A Self‐Regulated Electrostatic Shielding Layer toward Dendrite‐Free Zn Batteries

Abstract

Although aqueous Zn batteries have become a more sustainable alternative to lithium‐ion batteries owing to their intrinsic security, their practical applications are limited by dendrite formation and hydrogen reactions. The first application of a rare earth metal type addition to Zn batteries, cerium chloride (CeCl3), as an effective, low‐cost, and green electrolyte additive that facilitates the formation of a dynamic electrostatic shielding layer around the Zn protuberance to induce uniform Zn deposition is presented. After introducing CeCl3 additives, the electrochemical characterizations, in situ optical microscopy observation, in situ differential electrochemical mass spectrometry, along with density functional theory calculations, and finite element method simulations reveal resisted Zn dendritic growth and enhanced electrolyte stability. As a result, the Zn–Zn cells using the CeCl3 additive exhibit a long cycling stability of 2600 h at 2 mA cm−2, an impressive cumulative areal capacity of 3.6 Ah cm−2 at 40 mA cm−2, and a high Coulombic efficiency of ≈99.7%. The fact that the Zn–LiFePO4 cells with proposed electrolyte retain capacity significantly better than the additive‐free case is even more exciting.

Engineering a self-adaptive electric double layer on both electrodes for high-performance zinc metal batteries

“…Apparently, when ImS/ZSO electrolyte was used, the cell delivered over 2100 plating/stripping cycles with an ultrahigh average CE of 99.9%, which further demonstrates the inhibitory effect of ImS additive on parasitic reactions. The CE of the Zn//Cu cell in ImS/ZSO electrolyte can still reach ∼99.8% after 200 cycles and even the current density and capacity are increased to 40 mA cm −2 and 10 mA h cm −2 , which outperform the current study 19,37,50–54 (Fig. 3i).…”

“…5f. In the pure ZSO electrolyte, the current density at the tip of the Zn dendrite was higher than that at other locations, indicating a remarkably uneven localized electric field with intensity increase at the surface protuberance sites, 54,73 which is significantly improved to uniformity in the ImS/ZSO electrolyte. The ImS additive with a π–π conjugation imidazolium cation provides a positively charged electrostatic layer, which leads to an even distribution of the Zn 2+ on the interface, and thus the uniform current density distribution.…”

“…Those outstanding results are attributed to the suppressed hydrogen evolution reaction and dendrite growth by ImS additive. As proposed in previous reports, 50,51,54,55 the CE should comprehensively take the current density and capacity plated per cycle and cumulative plated capacity (CPC) into account. Therefore, Fig.…”

Enabling Highly Reversible Zn Anode by Multifunctional Synergistic Effects of Hybrid Solute Additives

“…However, the results showed that the surface of the Zn electrode in ULE did not detect the expected SEI and was not significantly different from the Zn electrode in the pristine electrolyte (Figures S14 and S15). Therefore, we speculate that the texture orientation may be attributed to the electrostatic shielding effect brought by Li + , according to previous research. − Considering that both the (101) and (100) planes are inclined or vertical to the Zn plate, it inevitably leads to the tip effect that makes the Li + adsorb on the edge and tip, inhibiting their further growth. Since Li + suppresses the deposition of (101) and (100) planes caused by concentration polarization, Zn crystals retain the tendency to deposit on the lowest surface energy (002) planes to the maximum extent .…”

Long life exceeding 10 000 cycles for aluminum-ion batteries based on an FeTe2@GO composite as the cathode

“…4 Therefore, it is urgent to develop new battery systems with high energy densities, long lifespans, and the absence of safety issues. 5 Rechargeable aluminum-ion batteries (AIBs) are considered to be one of the most attractive alternatives due to their distinctive advantages of low cost, high safety and environmental friendliness. 6 However, the study of AIBs is still in its infancy.…”