Phosphide-Based Nanocomposites As High-Performance Anode Materials for Na-Ion Batteries

• Published in: Meeting abstracts (Electrochemical Society) Vol. MA2016-02; no. 5; p. 807
• Main Authors: Hong, Kyung-Sik, Nam, Do-Hwan, Lim, Sung-Jin, Sohn, DongRak, Kim, Tae-Hee, Kwon, HyukSang
• Format: Journal Article
• Language: English
• Published: 01.09.2016
• DOI: 10.1149/MA2016-02/5/807
• ISSN: 2151-2043

Recently, Li-ion batteries are widely used as energy sources for portable devices and electric vehicles. However, the price of Li sources is expected to rise due to the increase in the Li demand. Na-ion batteries are considered as promising energy sources for large-scale systems because of the great abundance and the low cost of the Na sources. For the anodic Na storage materials, phosphorus has great potential due to the highest theoretical capacity, the low cost, and non-toxic nature of the raw materials. However, all the previous reports on phosphorus-based materials were not able to utilize fully their theoretical Na storage capacity (2596 mAh/g) and showed poor rate capability because of low electrical conductivity. Herein, to solve this problem, we employed reducing particle size and designing a composite with conductive carbon by simple mechanical ball-milling method. The as-obtained tin phosphides, red phosphorus and carbon nanocomposites delivered a reversible charge capacity of 1266.8 mAh/g at the current density of 300 mA/g. Moreover, the electrode exhibited superior rate capability with a stable capacity of 426.9 mAh/g at the current density of 7500 mA/g. The improved electrochemical performances resulted from the nanosized tin phosphide particles reducing the diffusion length of the sodium ions and amorphous red phosphorus/carbon matrix effectively buffering the volume expansion during the cycling. Figure 1