Synthesis, physical and electrical characterization of polymer electrolytes and polymer complexes containing polyhalides

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7267787

Tipton, A L

The conductivity and dielectric response was determined for poly (propylene oxide) (PPO), the polymeric solid electrolytes (PPO)[sub 8]NH[sub 4]SO[sub 3]CF[sub 3], (PPO)[sub 16]NaI, (PPO)[sub 10]NaI and (PPO)[sub 8]NaI and the sodium polyiodide complex, (PPO)[sub 8]NaI[sub 9], in the frequency range from dc to 6 GHz and the temperature range from 173-323 K at 3 GHz. These data were used to make the first comparisons between an amorphous host polymer and its salt complexes. The addition of salt to PPO results in a considerable change in dielectric properties. The dielectric loss spectrum of PPO displays a broad [beta]-relaxation attributed to the micro-Brownian motion of the polymer while no appreciable relaxation peak is observed for (PPO)[sub 8]NH[sub 4]SO[sub 3]CF[sub 3]. The conductivity of the previously characterized (PEO)[sub 8]NH[sub 4]SO[sub 3]CF[sub 3] is higher than (PPO)[sub 8]NH[sub 4]SO[sub 3]CF[sub 3] over the entire frequency range covered. The methyl group on PPO apparently sterically restricts the local motions of the polymer necessary for ion conduction. The dielectric loss spectrum of (PPO)[sub 8]NaI displays a narrow relaxation peak around 10 MHz, possibly associated with the motions of NaI aggregates. (PPO)[sub 8]NaI[sub 9] displays a much higher conductivity than simple polymer-salt complexes. The lack of frequency dependence of the (PPO)[sub 8]NaI[sub 9] conductivity compared to that of the simple polymer-salt complexes suggests that long range charge transport in (PPO)[sub 8]NaI[sub 9] is dominated by a process that is much faster than the diffusion of ions in the polymer solvent. Resonance Raman spectra reveal the presence of a rich variety of polyhalide species in the products resulting from the addition of Br[sub 2], IBr or I[sub 2] to PPO-LiBr or PPO-LiI salt complexes. Impedance measurements demonstrate high bulk conductivities. There appears to be little correlation between conductivity and iodine or bromine content.

• Research Organization: Northwestern Univ., Chicago, IL (United States)
• OSTI ID: 7267787
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
ALKALI METAL COMPLEXES
CHALCOGENIDES
COMPLEXES
DIELECTRIC PROPERTIES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROLYTES
HALIDES
HALOGEN COMPOUNDS
LITHIUM COMPLEXES
MOLECULAR STRUCTURE
ORGANIC COMPOUNDS
ORGANIC POLYMERS
ORGANIC SULFUR COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLYMERS
POLYOLEFINS
POLYPROPYLENE
SODIUM COMPLEXES
SOLID ELECTROLYTES