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

Abstract

Non-stoichiometric SiO_x 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) (PEDOT:PSS), is employed as a flexible electrical interconnector to improve the electrochemical performance of Si/SiO_x nanosphere anode materials for lithium ion batteries (LIBs). The resulting Si/SiO_x -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 h g^-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.

Keywords: core-shell materials; lithium-ion batteries; metal oxides; polymers; silicon.