Si/SiOx-Conductive Polymer Core-Shell Nanospheres with an Improved Conducting Path Preservation for Lithium-Ion Battery

Abstract

Non-stoichiometric SiOx based materials have gained much attention as high capacity lithium storage materials. However, their anode performance of these materials should be further improved for their commercial success. A conductive polymer, poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PE-DOT:PSS), is employed as a flexible electrical interconnector to improve the electrochemical performance of Si/SiOx nanosphere anode materials for lithium ion batteries (LIBs). The resulting Si/SiOx-PEDOT: PSS core-shell structured material with the small amount (1 wt%) of PEDOT: PSS shows the improved initial reversible capacity of 968.2 mA hg(-1) with excellent long-term cycle performance over 200 cycles. These promising properties can be attributed to the use of the electroconductive and flexible PEDOT: PSS shell layer, which protects the electrical conduction pathways in the electrode from the large volume changes of silicon during cycling.