Self‐Healing SeO₂ Additives Enable Zinc Metal Reversibility in Aqueous ZnSO₄ Electrolytes

Abstract

The development of aqueous zinc metal batteries (AZMBs) is significantly impeded by the poor cycle stability of Zn anodes due to the uncontrolled dendrite growth and low Coulombic efficiency (CE). Herein, for the first time, SeO 2 additives are introduced into ZnSO 4 electrolyte to enhance the stability of the Zn anode. According to the experimental results, the protective ZnSe layer is initially in-situ formed on the Zn surface prior to the Zn plating, which acts as a shield for inhibiting the parasitic reactions and dendrite formation. Moreover, this additive strategy yields the unique characteristic of self-healing for recovering the cracks in the consequence of huge volume change, ensuring the durability of ZnSe layer. Consequently, Zn|Zn symmetric cell using SeO 2 additive delivers an enhanced cumulative plated capacity of 2.1 Ah cm −2 under practical test conditions, which far exceeds the previously reported works. Meanwhile, the average CE of 99.6% for 250 cycles is also demonstrated in Zn|Cu half cells with the presence of the SeO 2 additive. In addition, the positive effect of the SeO 2 additive is further illustrated in the Zn-MnO 2 full cells with a limited Zn.

Biomolecular Regulation of Zinc Deposition to Achieve Ultra‐Long Life and High‐Rate Zn Metal Anodes

“…The above experimental results reveal the fact that FI additive can effectively elevate the reversibility and lifespan of the Zn plating/stripping, facilitating the development of aqueous ZIBs. Compared with other reported electrolyte additives, our battery with a small dosage of FI additive is state-of-the-art among the previous literature, [18,25,28,33,[42][43][44][45][46][47] as shown in Figure 5d and Table S1, Supporting Information.…”

Methods for Rational Design of Advanced Zn‐Based Batteries

“…SeO 2 is a recently reported additives, which could induce the in situ formation of ZnSe film on the Zn anode surface prior to the Zn plating (Figure 10a), thus preventing the side reaction between Zn anode and electrolyte. [129] The Zn/Zn symmetric cell using SeO 2 -ZnSO 4 electrolyte displayed a superior cycle stability of 2100 h at 2 and 2 mAh cm Such high reversibility was assigned to the reason that the Zn 2+ was surrounded by TFSIrather water, which effectively prevented the H 2 evolution. However, the high cost of Zn(TFSI) 2 hindered its further application.…”

“…[139][140][141] For example, Hu et al fabricated a decoupled Zn//MnO 2 battery with two membrane three-champers, which displayed an open-circuit voltage of 2.83 V and an excellent cycling stability (98% capacity retention after deep cycling for 200 h). [142] More importantly, the as-designed device [129] Copyright 2022, Wiley-VCH. b) Optical photographs of ZnCl 2 /Zn(OAc) 2 electrolytes with different molar ratios.…”

“…Figure 10. a) Schematic illustration of Zn deposition in SeO 2 -ZnSO 4 electrolyte. Reproduced with permission [129]. Copyright 2022, Wiley-VCH.…”

Research progress on ZnSe and ZnTe anodes for rechargeable batteries

“…In recent years, some other new energy storage systems based on Earth-abundant multivalent ions as shuttle carries have been emerging; e.g., ZnSe (or ZnTe/ZnTe 2 ), and bimetallic selenides are also emerging as a kind of positive electrode (cathode) for rechargeable aluminum batteries (RABs) or aluminum-ion batteries (AIBs), [134][135][136] or as protective/SEI layer materials of Zn anodes for rechargeable zinc-ion batteries (ZIBs) or zinc metal batteries (ZMBs) to eliminate dendrites and side reactions (i.e., to enhance the stability of Zn anode). [137][138][139] Although some work showed encouraging results, it is still in the infant stage, and much effort is needed to achieve the balanced capacity, rate performance and cycling stability. In addition, ZnSe and their hybrids/composites can also be applied in advanced lithium-sulfur batteries (LSBs) of low cost and high energy density via the enhancement of adsorption sites, redox kinetics and volume expansion buffering, 140,141 e.g., hollow ZnSe/NHC polyhedra as both an adsorber and a catalyst for lithium polysulfides/sulfides, 142 and catalytic CoSe-ZnSe heterojunctions for accelerated bidirectional sulfur conversion reactions along with robust adsorption toward polysulfides, 143,144 and thus for higher initial capacities (or ICE), excellent rate capability, and more stable cycling performance.…”