Cu-Fe-Mn层状氧化物钠离子电池正极材料前驱体的共沉淀制备及其电化学性能OA

In order to overcome the shortcomings of the traditional solid-phase synthesis method,the ammonia-alkali method and the oxalate coprecipitation methods were used to prepare the precursors of the Cu-Fe-Mn based cathode material for sodium-ion batteries.Subsequently,O3-type Na0.9[Cu0.22Fe0.30Mn0.48]O2 cathode materials were synthesized using these different precursors.The morphological structures and electrochemical properties of the precursors as well as the corresponding cathode materials prepared by various methods were systematically analyzed.The results showed that the primary particle sizes of the precursors prepared by two different methods were both in the range of also about 100-200 nm,with a uniform distribution.The layered oxide materials pre-pared from the two precursors were all flake crystals.The layered oxide prepared by the ammonia-alkali method has a particle size of approximately 2 μm,while the cathode material obtained via the oxalate precipitation method has a particle size of about 5-6 μm.Both of them possess an O3-type layered structure,with interlayer spacing of 0.333 29 nm and 0.327 34 nm respectively for the sodium layers.The first-cycle discharge specific capacities of the oxides obtained by the ammonia-alkali method and oxalate precipitation method were 90.50 and 90.04 mA·h/g at 0.1 C,respectively.After 50 cycles,the specific capacities were 89.26 and 80.92 mA·h/g,with capacity retentions of 98.63%and 89.87%,respectively.