The Na1+xAlxTi2?x(PO4)3/C (x?=?0, 0.05, 0.10, 0.20) composites serving as anode for aqueous sodium ion battery are successfully synthesized through a facile sol–gel route. The results indicate that introduction of proper amount of aluminum has no obvious effect on the structure and morphology of NaTi2(PO4)3/C. Among the four synthesized samples, Na1.1Al0.1Ti1.9(PO4)3/C (NATP-0.10) exhibits the best electrochemical performance. NATP-0.10 delivers a discharge specific capacity of 115.8, 106.9, 98.4, and 89.1 mAh g?1 at 2, 5, 10, and 20 C rate, respectively, and still retains 114.7 mAh g?1 when the current density comes back to 2 C. Additionally, NATP-0.10 exhibits an initial discharge capacity of 102.9 mAh g?1 and still retains a reversible capacity of 90.1 mAh g?1 at 10 C rate after 200 cycles. Cyclic voltammetry and electrochemical impedance spectroscopy demonstrate the better electrochemical performance of NATP-0.10 is due to the faster sodium migration and enhanced electrochemical kinetics.
Graphical abstract
Al doping Na1+xAlxTi2?x(PO4)3/C (x?=?0, 0.05, 0.10, 0.20) composites were firstly used as anodes in aqueous SIBs. The electrochemical performance of NaTi2(PO4)3/C has been improved by introducing a proper amount of Al.
In this paper, we describe the reliability evaluation for MEMS devices, especially designed tbr DVD(Digital Video Disk) application.
These MEMS devices are fabricated as a mirror plane (shutter plane) used in DVD data picking up. This micromachined annular
shutter mirror (ASM) acts as an adjusting means of the numerical aperture. The electrostatic force can drive the upper plane
up and down for focusing or defocusing of incident laser beam to the selected recording plane. So we need to evaluate the
micromechanical properties of thin film structural materials to ensure the reliability of those MEMS devices. For those, we
perfl)rm the fatigue tests onto the devices in the conditions of much accelerated than those of normal driving. The applied
electrostatic force can induce the change of the thin film properties, and those are observed by direct and indirect methods
(XRD and electrical system). And then, we compare the fatigue effects with electrical, optical data from the intentionally-fatigue-applied
specimen and as-fabricated one under accelerated conditions. Consequently, we can estimate the structural reliability and
will provide the effective suggestion data for the fabrication of stable mirror material before commercialization. 相似文献