Superior Sodium Research Articles

Pseudocapacitive sodium-ion storage in one-dimensionally structured anatase TiO2 nanofiber anode for high performance sodium-ion batteries

Nanofibers provide high surface area to volume ratio, vectoral conduction, fast ionic diffusion, and short pathways for sodium ions. Titania nanofibers exhibit excellent electrochemical performance when used for sodium-ion storage. One-dimensional titania nanofiber was synthesized by an electrospinning process as an anode material for high capacity sodium-ion batteries. The electrochemical kinetics of titania nanofiber for sodium-ion storage were examined. Titania nanofiber exhibited pseudocapacitive capacitive properties with high rate performance, giving capacity of 97 mA h g−1 after 1000 cycles with a current density of 1000 mA g−1. Even when current rate returned to the initial current density of 50 mA g−1, titania nanofiber electrode capacity climbed to 206 mA h g−1 again without capacity fading, which indicated good rate performance, superior sodium insertion/extraction reaction, and high reversible capacity.

Superior sodium and lithium storage in strongly coupled amorphous Sb2S3 spheres and carbon nanotubes

Superior sodium and lithium storage in strongly coupled amorphous Sb2S3 spheres and carbon nanotubes

Nitrogen and sulfur co-doped hollow carbon nanofibers decorated with sulfur doped anatase TiO2 with superior sodium and lithium storage properties

Nitrogen and sulfur co-doped hollow carbon nanofibers decorated with sulfur-doped anatase TiO2 (NSHCNF@STiO2) has been synthesized through a simple hydrothermal reaction process followed by a calcination treatment, in which uniform sulfur-doped anatase TiO2 nanoparticles are firmly attached to the nitrogen and sulfur co-doped HCNF matrix. When the as-designed NSHCNF@STiO2 composite is utilized as anode material for sodium and lithium storage, it delivers an enhanced electrochemical performance, which can be attributed to three synergic effects: (1) the core–shell and stable 3D network-like structures woven by nitrogen and sulfur co-doped HCNF in the NSHCNF@STiO2 composite can accommodate stress from cycling and provide a beneficial conductive environment; (2) the doping of sulfur can lower the electronic resistance of TiO2 and increase the interlayer distance of carbon; (3) the uniform sulfur-doped anatase TiO2 attachment can further shorten the electron and ion pathways during electrochemical cycling. These findings indicate that the NSHCNF@STiO2 composite has a great potential as TiO2-anode materials for sodium and lithium storage.

Renal and hormonal responses to prolonged atrial stretch

The relationship between prolonged (6 h) atrial stretch, urine output, and plasma atrial natriuretic factor (ANF) was investigated in conscious rats. On inflation of a balloon at the superior venal caval-right atrial junction, urine volume and sodium output increased. However, this renal response was no longer apparent after the first hour, and there were no further changes in urine output when the balloon was deflated. This transient renal response was most marked during the first 30 min of balloon inflation, at which time plasma ANF was also elevated. At 6 h, plasma ANF was still elevated, although urine output had, by then, returned to normal. On deflation of the balloon, plasma ANF levels returned to normal. It is clear that the renal and hormonal responses to atrial stretch may be temporally uncoupled. This probably reflects adaptation of the atrial volume receptors in the absence of such an effect on ANF release. Although this might be interpreted to mean that ANF is not of physiological importance in fluid and electrolyte balance, a more plausible explanation is that ANF needs the backing of the reflex pathways arising from stimulation of the atrial receptors to express its natriuretic activity.