An Industrially Applicable Passivation Strategy for Significantly Improving Cyclability of Zinc Metal Anodes in Aqueous Batteries

Abstract

The cycling instability of metallic Zn anodes hinders the practicability of aqueous Zn‐ion batteries, though aqueous Zn‐ion batteries may be the most credible alternative technology for future electrochemical energy storage applications. Commercially available trivalent chromium conversion films (TCCF) were successfully employed as robust artificial interphases on Zn metal anodes (ZMAs). Fabricated through a simple immersion method, the TCCF‐protected Zn (TCCF@Zn) electrode enables a super‐low nucleation overpotential for Zn plating of 6.9 mV under 1 mA cm−2, outstanding Coulombic efficiency of 99.7% at 3 mA cm−2 for 1600 cycles in Zn||Cu asymmetric cells and superior cyclability in symmetric Zn||Zn batteries at 0.2, 2 and 5 mA cm−2 for 2500 h and 10 mA cm−2 for 1200 h. More importantly, the TCCF@Zn||V2O5 full cell exhibited a specific capacity of 118.5 mAh g−1 with a retention of 53.4% at 3 A g−1 for 3000 cycles, which is considerably larger than that of the pristine Zn||V2O5 full cell (59.7 mAh g−1 with a retention of 25.7%). This study demonstrates a highly efficient and low‐cost surface modification strategy derived from an industrially applicable trivalent chromium passivation technique aimed at obtaining dendrite‐free ZMAs with high reversibility for practical Zn batteries in the near future.This article is protected by copyright. All rights reserved

Trace Amount of High-Concentration Electrolyte for High-Performance Aqueous Zn Metal Anodes

“…T denotes the test temperature. This is illustrated in Figure c; the calculated E a value in 3 M ZnSO 4 is 35.39 kJ mol –1 , which is smaller than the E a (88.53 kJ mol –1 ) of saturated ZnSO 4 electrolyte, indicating that 3 M ZnSO 4 electrolyte is helpful to accelerate the diffusion kinetics of Zn 2+ compared with saturated ZnSO 4 . − It is worth noting that the 1 M electrolyte has the smallest E a and rapid deposition kinetics. However, its morphology shows uncontrollable dendritic growth, so its electrochemical stability is poor.…”

“…When the electrolyte concentration is 3 M, the symmetric cell has the smallest overpotential change and the best rate performance. The exchange current density i 0 acts as a crucial part in assessing the kinetics of charge transfer, which can be calculated from the rate performance results using the following formula ): i ≈ i 0 F R T η 2 …”

Functionalized Non-Glass Fiber Nanoporous Separator for High-Performance Aqueous Zinc Ion Batteries

“…24 Concerning cathode materials, structural collapse, and dissolution during charge/discharge cycling are critical factors impacting battery cycling stability. 25,26 Researchers have developed effective strategies to address AZIBs challenges, including anode structure design, 27,28 electrolyte optimization, 29,30 cathode material modification, 31−33 and separator modification. 34,35 The separator is vital for segregating positive and negative electrode active materials and preventing short circuits due to direct contact.…”

“…However, due to dendrite growth and interfacial side reactions in zinc metal anodes, issues arise, potentially causing short-circuit and rapid capacity degradation with low Coulombic efficiency (CE) . Concerning cathode materials, structural collapse, and dissolution during charge/discharge cycling are critical factors impacting battery cycling stability. , Researchers have developed effective strategies to address AZIBs challenges, including anode structure design, , electrolyte optimization, , cathode material modification, − and separator modification. , The separator is vital for segregating positive and negative electrode active materials and preventing short circuits due to direct contact . Moreover, during charging and discharging, it maintains the necessary electrolyte, forms ion channels, and functionalized separators accelerate ion migration, homogeneous ion distribution, and promote zinc ion desolvation.…”

Concentration-Driven Interfacial Amorphization toward Highly Stable and High-Rate Zn Metal Batteries

“…In contrast, amorphous materials are characterized as disordered microstructures with isotropic ionic transportation pathways, higher conductivity, and a grain boundary-free state, which homogenizes the distribution of ions and electrons at the electrode interface effectively. , However, experimental fabrication of the amorphous ASEI presents a formidable challenge due to the metastable thermodynamic preference of dissolution and recrystallization in solutions. , Essentially, our understanding crystal-structure transformations involved in improving deposition kinetics and manipulating Zn 2+ migration remains incomplete. Furthermore, despite the significant interest garnered by aqueous zinc metal batteries, their commercial feasibility is hindered by the absence of practical and scalable processing methods that are in line with the increasing demands of AZMB applications …”