Atomic Insights into Ti Doping on the Stability Enhancement of Truncated Octahedron LiMn2O4 Nanoparticles

Ti-doped truncated octahedron LiTixMn2-xO4 nanocomposites were synthesized through a facile hydrothermal treatment and calcination process. By using spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM), the effects of Ti-doping on the structure evolution and stability enhancement of LiMn2O4 are revealed. It is found that truncated octahedrons are easily formed in Ti doping LiMn2O4 material. Structural characterizations reveal that most of the Ti4+ ions are composed into the spinel to form a more stable spinel LiTixMn2−xO4 phase framework in bulk. However, a portion of Ti4+ ions occupy 8a sites around the {001} plane surface to form a new TiMn2O4-like structure. The combination of LiTixMn2−xO4 frameworks in bulk and the TiMn2O4-like structure at the surface may enhance the stability of the spinel LiMn2O4. Our findings demonstrate the critical role of Ti doping in the surface chemical and structural evolution of LiMn2O4 and may guide the design principle for viable electrode materials

FIB-Assisted Fabrication of Single Tellurium Nanotube Based High Performance Photodetector

Nanoscale tellurium (Te) materials are promising for advanced optoelectronics owing to their outstanding photoelectrical properties. In this work, high-performance optoelectronic nanodevice based on a single tellurium nanotube (NT) was prepared by focused ion beam (FIB)-assisted technique. The individual Te NT photodetector demonstrates a high photoresponsivity of 1.65 × 104 AW−1 and a high photoconductivity gain of 5.0 × 106%, which shows great promise for further optoelectronic device applications

FIB-Assisted Fabrication of Single Tellurium Nanotube Based High Performance Photodetector

Nanoscale tellurium (Te) materials are promising for advanced optoelectronics owing to their outstanding photoelectrical properties. In this work, high-performance optoelectronic nanodevice based on a single tellurium nanotube (NT) was prepared by focused ion beam (FIB)-assisted technique. The individual Te NT photodetector demonstrates a high photoresponsivity of 1.65 × 104 AW−1 and a high photoconductivity gain of 5.0 × 106%, which shows great promise for further optoelectronic device applications

Atomic Insights into Ti Doping on the Stability Enhancement of Truncated Octahedron LiMn₂O₄ Nanoparticles

Ti-doped truncated octahedron LiTixMn2-xO4 nanocomposites were synthesized through a facile hydrothermal treatment and calcination process. By using spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM), the effects of Ti-doping on the structure evolution and stability enhancement of LiMn2O4 are revealed. It is found that truncated octahedrons are easily formed in Ti doping LiMn2O4 material. Structural characterizations reveal that most of the Ti4+ ions are composed into the spinel to form a more stable spinel LiTixMn2−xO4 phase framework in bulk. However, a portion of Ti4+ ions occupy 8a sites around the {001} plane surface to form a new TiMn2O4-like structure. The combination of LiTixMn2−xO4 frameworks in bulk and the TiMn2O4-like structure at the surface may enhance the stability of the spinel LiMn2O4. Our findings demonstrate the critical role of Ti doping in the surface chemical and structural evolution of LiMn2O4 and may guide the design principle for viable electrode materials

Atomically intimate solid electrolyte/electrode contact capable of surviving long-term cycling with repeated phase transitions

The electrode–electrolyte contact issue within the composite electrode layer is a grand challenge for all-solid-state Li batteries. In order to achieve cycling performances comparable to Li-ion batteries based on liquid electrolyte, the aforementioned solid–solid contact not only needs to be sufficiently thorough but also must tolerate repeated cycling. Simultaneously meeting both requirements is rather challenging. Here, we discover that epitaxy may effectively overcome such bottlenecks even when the electrode undergoes repeated phase transitions during cycling. Through epitaxial growth, the perovskite Li0.33La0.56TiO3 solid electrolyte was found capable of forming atomically intimate contact with both the spinel Li4Ti5O12 and rock-salt Li7Ti5O12. In contrast to conventional expectations, such epitaxial interfaces can also survive repeated spinel-to-rock-salt phase transitions. Consequently, the Li4Ti5O12–Li0.33La0.56TiO3 composite electrode based on epitaxial solid–solid contact delivers not only a rate capability comparable to that of the surry-cast one with solid–liquid contact but also an excellent long-term cycling stability