Ampere‐Hour‐Scale Aqueous Nickel–Organic Batteries based on Phenazine Anode

Aqueous nickel-organic batteries exhibit significant promise for large-scale energy storage applications. This work employs high-concentration KOH electrolytes to suppress the undesirable dissolution of organic phenazine(PZ) anode. The phenazine anode offers a high initial specific capacity and excellent cycle life. Moreover, ampere-hour-scale PZ/Ni(OH)₂ batteries are successfully assembled and achieve 50 Wh kg⁻¹ based on total mass.

Abstract

Aqueous nickel-based batteries, particularly nickel-organic batteries, are promising candidates for large-scale energy storage applications owing to their environmental friendliness, abundant resources, and intrinsic safety. However, organic anode materials suffer from serious dissolution in electrolytes during discharge/charge processes and ampere-hour-scale nickel-organic batteries are still absent. Here, phenazine (PZ) is screened as the anode and utilizes 10 m KOH as the electrolyte to construct ampere-hour-scale PZ/Ni(OH)₂ batteries to demonstrate the practicability. In situ, UV–vis and molecular dynamics simulations demonstrate the inhibited dissolution of PZ in high-concentration of 10 m KOH. The PZ anode can provide a high initial specific capacity of 281.6 mAh g⁻¹ at 0.5 C with a Coulombic efficiency of 98.6% and ultralong cycle life with a capacity retention of 74.3% after 14 000 cycles at 30 C. Moreover, the fabricated pouch-type PZ/Ni(OH)₂ battery with a high PZ mass-loading of 48 mg cm⁻² delivers a capacity of 1.23 Ah and achieves a high energy density of 50 Wh kg⁻¹ (based on the total mass of the cell). The abundant resources, excellent stability, and cost-effectiveness of phenazine endow nickel-organic batteries with promising potential for large-scale energy storage applications.