Multistage channel PVDF-HFP pregnant ZIF-8@SiO2 quasi-solid electrolyte for lithium-metal batteries

The development of lithium-metal batteries (LMBs) with high energy density and safety is considered a top priority for the next generation of rechargeable batteries. However, the mitigation of the inevitable reaction between lithium and the liquid electrolyte (LE), as well as the subsequent formation of Li dendrites, poses a crucial challenge that needs to be addressed. Upgrading traditional LEs serves as a pivotal strategy in achieving this objective. Here, we report a ZIF-8@SiO2/PVDF-HFP (ZSPH) quasi-solid electrolyte (QSE) with ultra-multistage pore crosslinked network structure. The interconnected micro-stage pore structure in a honeycomb-like morphology of polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) and the rich multistage pore structure of nanoscale SiO2 "armored" zeolite imidazolium ester backbone-8 (ZIF-8@SiO2) collectively establish a multi-stage ion transport channel. This unique structure facilitates appreciable ionic conductivity (2.21 × 10−3 S cm−1 at 30 °C) and provides a wide and stable electrochemical window (approximately 5.0 V). The Li/ZSPH9-LiPF6/Li quasi-solid-state cell demonstrates an impressive longevity of over 1800 h at a current density of 0.2 mA cm−2. The high compatibility of the interface between electrode and ZSPH QSE and effective inhibition of Li dendrites growth create synergistic effects, which make it possible to realize high energy density and safe LMBs.