With the development of renewable energy sources,emerging energy storage systems have received a lot of attention. Sodium-on batteries have attracted extensive attention in the field of large-scale energy storage due to their abundant sources, safety,low cost,environmental friendliness and ease of use.The cathode materials of sodium-ion batteries affect the key properties of the battery such as energy density,cycling performance and multiplication characteristics.Currently,three cathode materials for sodium ion batteries have entered the industrialization horizon,namely layered transition metal oxides,polyanionic compounds and Prussian blue compounds.This paper summarizes the classification,properties,and research progress of main cathode materials for sodium-ion batteries,and anticipates the prospect of the potential research.

The preparation of activated carbon from residue of a distillation reactor is an efficient and economical strategy for the utilization of hazardous waste resources.However,the prepared activated carbon is generally powdered,which is difficult to meet the requirements of industrial application.In this work,the activated carbon microspheres were prepared based on the rectification residue activated carbon from the powders,using deionized water as the solvent and polyacrylic acid (PAA),sodium alginate (SA) and Ca²⁺ as the additives.The effects of SA,Ca²⁺ and PAA amount on the structure and mechanical strength of the activated carbon microspheres were investigated.X?ray diffraction,Fourier transform infrared spectroscopy and Raman spectroscopy were used to investigate the shaping mechanism of activated carbon microspheres.The activated carbon microspheres were applied in the tetracycline adsorption,and the maximum adsorption capacity of tetracycline was up to 257.8 mg/g.At the same time,after 9 months of water stability test,the activated carbon microspheres still had good adsorption performance and mechanical strength. This shaping strategy adopted green and economical raw materials,which could effectively solve the problems of powder shaping and poor performance of microspheres,and provide the effective solution for the industrial application of high?performance materials.