초록 |
Li ion batteries have become widely accepted as an effective device for storing electric energy in recent decades. In practice, it can play an important role in present energy industries for offering the highest energy density. However, there are still problems to be solved such as limit in remote, cost, and safety. To date, Na ion batteries has been considerably interested in the field of large energy storage system (ESS) because of needs to go beyond the limits of Li ion batteries. Extensive investigations on alloying reactions of various transition metal (Sn, Sb, Ge, Si etc) as anode materials have been carried out because of their high theoretical capacity. Inspired by this point, phosphorus is one of the most promising candidate with a high theoretical specific capacity (2596 mA h g-1) at the discharge potential range of 0.4-1.2 V. In this paper, we have synthesized 3D structured red P-Carbon composite by facile templating method. For this process, we anticipated a lot of merits such as suppressing the large volume expansion (~300%), offering large reaction site, and minimizing the unnecessity like binders and additives. The electrochemical performance of red P-CNT composites were tested in sodium non-aqueous electrolytes. It could maintain the reversible capacity in high C-rate because of their structural advantage. In addition, differences of structural phase differences and conductivity during the alloying reactions in sodium system will be discussed. |