When developing high performance lithium-ion batteries,high capacity is one of the key indicators.In the last decade,the progress of two-dimensional(2D)materials has provided new opportunities for boosting the storage capacity.Here,based on first-principles calculation method,we predict that MnN monolayer,a recently proposed 2D nodal-loop half-metal containing the metallic element Mn,can be used as a super high-capacity lithium-ion batteries anode.Its theoretical capacity is above 1554 mA·h/g,more than four times that of graphite.Meanwhile,it also satisfies other requirements for a good anode material.Specifically,we demonstrate that MnN is mechanically,dynamically,and thermodynamically stable.The configurations before and after lithium adsorption exhibit good electrical conductivity.The study of Li diffusion on its surface reveals a very low diffusion barrier(～0.12 eV),indicating excellent rate performance.The calculated average open-circuit voltage of the corresponding half-cell at full charge is also very low(～0.22 V),which facilitates higher operating voltage.In addition,the lattice changes of the material during lithium intercalation are very small(～1.2％-～4.8％),which implies good cycling performance.These results suggest that 2D MnN can be a very promising anode material for lithium-ion batteries.