Universal Source‐Template Route to Metal Selenides Implanting on 3D Carbon Nanoarchitecture: Cu2−xSe@3D‐CN with SeC Bonding for Advanced Na Storage

Abstract The development of high‐performance sodium ion batteries (SIBs) is heavily relied on the exploration of the appropriate electrode material for Na + storage, which ought to feature merits of high capacity, easy‐to‐handle synthesis, high conductivity, expedite mass transportation, and stable structure upon charging–discharging cycle. Herein, a universal source‐template method is reported to synthesize a variety of transition metal (e.g., V, Sb, W, Zn, Fe, Co, Ni, and Cu) selenides implanting on N doped 3D carbon nanoarchitecture hybrids (M m Se n @3D‐CN) with powerful SeC bonding rivet. Benefiting from the superior architecture and potent SeC bonding between Cu 2−x Se and N‐doped 3D carbon (3D‐CN), the Cu 2−x Se@3D‐CN nanohybrids, as anode of SIBs, show high capacity, high‐rate capability, and long‐cycle durability, which can deliver a reversible capacity of as high as 386 mAh g −1 , retain 219 mAh g −1 even at 10 A g −1 , and run durably over thousands of charging–discharging cycles. The Cu 2−x Se@3D‐CN as anode is also evaluated by developing a full SIB by coupling with the Na 3 V 2 (PO 4 ) 3 cathode, which can deliver high energy density and show excellent stability, shedding light on its potential in practical application.