Zn anodes suffer from poor Coulombic efficiency (CE) and serious dendrite formation due to the unstable anode/electrolyte interface (AEI). The electrical double layer (EDL) structure formed before cycling is of great significance for building stable solid electrolyte interphase (SEI) on Zn surface but barely discussed in previous research about the stabilization of Zn anode. Herein, saccharin (Sac) is introduced as electrolyte additive for regulating the EDL structure on the AEI. It is found that Sac derived anions are preferentially adsorbed on the Zn metal surface instead of water dipole, creating a new H2O‐poor EDL structure. Moreover, the unique SEI is also detected on the Zn surface due to the decomposition of Sac anions. Both are proved to be capable of modulating Zn deposition behavior and preventing side reactions. Encouragingly, Zn|Zn symmetric cells using Sac additive deliver a high cumulative plated capacity of 2.75 Ah cm−2 and a high average CE of 99.6% under harsh test condition (10 mA cm−2, 10 mAh cm−2). The excellent stability is also achieved at a high rate of 40 mA cm−2. The effectiveness of this Sac additive is further demonstrated in the Zn‐MnO2 full cells.

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.

Regulating the electrical double layer (EDL) structure via electrolyte additives is a promising strategy to improve the cycle stability of Zn anodes, but there are no general disciplines that can...

The solid electrolyte interphase (SEI)-forming additives strategy is of great significance for improving the cycle stability of zinc (Zn) anodes. Although various additives have been reported, the relationship between their molecular structures and SEI chemistries is poorly understood. Herein, a molecular design principle for sulfonamide-containing additives that endow Zn anodes with a robust SEI layer is proposed. The incorporation of the benzene ring and amino group (−NH 2 ) leads to high adsorption energy, low lowest unoccupied molecular orbital lowest unoccupied molecular orbital (LUMO), and a small highest occupied molecular orbital-LUMO (HOMO-LUMO) gap, facilitating the reduction process of sulfanilamide (SA) additives. Coupled with SA/ZnSO 4 electrolytes, Zn|Zn symmetric cells deliver an ultralong cycle life of 4800 h (200 days) at 2 mA cm −2 and 2 mAh cm −2 . Additionally, a high cumulative plated capacity (CPC) of 6000 mAh cm −2 and 2700 mAh cm −2 is also achieved at a capacity per cycle of 10 mAh cm −2 and 30 mAh cm −2 , respectively. More importantly, the versatility of SA additives is also demonstrated in Zn-V 2 O 5 , Zn-I 2 , and Zn-MnO 2 full cells at a low N/P ratio (the theoretical capacity ratio between the negative and positive electrode) of 5.3, 8.3, and 4.5, respectively. This molecular structure strategy provides a promising path to develop effective SEI-forming additives.

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Zinc anodes have been troubled with serious side reactions and uncontrollable dendrite growth, which is attributed to the unstable electrical double layer (EDL) structure. Herein, a nitrogen−based organic compound named...

The unstable anode/electrolyte interface (AEI) triggers the corrosion reaction and dendrite formation during cycling, hindering the practical application of zinc metal batteries. Herein, for the first time, l‐cysteine (Cys) is employed to serve as an electrolyte additive for stabilizing the Zn/electrolyte interface. It is revealed that Cys additives tend to initially approach the Zn surface and then decompose into multiple effective components for suppressing parasitic reactions and Zn dendrites. As a consequence, Zn|Zn symmetric cells using trace Cys additives (0.83 mm) exhibit a steady cycle life of 1600 h, outperforming that of prior studies. Additionally, an average Coulombic efficiency of 99.6% for 250 cycles is also obtained under critical test conditions (10 mA cm−2/5 mAh cm−2). Cys additives also enable Zn–V2O5 and Zn–MnO2 full cells with an enhanced cycle stability at a low N/P ratio. More importantly, Cys/ZnSO4 electrolytes are demonstrated to be still effective after resting for half year, favoring the practical production.

An interface self‐assembly followed by hydrothermal reduction method are proposed to obtain a tannic acid (TA)‐modified reduced graphene oxide composite film (|TA/RGO|). This unique method endows |TA/RGO| with several advantages: (1) TA is adopted as a redox‐active spacer between adjacent interlayers for enlarging the ion‐accessible area and contributing to pseudocapacitance; (2) due to the intensive pressure exerted by the sandwich‐like device during the hydrothermal reduction process, appropriate expansion and a relatively flat layered structure are achieved which will facilitate the ion transport. As a result, the |TA/RGO| film shows an ultrahigh volumetric performance of 701 F cm−3 with a high density of 1.91 g cm−3 using a three‐electrode system. When assembled into a symmetric supercapacitor, |TA/RGO| film delivers a high volumetric capacitance of 244.8 F cm−3 and a high capacitance retention of 100 % after 5000 cycles at the current density of 2 A g−1, showing a great potential for large‐scale application.