Design and preparation of carbon-coated NaZnFe(MoO4)3 composite as novel anode materials for lithium/sodium-ion batteries

The investigation of new anode materials with novel crystal structure and high ionic conductivity is of great significance for potential applications in lithium/sodium-ion batteries. Herein, carbon-coated NaZnFe(MoO₄)₃ composite was produced by solid state method coupled with the mechanical ball milling technique. The crystal and morphology were accurately confirmed by XRD, XPS and SEM techniques. When tested with lithium-ion batteries, the charging capacity reached an impressive 1005 mA h g⁻¹ during the initial cycle and 840 mA h g⁻¹ after 50 cycles, resulting in a capacity retention of 84.2 %. This performance is 40 % higher than that of the sample without a carbon layer coating. When utilized as an anode for sodium-ion batteries, the carbon-coated NaZnFe(MoO₄)₃ composite electrode exhibited a remarkable specific capacity of 152 mA h g⁻¹ and a high capacity retention of 74.9 % after 100 cycles at a rate of 100 mA g⁻¹. Furthermore, the charge capacity was measured at 105 mA h g⁻¹ after 500 cycles test conducted at 500 mA g⁻¹, with a capacity retention of 86.0 %. The advantages of polyanionic molybdate NaZnFe(MoO₄)₃ combined with the simple carbon coating strategy make it possible to application in the next generation of Li/Na secondary batteries.