Improvement of surface stability of Zn anode by a cost-effective ErCl(3) additive for realizing high-performance aqueous zinc-ion batteries.

Rechargeable aqueous-zinc ion batteries (AZIB) have notable benefits in terms of high safety and low cost. Nevertheless, the challenges, such as dendrite growth, zinc anode corrosion, and hydrogen evolution reaction, impede its practical implementation. Hence, this study proposes the introduction of an economical ErCl3 electrolyte additive to stabilize the Zn anode surface and address the aforementioned issues. The introduced Er3+ will cover the raised zinc dendrite surface and weaken the "tip effect" on the surface of the zinc anode via the "electrostatic shielding" effect. Simultaneously, the introduced Cl- can reduce the polarization of the zinc anode. Due to the synergistic effect of Er3+ and Cl-, the zinc anode corrosion, dendrite growth and hydrogen evolution have been efficiently inhibited. As a result, the Zn||Zn-symmetric battery using ErCl3 additive can stably cycle for 1100 h at 1 mA cm-2, 1 mAh cm-2, and exhibit a high average coulomb efficiency (99.2 %). Meanwhile, Zn||MnO2 full battery based on ErCl3-added electrolyte also demonstrates a high reversible capacity of 157.1 mAh/g after 500 cycles. Obviously, the capacity decay rate of the full battery is also improved, only 0.113 % per cycle. This study offers a straightforward and economically efficient method for stabilizing the zinc anode and realizing high-performance AZIBs.

Xiong Y ，Gu X ，Liu Z ，Ren X ，Jiang Y ，Xu H ，Zhuo L ，Jiang G ... -  《-》

An efficient electrolyte additive of tetramethylammonium sulfate hydrate for Dendritic-Free zinc anode for aqueous Zinc-ion batteries.

Recently, zinc metal has been considered as a promising metal anode for aqueous rechargeable metal ion batteries due to its low electrochemical potential and high theoretical capacity. However, zinc metal suffers from hydrogen evolution reaction (HER) and dendrite growth during plating/stripping. Here, we propose a low-cost, effective and non-toxic electrolyte additive, tetramethylammonium sulfate hydrate (TMA2SO4), as a simple cationic surfactant additive for zinc-ion batteries, to trigger the smooth Zn deposition during charging and discharging process. It is found that TMA2SO4 enable the realization of the deposition of Zn ions along the surface of zinc foil laterally without stacking and thus dendrite growth and side reactions are greatly mitigated by the electrolyte additive of TMA2SO4 even when the amount of the additive is as low as 0.25 mM. As a result, the TMA2SO4 additive induces excellent cycling stability over 1800 h at the current density of 0.5 mA cm-2 with the limited capacity of 0.5 mAh cm-2 for the Zn-Zn symmetrical cell. Moreover, the electrolyte with TMA2SO4 can well match with MnO2 cathode, which achieves the high initial capacity of 181.3 mAh g-1 at 0.2 A g-1 and long-term cycling stability with the capacity retention of 98.72 % after 200 cycles for the Zn/MnO2 full cell. This work provides a general electrolyte design strategy to suppress zinc dendrite growth and side reactions to achieve long-lifespan zinc metal anodes for aqueous zinc ion batteries by electrostatic shielding effect.

Cao H ，Huang X ，Liu Y ，Hu Q ，Zheng Q ，Huo Y ，Xie F ，Zhao J ，Lin D ... -  《-》

Simultaneously Tailoring Zinc Deposition and Solvation Structure by Electrolyte Additive.

Hu S ，Ma H ，Fan X ，Tao H ，Yang X ... -  《-》

Efficient Suppression of Dendrites and Side Reactions by Strong Electrostatic Shielding Effect via the Additive of Rb(2) SO(4) for Anodes in Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (AZIBs) have attracted considerable attention due to their low cost and environmental friendliness. However, the rampant dendrite growth and severe side reactions during plating/stripping on the surface of zinc (Zn) anode hinder the practicability of AZIBs. Herein, an effective and non-toxic cationic electrolyte additive of Rb2 SO4 is proposed to address the issues. The large cation of Rb+ is preferentially adsorbed on the surface of Zn metal to induce a strong shielding effect for realizing the lateral deposition of Zn2+ ions along the Zn surface and isolating water from Zn metal to effectively inhibit side reactions. Consequently, the Zn||Zn symmetric cell with the addition of 1.5 mm Rb2 SO4 can cycle more than 6000 h at 0.5 mA cm-2 /0.25 mAh cm-2 , which is 20 times longer than that without Rb2 SO4 . Besides, the Zn||Cu asymmetric cell with Rb2 SO4 achieves a very high average Coulombic efficiency of 99.16% up to 500 cycles. Moreover, the electrolyte with Rb2 SO4 well matches with the VO2 cathode, achieving high initial capacity of 412.7 mAh g-1 at 5 A g-1 and excellent cycling stability with a capacity retention of 71.6% at 5 A g-1 after 500 cycles for the Zn//VO2 full cell.

Zhang X ，Chen J ，Cao H ，Huang X ，Liu Y ，Chen Y ，Huo Y ，Lin D ，Zheng Q ，Lam KH ... -  《-》

Toward the Rechargeable Aqueous Zinc Ion Batteries with Improved Overall Performance: Electrolyte with Surface Adsorptive Additive.

Aqueous zinc-ion batteries (AZIBs) with slightly acidic electrolytes process advantages such as high safety, competitive cost, and satisfactory electrochemical performance. However, the failure behaviors of both electrodes, regarding zinc dendrite growth, interfacial parasitic reactions, and the collapse of cathode materials hinder the practical application of ZIBs. To alleviate the issues of both anode and cathode at the same time, D-xylose (DX) is introduced to the electrolyte as a multifunctional additive. As a result, the side reaction of the anode is suppressed and the metallic deposition behavior is regulated due to the hydrogen bonding network reconstruction and preferential surface adsorption of DX; for the MnO2 cathode, the DX adsorption can help the interfacial charge transfer and increase the reactive sites. Benefiting from these merits, DX-optimized Zn//Zn battery displays reveal a prolonged lifespan of 6912 h and an ultra-high cumulative capacity of 17.28 Ah cm-2 at 5 mA cm-2. With the function of water reactivity suppression, the Coulombic efficiency reaches 99.91% at 2 mA cm-2; the Zn||MnO2 full batteries exhibit excellent cyclability over 2000 cycles at 5C with an increased capacity of 118.9 mAh g-1, indicating the dual functions to both of the electrodes for AZIBs.

Wang Y ，Zhao R ，Yang J ，Zou J ，Zhang A ，Han X ，Hu Z ，Lv M ，Wang X ，Wu C ，Bai Y ... -  《-》