A Critical Comparison of Mildly Acidic versus Alkaline Zinc Batteries

Abstract

Metrics & MoreArticle Recommendations * sı Supporting InformationA queous rechargeable batteries are cost-effective, easy to fabricate, and safe, deliver high energy output, and employ stable water-based electrolytes compared to organicbased lithium-ion batteries (LIBs). Aqueous Zn electrochemistry, specifically, has attracted researchers since the 1830s. Metallic Zn is a nearly ideal anode owing to its low cost (ca. 2 USD kg −1 ), existing supply chain, environmental benignity, relative safety, and high stability in water [−0.76 V vs standard hydrogen electrode (SHE)], as compared to Li. 1−3 The high theoretical capacity (2e − @ 820 mAh g −1 ) and low polarizability (6 × 10 −8 Ω m) further motivate Zn-based battery development, especially for stationary storage. 2,4 Alkaline Zn batteries (AZBs) and neutral/mildly acidic Znion batteries (MZIBs) are proposed as rivals to the established Pb-acid and LIBs owing to their competitive theoretical energy densities (∼200−400 Wh L −1 ). The efficiency of these inexpensive and safe battery technologies is dependent on the cathode type, Zn anode formulation, separator materials, and the electrolyte type (liquid, gel, solid state) and pH. While AZBs and MZIBs have commonalities, including Zn dendrite formation at high capacity utilization and inherent low voltage (Zn battery <3 V < LIB), unique materials chemistry challenges and operating principles distinguish them. For example, in AZBs, the preference is to prevent the crossover of the soluble anode oxidation product [zincate, Zn(OH) 4 2−

Advancement of electrically rechargeable multivalent metal-air batteries for future mobility

“…The traditional aqueous neutral composition for ZABs is based on the Leclanché battery electrolyte system, whereas ZIBs employ ZnSO 4 or Zn(CF 3 SO 3 ) 2 . A near-neutral electrolyte decreases Zn solubility, which minimizes electrode carbonation and Zn dendrite growth [19,94].…”

“…These technologies are crucial for large-scale applications like EVs, grid management, and mobile electronics [12]. However, they face challenges in efficiency, durability, corrosion, and cycle life, making them uncompetitive for widespread practical applications [12,13,[16][17][18][19]. Moreover, metal anodes and multivalent charge carrier ions can improve energy density, but their limitations and lack of transferrable knowledge from LIB research make them unsuitable for ordinary use [14].…”

Ionic Competition between Na+ and H+ in Aqueous Sodium-Ion Battery Electrolytes

“…It should be noticed that both Na + and H + coexist in aqueous Na-based electrolytes. − The presence of H + due to the slight ionization of water results in H + reduction at the anode together with the Na + reduction during the charging process. This leads to difficulties in the control of reactions and a series of side reactions at the interface between the anode and the aqueous electrolyte, resulting in anode corrosion and bubbles, which seriously impact the electrochemical stability and cause the risk of battery explosion.…”

Influence of Defects and Surfaces on the Electrochemical Performance of MnO2 Cathodes in Rechargeable Alkaline Zn/MnO2 Batteries: A First-Principles Study

“…16−22 In the absence of zinc, MnO 2 cathodes mixed with CuO and Bi 2 O 3 could be successfully cycled several thousand times without significant loss of delivered capacity; 20,23−27 however, the delivered capacity is derived from accessing available MnO 2 , Cu, and Bi 2 O 3 capacity. 5 There is significant ongoing research focused on understanding the redox mechanism of MnO 2 cathodes in rechargeable Zn/MnO 2 batteries.…”

“…Electrical energy storage is essential for the efficient grid integration of renewable energy systems. Rechargeable alkaline Zn/MnO 2 batteries present an attractive option for large-scale electrical energy storage because of their low cost, nontoxicity, and high energy density. − In primary Zn/MnO 2 batteries, the rechargeability of MnO 2 cathodes is hindered by the formation of irreversible discharge reaction products. ,,− It has been shown that the rechargeability of MnO 2 cathodes in alkaline Zn/MnO 2 batteries could be substantially improved either by restricting the depth of discharge ,,− or by using MnO 2 cathodes modified with Cu and Bi additives. − In the absence of zinc, MnO 2 cathodes mixed with CuO and Bi 2 O 3 could be successfully cycled several thousand times without significant loss of delivered capacity; ,− however, the delivered capacity is derived from accessing available MnO 2 , Cu, and Bi 2 O 3 capacity . There is significant ongoing research focused on understanding the redox mechanism of MnO 2 cathodes in rechargeable Zn/MnO 2 batteries.…”