Absorption of CO2 by alkaline electrolyte and its effect on electrical discharge

Ko, Hsien-Wen; Juang, Hsun-Kai

doi:10.1007/bf00615821

“…Mao and White [31] extend Sunu's model resolving the separator region. It is found that potassium zincate does not precipitate under realistic conditions [36]. Deiss et al [32] describe a similar model for secondary zinc-air cells based on dilute solution theory, which reaches a fairly good agreement with experimental discharge curves.…”

Section: Introductionmentioning

confidence: 85%

“…The battery cell finally fails due to this decrease in hydroxide concentration and zincate solubility which slow down the further dissolution of Zn. Note that this mechanism does not involve the precipitation of solid carbonates as shown for alkaline electrolytes before [36]. Instead, the reduction in pH is the major consequence of carbon dioxide absorption and the cause for cell failure.…”

Section: Lifetime Analysismentioning

confidence: 97%

See 1 more Smart Citation

Modeling nucleation and growth of zinc oxide during discharge of primary zinc-air batteries

Stamm

¹

,

Varzi

²

,

Latz

³

et al. 2017

Journal of Power Sources

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Metal-air batteries are among the most promising next-generation energy storage devices. Relying on abundant materials and offering high energy densities, potential applications lie in the fields of electro-mobility, portable electronics, and stationary grid applications. Now, research on secondary zinc-air batteries is revived, which are commercialized as primary hearing aid batteries. One of the main obstacles for making zinc-air batteries rechargeable is their poor lifetime due to the degradation of alkaline electrolyte in contact with atmospheric carbon dioxide. In this article, we present a continuum theory of a commercial Varta PowerOne button cell. Our model contains dissolution of zinc and nucleation and growth of zinc oxide in the anode, thermodynamically consistent electrolyte transport in porous media, and multi-phase coexistance in the gas diffusion electrode. We perform electrochemical measurements and validate our model. Excellent agreement between theory and experiment is found and novel insights into the role of zinc oxide nucleation and growth and carbon dioxide dissolution for discharge and lifetime is presented. We demonstrate the implications of our work for the development of rechargeable zinc-air batteries. Highlights• Modeling and simulating of VARTA button cell • Validation of galvanostatic discharge and lifetime analysis• Nucleation and growth of ZnO and its impact on discharge curve• Degradation due to carbonation of alkaline electrolyte (Birger Horstmann) promising candidates to fulfill this demand, because of their high specific energy density and the use of cheap and abundant materials. These batteries are open at the cathode and use atmospheric oxygen.Several metals, e.g., lithium, sodium, and zinc, are potential active anode materials in metal-air cells [1]. The high theoretical energy density of lithium-air batteries has stimulated a lot of research [2]. For aprotic electrolytes, the challenge is to influence growth mechanisms in order to maximize capacity, while maintaining sufficient reversibility [3,4,5,6,7,8,9]. Aqueous lithium-air batteries require a stable lithium conducting anode protection [10,11,12,13]. Non-aqueous sodium-air cells rely

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“…The carbonate reaction is the major degradation process [24]. Atmospheric carbon dioxide dissolves and reacts to carbonate [36] CO…”

Section: Reactionsmentioning

confidence: 99%

Modeling Nucleation and Growth of Zinc Oxide During Discharge of Primary Zinc-Air Batteries

Stamm,

Varzi,

Latz

et al. 2016

Preprint

0

View full text Add to dashboard Cite

Metal-air batteries are among the most promising next-generation energy storage devices. Relying on abundant materials and offering high energy densities, potential applications lie in the fields of electro-mobility, portable electronics, and stationary grid applications. Now, research on secondary zinc-air batteries is revived, which are commercialized as primary hearing aid batteries. One of the main obstacles for making zinc-air batteries rechargeable is their poor lifetime due to the degradation of alkaline electrolyte in contact with atmospheric carbon dioxide. In this article, we present a continuum theory of a commercial Varta PowerOne button cell. Our model contains dissolution of zinc and nucleation and growth of zinc oxide in the anode, thermodynamically consistent electrolyte transport in porous media, and multi-phase coexistance in the gas diffusion electrode. We perform electrochemical measurements and validate our model. Excellent agreement between theory and experiment is found and novel insights into the role of zinc oxide nucleation and growth and carbon dioxide dissolution for discharge and lifetime is presented. We demonstrate the implications of our work for the development of rechargeable zinc-air batteries. Highlights• Modeling and simulating of VARTA button cell • Validation of galvanostatic discharge and lifetime analysis• Nucleation and growth of ZnO and its impact on discharge curve• Degradation due to carbonation of alkaline electrolyte

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“…Despite its high theoretical specific energy (1,352 Wh/kg Zn ), primary alkaline Zn–air batteries could achieve only up to 700 Wh/kg Zn while secondary alkaline Zn–air batteries are limited to 300–500 Wh/kg Zn (Li et al, 2013; Li and Dai, 2014). The technical challenges mainly originate from (i) shape change, stability, and cyclability of Zn anode (Arlt et al, 2014; Turney et al, 2017; Lee et al, 2019), (ii) inefficient bifunctional catalysts (Cheng and Chen, 2012; Wang et al, 2014; Niu et al, 2018), (iii) stability of carbon-based air cathode (Cheng and Chen, 2012; Wang et al, 2014; Li and Lu, 2017), and (iv) impurities in ambient air composition (e.g., CO 2 ) (Ko and Juang, 1983; Drillet et al, 2001; Schröder et al, 2015). These aforementioned challenges are mostly specific for alkaline Zn–air batteries; employing the conventional alkaline electrolyte is highly attractive as it offers superior ionic conductivities (Gilliam et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Influence of Al Alloying on the Electrochemical Behavior of Zn Electrodes for Zn–Air Batteries With Neutral Sodium Chloride Electrolyte

Durmus

¹

,

Guerrero

²

,

Tempel

³

et al. 2019

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Zn alloy electrodes containing 10 wt. % Al were prepared to examine the applicability as anodes in primary Zn–air batteries with neutral 2M NaCl electrolyte. These electrodes were investigated by electrochemical measurements and microscopic techniques (SEM, LSM, AFM). Based on the cyclic voltammetry and intermediate term (24 h) discharge experiments, the only active element in the as-prepared alloy was found to be Zn. It was further confirmed by LSM that Zn rich areas dissolved while Al remained passive during discharge. The passive state of Al was also demonstrated by conductive AFM investigations on the as-cast alloy surfaces. The results on potentiodynamic polarization and weight loss measurements indicated that the alloy electrode was less prone to corrosion than pure Zn electrode. The electrochemical behavior of the electrodes was modified under certain cathodic polarization previous to measurements. Accordingly, originating from Al activation due to application of cathodic potentials, potentiodynamic polarization studies showed a clear shift on the corrosion potentials of the alloy toward more negative values. On the basis of these results, with the precondition of Al activation prior to discharge experiments, the effect of Al alloying on the Zn electrodes was revealed as temporarily enhanced potentials on the discharge profiles in comparison to pure Zn electrodes.

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Absorption of CO2 by alkaline electrolyte and its effect on electrical discharge

Cited by 13 publications

References 10 publications

Modeling nucleation and growth of zinc oxide during discharge of primary zinc-air batteries

Modeling nucleation and growth of zinc oxide during discharge of primary zinc-air batteries

Modeling Nucleation and Growth of Zinc Oxide During Discharge of Primary Zinc-Air Batteries

Influence of Al Alloying on the Electrochemical Behavior of Zn Electrodes for Zn–Air Batteries With Neutral Sodium Chloride Electrolyte

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