Dense and high loading sulfurized pyrolyzed poly (acrylonitrile)(S@pPAN) cathode for rechargeable lithium batteries

Abstract

High energy density lithium-sulfur (Li-S) batteries have been extensively investigated in recent years due to the urgent demands for advanced energy storage systems. Among various sulfur cathodes reported in past decades, sulfurized pyrolyzed poly (acrylonitrile) (S@pPAN) cathode displayed several superiorities on electrochemical behaviors. However, further scale-up practical application of Li-S battery with S@pPAN cathode has been plagued by high-loading sulfur electrode preparation. Herein, a network binder system (i.e., guar gum and poly(acrylic acid)) is constructed through binding effect between substantial functional groups. The network binder ensures a simple blade-cast method for high-loading S@pPAN cathode up to 17.5 ​mg ​cm-2 on planar aluminum-based current collector. The optimization of dense sulfur electrode after rolling pressure reached a compacted density close to 1.15 ​g ​cm-3 and demonstrated a high areal capacity of 6 ​mAh cm-2 after 120 cycles. Benefiting from the simple method to prepare dense and high-loading S@pPAN cathode, the correlation between areal specific capacity with rolling pressure applied on electrodes was carefully analyzed. This study sheds light on the key issues of sulfur electrode preparation for high energy density lithium sulfur batteries.