Search

The application of portable aluminum‐air batteries (AABs) in extreme environments is an inevitable demand for future development. Aqueous electrolyte freezing is a major challenge for low‐temperature operations. Conventionally, enlightened by the organic system in metal ion batteries, blindly increasing the concentration is regarded as an efficient technique to reduce the freezing point (FP). However, the underlying contradiction between the adjusting mechanism of the FP and OH− transportation is ignored. Herein, the aqueous alkali solution of CsOH is researched as a prototype to disclose the intrinsic conductive behavior and related solvent structure evolution. Different from these inorganic electrolyte systems, the concept of a critical anti‐freezing concentration (CFC) is proposed based on a specific temperature. The relationship between hydrogen bond reconstruction and de‐solvation behavior is analyzed. A high conductivity is obtained at −30 °C, which is also a recorded value in an intrinsic aqueous AAB. The homogenous dissolution of the Al anode is also observed. As a general rule, the CFC concept is also applied in both the KOH and NaOH systems. [ABSTRACT FROM AUTHOR]

The Hall-Petch strengthening coefficient of face-centered cubic alloys has the potential to increase. Herein, we experimentally determined an unconventionally large Hall-Petch coefficient equal to 1100 MPa·µm1/2 and a large lattice friction stress for novel Co0.95Cr0.8Fe0.25Ni1.8Mo0.475 high-entropy alloys (Mo0.475 HEAs). Detailed microstructural characterizations showed Mo segregation at grain boundaries (GBs) and no apparent nano-clustering in the matrix. With the increased Mo content, Mo segregating at GBs is an unexpected outcome. The unconventionally large Hall-Petch coefficient is ascribed to the newly generated effect due to Mo segregation at GBs, besides the factors in the grain interior, e.g. the increased solid-solution strengthening. This study is dedicated to enriching the diversity of Hall-Petch strengthening mechanisms for the development of high-strength materials. [ABSTRACT FROM AUTHOR]

While sulfide solid electrolytes such as Na11Sn2PS12 can allow fast transport of Na+ ions, their utilization in solid sodium ion batteries is rather unsuccessful since they are not electrochemically compatible to both high‐voltage cathodes and sodium metal anode. In this work, we devise an effective approach toward realizing solid sodium ion batteries, using the Na11Sn2PS12 electrolyte and slurry‐coated NASICON‐type Na3MnTi(PO4)3@C as high‐voltage cathode, highly beneficial for low processing cost and high content/loading of active cathode matter. We report that through significantly improved integrity of electrolyte‐cathode interface, such solid sodium ion batteries can deliver outstanding cycling and rate performance, with a charge voltage resilience up to 4.1 V, a high cathode discharge capacity of 128.7 mAh g−1 against the Na3MnTi(PO4)3@C in cathode is achieved at 0.05 C, and capacity retention ratio of 82% with a rate of 0.1 C is realized after prolonged cycling at room temperature. Besides, we demonstrate that such a solid sodium ion battery can even perform at a sub‐zero Celsius temperature of −10°C, when the conventional control cell using liquid electrolyte completely fail to function. This work is to offer a dependable avenue in engineering next generation of safe solid ion batteries based on highly sustainable and much cheaper material resources. [ABSTRACT FROM AUTHOR]

The main bottleneck against industrial utilization of sodium ion batteries (SIBs) is the lack of high‐capacity electrodes to rival those of the benchmark lithium ion batteries (LIBs). Here in this work, we have developed an economical method for in situ fabrication of nanocomposites made of crystalline few‐layer graphene sheets loaded with ultrafine SnO2 nanocrystals, using short exposure of microwave to xerogel of graphene oxide (GO) and tin tetrachloride containing minute catalyzing dispersoids of chemically reduced GO (RGO). The resultant nanocomposites (SnO2@MWG) enabled significantly quickened redox processes as SIB anode, which led to remarkable full anode‐specific capacity reaching 538 mAh g−1 at 0.05 A g−1 (about 1.45 times of the theoretical capacity of graphite for the LIB), in addition to outstanding rate performance over prolonged charge–discharge cycling. Anodes based on the optimized SnO2@MWG delivered stable performance over 2000 cycles even at a high current density of 5 A g−1, and capacity retention of over 70.4% was maintained at a high areal loading of 3.4 mg cm−2, highly desirable for high energy density SIBs to rival the current benchmark LIBs. [ABSTRACT FROM AUTHOR]

Nb-doped TiO2 (NTO) thin films were sputtered on glass substrate followed by a simple annealing process in air. The photoelectric cooperative optimization was discussed based on the structural, optical and electrical characteristics. The influence of oxygen flow during deposition on materials chemistry and performance was analyzed. Hall measurement showed a strong dependence of transparent conductivity on the oxygen flow. Oxygen vacancies are related to the phase transitions from the rutile to anatase TiO2 during annealing. The chemical states of Nb, Ti and O before and after annealing were discussed. The achievement of optimized transparent conductivity was resultant from the fine-tuning of the doped chemistry and special interplay of dopants and host lattice. [ABSTRACT FROM AUTHOR]

Background: Persistent host immune responses initiated by oral bacteria protect host against infection but may also elicit the process of sustained periodontal inflammation and subsequent alveolar bone loss. Interleukin-10 (IL-10), an anti-inflammatory cytokine, can downregulate pro-inflammatory cytokine and inhibit neutrophil migration in inflammation. IL-10-expressing regulatory B cells (B10) is termed by negatively regulating immune response through IL-10 and are mainly restricted in CD19+ CD1dhi CD5+ B cells in mice. Our current study was aimed to explore the effect of locally transferred CD19+ CD1dhi CD5+ B cells on inflammation and alveolar bone loss in an experimental periodontitis mouse model.Methods: Ligation plus P. gingivalis (Pg) infection was used to induce periodontitis in a mouse model. CD19+ CD1dhi CD5+ B cells were sorted by flow cytometry and transferred into the gingivae immediately on the fifth day after ligation. All the mice were sacrificed on day 14 after ligation.Results: H&E staining showed that inflammatory cell infiltration was significantly reduced by the CD19+ CD1dhi CD5+ B cells. Toluidine blue staining showed that the CD19+ CD1dhi CD5+ B cells alleviated alveolar bone loss in the ligature/Pg-induced periodontitis in mice. Immunohistochemical staining showed Receptor Activator of NF-KappaB Ligand (RANKL), Interleukin-1β(IL-1β) and Interleukin-17 (IL-17) were decreased after the CD19+ CD1dhi CD5+ B cell transfer. Immunofluorescent staining showed that IL-10 was increased while the number of Ly6G+ neutrophil and its RANKL production were decreased in gingival tissue.Conclusions: These results indicated that locally transferred CD19+ CD1dhi CD5+ B cells may alleviate alveolar bone loss through inhibiting pro-inflammatory cytokine expression and RANKL-expressing neutrophils in the periodontitis mouse model. [ABSTRACT FROM AUTHOR]