MoS ₂ Nanosheets on Co _NPs -NC as a Bifunctional Catalyst for Oxygen Reduction/Evolution Reactions for High-Performance Li–O ₂ Batteries

Lithium–oxygen (Li–O 2 ) batteries exhibit an ultrahigh theoretical energy density, however, sluggish reaction kinetics and adverse parasitic reactions hinder their further development. Although carbon materials are widely used as oxygen reduction reaction (ORR) electrocatalysts due to their effective adsorption and stabilization of oxygen-rich intermediates (e.g., O 2 –, LiO 2 ), their inefficient electron transfer interfaces and severe parasitic reactions limit the oxygen evolution reaction (OER) performance. To address these issues, we designed an interface-engineered MoS 2 /Co NPs -NC heterostructured catalyst by in situ growth of MoS 2 nanosheets on MOF-derived Co NPs -NC substrates. The introduction of MoS 2 facilitates the in situ formation of Mo–N coupling centers; these Mo–N centers synergistically interact with the intrinsic Co–N x sites in Co NPs -NC to establish Co–N x /Mo–N dual-active catalytic centers─the core of the catalyst’s enhanced bifunctionality. This dual-coupling system effectively compensates for the insufficient OER activity of single Co NPs -NC catalysts while retaining its excellent ORR performance. These coordinated advantages enable the MoS 2 /Co NPs -NC cathode to deliver exceptional electrochemical performance: a low overpotential of 0.86 V, a high specific discharge capacity of 11,516.2 mAh g –1, and an extended cycling stability up to 206 cycles. This work underscores the exceptional potential of the MoS 2 /Co NPs -NC heterostructure as a high-performance catalytic cathode for advanced Li–O 2 battery systems.