Quasi-Solid-State Ion-Conducting Arrays Composite Electrolytes with Fast Ion Transport Vertical-Aligned Interfaces for All-Weather Practical Lithium-Metal Batteries

Abstract

The rapid improvement in the gel polymer electrolytes (GPEs) with high ionic conductivity brought it closer to practical applications in solid-state Li-metal batteries. The combination of solvent and polymer enables quasi-liquid fast ion transport in the GPEs. However, different ion transport capacity between solvent and polymer will cause local nonuniform Li+ distribution, leading to severe dendrite growth. In addition, the poor thermal stability of the solvent also limits the operating-temperature window of the electrolytes. Optimizing the ion transport environment and enhancing the thermal stability are two major challenges that hinder the application of GPEs. Here, a strategy by introducing ion-conducting arrays (ICA) is created by vertical-aligned montmorillonite into GPE. Rapid ion transport on the ICA was demonstrated by 6Li solid-state nuclear magnetic resonance and synchrotron X-ray diffraction, combined with computer simulations to visualize the transport process. Compared with conventional randomly dispersed fillers, ICA provides continuous interfaces to regulate the ion transport environment and enhances the tolerance of GPEs to extreme temperatures. Therefore, GPE/ICA exhibits high room-temperature ionic conductivity (1.08 mS cm−1) and long-term stable Li deposition/stripping cycles (> 1000 h). As a final proof, Li||GPE/ICA||LiFePO4 cells exhibit excellent cycle performance at wide temperature range (from 0 to 60 °C), which shows a promising path toward all-weather practical solid-state batteries.

The Critical Role of Fillers in Composite Polymer Electrolytes for Lithium Battery

“…Moreover, solid-state electrolytes exhibit excellent mechanical strength and chemical neutrality, which can reduce the side reactions with lithium metal and inhibit the growth of lithium dendrites [ 3 , 4 ]. Therefore, solid-state electrolytes are considered as a promising route for the preparation of lithium batteries with high safety performance, high stability and high energy density [ 5 , 6 ].…”

Building electrode skins for ultra-stable potassium metal batteries

“…These issues will cause the rupture of the interfacial SEI and the loss of active species 17 . Therefore, there are still huge obstacles for the practical use of metal batteries 18 , 19 .…”

Rational Design of High-Performance PEO/Ceramic Composite Solid Electrolytes for Lithium Metal Batteries

“…Gel electrolytes have higher ionic conductivity due to the presence of liquid component, but poor mechanical strength and the possibility of uncontrolled thermal runaway. However, solid-state electrolytes have sufficient mechanical strength and higher security [ 22 , 23 ]. Therefore, solid-state electrolytes could revive the possibility of using a high-energy-density Li metal anode, which is mainly divided into three categories according to their composition: solid ceramic electrolytes [ 24 , 25 ], solid polymer electrolytes [ 26 , 27 ] and composite solid electrolytes (CSEs) [ 28 – 30 ].…”