Facile synthesis of hollow Cu3P for sodium-ion batteries anode

Combining metal to form metal phosphide is a promising strategy to address the fast capacity decay of P rooted from its low electronic conductivity and large volume changes upon cycling. Cu3P, which possesses a high theoretical gravimetric and volumetric capacity of 363 mAh.g(-1) and 1028 Ah.L-1 and reasonable volume expansion of 156% during sodiation, was investigated as anode material in SIBs. Hollow-structured Cu3P electrode delivers an initial de-sodiation capacity of similar to 159.0 mAh.g(-1) with high capacity retention of similar to 85.1% over 50 cycles at 0.2C rate and exhibits good rate performance, retaining 70% of the capacity when the current density increases from 0.2C to 1.6C. A 3 V-class full cell consisting of P2-Na2/3Ni1/3Mn1/2Ti1/6O2 cathode and Cu3P anode was also assembled, which could achieve an energy density of similar to 189.3 Wh.kg(-1) (based on the mass of both electrode materials) and average discharge voltage of similar to 2.91 V when cycled in 1.0-4.3 V at 0.1C.