Improvement of the High-Performance Al-Doped LiNi1/3Co1/3Mn1/3O2 Cathode Material for New Electro-Optical Conversion Devices

The ternary cathode material LiNi1/3Co1/3Mn1/3O2 has been extensively focused on as the power sources for new electro-optical conversion devices and lithium-ion batteries. To improve the electrochemical performance, Al doping is one of the effective strategies. Based on the density functional theory of first-principles, the band gap, volume, partial density of states, lithiation formation energy, electron density difference, and electrons’ potential energy of Li1.0-xAlxNi1/3Co1/3Mn1/3O2 were simulated and analyzed with Materials Studio, Nanodcal and Matlab. Results show that Li0.9Al0.1Ni1/3Co1/3Mn1/3O2 has a better conductivity and cycling capability. The potential energy maps of Li1.0-xAlxNi1/3Co1/3Mn1/3O2 simulated in Matlab indicate that the rate capability of LiNi1/3Co1/3Mn1/3O2 is promoted after Al doping. Our theoretical advice could be an important choice for the power application of new optoelectronic devices. In addition, our methods could provide some theoretical guidance for the subsequent electrochemical performance investigations on doping of optoelectronic devices or lithium-ion battery materials.

1.5-W 520 nm Continuous-wave Output from a 50μm/0.22NA Fiber-Coupled Laser Diode Module

In this paper, a high brightness fiber-coupled module with a central wavelength of 520nm is simulated and designed by ray-tracing software ZEMAX, and then is experimentally implemented. Three 1-w continuous-wave green LD single emitters based on TO-9-package are successively collimated, spatially combined, and focused into an optical fiber with a core diameter of 50 μm and a numerical aperture of 0.22. The final output power of 1.53w is obtained, corresponding to an optical-optical conversion efficiency of 51% and an electro-optical conversion efficiency of 10%, and the tolerance between the simulation and the experimental result is analyzed and explained.

Improvement in luminescent properties and thermo-optical conversion mechanism of Na2SiF6:Mn4+,K+@GQDs

The optimal sample exhibits high stability due to large negative thermal quenching. The mechanism of negative thermal quenching is suggested to be the conversion of thermal energy into light energy.