Construction of ZIF-8 modified laponite to enable polyvinylidene fluoride-based solid-state electrolyte with high...

Solid-state electrolytes (SSEs) can replace the diaphragm and electrolyte in the traditional battery to solve safety perils such as electrolyte leakage and combustion, while their practical application is greatly hindered by their low ionic conductivity and poor ability to inhibit lithium dendrites. Herein, a laponite (LAP)/zeolitic imidazolate framework-8 (ZIF-8) hybrid material modified polyvinylidene fluoride (PVDF)-based composite polymer electrolytes (CPE) is reported. The in-situ modification of ZIF-8 induced by electrostatic interactions between LAP layers not only improves the dispersion of LAP, but also acts as an external bridge through hydrogen bonding with PVDF to construct a stable conductive network. The extended and compatible polymer-nanofiller hybrid interface enables continuous ion migration paths and effectively reduce the crystallinity of PVDF. Moreover, the Lewis acid site and high porosity of ZIF-8 can not only promote the dissociation of lithium bis (trifluoromethanesulphonyl) imide (LiTFSI), but also limit the movement of TFSI^-, further improving the ionic conductivity. Benefiting from the synergistic enhancement effect of hybrid interface, the obtained CPE demonstrated an excellent ionic conductivity of 6.77 × 10^-4 S cm^-1 at room temperature and a satisfactory ion transference number of 0.60 together with superior electrochemical window of 5.3 V and good mechanical strength. The assembled Li metal battery shows a high capacity retention rate is 95 % after 150 cycles at 1C, indicating a significant inhibitory effect on lithium dendrites.