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Abstract: Nano-sized Li4Ti5O12 powders with high dispersivity were fabricated by a sol–gel process using P123 as surfactant, which exhibited much better high rate performance towards Li+ insertion/extraction as compared to the densely aggregated Li4Ti5O12 particles although the primary grain sizes of both samples were almost the same. The Li4Ti5O12 electrode prepared from the well-dispersed nanopowders can preserve 88.6% of the capacity at 0.1Ag−1 when being cycled at 1Ag−1, which is obviously higher than that of the densely aggregated sample, in which only 30% capacity can be retained. By improving the dispersivity, the specific surface area of the Li4Ti5O12 nanoparticles, hence the electrode–electrolyte contact area was increased; meanwhile, more homogeneous mixing of the active materials with carbon black was achieved. All these factors might have resulted in the better high rate performance. [Copyright &y& Elsevier]

Abstract: Spinel lithium titanate, Li4Ti5O12, with novel hollow-sphere structure was fabricated by a sol–gel process using carbon sphere as template. The effect of the hollow-sphere structure as well as the wall thickness on the Li storage capability and high rate performance was electrochemically evaluated. High specific capacity, especially better high rate performance was achieved with this Li4Ti5O12 hollow-sphere electrode material with thin wall thickness. It is believed that this macroporous hollow-sphere structure has shortened the Li diffusion distance, increased the contact area between Li4Ti5O12 and electrolyte, and also led to better mixing of the active material with AB. All these factors have resulted in the good rate capability of the hollow-sphere structured Li4Ti5O12 electrode material. [Copyright &y& Elsevier]

Abstract: The lithium storage capability and high rate performance of nanocrystalline anatase TiO2 electrodes are highly dependent on the particle sizes. The electrode made from a very fine anatase powder of 6nm exhibited the highest capacity even at high current rates. It is believed that increasing the specific surface area of the nanocrystalline anatase electrodes has increased the weight ratio of the atoms resided near or on the surface layers and hence improved the surface Li storage; whereas decreasing the particle size has reduced the transport length for Li insertion in the bulk of anatase phase, and so made the Li insertion more efficiently. Besides that, it is found that the specific capacity contributed by the surface Li storage was very stable upon cycling or increasing the current rate; whereas the short Li diffusion length could greatly facilitate the Li insertion/extraction in/from the bulk of the anatase electrode. These two features of nanocrystalline anatase electrodes resulted in very good cycle performance. [Copyright &y& Elsevier]

Highlights: [•] The structured TiO2–SiC were prepared using a composite sol–gel method. [•] The p-type SiC foam support was used in photocatalysis for the first time. [•] The TiO2–SiC enhanced the photocatalytic efficiency by a synergistic effect. [ABSTRACT FROM AUTHOR]

As the holy-grail material, the Li-metal anode has been considered the potential anode of the next generation of Li-metal batteries (LMBs). However, issues of undesirable dendrite growth and unsatisfactory reversibility of the Li-plating/stripping process during the electrochemical cycling impede further application of LMBs. Herein, we innovatively introduce fluorinated graphene (F-Gr) species as a sacrificial effective electrolyte additive into EC/EMC-based electrolyte, which effectively triggers LiF-enriched (composition) and organic/inorganic species uniform-distributed (structure) SEI film architecture that features robustness and denseness, as well as good stability. With the F-Gr additive, efficient Li-metal anode protection (dendrite-free morphology on Li-metal surface and improved Li plating/stripping reversibility during electrochemical cycling) and significantly enhanced long-term lifespan of LMBs is achieved. Remarkably, classical electrochemical techniques, combined with the surface-sensitive characterizations (XPS and TOF-SIMS), comprehensively and systematically highlight critical structure-activity relationships between the SEI architecture (both composition and structure) and electrochemical performance. These techniques provide deep insights into the optimal electrolyte designation of Li-metal anode in LMBs.

Serum amyloid A (SAA) is an acute-phase protein produced in response to inflammatory proteins during infections, inflammation, trauma, surgery, cancer, and other conditions. Early and accurate detection of SAA is necessary for diagnosis and monitoring of disease progression. To meet this need, we developed a gradient lateral flow immunoassay test strip using Au nanoparticles as signal reporters. The test strip has three test (T1, T2, and T3) lines with progressively decreasing concentrations of SAA antibody, enabling the determination of high, medium, and low concentrations of SAA in serum. The test strip results were analyzed using three distinct readout methods, each with different sensitivity, accuracy, and precision for SAA concentration measurements. Qualitative judgment is based on the color of the T1 line. Semi-quantitative assessment of SAA concentration is determined by the number of colored T-lines. Specifically, color development in T1 line alone indicates a concentration range of 10-50 μg/mL, while T1 and T2 lines together indicate a range of 50-100 μg/mL, and development in all three lines (T1, T2, and T3) indicates a concentration of >100 μg/mL. Quantitative analysis was performed using either smartphone imaging or image scanning with ImageJ software. By using a five-parameter logistic function, we found a strong correlation (R 2  = 0.998) between the ratio of signal intensities of (T1 + T2 + T3) to the control (C) line and SAA concentrations ranging from 5 to 1000 μg/mL. At lower concentrations (0-100 μg/mL), we observed a proportional relationship between the value of (T1 + T2 + T3)/C and SAA concentration. The limit of detection for SAA was 9.33 ng/mL (or 6.53 μg/mL of SAA in undiluted serum samples) for the smartphone method and 3.06 ng/mL (or 2.14 μg/mL of SAA in undiluted serum samples) for the scanner method. The gradient test strip was highly consistent with a commercially available SAA immunochromatographic test strip when tested with real human serum samples. Passing-Bablok regression indicated that results obtained using the smartphone app and scanner methods of the gradient test strip were comparable to those obtained using the commercial test strip. The gradient test strip is flexible and adaptable, providing solutions for qualitative, semi-quantitative, and quantitative SAA measurements., (Copyright © 2023. Published by Elsevier B.V.)

Li-O 2 batteries (LOBs) with Li-metal as the anode are characterized by their high theoretical energy density of 3500 W h kg -1 and are thus considered next-generation batteries with an unlimited potential. However, upon cycling in a harsh O 2 atmosphere, the poor-quality solid electrolyte interphase (SEI) film formed on the surface of the Li-metal anode cannot effectively suppress the shuttle effect from O 2 , superoxide species, protons, and soluble side products. These issues lead to aggravated Li-metal corrosion and hinder the practical development of LOBs. In this work, a polyacrylamide- co -polymethyl acrylate (PAMMA) copolymer was innovatively introduced in an ether-based electrolyte as a sacrificial additive. PAMMA was found to preferentially decompose and promote the formation of a dense and Li 3 N-rich SEI film on the Li-metal surface, which could effectively prohibit the shuttle effect from a series of detrimental species in the Li-O 2 cell during the discharge/charge process. Using PAMMA, well-protected Li-metal in a harsh O 2 atmosphere and significantly enhanced cycling performance of the Li-O 2 cell could be achieved. Thus, the use of a sacrificial polymer additive provides a promising strategy for the effective protection of Li-metal in Li-O 2 cells in a severe O 2 atmosphere during practical applications.

A hybrid structure of GaN/Ga 2 O 3 microrods was fabricated on carbon cloth (CC) using a hydrothermal process combined with a high-temperature nitridation followed by an air annealing process. By elevating the post-annealing temperature to 500 °C, both electron density ( N D ) and specific capacitance ( C a ) of the composite electrode were significantly enhanced. Symmetric SCs assembled with GaN/CC-500 showed great potential in both 1 M H 2 SO 4 aqueous solution and a PVA-H 2 SO 4 gel-like electrolyte. The aqueous symmetric GaN/CC-500 SC exhibited an excellent capacitance (1301.20 mF cm -2 , 0.5 mA cm -2 ), high rate capability (75.23% of capacitance retention at 10 mA cm -2 ), outstanding cycling stability (77.27% of capacitance retention after 20 000 cycles, 10 mA cm -2 ), and large energy storage capability (27.53 μW h cm -2 of energy density, 0.10 mW cm -2 of power density). All-solid-state symmetric GaN/CC-500 SC also manifested a high capacitance (1183.35 mF cm -2 , 0.5 mA cm -2 ) and good rate capability (53.98% capacitance retention, 10 mA cm -2 ). The high electrochemical performance of the GaN/CC-500 electrode is attributed to the GaN/Ga 2 O 3 hybrid structure, with α-Ga 2 O 3 providing absorption/redox active sites on the surface, and the heavily oxygen-doped GaN enabling fast electron transport. The microrods with the GaN/Ga 2 O 3 hybrid structure as the active material for solid SCs can deliver an energy density of 0.58 W h kg -1 (3.54 mW h cm -3 ) with a power density of 154 W kg -1 (0.94 W cm -3 ). The mechanism identified in this work would be helpful in designing GaN-based energy storage devices with better performances in the future.