Y. Asai et al., Peripherally polymerized octacyanophthalocyanine as cathode material of lithium rechargeable batteries, POLYM ADV T, 12(3-4), 2001, pp. 259-265
Highly pure metal-free octacyanophthalocyanine (H2PcOC) was further convert
ed into two-dimensional polymers (PPcCN) by solid-phase reaction in presenc
e of tetracyanobenzene. PPcCN showed the electric conductivity as high as a
bout 5.10(-4) S cm(-1), 2-orders of magnitude larger than that of H2PcOC. S
ince PPcCN exhibited reversible multi-electron redox reaction at relatively
positive potential near -0.3 V vs. NHE and was insoluble throughout the re
dox reaction in any ic electrolyte solutions, this polymer is useful in lit
hium (ion) rechargeable batteries as cathode-active material. When the dept
h of discharge was controlled to 150 mAh g(-1), the cell composed of [metal
lic Li/electrolyte/PPcCN] gave very stable cycle property for several hundr
ed charge-discharge cycles with the average output voltage of 2.73 V and th
e energy density of 409 Wh kg(-1) of which value is comparable to commercia
l lithium ion batteries based on Li-x(CoO2)(y) cathode. Copyright (C) 2001
John Wiley & Sons, Ltd.