Cobalt nanoparticles decorated hollow N-doped carbon nanospindles enable high-performance lithium-oxygen batteries

Despite the ultrahigh theoretical energy density and cost-effectiveness, aprotic lithium-oxygen (Li-O 2 ) batteries suffer from slow oxygen redox kinetics at cathodes and large voltage hysteresis. Here, we well-design ultrafine Co nanoparticles supported by N -doped mesoporous hollow carbon nanospindles (Co@HCNs) to serve as efficient electrocatalysts for Li-O 2 battery. Benefiting from strong metal-support interactions, the obtained Co@HCNs manifest high affinity for the LiO 2 intermediate, promoting formation of ultrathin nanosheet-like Li 2 O 2 with low-impedance contact interface on the Co@HCNs cathode surface, which facilitates the reversible decomposition upon charging. The mesoporous hollow nanospindles can provide abundant electron/ions transport channels to synergistically accelerate the formation and decomposition of discharge products. The Li-O 2 battery based on Co@HCNs displays remarkably reduced discharge/charge polarization of 0.92 V, impressive rate performance, and stable operation for 250 cycles. This work will provide a new avenue to design advanced oxygen electrocatalysts for high-performance Li-O 2 battery.