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Background: CD4 + T helper (Th)22 cells play a regulatory role in autoimmune diseases such as type 1 diabetes mellitus. The Th22-related cytokine interleukin (IL)-22, the expression of which is increased in diabetes mellitus (DM), can act as a neurotrophic factor to protect neurons from apoptosis. Paradoxically, neuronal apoptosis and learning and memory decline occur in DM. In this study, we investigated the relationship between IL-22 and its receptors IL-22Rα1 and IL-22 binding protein (IL-22BP, a soluble inhibitor of IL-22) in diabetic encephalopathy (DE) and the effects of IL-22 on hippocampal neurons, learning and memory. Methods: A C57BL/6 mouse model of diabetes was constructed by intraperitoneal injection of streptozotocin. The mice were randomly divided into 4 groups: the control group, diabetes group, diabetes + recombinantIL-22 (rIL-22) group and diabetes + IL-22BP group. The Morris water maze test was used to evaluate learning and memory, the expression of IL-22 was measured by ELISA, and Evans Blue staining was used to evaluate blood–brain barrier permeability. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to measure the mRNA expression of IL-22 and IL-22Rα1 in the hippocampus. The morphology and number of hippocampal neurons were assessed by Nissl staining, and TUNEL staining was used to detect hippocampal neuronal apoptosis. Immunofluorescence was used to analyze IL-22Rα1 expression and localization in hippocampus, and Western blotting was used to evaluate the expression of IL-22, IL-22Rα1, IL-22BP, and the apoptosis related proteins Caspase-3 and C-caspase-3. Results: Compared with those in the control group, mice in the diabetes group showed cognitive decline; apoptosis of hippocampal neurons; increased expression of hippocampal Caspase-3, C-Caspase-3, IL-22, IL-22Rα1, and IL-22BP; and a decreased IL-22/IL-22BP ratio. Learning and memory were improved, neuronal apoptosis was attenuated, IL-22Rα1 expression and the IL-22/IL-22BP ratio were increased, and caspase-3 and C-caspase-3 expression was decreased in the rIL-22-treated group compared with the diabetes group. IL-22BP treatment aggravated diabetic cognitive dysfunction and pathological alterations in the hippocampus, decreased the IL-22/IL-22BP ratio, and increased the expression of caspase-3 and C-caspase-3 in mice with diabetes. Conclusion: A decrease in the IL-22/IL-22BP ratio plays an important role in diabetic cognitive dysfunction, and rIL-22 can effectively alleviate DE. Herein, we shed light on the interaction between IL-22 and IL-22BP as therapeutic targets for DM. [ABSTRACT FROM AUTHOR]

Long-term hypoxia can induce oxidative stress and apoptosis in hippocampal neurons that can lead to brain injury diseases. Astragaloside IV (AS-IV) is widely used in the antiapoptotic therapy of brain injury diseases. However, its mechanism of action is still not fully understood. In this study, we investigated the effect of AS-IV on hypoxia-induced oxidative stress and apoptosis in hippocampal neurons and explored its possible mechanism. In vivo, mice were placed in a hypoxic circulatory device containing 10% O2 and gavaged with AS-IV (60 and 120 mg/kg/d) for 4 weeks. In vitro, mouse hippocampal neuronal cells (HT22) were treated with hypoxia (1% O2) for 24 hours in the presence or absence of AS-IV, MDL-28170 (calpain-1 inhibitor), or YC-1 (HIF-1α inhibitor). The protective effect of AS-IV on brain injury was further explored by examining calpain-1 knockout mice. The results showed that hypoxia induced damage to hippocampal neurons, impaired spatial learning and memory abilities, and increased oxidative stress and apoptosis. Treatment with AS-IV or calpain-1 knockout improved the damage to hippocampal neurons and spatial learning and memory, attenuated oxidative stress and inhibited cell apoptosis. These changes were verified in HT22 cells. Overexpression of calpain-1 abolished the improvement of AS-IV on apoptosis and oxidative stress. In addition, the effects of AS-IV were accompanied by decreased calpain-1 and HIF-1α expression, and YC-1 showed a similar effect as AS-IV on calpain-1 and caspase-3 expression. In conclusion, this study demonstrates that AS-IV can downregulate the calpain-1/HIF-1α/caspase-3 pathway and inhibit oxidative stress and apoptosis of hippocampal neurons induced by hypoxia, which provides new ideas for studying the antiapoptotic activity of AS-IV. [ABSTRACT FROM AUTHOR]

[Display omitted] • The nanodrug delivery systems are able to reach gliomas in situ through the blood–brain barrier. • The nanodrug delivery systems have slow-release behavior. • The nanodrug delivery systems have redox reactivity and pH sensitive release characteristics. Brain glioma is a highly comorbid tumor with high mortality. In this study, plasma complex component-functionalized manganese-doped mesoporous silica nanoparticles (PMMSN) were prepared and loaded with paclitaxel (PTX) by adsorption for brain glioma treatment. The nanodrug delivery system crossed the blood–brain barrier (BBB) and exhibited redox responsiveness and pH-sensitive release characteristics. In vivo imaging revealed the ability of the preparation to cross the BBB, and oxidative stress studies revealed the redox properties of the carrier material. The drug release data indicated that the amount of drug released from the drug-loaded samples (PMMSN-PTX) in medium at pH 5.0 was 84.1 ± 1.62 % after 10 h, whereas it was 53.7 ± 1.53 % in pH 7.4 medium after 24 h. These findings demonstrated that the drug was pH sensitive and released slowly. In vitro cell-based assays, including cellular uptake, flow cytometry, western blotting, and immunofluorescence staining, showed that PMMSN-PTX facilitated drug delivery across the BBB and promoted tumor cell apoptosis. These in vivo antitumor effects further demonstrated that it significantly inhibited tumor cell proliferation. We believe that PMMSN-PTX is a promising bionic nanosystem agent that could be used as a new agent for treating glioma. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the role of salidroside (SAL) in the cellular communication between Müller cells and retinal ganglion cells in diabetic mice. The diabetes mellitus (DM) animal models were established by the intraperitoneal injection of streptozotocin and treatment with SAL via gavage or by the injection of IL-22BP into the vitreous cavity. Immunohistochemistry was used to measure the expression of the glial fibrillary acidic protein in Müller cells. The expression of IL-22 and IL-22Rα1 in retinal tissues was assessed by immunofluorescence. Western blotting was used to measure the expression of inflammatory and apoptosis-related proteins. Hematoxylin–eosin staining, TUNEL staining, and flow cytometry were used to analyze the apoptosis of retinal ganglion cells. The effect of cellular interactions was explored by Transwell assays. Western blotting showed that glial fibrillary acidic protein, IL-22 protein expression was significantly upregulated in the DM animal models compared with the control mice. Immunofluorescence showed that IL-22 was highly expressed in Müller cells and IL-22Rα1 was expressed in ganglion cells in the retina of DM mice. Hematoxylin–eosin and TUNEL staining results showed an increase in the number of ganglion cells apoptotic in DM. However, SAL reversed these phenomena. Meanwhile, after coculture with Müller cells, Western blotting suggested that ganglion cells secreted p-STAT3, and c-caspase3 protein expression was increased. More interestingly, the treatment of IL-22BP and SAL inhibited the expression of the p-STAT3 and c-caspase3 proteins. Flow cytometry indicates that compared with the control group, the apoptosis rate of ganglion cells was increased in the high glucose group, while the apoptosis rate of cells in the recombinant IL-22 protein group was significantly increased, while the SAL inhibited ganglion cells apoptosis. SAL inhibits the apoptosis of retinal ganglion cells via the IL-22/STAT3 pathway in Müller cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • β-1, 3-galactosyltransferase 2 (B3galt2) contributes to diabetic encephalopathy. • F3/contactin is involved in B3galt2-mediated hippocampus neuron apoptosis. • Diabetic cognitive dysfunction can be alleviated by salidroside. • B3galt2/F3/Contactin pathway plays a vital role in diabetic cognitive dysfunction. Diabetes is frequently accompanied by cognitive impairment with insidious onset, and progressive cognitive and behavioral changes. β-1, 3-galactosyltransferase 2 (B3galt2) contributes to glycosylation, showing a clue for neuronal apoptosis, proliferation and differentiation. However, the role of B3galt2 in diabetic cognitive dysfunction (DCD) has not been investigated. In the present study, we aimed to explore the role of B3galt2 in DCD. Additionally, the potential therapeutic effects of salidroside on DCD was also explored. Diabetic C57BL/6J mice showed cognitive dysfunction together with down-regulated B3galt2. Overexpression of B3galt2 reversed the cognitive decline of diabetic C57BL/6J. Moreover, cognitive impairment was aggravated in B3galt2+/− diabetic mice compared with C57BL/6J diabetic mice. Immunohistochemistry fluorescence indicated that B3galt2 and F3/Contactin were co-localized in the hippocampal regions. Importantly, the expression of F3/Contactin can be regulated by the manipulation of B3galt2, overexpression of which assuaged hippocampal neuronal damage, protected the synapsin, and reduced neuronal apoptosis in diabetic mice. Interestingly, SAL alleviated DCD and reversed the expression of B3galt2 in diabetic C57BL/6J mice. These findings indicate that inhibition of B3galt2/F3/Contactin pathway contributes to DCD, and participates in SAL reversed DCD. [ABSTRACT FROM AUTHOR]

T helper 22 (Th22) cells have been implicated in diabetic retinopathy (DR), but it remains unclear whether Th22 cells involve in the pathogenesis of DR. To investigate the role of Th22 cells in DR mice, the animal models were established by intraperitoneal injection of STZ and confirmed by fundus fluorescein angiography and retinal haematoxylin–eosin staining. IL-22BP was administered by intravitreal injection. IL-22 level was measured by ELISA in vivo and in vitro. The expression of IL-22Rα1 in the retina was assessed by immunofluorescence. We assessed GFAP, VEGF, ICAM-1, inflammatory-associated factors and the integrity of blood–retinal barrier in control, DR, IL-22BP, and sham group. Müller cells were co-cultured with Th22 cells, and the expression of the above proteins was measured by immunoblotting. Plasmid transfection technique was used to silence Act1 gene in Müller cells. Results in vivo and in vitro indicated that Th22 cells infiltrated into the DR retinal and IL-22Rα1 expressed in Müller cells. Th22 cells promoted Müller cells activation and inflammatory factor secretion by secreting IL-22 compared with high-glucose stimulation alone. In addition, IL-22BP ameliorated the pathological alterations of the retina in DR. Inhibition of the inflammatory signalling cascade through Act1 knockdown alleviated DR-like pathology. All in all, the results suggested that Th22 cells infiltrated into the retina and secreted IL-22 in DR, and then IL-22 binding with IL-22Rα1 activated the Act1/TRAF6 signal pathway, and promoted the inflammatory of Müller cells and involved the pathogenesis of DR. [ABSTRACT FROM AUTHOR]

In this study, a spinel binary transition metal sulphide Co 1.5 Ni 1.5 S 4 dendrite/quasi-spherical nanocomposite with high electronic conductivity and a suitable porous structure was synthesized via a facile hydrothermal process. The morphology and structure of the Co 1.5 Ni 1.5 S 4 nanocomposite were easily manipulated by tuning the hydrothermal reaction time. To the best of our knowledge, due to its good electronic conductivity and suitable structure for the electrochemical redox reaction, the Co 1.5 Ni 1.5 S 4 electrode exhibited the highest areal specific capacitance of 41.0 F cm −2 . The electrochemical impedance spectroscopy (EIS) results demonstrate that Co 1.5 Ni 1.5 S 4 possesses a higher electronic conductivity and faster charge transfer than single-component sulphides (CoS and NiS) or cobalt-nickel hydroxides and oxides. These characteristics contribute to the high specific capacitance of the Co 1.5 Ni 1.5 S 4 electrode even at high material loading, corresponding to an ultrahigh areal specific capacitance. An asymmetric supercapacitor, which was assembled with Co 1.5 Ni 1.5 S 4 as the positive electrode active material and HNO 3 -treated activated carbon as the negative electrode active material, exhibited a superior energy density of 32.4 Wh kg −1 at a power density of 103.4 W kg −1 and 25.0 Wh kg −1 at a high power density of 5.5 kW kg −1 . [ABSTRACT FROM AUTHOR]

Monodispersed hollow spindle-like nanosphere (HS-NS) and tetrapod nanorod (TP-NR) MnS nanocrystals are obtained via a facile template-free hydrothermal process. The MnS nanocrystals are used as supercapacitor materials and they exhibit high performances. The TP-NR nanocrystals show a higher specific capacitance of 704.5 F g−1 compared to the HS-NS nanocrystals, and both show higher values compared to manganese oxide. [ABSTRACT FROM AUTHOR]

In this work, various nickel cobalt double hydroxide nanoflowers with different Ni/Co ratios (denoted as Ni x Co (1−x) (OH) 2 ), assembled by filmy nanoflakes, are prepared via a facile template-free hydrothermal process. The sizes of these nanoflowers are easily tuned by the Ni/Co ratio in the precursors. The formation mechanism of flower-like nickel cobalt hydroxide, based on the synergistic effect of ammonia complexation, Ni/Co ratios, precipitators and solvents in the template-free hydrothermal system, is demonstrated in detail. As the battery materials, the as prepared flower-like nickel cobalt double hydroxides exhibit excellent specific capacities and high rate performance. Ni 0.28 Co 0.72 (OH) 2 displays the highest capacity of 206.7 mA h g −1 at 1 mV s −1 and 174.3 mA h g −1 at 1 A g −1 , respectively. The capacity retention of Ni 0.28 Co 0.72 (OH) 2 is 59.1% (from 206.7 to 122.2 mA h g −1 ) at the potential scan rate from 1 to 25 mV s −1 . Due to the high rate performance corresponding to high power energy, Ni 0.28 Co 0.72 (OH) 2 is used as positive material to assemble the hybrid device (asymmetric supercapacitor) with activated carbon as negative material. The as-prepared asymmetric supercapacitor exhibits 19.4 Wh kg −1 at 80.5 W kg −1 , and even 20.6 Wh kg −1 at 3.93 kW kg −1 . [ABSTRACT FROM AUTHOR]

Three commercial carbon materials for supercapacitor were investigated by physicochemical characterization, electrochemical measurements and surface treatment to explore the effects of specific surface area, electrolyte and surface functional groups on the specific capacitance, charge storage mode and high rate performance of carbon materials. Results indicate that the specific surface area of carbon material plays dominate role in the specific capacitance. The electrolytes have remarkable effects on the specific capacitance and high rate performance. Investigation of HNO treated Vulcan XC-72 carbon material reveals that the treatment can increase the specific surface area and surface functional groups, which observably improve the specific capacitance of the XC-72 carbon material. The surface functional groups contribute to the pseudo-capacitance of the carbon material. [ABSTRACT FROM AUTHOR]

Abstract: A facile hydrothermal process with hexadecyltrimethyl ammonium bromide (CTAB) as the soft template is proposed to tune the morphology and size of cobalt hydroxide (Co(OH)2). Monodisperse β-phase Co(OH)2 nanowires with uniform size are obtained by controlling the CTAB content and the reaction time. Due to the uniform well-defined morphology and stable structure, the Co(OH)2 nanowires material exhibits high capacitive performance and long cycle life. The specific capacitance of the Co(OH)2 nanowires electrode is 358 F g−1 at 0.5 A g−1, and even 325 F g−1 at 10 A g−1. The specific capacitance retention is 86.3% after 5000 charge–discharge cycles at 2 A g−1. Moreover, the asymmetric supercapacitor is assembled with Co(OH)2 nanowires and nitrite acid treated activated carbon (NTAC), which shows an energy density of 13.6 Wh kg−1 at the power density of 153 W kg−1 under a high voltage of 1.6 V, and 13.1 Wh kg−1 even at the power density of 1.88 kW kg−1. [Copyright &y& Elsevier]

Highlights: [•] Flower-like nickel hydroxide was synthesized by a facile hydrothermal process. [•] The as-prepared nickel hydroxide exhibits high specific capacitance. [•] The as-prepared nickel hydroxide exhibits excellent high rate performance. [Copyright &y& Elsevier]

Abstract: Carbon supported polyhedral Pd–Pt nanocrystallines (Pd–Pt/C) are synthesized using a facile surfactant-free process. The morphology of nanocrystallines is tailored by ammonia complexation and Pd/Pt ratios of the metallic precursors. The as-prepared Pd–Pt/C catalysts with low Pt content exhibit oxygen reduction reaction (ORR) activity comparable to that of the commercial Pt/C catalyst, while having much higher methanol tolerance. Compared with the spherical Pd6Pt/C catalyst, the polyhedral Pd6Pt/C catalyst shows 1.56-fold higher mass specific activity for ORR, while its electrochemical surface area (ECSA) is only half of the former. The superior ORR activity may be attributed to the more exposed regular (111) planes, the higher ratio of metallic form and the surface enrichment of Pt atoms. [Copyright &y& Elsevier]

Abstract: Amorphous carbon nanoparticles (a-CNPs) on a graphene nanosheet (GNS) film, deposited on a silicon substrate, were synthesized using simultaneous electrodeposition from a methanol suspension of polydiallyldimethylammonium chloride-modified GNSs. The a-CNPs are homogeneously deposited on the surfaces of the GNSs, forming a dense electrically conductive a-CNP/GNS composite film with good adhesion to the substrate. Such simple and low-cost simultaneous electrodeposition technique makes the a-CNP/GNS composite film attractive for various applications, such as electrodes, capacitors, batteries and field emitters. [Copyright &y& Elsevier]

Nickel compounds, especially Ni(HCO3)2 (here denoted as NiC), have been widely combined with other materials to obtain composites with a more favorable structure that exhibit excellent electrochemical performance as supercapacitors. Unfortunately, the complicated processes for preparing such composites directly restrict their further application. Herein, we prepared a NiC/nickel tetraphosphate (Ni(P4O11)) nanocomposite (NiC/NiP) by introducing ions into the NiC reaction system; this composite can be applied in high-performance supercapacitors. The micromorphology of NiC/NiP material displayed an appropriate combination of NiP nanowires and thin NiC nanosheets, which provide sufficient active sites, short ion diffusion paths and fast ion diffusion speeds. NiC/NiP material exhibited an excellent rate performance of 70.2% retained capacity, although the current was increased by 15 times (1196 F g−1 at 2.0 A g−1 and 840 F g−1 at 30 A g−1). The energy density of a NiC/NiP//active carbon (AC) asymmetric supercapacitor fabricated in 6 M KOH was as much as 39.02 W h kg−1 and 26.67 W h kg−1 under corresponding power densities of 160 W kg−1 and 8000 W kg−1, respectively. The asymmetric supercapacitor delivered a stable cyclic performance of 78% capacitive retention after 5000 continuous charge/discharge cycles. More importantly, a 2.5 V light-emitting diode was lit successfully by two NiC/NiP//AC asymmetric supercapacitors in series. These results confirm that NiC/NiP nanocomposite has great potential in practical applications of electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

The flexible F-CuS-CNT electrode exhibits improved electrochemical performance in Li-Mg hybrid battery, which is ascribed to the stable electrode structure and excellent conductive network. The hybrid magnesium-lithium-ion batteries (MLIBs) are promising alternatives in large-scale energy storage field owing to low cost and high safety of magnesium batteries and fast diffusion rate of Li-ion in the electrode. Herein, a free-standing and binder-free copper sulfide/Multi-walled carbon nanotubes film cathode (F-CuS-CNT), along with Mg-Li dual-salt electrolyte and dendrite-free Mg anode, is employed to construct the MLIBs. At room temperature (25 °C), the F-CuS-CNT electrode with a CuS content up to 70% exhibits a high initial specific capacity of 479 mAh g−1 (∼85.5% of the theoretical capacity) and a considerable cycling stability (165 mAh g−1 even after 100 cycles at the current density of 30 mA g−1), which far surpasses those of conventional CuS electrode. The excellent electrochemical performances of the F-CuS-CNTs electrode can be attributed to its excellent flexible network architecture as well as abundant pores, which provide more stable conductive buffering layers for CuS particles and higher Li+ diffusion dynamics during the charging/discharging process. This work demonstrates that constructing a flexible and free-standing film electrode could improve the electrochemical performances of MLIBs and may be an appropriate select of preparing flexible MLIBs. [ABSTRACT FROM AUTHOR]

PC-Zn@SSM electrode with prominent compatibility to seawater and optimized reaction interface demonstrates superior electrochemical performance. The in/ex-situ techniques were further conducted to reveal the working mechanism. [Display omitted] • Zn anode in-situ growth on SSM is prepared via in-system synthesis technique. • Interface regulation improves compatibility and mechanical stability of Zn anode. • Prepared Zn electrode shows excellent performance and anti-interference capability. • The dendrite-free self-regulation mechanism is verified via in/ex-situ techniques. • The assembled seawater Zn-air battery shows a maximum energy density of 285 Wh m−2. In this work, Zn anode with a high compatibility to seawater system is fabricated on stainless steel mesh using an ultra-simple in-system synthesis technique. Physical characterizations reveal that the film electrode is composed by cross-linked Zn nanoflakes structure with outstanding adhesion and mechanical deformation tolerance. Being adopted as seawater-compatible anode, the as-synthesized Zn electrode exhibits a high reversible capacity of 30 mAh cm−2 with obvious advantages such as outstanding rate capability, strong tolerance to real-time varied current, low capacity decay, and good long-term cycling stability. The assembled Zn-air battery performs a maximum energy density of 285 Wh m−2 and successfully lights up various electronic devices. Furthermore, the self-regulation working mechanism and the growth kinetic of Zn electrode are further investigated using in-situ optical microscopy observations and in-situ electrochemical impedance spectroscopy (EIS) techniques. This work demonstrates a promising feasibility for fabricating highly reversible and low-cost Zn electrode in seawater system aiming to large-scale energy storage. [ABSTRACT FROM AUTHOR]

Rechargeable lithium/sulfur batteries have been proposed as the most promising high-performance batteries due to their high theoretical capacity and low cost. However, the poor electrical conductivity and structural stability of elemental sulfur and the dissolution of the polysulfides have confined the utilization of elemental sulfur and the cyclic retention of capacity. A novel in-situ route by transforming ZnO nanotemplates into sulfur nanoparticles during the preparation of carbon/sulfur composite is reported for synthesizing sulfur nanoparticles/disordered mesoporous carbon composite, which shows a high specific capacity of 660.8 mAh/g (composite) during the first cycle and an excellent cyclic retention of 87.9% after 100 cycles. [ABSTRACT FROM AUTHOR]

Evolution processes of the corrosion behavior and structural characteristics of the plasma electrolytic oxidation (PEO) coated AZ31 magnesium alloy were investigated by using scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), potentio-dynamic polarization curves and electrochemical impedance spectroscopy (EIS) measurements. Detached coating samples were fabricated by an electrochemical method and more details of the internal micro-structure of coatings were clearly observed on the fractured cross-section morphologies of the samples compared to general polished cross-section morphologies. Evolution mechanisms of the coating corrosion behavior in relation to the evolution of micro-structural characteristics were discussed in detail. [ABSTRACT FROM AUTHOR]

In this study, plasma electrolytic oxidation (PEO) coatings were produced on pure aluminum in an in-house developed composite electrolyte at three current densities of 2.2 A/dm 2 , 4.4 A/dm 2 and 8.8 A/dm 2 , respectively. The coatings were investigated based on the observation and measurement of the working voltage, surface microdischarges and morphologies of surface, polished cross-section, fracture cross-section and inner surface of the coatings, by using scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS), data acquisition module, single-lens reflex camera. Especially, an in-house developed electrochemical detachment technique of the coatings was employed to observe some details of the internal micro-structure and coating/substrate interface morphology of the coatings. It was noted that the results from the above investigations are much related to the current densities going through the PEO coatings and the different growth mechanisms of coatings at low and high current densities were proposed and discussed. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide (rGO) anchored spinel nickel cobalt binary sulfides nanosheets (Ni x Co 3-x S 4 /rGO) with sandwich-like structure are synthesized via a facile hydrothermal process. The synergistic effect of nickel and cobalt on the superior electrochemical properties of the Ni x Co 3-x S 4 /rGO nanocomposites is firstly illustrated in detail through the comparison of the phase structures, metal valent states and electrochemical behaviors of the nickel doped cobalt sulfide (Ni 0.3 Co 2.7 S 4 /rGO), cobalt doped nickel sulfide (Ni 2.7 Co 0.3 S 4 /rGO) and nickel cobalt binary sulfide (Ni 1.5 Co 1.5 S 4 /rGO). Results indicate that the fast valence change of nickel species mainly contributes the faradaic reaction of the active materials, while the cobalt species offer the high electronic conductivity and assist the charge transfer process. Due to the synergistic effect of cobalt and nickel, the Ni 1.5 Co 1.5 S 4 /rGO electrode with sandwich-like structure exhibits superior electrochemical performances, such as high specific capacity (347.5 mAh g −1 based on metal sulfide), high areal specific capacity (4.3 mAh cm −2 ), high cyclic stability (85.0% retention after 2000 cycles). An asymmetric device, with the Ni 1.5 Co 1.5 S 4 /rGO as positive material and a home-made activated carbon as negative material, delivers high energy density of 61.6 Wh kg −1 at the power density of 563.1 W kg −1 and still remains 49.3 Wh kg −1 even at high power density of 11.0 kW kg −1 . [ABSTRACT FROM AUTHOR]

Carbon supported Pt-Pd (Pt-Pd/C) catalysts with different Pt/Pd ratios were prepared by microwave assisted ethylene glycol method and characterized by X-ray diffraction (XRD), transmission electron spectroscopy (TEM) and electrochemical measurements. The results reveal that the metal nanoparticles of Pt-Pd/C catalysts are uniformly dispersed on the carbon support and exist as alloys with face centered cubic (FCC) structures. The effects of both preparation process and Pt/Pd ratios on the structure and catalytic activity of the Pt-Pd/C catalysts were investigated. With the increase of Pd content, the catalytic activity for ORR is deteriorated due to the increased metal particle size of Pt-Pd/C catalysts, while improving the methanol tolerance. Among the Pt-Pd/C catalysts with different Pt/Pd ratios, the PtPd/C catalyst, which have the highest Pt/Pd ratios, exhibits higher specific mass activities toward oxygen reduction reaction (ORR) than that of the commercial Pt/C catalyst. [ABSTRACT FROM AUTHOR]

• NME exhibits extremely moldability more than flexibility. • NME shows both excellent mechanical and electrochemical properties. • NME owns both energy storage and ORR catalytic activity. • Reaction mechanism of NME is studied by in-situ Raman and EIS. Herein bifunctional NiO moldable electrode (NME) is successfully fabricated which exhibits satisfied flexibility, moldability and ductility. The ultimate elongation of NME is 43.5% and the area can be spread to as high as 525%. As a bifunctional electrode, the NME can not only provide activity through its own NiOOH/NiO redox mechanism, but also continue to work as a catalytic cathode based on oxygen reduction reaction (ORR) catalysis, which greatly expands its application prospects. The NME-assembled single cell achieves extraordinary moldability and compatibility, which could maintain stable electrochemical performance while being arbitrarily cut or bent. More promisingly, the as-test Zn-air system further demonstrates its bifunction for energy storage, especially based on its good ORR catalytic activity for a longer running time. In-situ Raman technology is performed to further study the reaction dynamic of NME during the whole energy storage process. The development of bifunctional NME paves a new and promising avenue towards the future design of solid-state batteries. A bifunctional moldable NiO electrode exhibits excellent mechanical properties, meanwhile, it presents great energy storage activity and oxygen reduction reaction activity as cathode for both aqueous flexible solid-state energy storage devices and Zn-air system, and this work paves a promising avenue towards the future design of solid-state batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Carbide derived carbons (CDCs) are porous carbons produced by extraction metals from metal carbides. In this paper, nanoporous carbon with large surface area of above 1000 m2/g has been prepared by thermo-chemical etching of titanium carbide (TiC) in chlorine atmosphere. An improved design of accurate control on the reaction time with high yield percentage above 98% is reported. Transmission electron microscope (TEM) and X-ray diffraction (XRD) analysis showed the existence of ordered graphite phase in this mostly amorphous titanium carbide derived carbon (TiC-CDC), and the degree of ordering increased with chlorination temperature. Raman spectra study demonstrated that the TiC-CDC consisted of both D-band and G band of graphitic carbon, and the ratio of the integrated intensities ID/IG decreased with chlorination temperature. T-plot nitrogen sorption measurements proved the co-existence of micropores (<2 nm) and mesopores (2–50 nm), while the highest specific surface area was achieved from sample synthesized at 400 °C. Cyclic voltammetry measurements on the TiC-CDC did not show any major Faradic reactions within the experimental voltage range. A specific capacitance of 138.3 F/g was achieved from sample synthesized at 400 °C. The specific capacitance increased with increasing the amount of microporous area. [Copyright &y& Elsevier]

In this paper, Zn2TiO4and TiN nanofibers were prepared by a facile combination of electrospinning followed by thermolysis under different atmospheres. An N,N-dimethyl formamide (DMF)–ethanol solution of poly(vinylpyrrolidone) (PVP), Ti(iv)–isopropoxide (Ti(OC4H9)4) and zinc acetate (ZnAc) was used as the electrospinning precursor and the electrospun nanofibers were calcined at 600 °C in air to generate Zn2TiO4nanofibers. Subsequently, a conversion from Zn2TiO4nanofibers to TiN nanofibers was realized through a heat treatment at 1000 °C under an ammonia atmosphere. Investigations using field-emission scanning electron and transmission electron microscopes (FESEM and TEM) revealed the nano-scale fibrous morphology of the obtained products. Energy-dispersive spectroscopy (EDS) and X-ray diffraction (XRD) studies confirmed the chemical composition and crystalline structure of the Zn2TiO4and TiN nanofibers, respectively. The electrochemical properties of the as-prepared TiN nanofibers indicated that the capacitance characteristic of the TiN phase was the electric double-layer capacitance. The value of the specific capacitance gradually decreased with the increase of discharge current density. [ABSTRACT FROM AUTHOR]

Nowadays, sodium-ion batteries (SIBs) have received extensive attention for their abundant resources and low price. Some quinone compounds have the advantages of high specific capacity, diverse structures, environmental friendliness and good redox reversibility, are ideal cathode materials. Calix[4]quinone (C4Q) with a high theoretical specific capacity of 446 mA h g−1 is synthesized as cathodes, while it is still puzzled over low conductivity and high dissolution rate in organic electrolytes. In this study, a kind of economical and practical biocarbon-PPL with porous tubular structures is prepared by pyrolysis of Physalis Peruviana L. Calyx to immobilize C4Q in SIBs for the first time. The C4Q/PPL cathode presents an initial capacity of 435 mA h g−1 with stable cyclability (195 mA h g−1 after 100 cycles at 0.1 C) and great rate performance (170 mA h g−1 at 1 C). Using cheap and readily available biocarbon PPL as both an immobilization material for C4Q and a conductive agent makes a great success in inhibiting the dissolution of C4Q in organic electrolytes. It shows an initial capacity of 435 mA h g−1 and remains at 195 mA h g−1 after 100 cycles in SIBs. Image 1 • Biocarbon PPL is used as immobilization material for Calix[4]quinone (C4Q) cathode SIBs for the first time. • PPL not only serves as a kind of immobilization material but conductive agent. • The content of active substances is greatly increased. • High specific capacity and good cycling performance of C4Q/PPL are achieved. [ABSTRACT FROM AUTHOR]

Understanding the material process and the mechanism behind during battery operation is essential to discover or identify new electrode for the sodium ion batteries. Using first-principles calculations, we systematically investigated the fundamental physical properties, electrochemical activity as well as sodium ion diffusion of the new discovered cathode material, Na 3 V(PO 4) 2. The results identified that the Na+ ion on Na 2 sites is preferentially extracted from the host, which is responsible for the electrochemical redox process, instead of that on Na 1 sites, proposed experimentally. The predicted cell voltage delivers two 'plateaus' with average voltage profile at ~ 3.1 and ~ 3.9 V vs. Na+/Na, corresponding to the V3+/V4+ and V4+/V5+ redox process, respectively, reproducing the experimental observations. Actually, the redox activity of V ions is accompanied with the formation of small polaron as manifested by the magnetic moments and spin density analysis. Furthermore, the fade of the reversible capacity is attributed to the considerable large volume variation (>5%) during the charging-discharging cycling, due to the flexibility of yavapaiite-type layers. The sodium ion diffusion is accomplished through the step-wise ion-exchange mode, in which the Na+ ions originated from both Na 1 and Na 2 sites migrate, progressively and independently, along the a axis between the yavapaiite-type layers, creating a zigzag Na 2 →Na 1 →Na 2 trajectory. Meanwhile, the activation energy is calculated to be reasonable for facile ion diffusion. In addition, the fundamental electronic structures on different charging stages are examined thoughtfully. Our results not only provide a valuable insight on the electronic properties, electrochemical behavior of sodium disintercalation process and diffusion mechanism of Na 3 V(PO 4) 2 , but also inevitably highlight the clues to suppress the large volume variation upon charge/discharge process, and then to improve the cycling capacity. Understanding the material process and the mechanism behind during battery operation is essential to discover or identify new electrode for the sodium ion batteries. Using first-principles calculations, we systematically investigated the fundamental physical properties, electrochemical activity as well as sodium ion diffusion of the new discovered cathode material, Na 3 V(PO 4) 2. Image 1 • Electrochemical properties and sodium ion diffusion in Na 3 V(PO 4) 2 have been explored. • The Na+ ion from Na 2 positions is preferentially extracted from the host, in contrast to the experimental proposition. • The sodium ion diffusion is accomplished through the step-wise ion-exchange mode. • The two-step nature of voltage-composition curve demonstrates that two Na ions participated in the redox reaction. [ABSTRACT FROM AUTHOR]