Constructing MOF-derived CoP-NC@MXene sandwich-like composite by in-situ intercalation for enhanced lithium and sodium storage

The development of dual-function anode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)is exceedingly essential.Herein,with rationally designed hierarchical metal-organic framework(MOF)@MXene as a precursor,a novel sandwich-like CoP-NC@Ti_(3)C_(2)T_(x) composite has been successfully fabricated by the following phosphorization reaction.As anode material for LIBs,the CoPNC@Ti_(3)C_(2)T_(x) composite exhibits remarkable electrochemical performance with high-rate capability(147.8 mAh g^(-1) at 2000 mA g^(-1);245.6 mAh g^(-1) at 100 mA g^(-1))and ultralong cycling life(2000 cycles with a capacity retention over 100%).For SIBs,it delivers a discharge capacity of 101.6 mAh g^(-1) at a current density of 500 mA g^(-1) after 500 cycles.The well-designed sandwich-like composite effectively supports the easy access to electrolyte,facilitate the Li/Na ion transportation,and protect the active material from pulverization upon long cycling.In addition,the electrochemical reaction kinetics and Li-migration kinetics of the CoP-NC@Ti_(3)C_(2)T_(x) composite have been pioneeringly illuminated by pseudocapacitive behavior calculation and density functional theory(DFT)computations,respectively.This work sheds light on the rational design and development of MOF/MXene-derived dual-function anode materials for Li/Na-storage.