Local electric field effect of montmorillonite in solid polymer electrolytes for lithium metal batteries. (December 2021)

• Record Type: Journal Article
• Authors: Wang, Yong; Li, Xinyang; Qin, Yanyang; Zhang, Dongyang; Song, Zhongxiao; Ding, Shujiang
• Is Part Of: Nano energy. Volume 90(2021)Part A
• Publication Date: 2021-12
• Subjects: Ultraviolet -- In situ cross-linking -- Montmorillonite -- Solid polymer electrolyte -- Lithium metal battery; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2021.106490
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Solid polymer electrolytes (SPEs) with in-built inorganic fillers are very promising for building safe solid-state batteries, owing to their excellent flexibility, prominent interfacial wettability and low costs. However, the morphology and surface state of inorganic fillers greatly affect ionic conductivity of SPEs. Here, we report that ultraviolet (UV) initiates in situ cross-linking of poly(ethylene glycol) methyl ether acrylate (MPEGA), poly(ethylene glycol) diacrylate (PEGDA) and montmorillonite (MMT) between cathodes and anodes of cell, to produce a solid composite electrolyte (CMP/MMT) that is composed of a robust interpenetrating polymer network matrix and layered MMT nanosheets. Surprisingly, the CMP/MMT delivers a high room-temperature ionic conductivity (~1.06 mS cm −1 ), large lithium-ions transference number (tLi+ = 0.79). The large ionic conductivity enhancement is ascribed to the local electric field effect of montmorillonite (MMT), which accelerates the lithium-ions fast transport in the interlayer of the MMT nanosheets. In addition, the density functional theory (DFT) is conducted to demonstrate the mechanism of improving ionic conductivity. As a result, a solid-state battery with CMP/MMT demonstrates a high capacity of ~140 mAh g −1 and excellent capacity retention of >98% at 0.3 C after 400 cycling. Graphical Abstract: ga1 Highlights: A solid composite electrolyte (CMP/MMT) is prepared by in situ cross-linking of liquid precursor between cathodes and anodes of cell. The CMP/MMT delivers a high room-temperature ionic conductivity (~1.06 mS cm −1 ) and large lithium-ions transference number (tLi+ = 0.79). The DFT demonstrated that the MMT assists in accelerating the dissociation of lithium salts and provides a "highway" for Li + fast transport by local electric field effect. A solid-state battery with CMP/MMT demonstrates a high capacity of ~140 mAh g −1 and excellent capacity retention of >98% at 0.3 C after 400 cycling.