Regulating Zn(002) Deposition toward Long Cycle Life for Zn Metal Batteries

Abstract

Regulating the Zn deposition orientation is an efficient way to suppress Zn dendrites and stabilize Zn anodes in aqueous Zn ion batteries (ZIBs). Few studies have been conducted to control Zn(002) deposition by altering the Zn2+ solvation structure with a cosolvent. Herein, the bifunctional high-polarity cosolvent hexamethylphosphoramide (HMPA) is proposed in an aqueous electrolyte. It not only suppresses the H2 evolution reaction via the reshaped Zn2+ solvation structure with decreased H2O activity but also induces Zn(002) deposition with a hexagonal-close-packed morphology due to the strong absorption ability of HMPA to Zn(002). With the optimized electrolyte, Zn dendrites and the HER are suppressed and an ultralong cycle life of 1500 cycles with 99.6% Coulombic efficiency is achieved in Zn||Cu cells. Zn||NH4V5O10 and Zn||polyaniline full cells exhibit improved cycling performances compared to that of the bare electrolyte. Our finding provides a feasible and promising way to stabilize Zn anodes and promote the commercial application of ZIBs.

Surface Overpotential as a Key Metric for the Discharge–Charge Reversibility of Aqueous Zinc-Ion Batteries

“… , Contrary to electrolytes that contain Li + ions, where HMPA selectively solvates the Li + ions based on its superior Lewis basicity, our spectroscopic results indicate that HMPA in the given concentration range does not preferentially solvate Zn 2+ ions despite its high donor number. This observation contrasts the findings in a recent article, which reported the dominant solvation of HMPA around the Zn 2+ ion. These comparative results imply that our case with the smaller amount of HMPA relies mainly on the role of this additive as an adsorbate on the Zn metal surface.…”

Rational design of zinc powder anode with high utilization and long cycle life for advanced aqueous Zn–S batteries

“…Besides, we assembled two kinds of pZn||pZn and pZn/In||pZn/In pouch cells with Zn loading of 250 mA h (5 × 5 cm −2 ) to explore the inhibition of the hydrogen evolution reaction (HER) in practical cell models. 32 As expected, the pouch cell with pZn anode displays a noticeable bulge after aging for two weeks (Fig. 3d).…”

A bio-inspired electrolyte with in situ repair of Zn surface cracks and regulation of Zn ion solvation chemistry to enable long life and deep-cycling zinc metal batteries

“…S11†), which is proved to guide smooth and dendrite-free Zn plating by many reported works. 38 In addition, the scanning electron microscopy (SEM) images with different magnifications further present parallel hexagonal Zn platelets on the Zn anode surface after 200 cycles (Fig. S12†).…”