Composite electrodes containing active materials, carbon and binder are widely used in lithium-ion batteries. Since the electrode reaction occurs preferentially in regions with lower resistance, reaction distribution can be happened within composite electrodes. We investigate the relationship between the reaction distribution with depth direction and electronic/ionic conductivity in composite electrodes with changing electrode porosities. Two dimensional X-ray absorption spectroscopy shows that the reaction distribution is happened in lower porosity electrodes. Our developed 6-probe method can measure electronic/ionic conductivity in composite electrodes. The ionic conductivity is decreased for lower porosity electrodes, which governs the reaction distribution of composite electrodes and their performances.

The aluminum rechargeable battery is a desirable device for large-scale energy storage owing to the high capacity derived from the properties of the aluminum metal anode. The development of cathode materials is needed to compose battery systems. However, the design principles of the cathode materials have not been determined. We focus on the high capacity FeS2 cathode materials and investigate the discharge/charge reaction mechanisms in chloroaluminate ionic liquids as the electrolyte at 55C. X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) measurements are performed for the discharged and charged samples. S 3p-orbitals are shown to play an important role in the redox reactions from the results of the S and Fe K-edge XANES spectra. As a result of the redox reaction, FeS2 is transformed into low crystalline FeS and amorphous Al2S3, as shown by the XRD and S, Al, and Fe K-edge XANES spectra. This reaction mechanism is different from the reaction observed with lithium ion.

A novel flower-like 3D ZnO superstructure with high uniformity was fabricated on a large scale through a facile aqueous solution route at room temperature. The as-prepared ZnO superstructures with a diameter of about 3 mm are assembled by large amounts of interleaving nanosheets, which have a uniform thickness of about 15 nm and a well-crystalline structure with {10 10} planes as basal facets. The hierarchical microstructures, which were formed via a two-stage nucleation-growth process, highly depend on the concentration of NaOH and trisodium citrate dihydrate. The photoluminescence result indicates that the ZnO superstructures possess a relatively strong UV emission. The photodecomposition of methyl orange indicates that such ZnO superstructures possess excellent photocatalytic activity.

Monodisperse ZnFe 2 O 4 nanoparticles were synthesized using a simple and low-cost polyol process based on thermal decomposition of the precursors of Fe(acac) 3 and Zn(acac) 2 in triethylene glycol without any surfactant. The as-prepared ZnFe 2 O 4 nanoparticles are highly crystalline, uniform in size, superparamagnetic and can be easily dispersed in aqueous media due to being coated by a layer of hydrophilic polyol ligands in situ. Magnetic study shown that the ZnFe 2 O 4 nanoparticles had a low magnetic anisotropy and low magnetic moment compared to the conventional Fe 3 O 4 nanoparticles. As a result, the as-prepared ZnFe 2 O 4 nanoparticles provide an optimized r 2 /r 1 ratio for T 1 -weighted magnetic resonance imaging (MRI) in the clinical field strength. A preliminary in vitro cytotoxicity test suggests that the zinc ferrite nanoparticles possess a good safety profile. Therefore, the as-prepared ZnFe 2 O 4 nanoparticles have great potential to serve as a novel non-lanthanide T 1 MRI contrast agent.

Copper-containing antimicrobials are highly valuable in the field of medical disinfectants owing to their well-known high antimicrobial efficacy. Artificially synthesized nanozymes which can increase the level of reactive oxygen species (ROS) in the bacterial system have become research hotspots. Herein, we describe the design and fabrication of degradable Cu-doped phosphate-based glass (Cu-PBG) nanozyme, which can achieve excellent antibacterial effects against Gram-positive and Gram-negative bacteria. The antibacterial mechanism is based on the generation of ROS storm and the release of copper. It behaves like a peroxidase in wounds which are acidic and exerts lethal oxidative stress on bacteria via catalyzing the decomposition of H2O2 into hydroxyl radicals (•OH). Quite different from any other reported nanozymes, the Cu-PBG is intrinsically degradable due to its phosphate glass nature. It gradually degrades and releases copper ions in a physiological environment, which further enhances the inhibition efficiency. Satisfactory antibacterial effects are verified both in vitro and in vivo. Being biodegradable, the prepared Cu-PBG exhibits excellent in vivo biocompatibility and does not cause any adverse effects caused by its long-time residence time in living organisms. Collectively, these results indicate that the Cu-PBG nanozyme could be used as an efficient copper-containing antimicrobial with great potential for clinical translation.