95 % capacity retention. This self-sacrificing template method for MOFs offers a new approach to developing high-capacity and cycling-stable potassium-ion battery materials, broadening their potential applications. [ABSTRACT FROM AUTHOR]

• Innovative porous structures formed by PVDF-Derived carbon: Our approach strategically coats active materials with carbon, creating effective porous structures. • Enhanced red phosphorus performance: The composite material promotes electron transfer and accommodates significant volume changes during sodium-ion cycling. • PVDF benefits: Using PVDF as a carbon source results in a structured, flexible, and mechanically strong carbon framework. • Outstanding capacity retention: P@C maintains 336.7mAh g−1 capacity after 200 cycles at 0.2 A g−1 and exhibits minimal degradation even after 500 cycles at 1 A g−1. Given the widespread availability of sodium on our planet, sodium-ion batteries (SIBs) hold substantial promise as cost-effective energy storage solutions. Red Phosphorus (red P) has emerged as a promising candidate for SIBs anodes due to its impressive theoretical capacity of 2596mAh g−1. However, red P faces inherent challenges, mainly due to its insulating nature and significant volume changes during cycling, which adversely affect its cycling and rate performance. To overcome these challenges, we have developed a novel material called P@C, composed of carbon-coated and porous carbon structures. The synthesis of P@C involves integrating red P with PVDF and a series of carefully controlled steps, including ultrasonic dispersion, magnetic stirring, centrifugation, and high-temperature calcination. This well-designed composite material facilitates electron transfer and provides ample space within its porous carbon structure to accommodate the substantial volume changes associated with phosphorus during sodium insertion/extraction. The use of PVDF as a carbon source contributes to the creation of a defined porous carbon framework, enhancing the material's flexibility, mechanical strength, and ease of processing. As a result, when employed as an anode material for SIBs, the P@C composite material exhibits exceptional cycling stability and remarkable rate performance. Notably, it demonstrates superior capacity retention, maintaining 336.7mAh g−1 after 200 cycles at 0.2 A/g, and excellent cycling durability, with minimal capacity degradation even after 500 cycles at 1 A/g.This innovative work, characterized by its strategic carbon-coating approach that effectively encapsulates the active material within porous structures, provides valuable insights into the development of high-performance electrode materials for metal-ion batteries and other energy storage applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • This pore-like structure promotes electrolyte penetration as well as provides good intergranular electrical contact, which shortens the Li+ transport distance of electrons and F doping enhances the loading of SnO 2 -NiO particles on the surface of carbon materials and enhances electron transport and Li+ diffusion in the composite. • The nano-SnO 2 particles can supply additional active sites for Li collection, which improves the reversible capacity and shortens the Li+ and electron transport distances, improving the rate performance. • The NiO nanoparticles with a unique hexagonal crystal structure are ideal for ion cycling and embedding which can stabilize the structure and prevent the SnO 2 from becoming coarser. • The carbon material encapsulated in the outer layer can effectively prevent volume expansion during the cycle as well. A novel fluorine-doped porous SnO 2 -NiO@C-F (SNCF) composite anode material was synthesized by NaCl template method through high-energy ball milling and calcination under nitrogen atmosphere. This pore-like structure promotes electrolyte penetration as well as provides good intergranular electrical contact, which shortens the Li+ transport distance of electrons and F doping enhances the loading of SnO 2 -NiO particles on the surface of carbon materials and enhances electron transport and Li+ diffusion in the composite. In addition, NiO with relatively small content and distribution along the carbon substrate can improve the irreversible decomposition process of Li 2 O due to the catalytic properties of Ni-based oxides. The encapsulated carbon can buffer the volume expansion and avoid the accumulation of active materials, thus improving the material properties. Hence, the porous SnO 2 -NiO@C-F composite has a large capacity of 989.2 mAh g−1 after 150 cycles at 0.2 A g−1, as well as a long-time cycling stability that still shows a capacity of 768.9 mAh g−1 after 1000 cycles at 1 A g−1. In addition, it has excellent rate property, reaching a capacity of 389.0 mAh g−1 even at 5 A g−1. Therefore, the porous SnO 2 -NiO@C-F is a prospering anode material for lithium ion batteries (LIBs). [ABSTRACT FROM AUTHOR]

Potassium ion batteries (PIBs) attract increasing attention due to abundant natural storage of potassium resources in the earth's crust, low cost, and high operating potential. However, larger radius of K+ compared to Na+/Li+, poor kinetics and unstable structure lead to inferior electrochemical performance for PIBs. Herein, we propose 3D fluorine-doped carbon@Ti 3 C 2 MXene (3D FC@Ti 3 C 2) composite as anode material for PIBs. In the composite, coating carbon can protect Ti 3 C 2 from oxidation and self-stack, fluorine-doped carbon can afford more defects and introduce numerous active site that can strongly adsorb K+. In addition, the composite can enlarge the interlayer spacing, and the 3D interconnected carbon framework can enhance conductivity and alleviate the volume expansion during cycling. Benefiting from these synergetic effects, the 3D FC@Ti 3 C 2 can obtain supernormal electrochemical property with high capacity of 288 mAhg−1 at 100 mAg−1 after 200 cycles and extraordinary cyclic stability of 174 mAhg−1 at 500 mAg−1 after 1000 cycles. • 3D FC@Ti 3 C 2 composite have been synthesized by freeze-drying and pyrolysis. • Carbon coating can protect Ti 3 C 2 from oxidation and self-stack. • Fluorine-doped carbon can strongly adsorb K+. • 3D interconnected carbon framework can enhance conductivity. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) arouse researchers' interest gradually because of the scarcity of lithium sources. VSe 2 is one of the transition metal dichalcogenides (TMDs) equipped with a huge interlayer distance to accommodate more Na+ ions, but the problems such as agglomeration, volume deformation, dissolution loss and so on hinder its further development. Therefore, a VSe 2 /B 4 C@HCG composite was fabricated by the simple high-energy ball milling method. The B 4 C and VSe 2 nanoparticles are mixed and restrict each other, then anchor on the graphene, which alleviates agglomeration and volume deformation of VSe 2 during cycling processes effectively, and improves the overall environmental stability and conductivity. As a result, the VSe 2 /B 4 C@HCG composite delivers a reversible capacity of 407.5 mAh g−1 with the coulombic efficiency of 98.5% after 450 cycles, superior rate performance of 524.2, 476.3, 413.7, 353.7, and 295.3 mAh g−1 at the different current density of 100, 200, 500, 1000, and 2000 mA g−1, and ultrastable long-term cycling property of 251.6 mAh g−1 at the current density of 1 A g−1 after 1000 cycles, indicating the VSe 2 /B 4 C@HCG composite shows utilization potentiality to be used as an excellent anode material for SIBs. [Display omitted] • VSe 2 is equipped with huge interlayer space that can accommodate more Na+ ions. • The VSe 2 /B 4 C@HCG composite was synthesized by a simple ball-milling. • The component of B 4 C and high conductive graphene can effectively improve the overall environmental stability and conductivity of VSe 2 /B 4 C@HCG composite. • Stable cycling performance, excellent rate properties and electrochemical kinetics are presented. [ABSTRACT FROM AUTHOR]

Potassium-ion and sodium-ion batteries (PIBs and SIBs) attract the attention of researchers because of their high earth abundance, low cost, and even similar principle to lithium-ion batteries. MOF-derived transition metal carbide composites are regarded as promising electrode materials because of their high specific capacity and excellent electrochemical activities while equipped with excellent sodiophilic for sodium nucleation and deposition. Therefore, Co 3 C/MXene@C composites with a large specific surface area are designed for both PIBs and SIBs. In detail, the Co 3 C component plays a key role in electrocatalysis of reversible conversion of some components of solid electrolyte interface films, while rich defective carbon and nitrogen content can improve the whole activity of the material. As results, the Co 3 C/MXene@C electrodes deliver an excellent reversible capacity of 236 mA h g−1 with the coulombic efficiency of 98.51% (for PIBs) and 275.9 mA h g−1 with the coulombic efficiency of 98.43% at 200 mA g−1 (for SIBs) after 100 cycles, superior rate performance of 80.6 mA h g−1 and 105 mA h g−1 at 2000 mA g−1 for PIBs and SIBs, respectively. With these outstanding electrochemical performances, the Co 3 C/MXene@C electrodes show a potential application prospect for potassium-ion and sodium-ion batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

Ti 3 C 2 /TiO 2 /rGO nanosheets were synthesized as anode materials for potassium ion batteries (KIBs) using modified Hummers, freeze drying, and thermal reduction in this paper. Layered Ti 3 C 2 /TiO 2 /rGO nanosheets were synthesized by in-situ formation of rGO and TiO 2 nanoparticles between Ti 3 C 2 layers. As one of the most important members of MXenes family, Ti 3 C 2 exhibits unique electronic characteristics, high specific surface area, strong electrical conductivity and chemically active surface, which can enhance electrode capacity. There are three ways to increase electrode conductivity and capacity: Firstly, rGO is applied as the substrate for the inlaying of TiO 2 and Ti 3 C 2 nanoparticles and nanosheets. Secondly, rGO may also buffer electrode volume changes during charging and discharging processes. In addition, the enormous surface area of rGO makes Ti 3 C 2 and TiO 2 nanoparticles dispersion well, and Ti 3 C 2 and TiO 2 nanoparticles can well separate rGO nanoparticles and prevent them from stacking up again. The synergistic effect of the three can efficiently relieve the stress and provide a rapid transport pathway between electrons and ions. The flake structure of Ti 3 C 2 /TiO 2 /rGO is advantageous to the stability of SEI film, which makes the material maintain good activity during charge and discharge process, and significantly increases its electrochemical performance. Therefore, Ti 3 C 2 /TiO 2 /rGO electrode has a high reversible capacity of 349.2 mAhg−1 after 200 cycles of 100 mAg−1 current, and a high stable capacity of 229.3 mAhg−1 after 500 cycles of 500 mAg−1 current, and has exceptional rate performance. The structure of Ti 3 C 2 /TiO 2 /rGO composite remains stable after 500 cycles, and no agglomeration occurs. The detailed reaction mechanism of Ti 3 C 2 /TiO 2 /rGO electrode as KIBs anode was analyzed by SEM, XRD, Raman, TGA, FT-IR, BET, TEM, XPS, EDS, CV, EX-situ XRD, ex-situ TEM, and so on. Therefore, it can be concluded that the Ti 3 C 2 /TiO 2 /rGO composite is an appropriate anode material for KIBs. [Display omitted] • Ti 3 C 2 /TiO 2 /rGO nanosheets were synthesized using modified Hummers, freeze drying, and thermal reduction. • The flake structure of Ti 3 C 2 /TiO 2 /rGO is advantageous to the stability of SEI film, which makes the material maintain good activity. • RGO acts as a substrate for TiO 2 and Ti 3 C 2 nanoparticles to buffer the volume change of the electrode during the charging and discharging process. • The synergistic effect of Ti 3 C 2 , TiO 2 , and rGO can efficiently relieve the stress and provide a rapid transport pathway between electrons and ions. • Ti 3 C 2 /TiO 2 /rGO electrode has a high reversible capacity of 349.2 mAhg−1 after 200 cycles of 100 mAg−1 , and 229.3 mAhg−1 after 500 cycles of 500 mAg−1. [ABSTRACT FROM AUTHOR]