Studies on the storage of electrochemically impregnated nickel/cadmium cells

Aravamuthan, S.; Annamma, C.V.; Pillai, Naresh; Nair, Manuja

doi:10.1016/0378-7753(93)01885-l

Cited by 8 publications

(4 citation statements)

References 4 publications

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“…Reducing reactions of CoOOH at low voltage (below 1.0 V) with hydrogen may be responsible for it since the same characteristic of discharge curve with capacity loss as shown in Fig. 3 was also found in both Ni-Cd and Ni-H 2 batteries [2,3].…”

Section: Discussionmentioning

confidence: 81%

“…Previous studies are focused on nickel-hydrogen (Ni-H 2 ) and nickel-cadmium (Ni-Cd) batteries. The work reported in references [1][2][3][4][5] indicates that CoOOH or Co(OH) 3 in the positive electrodes may be reduced slowly by hydrogen in the battery system at lower potential, thus results in capacity fading of them since the cobalt additive has been known to improve the active material utilization of nickel electrodes [6,7]. But for Ni-MH battery, AB 5 alloy is often used as active material in the negative electrodes.…”

Section: Introductionmentioning

confidence: 99%

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Corrosion of AB5 alloy during the storage on the performance of nickel-metal-hydride battery

Xia

2005

Journal of Alloys and Compounds

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Section: Discussionmentioning

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Corrosion of AB5 alloy during the storage on the performance of nickel-metal-hydride battery

Xia

2005

Journal of Alloys and Compounds

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“…There have been previous reports 8,9 dwelling on the appearance of small amounts of Co 3 O 4 within the Ni active positive electrode of Ni-Cd cells after long storage times. The authors account for their observation by assuming that cobalt species in solution could react with dissolved oxygen (provided by the electrolyte oxidation) to produce Co 3 O 4 according to the following reaction…”

Section: Resultsmentioning

confidence: 97%

“…This reduction mechanism was shown to involve a dissolution/crystallization process with the overall result being a nonuniform Co(OH) 2 phase distribution through the positive electrode, and, more specifically, preferential crystallization of Co(OH) 2 around the Ni current collector, thereby jeopardizing the cell performance. Occasionally, under specific chemical conditions 7 (in solution for T > 110ЊC) or electrochemically 8,9 (2 years storage of a Ni alkaline battery at low potential), other authors show evidence for the formation of the spinel phase Co 3 O 4 from CoOOH. The present study shows that well-defined crystals (a few micrometers in size) of the poorly conducting Co 3 O 4 spinel phase can easily be formed under "quasi" normal cell operations.…”

mentioning

confidence: 99%

Bismuth-Enhanced Electrochemical Stability of Cobalt Hydroxide Used as an Additive in Ni/Cd and Ni/Metal Hydride Batteries

Pralong

Delahaye‐Vidal

Beaudoin

et al. 2000

J. Electrochem. Soc.

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Ni-based rechargeable alkaline batteries, including Ni-Cd and the rapidly growing Ni-metal hydride (MH) technology, are widely used in today's power tools and portable applications and are in strong competition with the Li-ion technology. Such a competition is an incentive for improvements of both technologies in terms of autonomy, cycle-life, and reliability. For the Ni-MH technology, such improvements could come from improving either the metal hydride (MH) electrode or the Ni electrode, as reported below.Whatever the Ni/Cd or Ni/MH technology used, Co additives are added to the positive Ni electrode for better electrochemical performances. [1][2][3][4] However, these improvements were found to depend on whether Co is added by coprecipitation, (Ni 1Ϫx Co x (OH) 2 , or simply incorporated within the positive material composite under specific conditions (dispersed vs. coated). Detailed electrochemical studies 5,6 of the Co(OH) 2 /Cd cell have recently thrown some light on the Co(OH) 2 redox chemistry. Upon charging the cell, Co(OH) 2 is oxidized to CoOOH at 0.73 V. However, this oxidation mechanism was found to depend strongly on the reaction kinetics, producing at the end of charge "CoOOH" phases that differ in their chemical/physical properties. For instance, the formation of the electronically conducting nonstoichiometric phase, ␤-Co x 4ϩ Co 3ϩ 1Ϫx OOH 1Ϫx (0.1 < x < 0.2), previously reported by Butel et al., 4 was found to be favored at high charging rates >C/5. In contrast, low charging rates ( 110ЊC) or electrochemically 8,9 (2 years storage of a Ni alkaline battery at low potential), other authors show evidence for the formation of the spinel phase Co 3 O 4 from CoOOH. The present study shows that well-defined crystals (a few micrometers in size) of the poorly conducting Co 3 O 4 spinel phase can easily be formed under "quasi" normal cell operations. Thus, any chemical/physical means that could decrease or block the formation of Co 3 O 4 and Co(OH) 2 phases should help in improving the performance of the Co-containing nickel positive electrodes.Recently, Larcher et al. 10 succeeded in controlling the kinetics of -MnO 2 r ␣/␥-MnO 2 phase transformation that proceeds through a dissolution/crystalli...

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