The increasing interest in future energy storage technologies has generated the urgent need for alternative rechargeable magnesium ion batteries due to their innate merits in terms of raw abundance, theoretical capacity, and operational safety. Herein, we report an alternative pathway to a new energy storage regime: toward advanced rechargeable magnesium-ion batteries based on WSe2 nanowire-assembled film cathodes. The as-grown electrodes delivered efficient Mg(2+) intercalation/insertion activity, excellent cycling life, enhanced specific capacity, and excellent rate capability. We also evaluated the influence of Mg-intercalation behavior on Mg-ion batteries based on WSe2 film cathodes via the first-principles DFT computations. The results reveal the feasibility of using advanced magnesium-ion batteries based on WSe2 film as energy storage components in next-generation optoelectronic systems.

Harmonious compatibility of high ET and electron mobility for highly efficient OLEDs.

By incorporating the pyridine ring to the different position of rigid phenanthroimidazole skeleton, three new pyridine-containing phenanthroimidazole derivatives, 1-phenyl-2-(4-(pyridin-3-yl)phenyl)-1H-phenanthro[9,10-d]imidazole(CPI-p3Py), 2-phenyl-1-(4-(pyridin-3-yl)phenyl)-1H-phenanthro[9,10-d]imidazole(NPI-p3Py) and 1,2-bis(4-(pyridin-3-yl)phenyl)-1H-phenanthro[9,10-d]imidazole(CNPI-p3Py), were designed and synthesized as electron-transport materials (ETMs). Their photophysical properties, energy levels and electron mobilities can be readily regulated through changing the connecting position. Through optimizing electron mobility and energy levels trade-offs, CNPI-p3Py exhibits not only lower-lying HOMO/LUMO energy levels, but also relatively higher electron mobility around 10 -3 cm 2 V -1 s -1 , which is 2-fold greater than that of the widely used material BPhen. More interesting, the blue fluorescent OLEDs with CPI-p3Py or CNPI-p3Py as an electron-transporting layer (ETL) exhibited superior performance compared to that using Bphen, remarkably lowering the driving voltage and improving efficiencies. In particular, the device with CNPI-p3Py as an ETL showed a maximum current efficiency of 15.17 cd A -1 , a maximum power efficiency of 10.65 lm W -1 , a maximum external quantum efficiency (EQE) of 7.75% and low efficiency roll-off even at an illumination-relevant luminance of 10,000 cd m -2 by the efficient utilization of the up-conversion of a triplet excited state, which are among the most efficient ETMs and proposes a new strategy for the molecular design of high-performance ETMs.