Abstract Soft carbon has attracted tremendous attention as an anode in rocking‐chair batteries owing to its exceptional properties including low‐cost, tunable interlayer distance, and favorable electronic conductivity. However, it fails to exhibit decent performance for sodium‐ion storage owing to difficulties in the formation of sodium intercalation compounds. Here, microporous soft carbon nanosheets are developed via a microwave induced exfoliation strategy from a conventional soft carbon compound obtained by pyrolysis of 3,4,9,10‐perylene tetracarboxylic dianhydride. The micropores and defects at the edges synergistically leads to enhanced kinetics and extra sodium‐ion storage sites, which contribute to the capacity increase from 134 to 232 mAh g −1 and a superior rate capability of 103 mAh g −1 at 1000 mA g −1 for sodium‐ion storage. In addition, the capacitance‐dominated sodium‐ion storage mechanism is identified through the kinetics analysis. The in situ X‐ray diffraction analyses are used to reveal that sodium ions intercalate into graphitic layers for the first time. Furthermore, the as‐prepared nanosheets can also function as an outstanding anode for potassium‐ion storage (reversible capacity of 291 mAh g −1 ) and dual‐ion full cell (cell‐level capacity of 61 mAh g −1 and average working voltage of 4.2 V). These properties represent the potential of soft carbon for achieving high‐energy, high‐rate, and low‐cost energy storage systems.
Polycrystalline semi-hollow microrod soft carbon was tested as an anode for K-ion full batteries and it exhibits both high capacity and excellent cycling stability.
In article number 1602300, Bruce Dunn, Liqiang Mai, and co-workers present an overview of emerging novel, porous, one-dimensional nanostructures: from methodologies for rational and controllable synthesis to their successful application in different types of energy-storage devices, including lithium-ion batteries, sodium-ion batteries, lithium–sulfur batteries, lithium–oxygen batteries, and supercapacitors.
Branched nanostructures represent unique, 3D building blocks for the “bottom-up” paradigm of nanoscale science and technology. Here, we report a rational, multistep approach toward the general synthesis of 3D branched nanowire (NW) heterostructures. Single-crystalline semiconductor, including groups IV, III–V, and II–VI, and metal branches have been selectively grown on core or core/shell NW backbones, with the composition, morphology, and doping of core (core/shell) NWs and branch NWs well controlled during synthesis. Measurements made on the different composition branched NW structures demonstrate encoding of functional p-type/n-type diodes and light-emitting diodes (LEDs) as well as field effect transistors with device function localized at the branch/backbone NW junctions. In addition, multibranch/backbone NW structures were synthesized and used to demonstrate capability to create addressable nanoscale LED arrays, logic circuits, and biological sensors. Our work demonstrates a previously undescribed level of structural and functional complexity in NW materials, and more generally, highlights the potential of bottom-up synthesis to yield increasingly complex functional systems in the future.
Rechargeable aqueous zinc-ion batteries are highly desirable for grid-scale applications due to their low cost and high safety; however, the poor cycling stability hinders their widespread application. Herein, a highly durable zinc-ion battery system with a Na2V6O16·1.63H2O nanowire cathode and an aqueous Zn(CF3SO3)2 electrolyte has been developed. The Na2V6O16·1.63H2O nanowires deliver a high specific capacity of 352 mAh g-1 at 50 mA g-1 and exhibit a capacity retention of 90% over 6000 cycles at 5000 mA g-1, which represents the best cycling performance compared with all previous reports. In contrast, the NaV3O8 nanowires maintain only 17% of the initial capacity after 4000 cycles at 5000 mA g-1. A single-nanowire-based zinc-ion battery is assembled, which reveals the intrinsic Zn2+ storage mechanism at nanoscale. The remarkable electrochemical performance especially the long-term cycling stability makes Na2V6O16·1.63H2O a promising cathode for a low-cost and safe aqueous zinc-ion battery.
Bismuth-based materials have been recognized as promising catalysts for the electrocatalytic CO2 reduction reaction (ECO2 RR). However, they show poor selectivity due to competing hydrogen evolution reaction (HER). In this study, we have developed an edge defect modulation strategy for Bi by coordinating the edge defects of bismuth (Bi) with sulfur, to promote ECO2 RR selectivity and inhibit the competing HER. The prepared catalysts demonstrate excellent product selectivity, with a high HCOO- Faraday efficiency of ≈95 % and an HCOO- partial current of ≈250 mA cm-2 under alkaline electrolytes. Density function theory calculations reveal that sulfur tends to bind to the Bi edge defects, reducing the coordination-unsaturated Bi sites (*H adsorption sites), and regulating the charge states of neighboring Bi sites to improve *OCHO adsorption. This work deepens our understanding of ECO2 RR mechanism on bismuth-based catalysts, guiding for the design of advanced ECO2 RR catalysts.
Adv. Energy Mater. 2018, 8, 1803260 The x-axis of figure 6a was incorrectly labeled, the corrected figure 6a is shown below, The authors apologize for any inconvenience that this mistake may have caused.
Abstract The increasing demand for efficient, cost‐effective energy storage systems has spurred research into alternatives to lithium‐ion batteries. Among these alternatives, aluminum‐sulfur (Al‐S) batteries have become a promising option, demonstrating noteworthy advancements over the past decade. These batteries provide benefits such as high theoretical energy density, low cost, and improved safety. Nonetheless, certain fundamental electrochemical challenges, similar to those encountered by other sulfur‐based batteries, persist, including slow reaction kinetics, significant polysulfide shuttling, and uncontrollable dendrite growth on the anode. Herein, this review offers a comprehensive overview of recent advancements related to the critical challenges and optimization strategies for rechargeable Al‐S batteries. It begins by outlining the development history of Al‐S batteries and the challenges present in current systems. Next, efficient optimization strategies aimed at enhancing Al‐S batteries are summarized by focusing on optimizing each battery component, including the cathode, anode, electrolyte, and separator. Detailed examinations include structural features, electrochemical performance, structure‐property correlations, and enhancement mechanisms of key breakthroughs. Finally, the challenges and potential opportunities are explored for future research on rechargeable Al‐S batteries. This review aims to provide insightful guidance for the rational design of high‐performance Al‐S batteries and to accelerate their development for practical large‐scale energy storage applications.
High-energy-density nickel (Ni)–rich cathode materials are employed in commercial lithium (Li)–ion batteries for electric vehicles, but they suffer from severe structural degradation upon cycling as the mechanical fractures generated within the internal grains aggravate with an increment of the Ni content. Planar gliding and microcracking are seeds for fatal mechanical fracture in Ni-rich cathodes. However, the origin of planar gliding and microcracking remains largely unclear. Herein, we show that a ‘layer-by-layer delithiation’ mode is activated at high voltages during the charge process when the ‘lattice-collapse’ (the characteristic abrupt lattice contraction immediately after expansion at high voltage) occurs. The ‘layer-by-layer delithiation’ is evidenced by direct observation of the consecutive ‘lattice-collapse’ using in-situ scanning transmission electron microscopy (STEM). The collapsing of the lattice initiates in the expanded planes and consecutively extends to the whole crystal. The ‘layer-by-layer delithiation’ induces localized strain at lattice collapsing interface where the planar gliding and intragranular microcracks are generated to release this strain, and irreversible cracks will be induced when the defects occur at the same location repeatedly. Our study reveals that the ‘layer-by-layer delithiation’ at high voltages is the fundamental origin of the mechanical instability in Ni-rich cathodes and provides pathways to design a next generation of high-energy Ni-rich cathodes with high cyclability.
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