Search

Organic compounds have become a potentially important choice for a new generation of energy-storage electrode materials due to their designability, flexibility, green sustainability, and abundance. However, the applications of organic electrode materials are still limited because of their dissolution in electrolytes and low electrical conductivity, which in turn cause poor cycling stability. Here, for the first time, we report 2-amino-4-thiazole-acetic acid (ATA) and its sodium salt, sodium 2-amino-4-thiazol-derived polymer (PATANa), as an anode. The PATANa showed a two-dimensional (2D) nanosheet structure, offering a larger contact area with the electrolyte and a shorter ion-migration path, which improved the ion-diffusion kinetics. The polymer showed excellent cycling stability and outstanding rate capability when tested as an anode for sodium-ion batteries (SIBs). It could deliver a high reversible specific capacity of 303 mA h g−1 at 100 mA g−1 for 100 cycles and maintain a high discharge capacity of 190 mA h g−1 after 1000 long cycle numbers even at a high current density of 1000 mA g−1. This approach of salinizing the polymer opens a new way to develop anode materials for sodium-ion batteries. [ABSTRACT FROM AUTHOR]

Potassium‐ion batteries hold practical potential for large‐scale energy storage owing to their appealing cell voltage and cost‐effective features. The development of anode materials with high rate capability and satisfactory cycle lifespan, however, is one of the key elements for exploiting this electrochemical energy storage system at practical levels. Here, a template‐assisted strategy is reported for acquiring a bimetallic telluride heterostructure which is supported on N‐doped carbon shell (ZnTe/CoTe2@NC) that promotes diffusion of K+ ions for rapid charge transfer. It is shown that in telluride heterojunctions, electron‐rich Te sites and built‐in electric fields contributed by electron transfer from ZnTe to CoTe2 concomitantly provide abundant cation adsorption sites and facilitate interfacial electron transport during potassiation/depotassiation. The relatively fine ZnTe/CoTe2 nanoparticles imparted by the heterojunction result in high structural stability, together with a highly reversible capacity up to 5000 cycles at 5 A g−1. Moreover, using judiciously combined experiment and theoretical computation, it is demonstrated that the energy barrier for K+ diffusion in telluride heterojunctions is significantly lower than that in individual counterparts. This quantitative design for fast and durable charge transfer in telluride heterostructures can be of immediate benefit for the rational design of batteries for low‐cost energy storage and conversion. [ABSTRACT FROM AUTHOR]

Hierarchical hybrid heteroarchitectures possess attractive structural/compositional merits for lithium‐ion batteries (LIBs). Herein, a facile yet in situ growth strategy is proposed to scalably synthesize hierarchical porous ZnO/ZnFe2O4 hybrid nanofibers (NFs) with robust core/shell heterostructure toward LIBs. In such hybrids, 2D ZnFe2O4 nanosheets (NSs) are uniformly decorated on single‐crystalline ZnO core NFs, thereby affording more exposed active sites, a fast ion diffusion kinetic, and structural stability of electrodes during repeated cycling. As a result, benefiting from the unique hierarchical porous core/shell architecture and synergistic effects between the stable substrate of ZnO NFs and high‐capacity promoter of ZnFe2O4 NSs, the optimized ZnO/ZnFe2O4 hybrid as an anode for LIBs delivers a large reversible capacity of ≈688 mAh g−1 at 0.1 A g−1, high rate capability (≈288 mAh g−1 at 2.0 A g−1), and remarkable cyclability (≈491 mAh g−1 even over 250 cycles at 0.5 A g−1) for efficient lithium storage. This work highlights the rational design of a hierarchical architecture with a stable substrate and high‐capacity phases for next‐generation energy storage applications. [ABSTRACT FROM AUTHOR]

Among the various semiconductor materials, zinc telluride possesses the lowest electron affinity and ultrafast charge separation capability, facilitating improved charge transfer kinetics. In addition, ZnTe has a relatively high density, contributing to high volumetric capacity. Here, 1D N‐doped carbon‐coated ZnTe core‐shell nanowires (ZnTe@C) are designed and prepared via a facile ion‐exchange and carbonization technique. When evaluated as anode for metal ion batteries, it demonstrates superior electrochemical performance in both Li and Na ion storage, including high gravimetric and volumetric capacities (1119 mA h g−1 and 906 mA h cm−3, respectively, at 100 mA g−1 for Li ion storage), excellent high‐rate capability, and long‐term cycling stability. This remarkable electrochemical performance is attributed to the low electron affinity and high density of ZnTe, and the amorphous nature of the N‐doped carbon layer in the heterostructured ZnTe@C nanowires, which not only provide fast charge transfer paths, but also effectively maintain the structural and electrical integrity of the ZnTe. The strategy of embedding high density and high‐performance active materials in highly conductive nanostructures represents an effective way of achieving electrode materials with excellent gravimetric and volumetric capacities towards superior energy storage systems. [ABSTRACT FROM AUTHOR]

• Highly porous carbon nanofibers were prepared via an electrospinning method. • The carbon with hierarchical and entangled structure shows abundant active sites. • The porous carbon displays remarkable reversible capacity toward K ion storage. [Display omitted] Carbonaceous anode materials have been considered as a competitive candidate for the advanced potassium ion batteries (PIBs) owing to their high conductivity, low cost, relatively high theoretical capacity and stability. However, the poor ion transfer kinetics and undesired discharge capacity always limited their practical application. Herein, we reported the highly porous carbon nanofibers (HP-CNFs) prepared by using a facile electrospinning method for efficient K-storage. Due to its highly porous morphology, enlarged interlayer distance, N-doping, and abundant active sites, HP-CNFs can realize the rapid and reversible insertion/deinsertion of large-size K ions. HP-CNFs display reversible capacity of 311.7 mAh g−1 as an anode of PIBs even after 1000 cycles. This excellent electrochemical performance proves the feasibility of using HP-CNFs as a promising anode material for advanced PIBs. [ABSTRACT FROM AUTHOR]

Zn‐I2 batteries suffer from uncontrollable shuttle effects of polyiodine ions (I3− and I5−) at the cathode/electrolyte interface and side reactions induced by reactive H2O at the anode/electrolyte interface. In this study, a hydrated eutectic electrolyte is designed that synergizes the eutectic network and functional interfacial adsorbed layer to develop high‐performance Zn‐I2 batteries. The eutectic network can restrain active H2O molecules in the electrolyte to inhibit the side reaction at the anode/electrolyte interface and shuttle effect at the cathode/electrolyte interface. Additionally, the functional interfacial adsorbed layer guides the nucleation behavior of Zn2+ to inhibit the growth of dendrites and also separates the zinc anode from direct contact with active H2O molecules and polyiodine ions to inhibit corrosion. Theoretical calculation, in situ Ultraviolet–visible spectroscopy (UV‐vis) and Raman characterizations, and visualization experiments demonstrate that the hydrated eutectic electrolyte effectively inhibits the shuttling effect and improves the reversibility of zinc deposition/stripping behavior. Consequently, the Zn‐I2 battery can maintain a capacity of 133 mAh g−1 after 5000 cycles at 5 C. This highly efficient synergistic strategy offers a practical approach to the development of advanced Zn‐I2 batteries. [ABSTRACT FROM AUTHOR]

Si has attracted more attention as an ideal anode for next-generation Li-ion batteries (LIBs), due to its large theoretical capacity and low de-lithiation voltage. However, extreme volume change (about 300%) and low electronic conductivity severely hinder its practical application. Herein, to overcome these problems, via the electrospinning and pyrolysis processes, Si nanoparticles are embedded in porous N-doped carbon fibers (Si/P-NCFs) and interwoven into a flexible film. The binder-free and flexible Si/P-NCFs can significantly enhance the Li-ion storage capacity (1386 mAh g−1 after 100 cycles at 0.1 A g–1), cycling stability (942 mAh g−1 over 1000 cycles at 1 A g−1), as well as rate capability (381 mAh g−1 at 10 A g−1). These improvements are ascribed to the spatial confinement of carbon fibers and buffering effect of porous structure, which synergistically prevent the harm caused by the volume change. Additionally, porous N-doped carbon networks and binder-free structure can significantly enhance electron/ion conductivities. This work demonstrates an effective design to address the volume change and low electronic conductivity of Si towards advanced flexible Si-based anodes, as well as exhibits promising potential in practical use. [Display omitted] • Si are embedded in porous N-doped carbon fibers and interwoven into a flexible film. • Confinement of carbon fibers and porous structure can buffer volume change of Si. • Carbon fibers, N-doping, and porous structure can facilitate charges/ions transfer. • The binder-free and flexible Si/P-NCFs exhibits improved Li-ion storage properties. [ABSTRACT FROM AUTHOR]

Organic battery materials are ideal anodes for potassium ion batteries (PIBs) due to their structural diversity, abundant resources, and environmental friendliness. Herein, we report a conjugated polymer, polybenzo[1,2-b:4,5-b']dithiophene-4,8-dione (PBDTO), with a coaxial spiral structure. The plane rotation angle of each PBDTO molecule is about 20° apart, which is conducive to the exposure of reactive sites. Introducing reduced graphene oxide (rGO) drastically reduces the material's solubility in the electrolyte and finally obtains PBDTO/rGO with high conductivity, low solubility, and high capacity. As a result, PBDTO/rGO exhibits excellent potassium storage performance with a reversible capacity of 395 mAh g−1 at 100 mA g−1 and long-term cycling stability at high current density, for example, a capacity of 200 mAh g−1 after 1000 cycles at 1 A g−1. This work may inspire researchers to develop efficient organic battery electrodes for next-generation energy storage devices. [Display omitted] • Conjugated polymer with coaxial helical structure was prepared. • The polymer/rGO exhibits low solubility, high conductivity and activity. • The K+ storage capacity could reach 395 mAh g−1 at 100 mA g−1. [ABSTRACT FROM AUTHOR]