Supramolecular Self-Assembly of Methylated Rotaxanes for Solid Polymer Electrolyte Application

Imholt l, Dong D, Bedrov D, Cekic-Laskovic I, Winter M, Brunklaus G

Abstract

Li+-conducting solid polymer electrolytes (SPEs)obtained from supramolecular self-assembly of trimethylated cyclodextrin(TMCD), poly(ethylene oxide) (PEO), and lithium salt areinvestigated for application in lithium-metal batteries (LMBs) andlithium-ion batteries (LIBs). The considered electrolytes comprisenanochannels for fast lithium-ion transport formed by CD threadedon PEO chains. It is demonstrated that tailored modification of CDbeneficially influences the structure and transport properties of solidpolymer electrolytes, thereby enabling their application in LMBs.Molecular dynamics (MD) simulation and experimental data revealthat modification of CDs shifts the steady state between lithium ionsinside and outside the channels, in this way improving the achievableionic conductivity. Notably, the designed SPEs facilitated galvanostaticcycling in LMBs at fast charging and discharging rates for morethan 200 cycles and high Coulombic efficiency.