Porous-structured NiO nanosheets, synthesized by means of a facile alcohol-thermal method, were utilized as a noble metal free catalyst for non-aqueous Li–O ₂ batteries. The NiO showed good activity for the decomposition of Li ₂ O ₂ and Li ₂ CO ₃ .

Although possessing extremely high energy density, lithium-oxygen (Li-O₂) battery suffered from large charge overpotential, low round-trip efficiency and poor cycling life, which limited the practical application of this smart system. Ru particles functionalized graphene aerogels (Ru-GAs) were designed and directly used as a free-standing cathode for Li-O₂ battery. The Ru-GAs showed hierarchical pores, which had the pore volumes of 2.8 and 14.1 cm³ g⁻¹ below and above critical pore diameter of 100 nm. The Ru-GA cathode in Li-O₂ battery delivered a high capacity of more than 12 000 mAh g⁻¹ and excellent cycling retention, which was mainly attributed to the three-dimensional porosity, abundant active sites with Ru particles and chemical stability arising from the character of binder-free cathode. Based on the results of in situ gas chromatography–mass spectrometry analysis, the reaction mechanism during charge process in aprotic electrolyte was proposed by the theory of three oxidation stages.

Network structured carbonized bacterial cellulose-supported Ru nanoparticles (CBC/Ru), which provide sufficient space for Li₂O₂ deposition without a significant volume effect and improve the transport of oxygen and electrons, were used as the binder-free oxygen electrode in a Li–O₂ battery.