Search

Solid-state lithium batteries using inorganic electrolytes are expected to revolutionize energy storage systems due to their better safety and high energy density. However, their application is greatly hindered by the poor solid-solid interface between the solid-state electrolyte (SSE) and electrodes, particularly the cathode. Herein, we report a facile strategy to address the high cathode/SSE interfacial resistance through rapid, high-temperature microwave soldering. As a proof-of-concept demonstration, we soldered a garnet-type Li7La3Zr2O12 (LLZO) SSE with a V2O5 cathode, which feature high thermal stability and suitable melting temperatures. Our microwave soldering technique can selectively melt the surface of the granular V2O5 and rapidly form an intact and continuous cathode layer with tightly embedded carbon black nanoparticles, leading to a remarkable 690-time increase of the electronic conductivity of cathode. Additionally, the melted V2O5 cathode is conformally soldered to the garnet electrolyte, resulting in a 28-fold decrease of the cathode/garnet interfacial resistance (from 14.4 ​kΩ ​cm2to 0.5 ​kΩ ​cm2. As a result, this all-solid-state full cell displays a low overall resistance of 0.3 ​kΩ ​cm2 at 100 ​°C, which enables stable cyclability of the battery without the addition of liquid/polymer electrolyte. The fast microwave soldering strategy constitutes a significant step towards the development of the all-solid-state batteries.

The synergistic effects of the combination of acetylated distarch adipate and sesbania gum (C-ADA-SG) with the ratio of 5:0, 4:1, 2.5:2.5, 1:4, 0:5, accounting for 5% (w/w) of the starch on gelatinization and retrogradation properties of wheat starch (WS) were studied. Scanning Electron Microscopy (SEM) showed that the microstructure of gelatinized WASs (WS added with C-ADA-SG) tended to be smoother. Based on the results of Rapid Visco-Analyzer (RVA) and Differential Scanning Calorimetry (DSC), the pasting characteristics of WS were affected and the gelatinization process was retarded by C-ADA-SG. After seven-day storage at 4 °C, compared to WS, the gel firmness, syneresis, retrogradation enthalpy, and the relative crystallinity of WASs clearly decreased by 17.47–44.36 g, 11.16–17.93%, 0.22–0.80 J·g−1, and 4.06–8.61%, respectively. However, the band ratio 1639:1157 cm−1 by FTIR and loss tangent (tan δ) value were increased with C-ADA-SG addition. Meanwhile, X-Ray Diffraction (XRD) reflected that native WS showed A-type crystal structure, which transferred to B + V type after retrogradation. Furthermore, Low-Field Nuclear Magnetic Resonance (LF-NMR) declared that C-ADA-SG increased the water mobility and limited the diffusion and seepage of water during storage. Generally, ADA and SG produced a synergistic effect on retarding the gelatinization and retrogradation of WS.

Electric conductors are ubiquitously used for electromagnetic shielding, flexible electronics, and energy storage, with metals and carbon-based compounds as traditional choices for these applicatio...

Aerosol spray coupled with high-temperature pyrolysis is an emerging technique for continuous manufacturing of nanomaterials at large scale that demonstrates extremely high production efficiency. Current aerosol spray techniques using a tube furnace can only attain a low temperature range (generally 95%), during which salt decomposition and particle nucleation/growth occur. The high temperature critically enables homogeneous mixing of elements in the resultant nanoparticles and the short residence time is key to suppress particle growth and agglomeration. Compared with the traditional aerosol spray pyrolysis, the carbonized wood reactor can achieve a record high temperature (≥2000 K), a much shorter residence time (∼tens of milliseconds), highly efficient, uniform heating, and provide a platform for continuous nanomaterial manufacturing for a broad range of applications.

Fixed bed reactor is widely used in the petrochemical industry. The most rigorous description of it is particle-resolved simulation. In this study, a particle-resolved CFD model coupling reaction-diffusion was developed. The gas and porous particle phase were solved separately and the data of heat and mass is exchanged across the phase interface. Detailed flow and reaction process for synthesis of vinyl acetate were investigated by this model. The results showed that the local flow was not uniform under different flow patterns, which leads to the non-uniform distributions of temperature and concentration. In addition, the intra-particle pore diffusion influenced the reactor performance. The increase of particle pore size can obviously promote average reaction rate and decrease product concentration inside particles. The proposed modeling provided deep insight for local flow and reaction-diffusion process and can be extended to entire fixed bed reactor.

Transition-metal oxides (TMOs) are considered as promising anode materials for lithium ion batteries. However, the poor structural stability and relatively low electronic conductivity greatly limit their application in flexible electronic devices. Herein, a 3D hierarchical high performance MnO-based flexible electrode is fabricated through vacuum-assisted layer-by-layer assembly of 1D polydopamine coated MnO2 nanowires (MnO2@PDA NWs) and 2D graphene oxide nanosheets (GO NSs), followed by a thermal reduction process. The resulting composite (MnO@C-rGO) demonstrates excellent flexibility, structure stability and manifests outstanding lithium storage performance in terms of high reversible capacity (920 mAh g−1 at 0.2 A g−1), excellent rate capability (686 mAh g−1 at 2 A g−1 and 396 mAh g−1 at 10 A g−1) and impressive cycling stability (719 mAh g−1 at 2 A g−1 without fading after 800 cycles), exceeding most of recently reported MnO-based anodes. It is proved that the freestanding flexible MnO@C-rGO anode can be successfully applied in flexible full cell, which achieves superior flexibility and maintains good electrochemical performance during mechanical deformations.

In this study, citric acid (CA) esterified canna starch was firstly synthesized with the aid of vacuum, microwave and infrared radiation treatment. The changes in structural, physicochemical properties and in vitro digestibility of the modified starch were then investigated. The maximum degree of substitution (DS) reached 0.273 and the maximum thermo-stable resistant starch (RS) content reached 86.5 %. FT-IR confirmed the esterification reaction had successfully occurred, XRD and DSC results revealed that the crystalline and endothermic peaks of the samples disappeared after CA-treated, and TGA showed that the thermal degradation temperatures were above 280 °C. SEM showed the destroyed surface of the starch granules. All modified samples were lighter and generally whiter than native canna starch in color. These results suggest that the aid of vacuum treatment, microwave and infrared radiations for CA esterified of canna starch is an effective method for preparing high content of thermally stable RS4.

Konjac glucomannan octenyl succinate (KGOS) has excellent emulsifying and thickening properties as a new polymeric surfactant. The reaction extent of KGOS was determined by using high-performance liquid chromatography. The molecular aggregation state of KGOS was observed and analyzed by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The results showed that KGOS aggregated particles formed irregular spheres or ellipsoids, and the average particle diameter and height were approximately 30 nm and 5 nm, respectively. Thermal analysis indicated that the carbonization temperature of KGOS is slightly lower than that of konjac glucomannan (KGM). The steady shear rheology showed that KGOS solution fit to non-Newtonian fluid properties and the Carreau model, and the apparent viscosity increased with increase of KGOS concentration. The type and valence of the ions affected the apparent viscosity of KGOS solution. The trends of the dynamic mechanical spectra indicated KGOS solution could be an entanglement system. The ions had a similar effect on the dynamic modulus (G′, G″) and loss factor tanδ except for Fe3+ and H2PO4−.

The characteristics of octenyl succinic anhydride (OSA)-modified polysaccharide could be affected by its degree of reaction. Four konjac glucomannan octenyl succinate (KGOS) samples were prepared with different substitution rates (SRs) of 1.151%, 1.514%, 1.753% and 2.247%. The critical micelle concentration (CMC) of the four KGOS materials decreased with increasing SR. Fourier transform infrared (FT-IR) spectroscopy indicated that the increase in SR had little effect on the type of acyl peak. The viscosity test indicated that with SR increase, the viscosity increased slightly at low rotational speed. The emulsion capacity (EC) and stability (ES) also increased with increasing SR, but the extent of increase was not obvious when the SR exceeded 1.753%. A similar pattern was found in confocal scanning laser microscopy (CSLM) observations and ES tests of KGOS nanoemulsions. Considering the characteristics of KGOS and the economic benefits, it is preferable to prepare KGOS with an SR of 1.514% and additions of alkalizing agent and OSA (in proportion to konjac glucomannan (KGM), w/w) of 2% and 3%, respectively, during the KGOS preparation.

A uniform composite with NiCo2S4 nanoparticles anchored on graphene sheets is fabricated through an innovative one-step hydrothermal method. The XRD, Raman, XPS, SEM, HRTEM and EDS analyses are performed for characterizing the morphology and microstructure of the as-prepared NiCo2S4/graphene composite. It can be found that NiCo2S4 nanoparticles with a length of 20–50 nm were densely grown on the highly conductive graphene sheets, forming a 3D conductive network for rapid and efficient charge transport. The electrochemical performance is evaluated by CV, GCD and EIS, demonstrating that the NiCo2S4/graphene composite exhibits a very high specific capacitance (1040.6 F g−1) and greatly improved cycling stability (89.3% capacitance retention after 2000 cycles), which are due to the synergistic effect of graphene and NiCo2S4 nanoparticles. An asymmetric device has been assembled with NiCo2S4/graphene as positive electrode and graphene as negative electrode in PVA-KOH gel electrolyte solution. The as-prepared device demonstrates a energy density of 2.9 W h kg−1 with a power density of 872 W kg−1, indicating that the NiCo2S4/graphene composite can serve as a promising electrode material for asymmetric capacitor.

Carbon-black-supported nanoparticles (CNPs) have attracted considerable attention for their intriguing catalytic properties and promising applications. The traditional liquid synthesis of CNPs commonly involves demanding operation conditions and complex pre- or post-treatments, which are time consuming and energy inefficient. Herein, a rapid, scalable, and universal strategy is reported to synthesize highly dispersed metal nanoparticles embedded in a carbon matrix via microwave irradiation of carbon black with preloaded precursors. By optimizing the amount of carbon black, the microwave absorption is dramatically improved while the thermal dissipation is effectively controlled, leading to a rapid temperature increase in carbon black, ramping to 1270 K in just 6 s. The whole synthesis process requires no capping agents or surfactants, nor tedious pre- or post-treatments of carbon black, showing tremendous potential for mass production. As a proof of concept, the synthesis of ultrafine Ru nanoparticles (≈2.57 nm) uniformly embedded in carbon black using this microwave heating technique is demonstrated, which displays remarkable electrocatalytic performance when used as the cathode in a Li-O2 battery. This microwave heating method can be extended to the synthesis of other nanoparticles, thereby providing a general methodology for the mass production of carbon-supported catalytic nanoparticles.

Corn starch was esterified with octenyl succinic anhydride (OSA), in which semidry method assisted with vacuum-microwave treatment was used under the alkalescent condition. The effect of vacuum treatment on esterification was studied. The products were characterized by Fourier transform infrared (FT-IR) spectroscopy, 1H nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) and X-ray diffraction. And the emulsifying properties were investigated with the emulsifying capacity (EC), emulsion droplet size and confocal laser scanning microscopy (CLSM). The degree of substitution (DS) of OSA starch increased significantly (ρ

Constipation is one of the most prevalent gastrointestinal tract diseases. Konjac glucomannan (KGM) dietotherapy can effectively relieve the clinical symptoms of patients with constipation. However, the causal relationship among KGM, constipation and different gastrointestinal microbiome (i.e., the stomach {St}, small intestine {S}, and large intestine {L}) remains poorly understood. In this study, constipated mice were treated with KGM (75, 150, 300 mg/kg bw). Results showed that KGM treatment improved the general physiological state, fecal character, small intestinal propulsive rate, gastric emptying rate, MTL and AchE activities, ET-1, 5-HT, and NO levels, and SCFA concentrations. KGM in the diets of constipated mice reduced the diversity of St and S microbiota, while increased those in the L. The KGM intervention regulated the microbiota profile, which afterwards was closer to the normal mouse group: confirmation was provided by different changes of bacteria like Lactobacillus, Bifidobacterium and Allobaculum spp et al.

A peer-to-peer (P2P) file sharing system can be reduced into a system of addition-min fuzzy relation inequalities. Concept of lexicography minimum solution is introduced and applied to such system. It is found that the unique lexicography minimum solution can be selected from the minimal solution set of the corresponding fuzzy relation inequalities. However it is difficult to find the minimal solution set which is probably infinite. In order to avoid such difficulty, we propose a so-called Circulation Algorithm to find the unique lexicography minimum solution. The algorithm is developed step by step and illustrated by a numerical application example.

Mixing multimetallic elements in hollow-structured nanoparticles is a promising strategy for the synthesis of highly efficient and cost-effective catalysts. However, the synthesis of multimetallic hollow nanoparticles is limited to two or three elements due to the difficulties in morphology control under the harsh alloying conditions. Herein, the rapid and continuous synthesis of hollow high-entropy-alloy (HEA) nanoparticles using a continuous "droplet-to-particle" method is reported. The formation of these hollow HEA nanoparticles is enabled through the decomposition of a gas-blowing agent in which a large amount of gas is produced in situ to "puff" the droplet during heating, followed by decomposition of the metal salt precursors and nucleation/growth of multimetallic particles. The high active sites per mass ratio of such hollow HEA nanoparticles makes them promising candidates for energy and electrocatalysis applications. As a proof-of-concept, it is demonstrated that these materials can be applied as the cathode catalyst for Li-O2 battery operations with a record-high current density per catalyst mass loading of 2000 mA gcat. -1 , as well as good stability and durable catalytic activity. This work offers a viable strategy for the continuous manufacturing of hollow HEA nanomaterials that can find broad applications in energy and catalysis.

Three-dimensional (3D) few-layer graphite framework shows great potential in various fields such as energy storage and electrocatalysts, owing to their porous structure, superior electronic conductivity, and good structural mechanical stability. In this work, 3D hollow few-layer graphite framework is fabricated by a temperature-driven, dynamic catalytic strategy. The in-situ generated Ni nanoparticles serve as a catalyst to promote the graphitization of carbon source. By optimizing the activating temperature, the initial small Ni nanoparticles gradually aggregate and grow into larger ones, during which they act as a dynamic catalyst to induce the construction of the 3D few-layer graphite framework along their aggregation paths. When demonstrated as the anode in Li-ion battery, the as prepared 3D few-layer graphite framework exhibits excellent electrochemical performance. The present synthetic strategy potentially represents a general method that can be extended to the construction of other carbon-based architectures for diverse applications.

High temperature synthesis and treatments are ubiquitous in chemical reactions and material manufacturing. However, conventional sintering furnaces are bulky and inefficient with a narrow temperature range (