Rechargeable sodium ion batteries (SIBs) are surfacing as promising candidates for applications in large-scale energy-storage systems. Prussian blue (PB) and its analogues (PBAs) have been considered as potential cathodes because of their rigid open framework and low-cost synthesis. Nevertheless, PBAs suffer from inferior rate capability and poor cycling stability resulting from the low electronic conductivity and defi ciencies in the PBAs framework. Herein, to understand the vacancy-impacted sodium storage and Na-insertion reaction kinetics, we report on an in-situ synthesized PB@C composite as a high-performance SIB cathode. Perfectly shaped, nanosized PB cubes were grown directly on carbon chains, assuring fast charge transfer and Na-ion diffusion. The existence of [Fe(CN) 6 ] vacancies in the PB crystal is found to greatly degrade the electrochemical activity of the Fe LS (C) redox couple via fi rst-principles computation. Superior reaction kinetics are demonstrated for the redox reactions of the Fe HS (N) couple, which rely on the partial insertion of Na ions to enhance the electron conduction. The synergistic effects of the structure and morphology results in the PB@C composite achieving an unprecedented rate capability and outstanding cycling stability (77.5 mAh g −1 at 90 C, 90 mAh g − 1 after 2000 cycles at 20 C with 90% % capacity retention).

Lithium ion batteries have attained great success in commercialization owing to their high energy density. However, the relatively delaying discharge/ charge severely hinders their high power applications due to intrinsically diffusion-controlled lithium storage of the electrode. This study demonstrates an ever-increasing surface redox capacitive lithium storage originating from an unique microstructure evolution during cycling in a novel RGO-MnO-RGO sandwich nanostructure. Such surface pseudocapacitance is dynamically in equilibrium with diffusion-controlled lithium storage, thereby achieving an unprecedented rate capability (331.9 mAh g −1 at 40 A g −1 , 379 mAh g −1 after 4000 cycles at 15 A g −1 ) with outstanding cycle stability. The dynamic combination of surface and diffusion lithium storage of electrodes might open up possibilities for designing high-power lithium ion batteries. and high-rate lithium storage capability by tuning the surface pseudocapacitance.Herein, we successfully demonstrate ultrahigh-rate lithium storage in a novel RGO (reduced graphene oxide)-MnO-RGO sandwich nanostructure, in which dynamic equilibrium between surface pseudocapacitance and diffusion-controlled lithium storage is achieved after a novel cycle-induced microstructure evolution ( Figure 1 ). The top and bottom RGO layers provide fast pathway for charge transfer, constrain the aggregation of active materials, and suppress the stress across the whole electrode during lithiation/delithiation. More interestingly, the pulverized manganese oxide nanocrystals generated over cycling are confi ned and trapped on these RGO layers, forming hierarchical RGO-supported manganese oxide nanoclusters. Meanwhile, further oxidation of MnO to Mn 3 O 4 along with cycling, which contributes signifi cantly to the pseudocapacitance, is clearly demonstrated. All the cycle-induced features result in the steadily increased lithium pseudocapacitance with high-rate capability in the RGO-MnO-RGO sandwich nanostructure.

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Boosting power density is one of the primary challenges that current lithium ion batteries face. Alloying anodes that possess suitable potential windows stand at the forefront in pursuing ultrafast and highly reversible lithium storage to achieve high power/energy lithium ion batteries. Herein, ultrafast lithium storage in Sn-based nanocomposite anodes is demonstrated, which is boosted by pseudocapacitance benefitting from a high fraction of highly interconnected interfaces of Fe/Sn/Li O. By tailoring the voltage window in the range of 0.005-1.2 V for the alloying/dealloying reactions, such Sn-based nanocomposite anodes achieve simultaneous ultrahigh rate capability, superlong cycling performance, and close-to-100% Coulombic efficiency. The nanocomposite anode delivers a high reversible capacity (≈420 mAh g ) at 1 A g for more than 1200 cycles, corresponding to only 0.016% per cycle of capacity decay. A reversible capacity of 350 mAh g can be maintained at an ultrahigh current density of 80 A g , with 67.3% capacity retention relative to the capacity at 1 A g . This combination of pseudocapacitive lithium storage and spatially confined electrochemical reactions in Sn-based nanocomposite anode materials may pave the way for the development of high power/energy and long life lithium ion batteries.

Sweet osmanthus (Osmanthus fragrans Lour.) is among the top ten most well-known flowers in China and is recognized as both an aromatic plant and ornamental flower. Here, manual sectioning, scanning electron microscopy, and transmission electron microscopy of sweet osmanthus petals revealed that large amounts of lipids are present inside the petal cells and on the cell surfaces. However, no secretory structures were observed. Instead, the petal cells protrude slightly outward, and the surfaces of the cells are adorned with highly regular brush-shaped hairs. The surfaces of the ‘Yingui’ petals possessed mostly curled and more numerous hairs, whereas the ‘Dangui’ petals possessed fewer brush-shaped and more sparsely arranged hairs. In addition, many granular substances were attached to the brush-shaped hairs, and the granules were denser on the hairs of the ‘Yingui’ petals compared to the hairs on the ‘Dangui’ petals. Furthermore, 35 aromatic components in the ‘Yingui’ petals and 30 aromatic components in the ‘Dangui’ petals were detected via GC-MS. The main aromatic component of the ‘Yingui’ petals was β-ionone, whereas that of the ‘Dangui’ petals was linalool and its oxides. Transcriptome sequencing and qRT-PCR indicated that the high β-ionone content in the ‘Yingui’ petals was due to the overexpression of CCD1 and CCD4 and that the high linalool content in the ‘Dangui’ petals was due to the overexpression of MECS, HDR, IDI1, and LIS1, which function upstream of the linalool synthetic pathway. In particular, the expression levels of CCD4 and LIS1 were upregulated by 5.5- and 5.1-fold in the ‘Yingui’ and ‘Dangui’ petals, respectively. One transcription factor (ERF61) was cloned and named, and the expression pattern of ERF61 in sweet osmanthus petals was found to be generally consistent with that of CCD4. Tobacco transformation experiments, yeast one-hybrid experiments, and electrophoretic mobility shift assays indicated that ERF61 binds to the CCD4 promoter and stimulates CCD4 expression, thereby regulating the synthesis of β-ionone in sweet osmanthus petals.

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Aim Root turnover is an important process determining carbon and nutrient cycling in terrestrial ecosystems. It is an established fact that root turnover is jointly regulated by climatic, edaphic and biotic factors. However, the relative importance of these forces in determining the global patterns of root turnover time is far from clear. Location Global. Time period 1946–2017. Major taxa studied Grasslands. Methods We compiled a database of 141 sites with 433 observations on root turnover time and applied structural equation modelling (SEM) to investigate the relative contribution of climate, soil properties and vegetation type to the observed variations in root turnover time. Results Root turnover time was 3.1 years on average across the global grasslands and differed significantly among grassland types (tropical grassland and savanna, temperate grassland and meadow, alpine grassland and meadow, tundra and desert). It decreased with mean annual temperature, mean annual precipitation and Palmer drought severity index but increased with soil organic carbon content, total nitrogen content and carbon : nitrogen ratio. Soil bulk density and soil texture also significantly affected root turnover time, with clay content negatively correlating to root turnover time and explaining more variations than bulk density and sand content. The SEM showed that climatic factors had dominant effects on root turnover time when vegetation type was not considered. Vegetation type became the primary driver when it was included in the SEM. Main conclusions Our results indicate that the influences of climatic and edaphic factors on root turnover time are predominantly manifested through vegetation type. The critical role of precipitation as revealed for the first time in this study challenges our current understanding of climate impacts on root turnover time. The findings necessitate accurate representation of vegetation type in Earth system models to predict root function dynamics under global change.