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Potentially safe and economically feasible magnesium batteries (MBs) have attracted tremendous research attention as an alternative to high-cost and unsafe lithium ion batteries. In the current work, for the first time, we report a novel room-temperature approach to dope the atomic species sodium between the vanadium oxide crystal lattice to obtain NaV3O8·1.69H2O (NVO) nanobelts. The synthesized NVO nanobelts are used as electrode materials for MBs. The MB cells demonstrate stable discharge specific capacity of 110 mA h g-1 at a current density of 10 mA g-1 and a high cyclic stability, that is 80% capacity retention after 100 cycles, at a current density of 50 mA g-1. Moreover, the effects of cutoff voltages (ranging from 2 to 2.6 V) on their electrochemical performance were investigated. The reason for the limited specific capacity of MBs is attributed to the trapping of Mg ions inside the NVO lattices. This work opens up a new pathway to explore different electrode materials for MBs with improved electrochemical performance.

Although various kinds of catalysts have been developed for aprotic Li-O2 battery application, the carbon-based cathodes are still vulnerable to attacks from the discharge intermediates or products, as well as the accompanying electrolyte decomposition. To ameliorate this problem, the free-standing and carbon-free CoO nanowire array cathode was purposely designed for Li-O2 batteries. The single CoO nanowire formed as a special mesoporous structure, owing even comparable specific surface area and pore volume to the typical Super-P carbon particles. In addition to the highly selective oxygen reduction/evolution reactions catalytic activity of CoO cathodes, both excellent discharge specific capacity and cycling efficiency of Li-O2 batteries were obtained, with 4888 mAh gCoO(-1) and 50 cycles during 500 h period. Owing to the synergistic effect between elaborate porous structure and selective intermediate absorption on CoO crystal, a unique bimodal growth phenomenon of discharge products was occasionally observed, which further offers a novel mechanism to control the formation/decomposition morphology of discharge products in nanoscale. This research work is believed to shed light on the future development of high-performance aprotic Li-O2 batteries.

Spherical carbon material with large pore volume and specific area was designed for lithium/sulfur (Li/S) soft package battery cathode with sulfur loading over 75%, exhibiting good capacity output (about 1300 mAh g(-1)-S) and excellent capacity retention (70% after 600 cycles) at 0.1 C. The spherical carbon is prepared via in situ steam etching method, which has the advantages of low cost and easy scale up.