instance, lithium-ion hybrid capacitors (LIHCs) consisting of an activated carbon (AC) cathode and a prelithiated graphite anode have been successfully commercialized and widely applied in small portable electronics. [2a] Nevertheless, the limited reserves and high cost of Li resources likely hinder them from applying in large-scale energy storage devices. As a new class of hybrid capacitors, potassium-ion hybrid capacitors (PIHCs) show great potential as alternative to LIHCs due to the profusion and low cost of potassium resources. [3] In addition, the redox potential of the K + /K (−2.936 V vs standard hydrogen electrode) is quite close to that of Li + /Li (−3.040 V), indicating PIHCs can afford a considerably high working voltage and energy density. [4] Unfortunately, the relatively large radius of K + (1.38 Å) tends to behave sluggish redox reaction kinetics for most of potassium-ion batteries (PIBs) anodes.As compared to LIHCs, the research regarding PIHCs is still in its infant stage and thus calls for extensive exploration on newly favorable electrode materials, in the hope to enhance the kinetics of K + insertion/extraction so that it can match with the fast kinetics of capacitor-style cathodes. To date, various electrode materials, such as carbonaceous materials, [5] metal alloys, [6] oxides, [7] sulfides, [8] and MXene, [9] have been extensively studied as battery-type anodes. Among them, carbon-based material, thanks to the merits of abundant resources, low cost, and high conductivity, has been regarded as one of the most promising electrode materials for the practical application of PIHCs. [10] However, the implementation of carbon-based electrode material for high-performance PIBs requires high conductivity and a rather large interlayer spacing for facilitating insertion and extraction of bulky K + and improving the redox reaction Kinetics. Therefore, it still remains a grand challenge to address the major issues existed in carbon-based anodes, including limited reversible capacities, unsatisfactory cycling stability, and poor rate performance, which result from the large volume change (61% caused by KC 8 vs 10% by LiC 6 ). [5] Heteroatom-doped carbonbased materials have exhibited the enhanced electrochemical properties for potassium-ion storage due to the increased electric conductivity and more active sites for potassium-ion storage by generating extrinsic defects. [11] In comparison with nitrogen, sulfur has a relatively large size but small electronegativity, Potassium-ion hybrid capacitors (PIHCs) hold the advantages of high-energy density of batteries and high-power output of supercapacitors and thus present great promise for the next generation of electrochemical energy storage devices. One of the most crucial tasks for developing a highperformance PIHCs is to explore a favorable anode material with capability to balance the kinetics mismatch between battery-type anodes and capacitortype cathode. Herein, a reliable route for fabricating sulfur and nitrogen codoped 3D porous carbon nanosheets...

Hierarchical porous carbon nanofibers can efficiently eliminate kinetics and capacity mismatches between the anode and cathode of the potassium-ion hybrid capacitor.

Transition-metal dichalcogenides have emerged as promising anodes of sodium ion batteries (SIBs). Their practical SIB application calls for an easyto-handle synthetic technique capable of fabricating favorable properties with high conductivity and stable structure. Here, a solvothermal strategy is reported for bottom-up self-assembling of nanoflowers' building block, i.e., conductive interlayer-expanded 2D WS 2 nanosheets thanks to in situ interlayer modification by nitrogen-doped carbon matrix, into 3D hollow microflower bud-like hybrids (H-WS 2 @NC). The 3D nano/microhierarchical hollow structures are constructed by conductive interlayer-expanded WS 2 nanosheets' building blocks, providing abundant channels facilitating mass transport/ electrons transfer, robust protection layer to avoid the direct contact between WS 2 nanosheets and electrolyte, sufficient inner space for accommodating volume variation, and decreased ions diffusion energy barrier for accelerating electrochemical kinetics, as revealed by density functional theory calculations. As such, the 3D H-WS 2 @NC hybrids exhibit quite attractive sodium storage performance with high reversible capacity, superior rate capability, and impressively long cycling life. The 3D H-WS 2 @NC is further verified as anode of sodium-ion full cell pairing with Na 3 V 2 (PO4) 3 /rGO cathode, delivering a stable reversible capacity of 296 mAh g −1 at 0.5 A g −1 with high energy density of 128 Wh kg −1 total at a power density of 386 W kg −1 total .hierarchical hollow or porous architectures could effectively prevent the 2D subunits self-aggregation, shorten the Na + diffusion length, and alleviate the volume variation upon cycling, resulting in significantly improved cycling stability. [6] Moreover, the hollow structures would offer more accessible electroactive sites, which would promote reversible capacity. So far, most of the reported hollow structures involve impregnation of the desired materials or precursors on a structure desired template, followed by removal of the internal sacrificial template, [7] which tend to suffer from relatively high costs, tedious processes, as well as possible incompatibility between the internal template and external materials. Therefore, it is highly desirable albeit challenging to explore reliable and efficient strategies for fabrication of such hierarchical hollow architecture.Herein, we report a bottom-up template-free self-assembling solvothermal approach to fabricate 3D hierarchical hollow microflower bud hybrids constructed by nanoflowers building block of ultrathin WS 2 nanosheets embedded into nitrogendoped carbon framework (H-WS 2 @NC). Such distinctive nanomicrostructure synergistically combines the functionalities of few-layers (1-3 layers) and expanded interlayers distance (0.92 nm) of 2D ultrathin WS 2 nanosheets as well as nitrogendoped carbon incorporation a 3D hierarchical hollow porous construction. With these merits, the H-WS 2 @NC hybrids display extraordinary structural stability with high reversible capacity, outs...

This study investigated the stability of wine anthocyanins under simulated gastrointestinal pH and temperature conditions, and further studied the evolution of anthocyanin degradation products through simulated digestive conditions. The aim of this study was to investigate the relation between anthocyanins’ structure and their digestive stability. Results showed that a total of 22 anthocyanins were identified in wine and most of these anthocyanins remained stable under simulated gastric digestion process. However, a dramatic concentration decrease happened to these anthocyanins during simulated intestinal digestion. The stability of anthocyanins in digestive process appeared to be related to their structure. The methoxy group in the B-ring enhanced the stability of anthocyanins, whereas hydroxyl group resulted in a reduction of their stability. Acylation decreased the stability of malvidin 3-O-glucoside. Pyruvic acid conjugation enhanced the structural stability of pyranoanthocyanins, whereas acetaldehyde attachment weakened their stability. A commercial malvidin 3-O-glucoside standard was used to investigate anthocyanin degradation products under simulated digestion process, and syringic acid, protocatechuic acid and vanillic acid were confirmed to be the degradation products via anthocyanin chalcone conversion path. Gallic acid, protocatechuic acid, vanillic acid, syringic acid, and p-coumaric acid in wine experienced a significant concentration decrease during digestion process. However, wine model solution revealed that phenolic acids remained stable under gastrointestinal conditions, except gallic acid.

Vanadium nitride quantum dots within N-doped carbon hollow spheres exhibit excellent storage performance.

Sodium‐selenium (Na‐Se) battery has been emerging as one of the most prospective energy storage systems owing to their high volumetric energy density and cost effectiveness. Nevertheless, the shuttle effect of sodium polyselenide (NaPSe) and sluggish electrochemical reaction kinetics present the main bottlenecks for its practical implementation. Herein, a new Se host of 3D nitrogen‐doped hierarchical multicavity carbon nanospheres (3D NHMCs) is designed and synthesized via a facile self‐sacrifice templating strategy. The 3D NHMCs are verified to hold a favorable structure of a hollow macropore core and numerous micro/mesopores hollow shell for hosting Se, which can not only maximize Se utilization and alleviate the volumetric expansion but also promote the electrical/ionic conductivity and electrolyte infiltration. Moreover, the abundant self‐functionalized surfaces as an efficient NaPSe scavenger via robust physical‐chemical dual blocking effects demonstrate high‐efficiency in situ anchoring‐diffusion‐conversion of NaPSe, rendering rapid reaction kinetics and remarkable suppressive shuttle effect, as evidenced by systematic experimental analysis and density functional theory calculations. As a result, the high‐Se‐loading 3D NHMCs/Se cathode exhibits an ultrahigh volumetric capacity (863 mAh cm−3) and rate capability (377 mAh g−1 at 20 C) and unexceptionable stability over 2000 cycles at 2 C.

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Sodium‐based dual‐ion batteries (SDIBs) have been envisaged as one of the promising rechargeable energy storage devices by virtue of the low cost and considerably high energy density. But the exploration of high‐performance anode materials yet remain a grand challenge. Herein, an elaborate design is reported to fabricate nanohybrids of N‐doped carbon film modifying MoSSe nanosheets supported on hollow cubic N‐doped carbon (MoSSeNSs@NC/hC‐NC), which features abundant anionic defects, few‐layered MoSSe with expanded interlayer spacing, good conductivity, and hollow structure. These favorable properties and structure are greatly conducive for Na+ storage, as evidenced by displaying desirable electrochemical properties of high capacity, good rate capability, and excellent stability. The impressive capability for Na+ storage in the MoSSeNSs@NC/hC‐NC motivates to set up a full SDIBs device by coupling with EG cathode, which show a discharge capacity of 185 mA h g–1 at 1 A g–1 with the capacity retention of almost 100% over 2000 cycles.