Solid Polymer Electrolyte Based on Polymerized Ionic Liquid for High Performance All-Solid-State Lithium-Ion Batteries

Abstract

Polymerized ionic liquids (PILs) have several advantages over ionic liquids, such as easy handling, good electrochemical performance, and chemical compatibility. In this research, a solid-state electrolyte composite membrane was successfully fabricated by using an imidazolium-based polymerized ionic liquid as polymer matrix, a kind of porous fiber cloth as rigid frame, and lithium bis­(trifluoro­methane­sulfonyl)­imide (LiTFSI) as lithium salt. The ionic conductivity of the composite electrolyte with 2.0 mol/kg LiTFSI is 7.78 × 10–5 S cm–1 at 30 °C and reaches 5.92 × 10–4 S cm–1 at 60 °C, which is considered a satisfactory value for potential application in lithium-ion batteries. The specific discharge capacity of the LiFe­PO4/Li cell with as-prepared composite electrolyte is 138.4 mAh g–1, and 90% of the discharge capacity is retained after 250 cycles at 60 °C. In order to further improve the conductivity, Li1.3­Al0.3­Ti1.7­(PO4)3 (LATP) ceramic electrolyte particles are dispersed in a PIL polymer matrix to prepare the PIL-LiTFSI-LATP composite electrolyte. LiFe­PO4/Li cells using PIL-LiTFSI-LATP (10 wt % LATP) as a solid-state electrolyte exhibit excellent rate performance and high capacity retention (close to 97% after 250 cycles at 60 °C). This work may provide a unique way to prepare a new series of electrolytes for high-performance solid-state lithium batteries.

Ionic Liquid–Polymer Composites: A New Platform for Multifunctional Applications

“…They are used in the synthesis of the electrodes, [ 90 ] in the electrode slurry preparation, [ 91 ] in solid electrolyte interphase (SEI), [ 92 ] as electrolyte additive [ 93 ] and in polymer composite as solid polymer electrolyte. [ 94,95 ] In addition to battery systems, these polymer/IL composites can be used for supercapacitor, in which good compatibilization between IL and polymer matrix is essential to obtain a high ionic conductivity value and excellent mechanical properties. [ 96 ]…”

Sulfide and Oxide Inorganic Solid Electrolytes for All-Solid-State Li Batteries: A Review

“…Few attempts have been made to combine polymer electrolytes with LATP to obtain solid electrolyte composites. Ma et al [390] paired a 10% LATP and polymer electrolyte/ionic liquid composite with a LiFePO 4 cathode and reported a capacity of 138 mAh g −1 after 250 cycles with 98% capacity retention at 60 • C. In addition, Wang et al [391] and Jin et al [392] studied LATP polymer composites. Yu and Manthiram [393] fabricated a slurry cast PEO-LiCF 3 SO 3 -LATP composite membrane solid electrolyte and paired it with a LiFePO 4 cathode.…”

A Novel Polymer Electrolyte Matrix Incorporating Ionic Liquid into Waterborne Polyurethane for Lithium-Ion Battery

“…Li-ion batteries have been widely used in portable and consumable electronic devices, hybrid and all-electric vehicles nowadays [2]. However, as traditional electrolyte, liquid electrolyte will give rise to some serious problems when the operating temperature rises, such as leakage and gas explosions [3,4]. Thus, its practical applications were limited.…”