Researchers are accustomed to utilizing traditional solid-state and sol–gel routes to synthesize Na 3 V 2 (PO 4 ) 3 (NVP). No regulation mechanism is proposed to illustrate the growth process of NVP in solvothermal environment. In current work, uniform spherical particles with positive charge are synthesized by molecular self-assembly of nanosphere micelles using structural guiding agent polyethylene glycol (PEG) and surfactant Cetyltrimethylammonium bromide (CTAB). Nanoflower-shaped NVP sample is successfully prepared in the 100 % methyl alcohol medium, derived from the plate V 2 O 5 (negative charge) combining with the nuclear nanospheres (positive charge) with the induction of electrostatic attraction. Based on the multi-dimensional tests and molecular dynamic calculation, the protective mechanism of polar solution for NVP system is proposed for the first time, that is, methanol solvent system can better protect the morphological features of NVP than water environment to maintain the original special nanoflower morphology. Due to the distinctive and stabilized nanoflower construction, the optimized NVP60 sample can provide more extra active sites for the efficient de-intercalation of Na + and possess a large contacting area with electrolyte, resulting in the facilitated kinetic characteristics and superior electrochemical performance. The optimized NVP60 cathode possesses superior sodium storage property in both half cell and full cell. This work proposes a synergetic strategy combining theory and experiment to design and synthesize the modified NVP-based cathode materials from the molecular bonding aspect, further promoting the development of high performance cathode for SIBs.
Man Zhang,Rui Wang,Zhenqiang Shi,Xuelian Huang,Weifeng Zhao,Changsheng Zhao
A novel family of multi-responsive, tough, and reversible hydrogels were prepared by the combination of dipole-dipole interaction, hydrogen bonding interaction and slightly chemical cross-linking, using monomers of acrylonitrile, sodium allylsulfonate and itaconic acid. Reversible gel-sol transition was achieved by the flexible conversion of the dipole-dipole interactions between acrylonitrile-acrylonitrile and acrylonitrile-sodium thiocyanate, and the hydrogels could freely form desired shapes. The dipole-dipole and hydrogen bonding interactions improved the mechanical strength of the hydrogels with a compressive stress of 2.38 MPa. Meanwhile, the hydrogels sustained cyclic compressive tests with 60% strain, and exhibited excellent elastic property. The hydrogels were sensitive to pH and ionic strength, and could keep their perfect spherical structures without any obvious cracks even after immersing in strong ionic strength (or pH) solution for several reversible cycles. Furthermore, the hydrogels were recycled for environmental pollution remediation, and showed great potential to be applied in water treatments and other related fields.
危险品化学品经营许可证（带存储）