Lithium–sulfur batteries (LSBs) are considered to be one of the most promising alternatives to the current lithium‐ion batteries (LIBs) to meet the increasing demand for energy storage owing to their ...high energy density, natural abundance, low cost, and environmental friendliness. Despite great success, LSBs still suffer from several problems, including undermined capacity arising from low utilization of sulfur, unsatisfactory rate performance and poor cycling life owing to the shuttle effect of polysulfides, and poor electrical conductivity of sulfur. Under such circumstances, the design/fabrication of porous carbon–sulfur composite cathodes is regarded as an effective solution to overcome the above problems. In this review, different synthetic methods of porous carbon hosts and their corresponding integration into carbon–sulfur cathodes are summarized. The pore formation mechanism of porous carbon hosts is also addressed. The pore size effect on electrochemical performance is highlighted and compared. The enhanced mechanism of the porous carbon host on the sulfur cathode is systematically reviewed and revealed. Finally, the combination of porous carbon hosts and high‐profile solid‐state electrolytes is demonstrated, and the challenges to realize large‐scale commercial application of porous carbon–sulfur cathodes is discussed and future trends are proposed.
Carbon and sulfur: Despite great success, lithium–sulfur batteries (LSBs) still suffer from several problems. The design/fabrication of porous carbon–sulfur composite cathodes is regarded as an effective solution to overcome problems such as poor capacity arising from low utilization of sulfur, unsatisfactory rate performance and poor cycling life owing to the shuttle effect of polysulfides, and poor electrical conductivity of sulfur. In this review, different synthetic methods for porous carbon hosts and their corresponding integration into carbon–sulfur cathodes are thus summarized.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
An elastic and safe electrolyte is demanded for flexible batteries. Herein, a stretchable solid electrolyte comprised of crosslinked elastic polymer matrix, poly(vinylidene ...fluoride‐hexafluoropropylene) (PVDF‐HFP), and flameproof triethyl phosphate (TEP) is fabricated, which exhibits ultrahigh elongation of 450%, nonflammability and ionic conductivity above 1 mS cm−1. In addition, in order to improve the interface compatibility between the electrolyte and Li anode and stabilize the solid‐electrolyte interphase (SEI), a protecting layer containing poly(ethylene oxide) (PEO) is designed to effectively prevent the anode from reacting with TEP and optimize the chemical composition in SEI, leading to a tougher and more stable SEI on the anode. The LiFePO4/Li cells employing this double‐layer electrolyte exhibit an 85.0% capacity retention after 300 cycles at 1 C. Moreover, a flexible battery based on this solid electrolyte is fabricated, which can work in stretched, folded, and twisted conditions. This design of a stretchable double‐layer solid electrolyte provides a new concept for safe and flexible solid‐state batteries.
A stretchable polymer electrolyte is fabricated based on resilient copolymer and poly(vinylidene fluoride‐hexafluoropropylene) (PVDF‐HFP) with ultrahigh elasticity, nonflammability, and good ionic conductivity. A protective layer containing poly(ethylene oxide) (PEO) is designed to protect the electrolyte against the anode and stabilize the solid‐electrolyte interphase (SEI) during cycling. A flexible solid‐state battery is prepared using this double‐layer electrolyte, which can light a light emitting diode (LED) bulb under different deformed conditions.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Improving the utilization efficiency of active materials and suppressing the dissolution of lithium polysulfides into the electrolyte are very critical for development of high-performance ...lithium-sulfur batteries. Herein, a novel strategy is proposed to construct a three-dimensional (3D) N-doped carbon nanotubes (CNTs) networks to support lithium polysulfides (3D-NCNT-Li2S6) as a binder-free cathode for high-performance lithium-sulfur batteries. The 3D N-doped CNTs networks not only provide a conductive porous 3D architecture for facilitating fast ion and electron transport but also create void spaces and porous channels for accommodating active sulfur. In addition, lithium polysulfides can be effectively confined among the networks through the chemical bond between Li and N. Owing to the synergetic effect of the physical and chemical confinement for the polysulfides dissolution, the 3D-NCNT-Li2S6 cathodes exhibit enhanced charge capacity and cyclic stability with lower polarization and faster redox reaction kinetics. With an initial discharge capacity of 924.8 mAh g−1 at 1 C, the discharge capacity can still maintain 525.1 mAh g−1 after 200 cycles, which is better than that of its counterparts.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Pectinase is widely used in numerous industrial fields, including the food, wine, and paper industries. In this work, seven bacteria were isolated from orange peel and their pectinase production ...activity was assayed. One bacterium (OR-B2) identified as a
Bacillus
sp. showed the highest enzyme activity towards others. A gene encoding a pectate lyase designed as PelB-B2 in this work was amplified and heterogeneous expressed in
E.
coli
. PelB-B2 was defined as a member of the PelB pectate lyase family after phylogenic tree analysis. 3D model of PelB-B2 was constructed by SWISS-MODEL and PelB-B2 showed conserved para
-β
structure. After inducing culture and purified by Ni-affinity chromatography, the properties of the purified PelB-B2 were assayed. Optimal pH and temperature for PelB-B2 was pH 8.0 and 50 °C, respectively. PelB-B2 showed excellent pH stability and thermostability. It was stable within pH range 3.0–11.0 and retained more than 51% activity after incubation at 40 °C, 50 °C, or 60 °C for 1 h. Furthermore, we determined that PelB-B2 was a Ca
2+
-dependent pectinase and the pectin extracted from citrus was the benefit substrate for PelB-B2. The
K
m
and
V
max
of PelB-B2 were 1.64 g/L and 232.56 mol/(L min), respectively. The OR-B2 can be a new resource for pectinase production and the PelB-B2 has potential for industrial application.
Graphic abstract
7 bacteria were isolated from orange peel, namely OR-B1 to OR-B7 and their pectinase activities were assayed. One pectate lyase belongs to PelB family was cloned from OR-B2 and heterogeneous expressed in E. coli. Purified PelB-B2 was further studied with its properties. Effects of pH, temperature, chemicals, substrate on the enzyme activity were assayed and the enzyme kinetic was also measured.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Sodium manganese hexacyanoferrate (NaMnHCF) has emerged as a research hotspot among Prussian blue analogs for sodium-ion battery cathode materials due to its advantages of high voltage, high specific ...capacity, and abundant raw materials. However, its practical application is limited by its poor electronic conductivity. In this study, we aim to solve this problem through the in situ growth of NaMnHCF on carbon nanotubes (CNTs) using a simple coprecipitation method. The results show that the overall electronic conductivity of NaMnHCF is significantly improved after the introduction of CNTs. The NaMnHCF@10%CNT sample presents a specific capacity of 90 mA h g
, even at a current density of 20 C (2400 mA g
). The study shows that the optimized composite exhibits a superior electrochemical performance at different mass loadings (from low to high), which is attributed to the enhanced electron transport and shortened electron pathway. Surprisingly, the cycling performance of the composites was also improved, resulting from decreased polarization and the subsequent reduction in the side reactions at the cathode/electrolyte interface. Furthermore, we revealed the evolution of potential plateau roots from the extraction of crystal water during the charge-discharge process of NaMnHCF based on the experimental results. This study is instructive not only for the practical application of NaMnHCF materials but also for advancing our scientific understanding of the behavior of crystal water during the charge-discharge process.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The authors regret that Fig. 5(d) in page 1625 of the original paper needs to be corrected. The rate capability of C-MoSe
2
electrode was unfortunately mistaken. The correct Fig. 5(d) is shown below. ...The corresponding figure caption and conclusions are not affected and thus not to be changed. The authors would like to apologise for any inconvenience caused.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Microbial pectinases are important sources due to the ease of production and unique physicochemical properties. Here, DY2, a strain of
Bacillus licheniformis
, was identified from 14 strains of ...bacteria as a pectinase-producing bacterium with good application potential. Optimized carbon sources of submerged fermentation led to the identification of glucose as an ideal carbon source for activity and production of P-DY2, the pectinase produced by DY2. GC-MS based metabolomics was used to explore metabolic mechanisms mediated by glucose, showing the frustrated TCA cycle is necessary to elevate the activity and production of P-DY2. Decreased activity of α-ketoglutaric dehydrogenase and succinate dehydrogenase of DY2 in glucose-treated samples supports the conclusion that P-DY2 production is the TCA cycle-independent. These results reveal a metabolic mechanism of high-activity pectinase mediated by exogenous glucose. These findings highlight the way to understand metabolic mechanisms and promote pectinase yield through metabolomics approach and metabolic modulation, respectively.
Developing high-quality solid-state electrolytes is important for producing next-generation safe and stable solid-state lithium-ion batteries. Herein, a three-dimensional highly porous polymer ...electrolyte based on poly (vinylidenefluoride-hexafluoropropylene) (PVDF-HFP) with Li
6.4
La
3
Zr
1.4
Ta
0.6
O
12
(LLZTO) nanoparticle fillers (PVDF-HFP-LLZTO) is prepared using the electrospinning technique. The PVDF-HFP-LLZTO gel polymer electrolyte possesses a high ionic conductivity of 9.44 × 10
–4
S cm
−1
and a Li-ion transference number of 0.66, which can be ascribed that the 3D hierarchical nanostructure with abundant porosity promotes the liquid electrolyte uptake and wetting, and LLZTO nanoparticles fillers decrease the crystallinity of PVDF-HFP. Thus, the solid-state lithium battery with LiFePO
4
cathode, PVDF-HFP-LLZTO electrolyte, and Li metal anode exhibits enhanced electrochemical performance with improved cycling stability.
The small GTPase Cdc42 acts as a molecular switch essential for cell cycles and polar growth in model yeast, but has not been explored in
, an insect-pathogenic fungus serving as a main source of ...fungal formulations against arthropod pests. Here, we show the indispensability of Cdc42 for fungal insecticidal activity. Deletion of
in
resulted in a great loss of virulence to
, a model insect, via normal cuticle infection as well as defects in conidial germination, radial growth, aerial conidiation, and conidial tolerance to heat and UVB irradiation. The deleted mutant's hyphae formed fewer or more septa and produced unicellular blastospores with disturbed cell cycles under submerged-culture conditions. Transcriptomic analysis revealed differential expression of 746 genes and dysregulation of pyruvate metabolism and related pathways, which were validated by marked changes in intracellular pyruvate content, ATP content, related enzyme activities, and in extracellular beauvericin content and Pr1 protease activity vital for fungal virulence. These findings uncover a novel role for Cdc42 in the pathways of pyruvate metabolism and the pyruvate-involved tricarboxylic acid cycle (TCA cycle) and a linkage of the novel role with its indispensability for the biological control potential of
against arthropod pests.
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