Porous RuO2 nanosheet/CNT electrodes for DMSO-based Li-O2 and Li ion O2 batteries

Two-dimensional (2D) porous RuO2 nanosheets are synthesized using graphene oxide as the template, on which numerous holes of a few nanometers in diameter are simultaneously created. The holey RuO2 nanosheets are rationally assembled with carbon nanotube (CNT) interlayers to form a hybrid with highly enhanced mass/electron transport through the conductive, porous structure. The 2D/1D hybrid electrodes deliver exceptional performance in Li-oxygen batteries (LOBs). The first-principle calculations combined with microscopy reveal that Li2O2 interacts strongly with RuO2 and thermodynamically follows a Stranski-Krastanov growth mode. The state hybridization transforms inherently insulative Li2O2 conductive, reducing the overpotentials encouraged by the Ohmic loss. The highly LiO2-soluble dimethyl sulfoxide-based electrolyte is employed for the first time to prepare Li ion oxygen batteries (LIOBs) through refining the solid-electrolyte interphase and concentrated electrolyte. This approach effectively mitigates the energy mismatch present between the lowest unoccupied molecular orbitals of electrolyte and the work functions of Si/C anode. The LIOBs with the developed RuO2/CNT hybrid electrodes deliver cyclic stability and ultrahigh gravimetric energy and power densities up to 1897 W h kg(-1) and 1396 W kg-1, respectively. This work offers new insights into designing highly porous 2D/1D oxygen catalysts together with highly LiO2-soluble electrolytes for high-performance LOBs/LIOBs.