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The application of activated carbon is greatly limited by its low energy density. Here, the angelica herb residue–based activated carbon (AHRAC) materials modified by loading NiO and MnO2 were prepared via a hydrothermal reaction, respectively. The results of structure measurements and electrochemical tests reveal that NiO is more beneficial for improving the specific capacitance (about 678.2 F g−1) and energy density (about 30 Wh kg−1) of AHRAC owing to its unique flower-like morphology and abundant porosity. In addition, combining the density functional theory calculation (DFT), differential pulse voltammetry (DPV), and diffusion coefficient calculation, the difference between AHRAC@NiO and AHRAC@MnO2 was analyzed, which may be ascribed to the larger pseudo-capacitance contribution, bigger diffusion coefficient, and higher adsorption behavior for OH−. In this work, not only a porous carbon with a high specific surface area was prepared, but also the biomass waste was reused. [ABSTRACT FROM AUTHOR]

Aims/Introduction: This study aimed to evaluate the association between time in range (TIR) obtained from continuous glucose monitoring and the prevalence and degree of painful diabetic neuropathy. Materials and Methods: A total of 364 individuals with diabetic peripheral neuropathy were enrolled in this study. Sensor‐based flash glucose monitoring systems were used to monitor the participants' glucose levels, and the glycemic variability metrics were calculated, including the TIR, glucose coefficient of variation, standard deviation and the mean amplitude of glycemic excursions. The participants were asked to record any form of pain during the 2 weeks of monitoring, and score the pain every day on a numerical rating scale. Based on the numerical rating scale, the patients were divided into the pain‐free group, mild pain group and moderate/severe pain group. Results: Overall, 51.92% (189/364) of the participants were diagnosed with painful diabetic neuropathy. Compared with the pain‐free group, the level of TIR decreased significantly in the mild pain and moderate/severe pain groups (P < 0.05). The prevalence of mild pain and moderate/severe pain decreased with increasing TIR quartiles (all P < 0.05). Multiple linear regression analysis showed that TIR was significantly negatively correlated with the numerical rating scale score after adjustment for glycated hemoglobin, glycemic variability indicators and other risk factors (P < 0.05). Logistic regression analysis showed that a decreasing level of TIR was significantly associated with an increasing risk of any pain and moderate/severe pain (P < 0.05). Conclusions: TIR is correlated with painful diabetic neuropathy and is underscored as a valuable clinical evaluation measure. [ABSTRACT FROM AUTHOR]

LiBF4 has attracted much attention due to its better thermal stability, lower sensitivity to environmental humidity, and lower charge transfer resistance provided by its solution, especially at high voltage. Herein, the effects of the concentration of LiBF4 salt on the stability and electrochemical properties of LiNi0.5Mn1.5O4 (LNMO) cathode material have been investigated by using the mixed solvents of LiBF4 salt, vinyl carbonate (EC), and diethyl carbonate (DEC) as electrolytes. The surface morphology and structure of cycled LNMO electrode are studied by scanning electron microscopy (SEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The results show that the optimum concentration of LiBF4 salt is 1.4 M LiBF4-EC/DEC (1:5, by volume). Under optimum conditions, the LNMO cathode material has high electrochemical capacity and favorable rate performance. Meanwhile, the prepared electrolyte can easily form a thin and stable SEI film on the surface of LNMO electrode, which can effectively inhibit the continuous decomposition of the electrolyte. [ABSTRACT FROM AUTHOR]

The LiNi0.5Mn1.5O4 cathode material with high working voltage is a promising cathode material for next-generation lithium-ion batteries. In this investigation, LiNi0.5Mn1.5O4 materials with different particle sizes and crystal morphologies were synthesized by a modified solid-state method at different temperatures (750, 800, 850, and 900 °C). The evolution panorama of morphology and surface orientation with the temperature change of LiNi0.5Mn1.5O4 cathode materials were studied. The X-ray diffraction and scanning electron microscopy results showed that with the increase of temperature, the particle sizes increased and the crystal growth became more and more complete. Electrochemical tests showed that the material calcined under 850 °C exhibits a truncated octahedral structure and the best electrochemical performance. It delivers a discharge capacity of 124 mA h g−1 at 1 C; even at a high rate of 10 C, a capacity of 90 mA h g−1 can be obtained. The discharge capacity retention of the material is 91.2% after 150 cycles. In addition, the sample prepared by acetate reactant shows excellent electrochemical performance due to the truncated octahedron structure consisted of {111} and {100} surface as well as the appropriate particle size of ~ 1 μm. The {111} surface is conducive to stabilize the material structure, and {100} surface is conducive to the transfer of Li+ ion and electrons. At the same time, it also founded that the appropriate particle size could reduce the electrolyte corrosion of the material and easy for Li+ ion migration. As a result, the material exhibits an improved electrochemical performance. [ABSTRACT FROM AUTHOR]

By employment of nano-sized pre-prepared Mn3O4 as precursor, LiMn2O4 particles have been successfully prepared by facile solid state method and sol-gel route, respectively. And the reaction mechanism of the used precursors of Mn3O4 is studied. The structure, morphology, and element distribution of the as-synthesized LiMn2O4 samples are characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Compared with LiMn2O4 synthesized by facile solid state method (SS-LMO), LiMn2O4 synthesized by modified sol-gel route (SG-LMO) possesses higher crystallinity, smaller average particle size (~175 nm), higher lithium chemical diffusion coefficient (1.17 × 10−11 cm2 s−1), as well as superior electrochemical performance. For example, the cell based on SG-LMO can deliver a capacity of 85.5 mAh g−1 at a high rate of 5 °C, and manifests 88.3% capacity retention after 100 cycles at 0.5 °C when cycling at 45 °C. The good electrochemical performance of the cell based on SG-LMO is ascribed mainly to its small particle size, high degree of dispersion, and uniform element distribution in bulk material. In addition, the lower polarization potential accelerates Li+ ion migration, and the lower atom location confused degree maintains integrity of crystal structure, both of which can effectively improve the rate capability and cyclability of SG-LMO. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are a kind of porous crystalline polymeric material. They are constructed by organic module units connected with strong covalent bonds extending in two or three dimensions. COFs possess the advantages of low-density, large specific surface area, high thermal stability, developed pore-structure, long-range order, good crystallinity, and the excellent tunability of the monomer units and the linking reticular chemistry. These features endowed COFs with the ability to be applied in a plethora of applications, ranging from adsorption and separation, sensing, catalysis, optoelectronics, energy storage, mass transport, etc. In this paper, we will review the recent progress of COFs materials applied in photocatalytic CO 2 reduction. The state-of-the-art paragon examples and the current challenges will be discussed in detail. The future direction in this research field will be finally outlooked.