Analysis of Structure and Electrochemistry of Selenium-Containing Conductive Polymer Materials for Rechargeable Lithium Batteries

Abstract

Correlation between the structure of selenized poly(acrylonitrile) (Se/PAN) composite materials and their electrochemical properties for lithium batteries was studied. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements demonstrate that higher synthesis temperature results in a higher graphitization degree of the polymer skeleton and fewer Se-Se bonds. The Se/PAN electrodes present excellent rate capability and extra-long cycle life due to their fast electrochemical reaction kinetics and high structural stability. A reversible specific capacity of about 325 mA h g−1 for the Se/PAN composite synthesized at 500°C was obtained with a capacity decay of only 2.6% (based on the second cycle) after 1500 cycles. Furthermore, the correlation between their structure and electrochemical performance was elucidated. The Se/PAN composites obtained at higher temperature show better cycling stability but lower capacity.