High Capacity Rate Research Articles

Strain engineering of Bi2S3 microspheres via organic intercalation enabled high performance sodium storage

Strain engineering of Bi2S3 microspheres via organic intercalation enabled high performance sodium storage

Synergistic Engineering of CoO/MnO Heterostructures Integrated with Nitrogen-Doped Carbon Nanofibers for Lithium-Ion Batteries.

The integration of heterostructures within electrode materials is pivotal for enhancing electron and Li-ion diffusion kinetics. In this study, we synthesized CoO/MnO heterostructures to enhance the electrochemical performance of MnO using a straightforward electrostatic spinning technique followed by a meticulously controlled carbonization process, which results in embedding heterostructured CoO/MnO nanoparticles within porous nitrogen-doped carbon nanofibers (CoO/MnO/NC). As confirmed by density functional theory calculations and experimental results, CoO/MnO heterostructures play a significant role in promoting Li+ ion and charge transfer, improving electronic conductivity, and reducing the adsorption energy. The accelerated electron and Li-ion diffusion kinetics, coupled with the porous nitrogen-doped carbon nanofiber structure, contribute to the exceptional electrochemical performance of the CoO/MnO/NC electrode. Specifically, the as-prepared CoO/MnO/NC exhibits a high reversible specific capacity of 936 mA h g-1 at 0.1 A g-1 after 200 cycles and an excellent high-rate capacity of 560 mA h g-1 at 5 A g-1, positioning it as a competitive anode material for lithium-ion batteries. This study underscores the critical role of electronic and Li-ion regulation facilitated by heterostructures, offering a promising pathway for designing transition metal oxide-based anode materials with high performances for lithium-ion batteries.

Bismuth-constructed high-speed channeled for Bi/Sb2SnO5@PCFs composite as high-rate and long-life anode for sodium-ion batteries

Bismuth-constructed high-speed channeled for Bi/Sb2SnO5@PCFs composite as high-rate and long-life anode for sodium-ion batteries

A facile route to unlock the high capacity of molecular organic cathode for aqueous zinc-ion battery

A facile route to unlock the high capacity of molecular organic cathode for aqueous zinc-ion battery

Double-enhanced core-shell Sb@Sb2O3 heterostructure encapsulated in porous carbon for long life sodium storage

Double-enhanced core-shell Sb@Sb2O3 heterostructure encapsulated in porous carbon for long life sodium storage

Enhancing the Lithium Storage Performance of the Nb2O5 Anode via Synergistic Engineering of Phase and Cu Doping.

Nb2O5 has been viewed as a promising anode material for lithium-ion batteries by virtue of its appropriate redox potential and high theoretical capacity. However, it suffers from poor electric conductivity and low ion diffusivity. Herein, we demonstrate the controllable fabrication of Cu-doped Nb2O5 with orthorhombic (T-Nb2O5) and monoclinic (H-Nb2O5) phases through annealing the solvothermally presynthesized Nb2O5 precursor under different temperatures in air, and the Cu doping amount can be readily controlled by the concentration of the precursor solution, whose effect on the lithium storage behaviors of the Cu-doped Nb2O5 is thoroughly investigated. H-Nb2O5 shows obvious redox peaks (Nb5+/Nb4+ and Nb4+/Nb3+) with much higher capacity and better cycling stability than those for the widely investigated T-Nb2O5. When introducing appropriate Cu doping, the optimized H-Cu0.1-Nb2O5 electrode shows greatly enhanced conductivity and lower diffusion barrier as revealed by the theoretical calculations and electrochemical characterizations, delivering a high reversible capacity of 203.6 mAh g-1 and a high capacity retention of 140.8 mAh g-1 after 5000 cycles at 1 A g-1, with a high initial Coulombic efficiency of 91% and a high rate capacity of 144.2 mAh g-1 at 4 A g-1. As a demonstration for full-cell application, the H-Cu0.1-Nb2O5||LiFePO4 cell displays good cycling performance, exhibiting a reversible capacity of 135 mAh g-1 after 200 cycles at 0.2 A g-1. More importantly, this work offers a new synthesis protocol of the monoclinic Nb2O5 phase with high capacity retention and improved reaction kinetics.

Lightweight Carbon-Metal-Based Fabric Anode for Lithium-Ion Batteries.

Lithium-ion battery electrodes are typically manufactured via slurry casting, which involves mixing active material particles, conductive carbon, and a polymeric binder in a solvent, followed by casting and drying the coating on current collectors (Al or Cu). These electrodes are functional but still limited in terms of pore network percolation, electronic connectivity, and mechanical stability, leading to poor electron/ion conductivities and mechanical integrity upon cycling, which result in battery degradation. To address this, we fabricate trichome-like carbon-iron fabrics via a combination of electrospinning and pyrolysis. Compared with slurry cast Fe2O3 and graphite-based electrodes, the carbon-iron fabric (CMF) electrode provides enhanced high-rate capacity (10C and above) and stability, for both half cell and full cell testing (the latter with a standard lithium nickel manganese oxide (LNMO) cathode). Further, the CMFs are free-standing and lightweight; therefore, future investigation may include scaling this as an anode material for pouch cells and 18,650 cylindrical batteries.

Synergistic Strain Suppressing and Interface Engineering in Na4MnV(PO4)3/C for Wide-Temperature and Long-Calendar-Life Sodium-Ion Storage.

A Na4MnV(PO4)3 (NMVP) cathode is regarded as a promising cathode candidate for sodium-ion batteries (SIBs). However, issues such as low electronic conductivity and partial cation dissolution contribute to high polarization and structure distortion. Herein, we engineered the local electron density and reaction kinetic properties of NMVP cathodes with varying oxygen vacancies by introducing varying amounts of Zr doping and carbon coating. The optimized sample exhibited a high-rate capacity of 71.8 mAh g-1 at 30 C (83.1% capacity retention after 1000 cycles) and excellent performance over a wide temperature range (84.1 mAh g-1 at 60 °C and 61.4 mAh g-1 at -30 °C). In situ X-ray diffraction technology confirmed a redox solid solution and a two-phase reaction mechanism, revealing minor changes in cell volume and slight strain variations after Zr doping, effectively suppressing the structural distortion. Theoretical calculations illustrated that Zr doping largely shrinks the band gap of NMVP, enriches local electron density, and slightly alters the local element distribution and bond lengths. Moreover, full-cells have shown high energy density (259.9 Wh kg-1) and outstanding cycling stability (200 cycles). The work provides fresh insights into the synergistic effect of strain suppressing and interface engineering in promoting the development of wide temperature range and long-calendar-life SIBs.

An in situ-formed LiI interface layer for garnet-based lithium metal batteries

An in situ-formed LiI interface layer for garnet-based lithium metal batteries

Enhanced metal-free photocatalyst performance by synergistic Coupling of internal magnetic field and piezoelectric field

Graphitic carbon nitride (g-C3N4) is a promising metal-free photocatalyst; however, its high carrier recombination rate and insufficient redox capacity limit its degradation effect on antibiotics. In order to overcome these shortcomings, the photocatalytic activity is improved by regulating the spin polarization state, constructing the internal electric field, and applying the external piezoelectric field. In this paper, the chlorine-doped and nitrogen-deficient porous carbon nitride composite carbon quantum dots (Nv-Cl/UPCN@CQD) has been synthesized successfully. The doping position of chlorine and spin polarization properties are verified by DFT calculation. The key intermediates *O2- and *OOH for the synthesis of reactive oxygen species were detected by in-situ infrared testing, which promotes the production of •O2- and H2O2. The degradation rate constant of Nv-Cl/UPCN@CQD for removal of tetracycline is 8.45 times higher than that of g-C3N4. The active oxygen production and degradation efficiency of piezoelectric photocatalysis under the synergistic effect of intense stirring and vis-light irradiation are much higher than those of photocatalysis and piezoelectric catalysis, and the conversion of H2O2 to •OH is promoted by piezoelectric field. This paper provides a reliable way to improve the performance of piezoelectric photocatalysts by adjusting their energy band, electronic structure and piezoelectric force.

In Situ Defect Engineering in Carbon by Atomic Self-Activation to Boost the Accessible Low-Voltage Insertion for Advanced Potassium-Ion Full-Cells.

Enhancing the low-potential capacity of anode materials is significant in boosting the operating voltage of full-cells and constructing high energy-density energy storage devices. Graphitic carbons exhibit outstanding low-potential potassium storage performance, but show a low K+ diffusion kinetics. Herein, in situ defect engineering in graphitic nanocarbon is achieved by an atomic self-activation strategy to boost the accessible low-voltage insertion. Graphitic carbon layers grow on nanoscale-nickel to form the graphitic nanosphere with short-range ordered microcrystalline due to nickel graphitization catalyst. Meanwhile, the widely distributed K+ in the precursor induces the activation of surrounding carbon atoms to in situ generate carbon vacancies as channels. The graphite microcrystals with defect channels realize reversible K+ intercalation at low-potential and accessible ion diffusion kinetics, contributing to high reversible capacity (209mAhg-1 at 0.05Ag-1 under 0.8V) and rate capacity (103.2mAhg-1 at 1Ag-1). The full-cell with Prussian blue cathode and graphitic nanocarbon anode maintains an obvious working platform at ca. 3.0V. This work provides a strategy for the in situ design of carbon anode materials and gives insights into the potassium storage mechanism at low-potential for high-performance full-cells.

Critical Role of Aromatic C(sp2)-H in Boosting Lithium-Ion Storage.

Exploring high-sloping-capacity carbons is of great significance in the development of high-power lithium-ion batteries/capacitors (LIBs/LICs). Herein, an ion-catalyzed self-template method is utilized to synthesize the hydrogen-rich carbon nanoribbon (HCNR), achieving high specific and rate capacity (1144.2/471.8 mAh g-1 at 0.1/2.5 A g-1). The Li+ storage mechanism of the HCNR is elucidated by in situ spectroscopic techniques. Intriguingly, the protonated aromatic sp2-hybridized carbon (C(sp2)-H) can provide additional active sites for Li+ uptake via reversible rehybridization to sp3-C, which is the origin of the high sloping capacity. The presence of this sloping feature suggests a highly capacitance-dominated storage process, characterized by rapid kinetics that facilitates superior rate performance. For practical usage, the HCNR-based LIC device can deliver high energy/power densities of 198.3 Wh kg-1/17.9 kW kg-1. This work offers mechanistic insights on the crucial role of aromatic C(sp2)-H in boosting Li+ storage and opens up new avenues to develop such sloping-type carbons for high-performance rechargeable batteries/capacitors.

Enabling Rapid and Stable Sodium Storage via a P2-Type Layered Cathode with High-Voltage Zero-Phase Transition Behavior.

Currently, a major target in the development of Na-ion batteries is the concurrent attainment of high-rate capacity and long cycling stability. Herein, an advanced Na-ion battery with high-rate capability and long cycle stability based on Li/Ti co-doped P2-type Na0.67Mn0.67Ni0.33O2, a host material with high-voltage zero-phase transition behavior and fast Na+ migration/conductivity during dynamic de-embedding process, is constructed. Experimental results and theoretical calculations reveal that the two-element doping strategy promotes a mutually reinforcing effect, which greatly facilitates the transfer capability of Na+. The cation Ti4+ doping is a dominant high voltage, significantly elevating the operation voltage to 4.4V. Meanwhile, doping Li+ shows the function in charge transfer, improving the rate performance and prolonging cycling lifespan. Consequently, the designed P2-Na0.75Mn0.54Ni0.27Li0.14Ti0.05O2 cathode material exhibits discharge capacities of 129, 104, and 85mAhg- 1 under high voltage of 4.4V at 1, 10, and 20C, respectively. More importantly, the full-cell delivers a high initial capacity of 198mAhg-1 at 0.1C (17.3mAg-1) and a capacity retention of 73% at 5C (865mAg-1) after 1000 cycles, which is seldom witnessed in previous reports, emphasizing their potential applications in advanced energy storage.

Electronegativity Matching of Asymmetrically Coordinated Single‐Atom Catalysts for High‐Performance Lithium–Sulfur Batteries

AbstractAsymmetrically coordinated single‐atom catalysts are attractive for the implementation of high‐performance lithium–sulfur (Li─S) batteries. However, the design principle of the asymmetric coordination that can efficiently promote bidirectional conversion of polysulfides has not been fully realized. Herein, a series of Co─N3X1 (X refers to F, O, Cl, S, or P) configurations are established, and theoretically unravel that the relative electronegativity value (REV) can be used as an index parameter for characterizing the catalytic activity. By virtue of enhanced chemical affinity with sulfur species and lowered Li2S decomposition, chlorine‐atom‐constructed asymmetric configurations with an optimal REV exhibit stronger catalytic effect to inhibit shuttling. Such a REV‐related catalytic effect is termed as REV effect. Following this principle, a novel single‐atom catalyst with dominated Co─N3Cl1 configuration is successfully synthesized through an inside‐out thermal reaction strategy and used as a modified layer on the cathode‐side separator. Interestingly, the assembled Li─S batteries exhibit quite high rate capacity (804.3 mAh g−1 at 5.0 C), durable cyclability (0.023% capacity decay per cycle), and competitive areal capacity (7.0 mAh cm−2 under 7.5 mg cm−2 sulfur loading and lean electrolyte). The guideline provided in this work gives impetus to the pursuit of highly efficient single‐atom catalysts for practical Li─S batteries.

Regulation of morphology and particle size of spinel LiMn2O4 induced by Fe-B co-doping for high-power lithium ion batteries

Regulation of morphology and particle size of spinel LiMn2O4 induced by Fe-B co-doping for high-power lithium ion batteries

Local built-in electric field of oxygen vacancy generated in fluorine-doped Nb2O5 structure modified by sulfur/fluorine co-doped carbon improves lithium storage performance

Local built-in electric field of oxygen vacancy generated in fluorine-doped Nb2O5 structure modified by sulfur/fluorine co-doped carbon improves lithium storage performance

Regulating local chemical environment in O3-type layered sodium oxides by dual-site Mg2+/B3+ substitution achieves durable and high-rate cathode

Regulating local chemical environment in O3-type layered sodium oxides by dual-site Mg2+/B3+ substitution achieves durable and high-rate cathode

Soft and flexible polyvinyl alcohol/pullulan aerogels with fast and high water absorption capacity for facial mask substrates

Facial mask substrates commonly used in skincare are often considered unhealthy and environmentally unfriendly due to their composition of premoistened nonwovens containing various preservatives. This study aims to address this issue by developing a preservative-free degradable aerogel made from polyvinyl alcohol (PVA)/pullulan (PUL) using a unidirectional freeze-drying method. The aerogels had ordered three-dimensional porous structures and exhibited desirable mechanical properties. They were soft and flexible in both dry and wet states, and their Young's moduli were comparable to that of human skin. The aerogels had high porosity, ranging from 93.0% to 95.1%, and exhibited a high water absorption rate and water absorption capacity (ranging from 7.5g/g to 10.1g/g). After 30min of water evaporation, the aerogels showed excellent moisture retention, ranging from 88% to 93%. Additionally, the PVA/PUL aerogel efficiently loaded and released active ingredients, such as rapidly releasing ascorbic acid (> 90% within 30min). These findings suggest that the PVA/PUL aerogel has potential as a material for facial mask substrates.

Hard carbon with embedded graphitic nanofibers for fast-charge sodium-ion batteries

Hard carbon with embedded graphitic nanofibers for fast-charge sodium-ion batteries

Laser Etching Post‐Processing to Create Low‐Tortuosity Structured Electrodes for Advanced Sodium‐Ion Batteries

Constructing low‐tortuosity structure is a facile and effective strategy to significantly improve the electrochemical performances of thick electrodes of batteries. In this study, the low‐tortuosity structured electrodes with an array grooved structure are fabricated using a method of laser etching post‐processing, promoting excellent electrochemical performance of sodium‐ion batteries (SIBs). The effects of laser post‐processing parameters including the etching shape, interval, and scan number on the structures and electrochemical performances of the prepared electrodes are investigated. Results show that the array grooved structures of the laser‐treated electrodes not only reduce the tortuosity to enhance the ion transfer efficiency, but also provide extra space to accommodate more electrolyte, which helps strengthen the electrochemical reaction kinetics of the electrodes. The proposed electrode with a parallelogram etching shape, an interval of 0.1 mm, and a scan number of 10 can produce a high rate capacity of 120.7 mAh g−1 at 500 mA g−1 and an outstanding cycle performance with a high capacity maintenance rate of 97.8% after 200 cycles. This study validates a new method to create low‐tortuosity electrodes for SIBs by optimizing the process parameter, which can be potentially extended to the fabrication of other advanced energy storage devices.