Challenges in Zinc Electrodes for Alkaline Zinc–Air Batteries: Obstacles to Commercialization

Abstract

Alkaline zinc–air batteries are promising energy storage technologies with the advantages of low cost, ecological friendliness, and high energy density. However, the rechargeable zinc–air battery has not been used on a commercial scale because the zinc electrode suffers from critical problems such as passivation, dendrite growth, and hydrogen evolution reaction, which limit the practical applications of zinc–air batteries. Herein, the Perspective summaries the solutions to minimize the negative effects of zinc electrodes on discharge performance, cycling life, and shelf life. The future direction of academic research based on current studies of the existing challenges is proposed.

Effects of Crosslinker Concentration in Poly(Acrylic Acid)‐KOH Gel Electrolyte on Performance of Zinc‐Air Batteries

“…The redeposited Zn can take the form of mossy, layer‐like, boulder‐like and dendritic shapes. Among these, dendrites are needle‐like in nature and grow axially, which can either cause internal short circuits or detachment of Zn from the electrode, resulting in reduction of the battery capacity . Moshtev et al.…”

“…As mentioned in Section 2.1, diffusion of zincate ions dominates when the polymer mesh size is reduced. Zincate ions can accumulate at the Zn surface leading to formation of a ZnO insulating layer which terminates the discharge process and inhibits the reverse conversion to metallic Zn, limiting battery capacity and rechargeability . EDX analysis of the Zn electrode surface was done after cycling batteries operating with aqueous and polymer electrolytes (Figure S6).…”

Dendrites issues and advances in Zn anode for aqueous rechargeable Zn‐based batteries

“…Unlike traditional graphite anode based on insertion mechanism, metal anodes based on stripping and plating mechanism experienced infinite volume change because this “hostless” nature can trigger uncontrollable dendrites growth. Besides, the Zn anode aqueous system has other issues including corrosion, passivation, and hydrogen evolution, 29‐32 which are even severer in alkaline electrolytes.…”

“…The root cause of the revolution of hydrogen is that the Zn anode is thermodynamically unstable in an aqueous solution 29 . The hydrogen evolution reaction can be shown as follows: …”

Battery Technologies for Grid-Level Large-Scale Electrical Energy Storage

“…So far, numerous battery energy storage technologies have been developed to fulfill the demands of various fields based on specific application requirements, such as energy density, specific capacity, discharge performance, power output, response time, cycle life, safety, and cost. Various excellent review articles focus on the fundamentals and investigation of batteries [14][15][16][17][18][19][20][21][22][23], which will not be discussed in detail in this perspective. However, few studies focus on the battery energy storage technologies for application in GLEES, which depends more on the corresponding specific application requirements of grid-scale energy storage, including regional power grid peak shaving and load leveling, frequency modulation, voltage regulation, and emergency response.…”