Free-standing graphene/polyetherimide/ZrO2 porous interlayer to enhance lithium-ion transport and polysulfide interception for lithium-sulfur batteries

Abstract

Attributing to high theoretical specific capacity and energy density, lithium-sulfur batteries (LSBs) are receiving great attention. However, the commercialization of such technology is seriously hindered by the shuttle effect of polysulfides during the round-trip charge and discharge process. Herein, with three types of carbon materials and ZrO2 nanoparticles filled in polyetherimide (PEI) support framework with good stability, porous composite films were obtained by a simple non-solvent phase separation (NIPS) as free-standing interlayers for LSBs. The obtained interlayers can not only provide hierarchical channels for improving lithium-ion transfer number, but also own excellent physicochemical stability and strong adsorption capability towards lithium polysulfide (LiPS). Compared with the pristine one, the representative LSB with graphene/polyetherimide/ZrO2 interlayer (GPZ) shows good initial cycle discharge specific capacity (1280 mAh g−1), better capacity retention (749 mAh g−1 after 200 cycles) and good rate performance (580 mAh g−1 at 2C). This work provides a facile and promising way to achieve functional interlayer with high stability for high performance LSBs.