Electrochemical Properties According to the Particle Size Effect of Poly(ethylene oxide)-Poly(propylene oxide)-Poly(ethylene oxide) Triblock Copolymer Electrolyte.

The electrolyte of lithium secondary batteries is an important component. Among lithium secondary batteries, the lithium polymer battery, which has similar performance to the lithium secondary battery, is made of a solid polymer electrolyte. Lithium ions in a solid polymer electrolyte exist in the form of a solution by a polar group in a polymer matrix. Lithium ions in the solid polymer electrolyte migrate via the segmental motion of the polymer. That is, the properties of a polymer matrix in a solid polymer electrolyte can affect the conduction of lithium ions. Therefore, this study focused on the electrochemical properties of poly(ethylene oxide)-block-poly(propylene oxide)-blockpoly( ethylene oxide) copolymer-based solid polymer electrolyte. For this, poly(ethylene oxide)-blockpoly( propylene oxide)-block-poly(ethylene oxide) copolymer-based solid polymer electrolytes, which have spherical micelles, and various sizes of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) copolymer micelle, were prepared. Amino acids were added to the poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) copolymer-based solid polymer electrolyte as an ion dissociator to assist in the dissociation of a lithium salt and increase the ionic conductivity of the solid polymer electrolyte. The copolymer-based solid polymer electrolytes was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, impedance analysis, cyclic voltammetry, and linear sweep voltammetry.