Open AccessPolymer-in-Ceramic Nanocomposite Solid Electrolyte for Lithium Metal Batteries Encompassing PEO-Grafted TiO2 Nanocrystals
Author(s) -
Francesco Colombo,
Simone Bonizzoni,
Chiara Ferrara,
Roberto Simonutti,
Michele Mauri,
Marisa Falco,
Claudio Gerbaldi,
Piercarlo Mustarelli,
Riccardo Ruffο
Publication year - 2020
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/ab7c72
Subject(s) - materials science , nanocomposite , electrolyte , chemical engineering , ceramic , ionic conductivity , ethylene oxide , polymer , nanocrystal , oxide , lithium (medication) , faraday efficiency , polymer nanocomposite , nanotechnology , composite material , copolymer , electrode , metallurgy , chemistry , engineering , medicine , endocrinology
Lithium Metal Batteries (LMB) require solid or quasi-solid electrolytes able to block dendrites formation during cell cycling. Polymer-in-ceramic nanocomposites with the ceramic fraction exceeding the one normally used as the filler (>10 ÷ 15 wt%) are among the most interesting options on the table. Here, we report on a new hybrid material encompassing brush-like TiO 2 nanocrystals functionalized with low molecular weight poly(ethylene oxide) (PEO). The nanocomposite electrolyte membranes are then obtained by blending the brush-like nanocrystals with high molecular weight PEO and LiTFSI. The intrinsic chemical compatibility among the PEO moieties allows a TiO 2 content as high as ∼39 wt% (90:10 w/w functionalized nanocrystals/PEO-LiTFSI), while maintaining good processability and mechanical resistance. The 50:50 w/w nanocomposite electrolyte (18.8 wt% functionalized TiO 2 ) displays ionic conductivity of 3 × 10 −4 S cm −1 at 70 °C. Stripping/plating experiments show an excellent long-term behavior even at relatively high currents of 200 μ A cm −2 . Upon testing in a lab-scale Li/electrolyte/LiFePO 4 cell, the material delivers 130 mAh g −1 and 120 mAh g −1 after 40 and 50 cycles at 0.05 and 0.1 mA, respectively, with Coulombic efficiency exceeding 99.5%, which demonstrates the very promising prospects of these newly developed nanocomposite solid electrolyte for future development of LMBs.