In Situ Constructing of Rigid-Soft Coupling Solid-Electrolyte Interphase on Silicon Electrode toward High-Performance Lithium Ion Batteries.

The application of Si anodes is hindered by some critical issues such as large volume changes of bare Si and fragile solid-electrolyte interface (SEI), resulting in low coulombic efficiency and rapid capacity decay. Herein, a multifunctional SEI film with high content of LiF is in situ constructed via the surface grafting of carbon-fluorine functionalized groups on silicon nanoparticles (SiNPs) during cycling. Mechanical study demonstrates that the incorporation of LiF with high modulus and unbroken carbon-fluorine groups with highly elastic guarantee the rigid-soft coupling SEI film on Si electrode. Furthermore, it is demonstrated that the rigid-soft coupling SEI film can effectively accommodate the volume expansion of Si nanoparticles during lithiation process, with the electrode expanding rate of only 114.16% after 100 cycles (263.87% for bare Si without surface modification). Afterward, with the aid of well-designed rigid-soft coupling SEI, the initial Coulomb efficiency of 89.8% is achieved, showing a reversible capacity of 1477 mAh g-1 after 200 cycles at 1.2 A g-1 . This work provides a simple and efficient solution that can potentially facilitate the practical application of Si anodes.

Silicon Cutting Waste Derived Silicon Nanosheets with Adjustable Native SiO2 Shell for Highly-Stable Lithiation/Delithiation.

Silicon is an excellent candidate for the next generation of ultra-high performance anode materials, with the rapid iteration of the lithium-ion battery industry. High-quality silicon sources are the cornerstone of the development of silicon anodes, and silicon cutting waste (SCW) is one of them while still faces the problems of poor performance and unclear structure-activity relationship. Herein, a simple, efficient, and inexpensive purification method is implemented to reduce impurities in SCW and expose the morphology of nanosheets therein. Furthermore, HF is used to modulate the abundant native O in SCW after thermodynamic and kinetic considerations, realizing the mechanical support for the internal Si in the form of an amorphous SiO2 shell. Afterward, SCNS@SiO2 -2.5 with a 1.0 nm thick SiO2 shell exhibits a reversible capacity of 1583.3 mAh g-1 after 200 cycles at 0.8 A g-1 . Ultimately, the molecular dynamics simulations profoundly reveal that the amorphous SiO2 shell is transformed into the extremely ductile Lix SiOy shell to ditch stress and relieve strain during the lithiation/delithiation process.

Boron-Doped Spherical Hollow-Porous Silicon Local Lattice Expansion toward a High-Performance Lithium-Ion-Battery Anode.

Silicon (Si) attracts extensive attention as the advanced anode material for lithium (Li)-ion batteries (LIBs) because of its ultrahigh Li storage capacity and suitable voltage plateau. Hollow porous structure and dopant-induced lattice expansion can enhance the cycling stability and transporting kinetics of Li ions. However, it is still difficult to synthesize the Si anode possessing these structures simultaneously by a facile method. Herein, the lightly boron (B)-doped spherical hollow-porous Si (B-HPSi) anode material for LIBs is synthesized by a facile magnesiothermic reduction from B-doped silica. B-HPSi exhibits local lattice expansion located on boundaries of refined subgrains. B atoms in Si contribute to the increase of the conductivity and the expansion of lattices. On the basis of the first-principles calculations, the B dopants induce the conductivity increase and local lattice expansion. As a result, B-HPSi electrodes exhibit a high specific capacity of ∼1500 mAh g-1 at 0.84 A g-1 and maintains 93% after 150 cycles. The reversible capacities of ∼1250, ∼1000, and ∼800 mAh g-1 can be delivered at 2.1, 4.2, and 8.4 A g-1, respectively.

Si nanoflake-assembled blocks towards high initial coulombic efficiency anodes for lithium-ion batteries.

Assisted by artificial amorphous copper silicate, Si with a flake-like structure was obtained through a facile magnesiothermic reduction. The Si anodes exhibit excellent cyclic performance and rate performance. Particularly, a high initial coulombic efficiency of 85%-89% was obtained due to their greatly reduced surface and internal defects.

Relationship between resilience, social support as well as anxiety/depression of lung cancer patients: A cross-sectional observation study.

OBJECTIVE: The mood of patients with lung carcinoma would be greatly influenced by the diagnosing and treating processes. This study was aimed to explore the effects of resilience between social assistance and anxiety/depression of patients with lung cancer, which may assist in clinical intervention. DESIGN AND METHODS: A cross-sectional pilot study was conducted on lung cancer patients at Xiangya Hospital of Central South University, China. A total of 289 patients aged 25-81 years were included in this study. RESULTS: Correlational analyses revealed that anxiety/depression was negatively associated with psychological resilience and each dimension of social assistance, including subjective support, objective support along with the supports utilization (P < 0.01). Furthermore, psychological resilience was positively related to subjective support (P < 0.01), support utilization (P < 0.01) along with objective support (P < 0.05). Mediational analyses showed that, on the one hand, resilience could partially mediate the relation between anxiety and subjective support and totally mediate the relationship between support utilization and anxiety. On the other hand, resilience could totally mediate the relation between depression and subjective support and partially mediate the relation between support utilization and depression. However, resilience did not play an intermediary role between anxiety/depression and objective support. CONCLUSION: Lower psychological anxiety and depression would be experienced by lung cancer patients with higher resilience and social support. The level of anxiety and depression would be indirectly affected by social support through the mediation of resilience.