Electrochemical performance study of nano-Fe₃O₄/C modified separator for lithium-sulfur batteries

Abstract

In order to solve the problems of low cathode conductivity, shuttle effect, and poor electrochemical performance of Li-S batteries, we designed a porous carbon/nano-sized ferric oxide (Fe3O4) composite modified membrane. This improved both conductivity and adsorption capacity of lithium polysulfides (LiPSs) prepared with mesopores and high specific surface area C-Fe3O4@PE. The membrane can bind polysulfide via chemical and physical adsorption. Owing to these advantages, a Li-S battery based on C-Fe3O4@PE and with a separator exhibited excellent rate performance (965.9 mA h g–1 at 0.2 C and 437.5 mA h g–1 at 5 C), as well as a long cycle life (416.6 mA h g–1 after 300 cycles at 0.5 C, with a capacity retention rate of 50.5%).