Michiko Matsumoto

Synthesis and electrical properties of one-dimensional octacyanometallophthalocyanine (M≡Fe, Co) polymers

Improvement of electrical conductivity was attempted by polymerizing octacyanometallophthalocyanine (MPcOC; M≡Fe, Co) units into one-dimensional molecular complexes. The synthetic route to MPcOC was established by reacting tetracyanobenzene with a metal(II) acetate in sulfolane. Poly(μ-pyrazine)octacyanophthalocyaninatoiron(II) and -cobalt(II) were synthesized and their doping with lithium was carried out. The Fe(II) and Co(II) octacyanophthalocyanine complexes showed good electrical conductivities of the order of 10-8-10-4S cm-1. The electrical conductivities of the lithium-doped complexes were improved by two or three orders of magnitude in comparison with the corresponding monomeric and polymeric complexes.

Metal-free octacyanophthalocyanine as cathode-active material for a secondary lithium battery

Metal-free octacyanophthalocyanine (H2PcOC), one of the strongest organic acceptors with fair stability and electric conductivity, was examined as the cathode-active material of a lithium battery composed of (metallic lithium/electrolyte solution/H2PcOC). The capacity and energy density based on the quantity of cathode-active material were 137 mA h g−1 and 222 W h kg−1 at 1 V cutoff, respectively. The cycle life of this battery exceeded 20 at the discharge depth of three electron reduction (112 mA h g−1) per H2PcOC unit. It was found that H2PcOC is a promising candidate as the cathode-active material for lithium secondary batteries.

Synthesis and electrical properties of poly(μ-1,4-diisocyanobenzene) octacyanophthalocyaninatoiron(II)

Abstract Poly[(μ-1,4-diisocyanobenzene)octacyanophthalocyaninatoiron(II)],[FePcOC(dib)]n, was synthesized and its doping with lithium was studied. The chemical, spectral and electric properties of bridged polymer were characterized by IR, UV–vis and 1 H -NMR. The chain length of [FePcOC(dib)]n determined by gel permeation chromatography and TOF-mass was 12–15. The coordination state of the central metal of [FePcOC(dib)]n was iron(II) according to the results of ESCA analysis. In spite of its relatively large inter-ring distance, [FePcOC(dib)]n showed powder conductivity in the range of 10−7 S/cm. With lithium-doping, its electrical conductivity was improved by two orders of magnitude.

Octacyanophthalocyaninatoiron Polymer as Cathode Material for a Secondary Lithium Battery

The one-dimensional coordination polymers based on octacyanophthalocyanatoiron (FePcOC) and bidentate axial bridging ligands such as pyrazine, tetrazine, and diisocyanobenzene (dib) were synthesized and used as the cathode material of secondary lithium batteries. The lithium//electrolyte solution//FePcOC-dib polymer cell gave the best performance due to its stability upon discharging process. Especially when the 0.5 M LiPF 6 /dimethoxyethane solution was used as the electrolyte, the cell exhibited the energy density of 475 Wh kg -1 with the average output voltage of 3.2 V.

Lithium/Polyaniline Secondary Battery Composed of Transport‐Number‐Adjusted Aluminate Solid Polymer Electrolytes

Lithium salts, such as LiBF 4 . LiClO 4 . and LiPF 6 . were added to the single-ion solid polymer electrolyte poly[lithium bis{endomethyl-oligo(oxyethylene)oxy}oligo(oxyethylene)oxyaluminate] in which Li + is the only mobile ion, to adjust the transport number from t + = I (t - = 0: single-ionic) to t + t - 0.5, When LiBF 4 was used, the average transport number was found to deviate little over a wide salt concentration range. This characteristic meets a requirement for Li/polyaniline n+ (BF 4 - ) n batteries in which the salt concentration fluctuates with the ingress/egress of Li + and X - during the charging/discharging processes. A Li/polyaniline n+ (BF 4 - ) n cell using this transport-number-adjusted electrolyte exhibited a distinct discharge plateau at a reasonably high voltage and excellent cycle stability.