Erratum: “Comparative Potentiodynamic Study of Nickel in Still and Stirred Sulfuric Acid‐Potassium Sulfate Solutions in the 0.4–5.7 pH Range” [J. Electrochem. Soc., 135, 1077 (1988)]

Abstract

SOLID POLYMER ELECTROLYTE 1729-3~ 19 ~ and 24 ~ for X above 0.8, while no peaks were observed for X below 0.6. Since the positions of these two peaks were in complete agreement with those of PEa, the ethylene oxide (EO) chain of PEM is considered to crystallize. It is likely that the mobility of the EO chain is large enough to crystallize in this composition range due to the small cross-linking density, which decreases with increasing X. A marked decrease in the conductivity with time for X above 0.8 can be explained in terms of the interference of the ion conduction by the PEa crystalline phase involving no salt. In the amorphous system, ion conduction follows the free-volume regime, i.e., carrier ions migrate through the free volume of the polymer correlating with the segmental motion. In this case, it is well known that as the Tg of the electrolyte becomes lower, the conductivity increases (2). Figure 2 shows that Tg decreases as X increases. Thus, the regime reasonably explains the finding that the conductivity increases with increasing X up to 0.6. It should be noted that a stable amorphous electrolyte with the composition of X = 0.6 and Y = 0.03 exhibits a high conductivity (2.68 • 10 -5 Scm -1 at 22~ which is approximately 3.7 times greater than that of the PEa-based polyurethane system (4).Decreasing Tg (15~ smaller than that of the polyurethane system) increases the carrier mobility and this fact may be partly responsible for this result. Also, it has been reported that the dissolving power for the alkali metal salts of poly(methacrylate) with short-side chains of EO (PMAEO) is greater than that of PEa (7). Probably the EO of PMAEO is mobile, compared to that of PEa, so that it more stably coordinates to the alkali metal ion. Accordingly, in this photocross-linked electrolyte, a similar effect increasing the carrier density can also be expected, since PEM is much shorter than PEa which is usually used and one of its ends is dangling. ConclusionsWe have examined a novel photocross-linked electrolyte of KCF3SO3-PEM-PED system. It has been found that the morphology and the conductivity of the system are greatly dependent on the composition (X), and that the conductivity reaches a value of 2.68 • 10 .5 Scm -1 at 22~ under optimal conditions. The large conductivity could be rationalized in terms of an increase in the carrier mobility (due to its low Tg) and an increase in the carrier density (due to the relatively large mobility of the EO chain). Also, being a transparent elastomer, this electrolyte seems to be very promising for electrochromic windows (8).Manuscript submitted July 27, 1987; revised manuscript received Dec. 14, 1987. Nippon Sheet Glass Company, Limited assisted in meeting the publication costs of this article. REFERENCES 1. P. V. Wright, Br. PoIym. J., 7,319 (1975 89, 987 (1985). 8. C.M. Lampert, Solar Energy Mater., 11, 1 (1984). ErratumIn the paper "Comparative Potentiodynamic Study of Nickel in Still and Stirred Sulfuric Acid-Potassium Sulfate Solutions in the 0.4-5.7 pH Range" by M.

Electrochemical dissolution and passivation of nickel powder randomly dispersed in a graphite + polypropylene matrix

“…Compared with previously obtained results for nickel powder randomly dispersed in a polymeric matrix [8], this anodic peak is interpreted as corresponding to the active anodic dissolution/passive transition for the nickel component of the electrode material. Similar peaks were also observed for a polycrystalline nickel electrode under the same experimental conditions and interpreted as associated with the active anodic dissolution/passive transition [8,9,11].…”

“…When successive voltammetric cycles were performed, the observed behaviour of the composite material was very similar to that of a polycrystalline nickel electrode [9][10][11]. As seen in Figure 2, the peak current values decrease in successive cycles.…”

“…Nickel electrodissolution in acid medium takes place by two single electron transfer steps followed by a transport step [9][10][11][12]. Under voltammetric conditions, the appearance of one or two anodic peaks defines the active anodic dissolution/ passive transition of nickel in acid media [8][9][10][11]. The same feature is also observed for a nickel powder randomly dispersed in a polymeric matrix [8].…”

“…Moreover, nickel is an element included in many alloys to increase their corrosion resistance [4][5][6]. Nickel has been the subject of many electrochemical studies regarding electrodissolution and passivation processes [7][8][9][10][11]. Nickel electrodissolution in acid medium takes place by two single electron transfer steps followed by a transport step [9][10][11][12].…”

“…Nickel has been the subject of many electrochemical studies regarding electrodissolution and passivation processes [7][8][9][10][11]. Nickel electrodissolution in acid medium takes place by two single electron transfer steps followed by a transport step [9][10][11][12]. Under voltammetric conditions, the appearance of one or two anodic peaks defines the active anodic dissolution/ passive transition of nickel in acid media [8][9][10][11].…”