For more information, please follow the official account - "CamCellLab" introduction: Sodium ion batteries are favored in fixed and large-scale power storage due to their low cost, good safety, non-toxicity and zero-voltage transportation. Among the positive electrode materials o

For more information, please follow the official account--"CamCellLab"

Introduction: Sodium ion battery is favored in fixed and large-scale power storage due to its low cost, good safety, non-toxicity and zero-voltage transportation. Among the positive electrode materials of sodium ion batteries, there are three main types, namely layered oxides, Prussian types and polyanions. Taking into account cost factors, the cheapness of the processing method will directly affect the use of lithium-ion battery .

In the world-renowned journal Nature, it recently published a new method developed by researchers from the City of Science Research and Technology Application in Alexandria, Egypt. The cost and time required for each preparation step is greatly reduced.

researchers used Egyptian straw ash as a microwave absorber to synthesize, crystallize and carbon-coated mixture of sodium iron phosphate-carbon composites (NaFePO 4 -C).

Figure 1: First discharge curve showing the discharge capacity (0.2 C magnification) of samples prepared by microwave heating at different times

This positive electrode active material can be prepared using different microwave heating times. The researchers found that the optimal synthesis time for sodium ion batteries is 1 minute. The synthetic material is discharged at 0.2C and an energy density of nearly 110 mAh/g can be obtained. After 40 cycles, the capacity can still be maintained at 93%. The biggest feature of this method is that it does not require high-purity inert gas, thereby reducing costs.

"CamCellLab" official account found that the rapid heating of this method does not allow crystal growth to be completed, and the shape and size of the particles produced are irregular and uneven. These particles tend to agglomerate, forming larger particles with an average size of about 300 nm, which limits the diffusion of sodium ion . This is what this method needs to be improved in the future. At the same time, the extremely short synthesis time and low energy consumption of this sodium ion battery cathode material are incomparable to any previous manufacturing method.