Improving the Stability of Microporous Red Phosphorus Anodes Using Conductive Polymer coating in lithium batteries

Abstract

Red phosphorous (Red P) has attracted considerable attention as a new anode material for a lithium or sodium ion batteries (LIB/ SIB) due to its high theoretical specific capacity (2596 mAh g-1), low cost, and environmental friendliness. However, in practical applications as an anode, the red P has critical challenges, such as extremely low electrical conductivity (10-12 S m-1) and large volume expansion (~300%) during the process of charge and discharge in both LIB and SIB. In particular, the large volume change leads to the repeated pulverization of the electrode material, formation of unstable solid electrolyte interphase (SEI), and thus rapid capacity decay. Therefore, to solve the problematic behaviors of red P, we prepared the conductive polymer-coated microporous red P composite anodes. Specifically, the formation of micropores inside composites alleviates the volume expansion, and the conductive polymer contributes to the improvement of electrical conductivity. From TEM bright-field images of the composites, it was observed that the conductive polymer was successfully formed and uniformly distributed on the microporous red P. Moreover, from the charge＆ndash;discharge profile tests, it was confirmed that the conductive polymer-coated microporous red P showed the improved stability and capacity compared to untreated one.