Performance evaluation of carbon/PrBaCo₂O_5+δ composite electrodes for Li–O₂ batteries

Herein, a new type of perovskite oxide PrBaCo₂O_5+δ (PBCO) was synthesized and optimized by cooperating with carbon nanotubes (CNT) or carbon nanoparticles (BP2000), which was further applied into Li–O₂ battery cathode as a bi-functional cathode catalyst, achieving a high discharge capacity of 15.1 mA h, the number of which is over four times than that of single PBCO or CNT cathode, and seven times than single BP2000 cathode. Furthermore, a significantly enhanced stability was achieved as sustained more than 290 cycles at a fixed capacity, the number of which exceeds most carbon-based and even other perovskite catalytic Li–O₂ batteries. The charge transfer resistance (R_ct) of PBCO was reduced 46.6% after cooperating with carbon materials, which is almost half of single PBCO. All these results demonstrated that the big defect of PBCO can be remedied through the surface decorating with electronic conductors, such as, carbon nano-materials, and thus resulting in a substantially enhanced cathodic performance.