Effectively Elevating Ceramic Fillers’ Dispersity in Gel Hybrid Electrolyte through Bridge–Linked Construction for High–Performance Lithium Metal Batteries
Minghua Chen, Wannian Liu, Ziyu Yue, Yang Wang, Yixin Wu, Yu Li, Zhen Chen
Abstract
Gel polymer-ceramic hybrid electrolytes (GHEs) have emerged as desirable candidates for preparing high energy density and excellent practicability gel batteries. However, the agglomeration of ceramic particles in polymer matrix leads to a decrease in cycling stability and low mechanical properties of GHEs. Here, we present a feasible method for improving the dispersity of Li0.24La0.59TiO3 (LLTO) nanorods in the polyvinylidenefluoride (PVDF)/poly(propylene carbonate) (PPC) co-blended matrix (K–LLTO/PVDF/PPC) by γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560) surface treatment. The as-prepared GHE with 10% K–LLTO filler (10% GHE) exhibits a high ionic conductivity (3.01 mS cm−1) and an appropriate lithium-ion transference number (0.55). The Li|10% GHE|Li symmetric cell shows an exceptional lithium stripping-plating lifetime of > 2000 h at 0.1 mA cm−2. The assembled LiFePO4 (LFP)|10% GHE|Li full cells show satisfactory cycling stability in the 2.5–4.2 V electrochemical window by recovering 84% of the initial capacity at 2 C over 500 cycles. The uniformly dispersed K–LLTO within the polymer matrix is ascribed to the formation of a bridge-linked network via Si–O–Ti bonds between KH560 and LLTO, and plenty of hydrogen bonds within the polymer matrix. This modification method provides a feasible strategy for fabricating GHEs with good repeatability, which may easily adapt to the high requirements of commercial production.