Inert Filler Selection Strategies in Li-Ion Gel Polymer Electrolytes

Abstract

The main role of inert fillers in polymer electrolytes is to enhance ionic conductivity. However, lithium ions in gel polymer electrolytes (GPEs) conduct in liquid solvent rather than along the polymer chains. So far, the main role of inert fillers in improving the electrochemical performance of GPEs is still unclear. Here, various low-cost and common inert fillers (Al2O3, SiO2, TiO2, ZrO2) are introduced into GPEs to study their effects on Li-ion polymer batteries. It is found that the addition of inert fillers has different effects on ionic conductivity, mechanical strength, thermal stability, and, dominantly, interfacial properties. Compared with other gel electrolytes containing SiO2, TiO2, or ZrO2 fillers, those with Al2O3 fillers exhibit the most favorable performance. The high performance is ascribed to the interaction between the surface functional groups of Al2O3 and LiNi0.8Co0.1Mn0.1O2, which alleviates the decomposition of the organic solvent by the cathode, resulting in the formation of a high-quality Li+ conductor interfacial layer. This study provides an important reference for the selection of fillers in GPEs, surface modification of separators, and cathode surface coating.

Recent Progress and Prospects on Sodium-Ion Battery and All-Solid-State Sodium Battery: A Promising Choice of Future Batteries for Energy Storage

“…Currently, gel polymer electrolytes that have received significant attention include poly­(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) and poly­(ethylene oxide) (PEO). Additionally, the development of hybrid ceramic-polymer electrolytes also holds great value for ASSBs. − …”

An Ultrahigh Modulus Gel Electrolytes Reforming the Growing Pattern of Li Dendrites for Interfacially Stable Lithium‐Metal Batteries

“…Up to now, considerable efforts have been dedicated to compensate for the intrinsic mechanical drawbacks of GPEs. One of the acceptable approaches is to blend inorganic fillers (e.g., TiO 2 , Al 2 O 3 , and SiO 2 ), [6,7] and organic additives (e.g., Metal-organic frameworks and nanofibrils) into the gel electrolytes. [8,9] It is believed that the addition of functional fillers can enhance the mechanical and electrochemical performances of GPEs by the Lewisacid-based interplay between additives and polymer segments.…”