Phase-transition tailored nanoporous zinc metal electrodes for rechargeable alkaline zinc-nickel oxide hydroxide and zinc-air batteries

Abstract

Secondary alkaline Zn batteries are cost-effective, safe, and energy-dense devices, but they are limited in rechargeability. Their short cycle life is caused by the transition between metallic Zn and ZnO, whose differences in electronic conductivity, chemical reactivity, and morphology undermine uniform electrochemical reactions and electrode structural stability. To circumvent these issues, here we propose an electrode design with bi-continuous metallic zinc nanoporous structures capable of stabilizing the electrochemical transition between metallic Zn and ZnO. In particular, via in situ optical microscopy and electrochemical impedance measurements, we demonstrate the kinetics-controlled structural evolution of Zn and ZnO. We also tested the electrochemical energy storage performance of the nanoporous zinc electrodes in alkaline zinc-nickel oxide hydroxide (NiOOH) and zinc-air (using Pt/C/IrO2-based air-electrodes) coin cell configurations. The Zn | |NiOOH cell delivers an areal capacity of 30 mAh/cm2 at 60% depth of discharging for 160 cycles, and the Zn | |Pt/C/IrO2 air cell demonstrates 80-hour stable operation in lean electrolyte condition.

Interface Engineering of Zinc Electrode for Rechargeable Alkaline Zinc‐Based Batteries

“…Accordingly, all these problems involved in zinc electrode are highly associated with the electrons and ions transport behavior at the interface of zinc anode. In past years, considerable endeavors have been devoted to modifying the electrode such as construction of 3D porous zinc electrode, [19] introduction of electrode and electrolyte additives, [20,21] coating of protective layers. [22] At the same time, some reviews have presented the challenges and progresses achieved to improve the reversibility of zinc-based batteries.…”

Light‐Assisted Metal–Air Batteries: Progress, Challenges, and Perspectives

“…The electricity is generated by the redox reactions between the metal anode and the air cathode. Depending on the type of electrolyte, metal–air batteries are divided into non‐aqueous and aqueous systems, in which non‐aqueous Li–O 2 and aqueous Zn–air batteries receive the most research interest due to their high theoretical specific energy [42–47] . The non‐aqueous Li‐CO 2 battery has a similar configuration and working mechanism to a Li–O 2 battery [48, 49] .…”

“…Depending on the type of electrolyte, metal-air batteries are divided into non-aqueous and aqueous systems, in which non-aqueous Li-O 2 and aqueous Zn-air batteries receive the most research interest due to their high theoretical specific energy. [42][43][44][45][46][47] The nonaqueous Li-CO 2 battery has a similar configuration and working mechanism to a Li-O 2 battery. [48,49] The working mechanisms for typical Li-O 2 , Li-CO 2 , and Zn-air batteries are described by the following equations.…”

Bicontinuous Nanoporous Metals with Self-Organized Functionalities

“…For BNP Au (φ B ∼ 0.5) with a typical length scale (30–40 nm), the electric conductivity was measured by Fujita et al to be a third of that of bulk Au (κ 0 ), which decreased to one-sixth at a length scale of 14 nm due to surface scattering . The good electric conductivity, though often overshadowed by other outstanding properties, has been identified through careful impedance analyses as a crucial factor in the homogenization of the oxidation reaction of BNP Zn anodes , and the stabilization of BNP Ir during the electrocatalysis of oxygen evolution, partly because in both cases the metals were partly converted to poorly conductive oxides. In the pores, conductivities or diffusivities of common electrolytes and molecules were determined to be generally around 30–50% of the bulk values for BNP Au samples (mostly of φ p ∼ 0.5), ,, although I cannot further narrow down the range given the differences in the diffusing molecules or ions, the structures, and the measurement methods.…”

“…The mechanism of dealloying, initially studied for its role in corrosion and stress corrosion, lays the groundwork for precise processing–structure relationships for the burgeoning functional applications of BNP metals. Today, BNP metals and their derivatives offer robust catalysis toward oxygen reduction and carbon monoxide oxidation, powering high-rate batteries and supercapacitors, and actuating under unprecedented stresses …”