Facile fabrication of two-dimensional reduced graphene oxide/CoAl-layered double hydroxides nanocomposites for lithium-oxygen battery with improved electrochemical performance

Hybrids of layered double hydroxides (LDHs) and graphene-based nanocomposites have invoked a great deal of interest due to the unique and highly tunable composition and properties. Herein, CoAl-LDHs nanosheets were in-situ incorporated with reduced graphene oxide (rGO) via a simple one-step reflux method to improve the electrochemical performance of lithium-oxygen (Li−O2) battery. The obtained nanocomposites tended to decrease the particle size of CoAl-LDHs nanosheets and endowed more catalytic active sites. Benefiting from the synergistic effect, the fabricated rGO/CoAl-LDHs nanocomposites enhanced the charge transfer process and the first discharge specific capacity up to 300% higher than the pristine rGO under the same condition. In addition, the battery showed excellent cycling stability with no capacity loss over 30 cycles, as well as markedly lower recharge voltage. The results provide a facile way to prepare two-dimensional cathode material for Li−O2 battery. [Display omitted] •2D rGO/CoAl-LDHs nanocomposites is fabricated via a simple one-step reflux method.•The CoAl-LDHs nanosheets induce the uniform deposition of Li2O2.•The CoAl-LDHs nanocomposites exhibit high capacity and good cycling stability.•The performance is ascribed to the unique structure of the nanocomposites.