Selenium-impregnated carbon composites were synthesized by infusing Se into mesoporous carbon at a temperature of 600 °C under vacuum. Ring-structured Se8 was produced and confined in the mesoporous carbon, which acts as an electronic conductive matrix. During the electrochemical process in low-cost LiPF6/EC/DEC electrolyte, low-order polyselenide intermediates formed and were stabilized by mesoporous carbon, which avoided the shuttle reaction of polyselenides. Exceptional electrochemical performance of Se/mesoporous carbon composites was demonstrated in both Li-ion and Na-ion batteries. In lithium-ion batteries, Se8/mesoporous carbon composite cathodes delivered a reversible capacity of 480 mAh g(-1) for 1000 charge/discharge cycles without any capacity loss, while in Na-ion batteries, it provided initial capacity of 485 mAh g(-1) and retained 340 mAh g(-1) after 380 cycles. The Se8/mesoporous carbon composites also showed excellent rate capability. As the current density increased from 0.1 to 5 C, the capacity retained about 46% in Li-ion batteries and 34% in Na-ion batteries.

A method that is used by space-confining NaAlH 4 into the as-synthesized ordered mesoporous silica (OMS) is presented in the present work. NaAlH 4 in the pores of OMS is obtained by impregnation and drying techniques. It has been found that the space-confined NaAlH 4 in the pores of OMS shows the lower temperature and faster kinetics for dehydrogenation than that of the pristine NaAlH 4 . Moreover, in the absence of a catalyst, the rehydrogenation in a dehydrogenated NaAlH 4 system with nanoscale particles and phases can be achieved even with the temperatures of 125-150 °C and the hydrogen pressures of 3.5-5.5 MPa. The physical limitation of the NaAlH 4 particles, as well as the resulting Al and NaH phases, to be nanoscale in size by the pores of OMS is believed to be responsible for these.

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The lithium-sulfur battery is currently considered to be a promising candidate for next-generation energy storage devices. However, its commercial application is severely restricted by rapid capacity decay mainly arising from unavoidable dissolution of intermediate lithium polysulfide of the S-based cathodes. Herein, multifunctional stripped grapheme-carbon nanotubes (SG-CNT) with 1D/2D interwoven and hierarchical pore structure as a promising host to stabilize S was constructed by cheaper raw materials and a facile strategy. Based on comprehensive analysis, the interwoven network and hierarchical pores along with abundant oxidative functional groups in matrix provided large contact area with S, short transport pathway for electrons/Li-ions, sufficient space to accommodate volumetric change, and superior confinement ability for S/polysulfides, thus resulting in effectively stabilizing the S cathode with high S loading and increasing its utilization. Therefore, the S@SG-CNT cathodes exhibited a high reversible capacity of 1227 mAh g -1 at 0.1 A g -1 , excellent cyclability with a capacity of 773 mAh g -1 after 500 cycles at 0.2 A g -1 , and ultra-long cycling performance with capacity decay less than 0.01% per cycle at 2 A g -1 . This facile strategy and unique construction of superior performance cathode provide a new avenue for next commercial application.