Long Shelf‐Life Efficient Electrolytes Based on Trace l‐Cysteine Additives toward Stable Zinc Metal Anodes

Abstract

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.

Selection criteria for electrical double layer structure regulators enabling stable Zn metal anodes

“…S5 (ESI†) presents the adsorption energy of these additives on the Zn (0001) surface. As expected, these solvents both delivered lower adsorption energy than H 2 O (−0.22 eV), 48 suggesting their higher affinity to the Zn surface, which enables them to replace the partial H 2 O in the EDL structure. Based on the above analysis, we concluded that the major role of these solvents is to regulate the EDL structure instead of the bulk properties of electrolytes (Fig.…”

“…Recently, the shelf life of electrolytes has also attracted attention due to the required long storage period of practical products. 48 Therefore, Sul/ZnSO 4 solutions were aged for 12 months and then employed as electrolytes to assemble Zn|Cu half cells. As shown in Fig.…”

Interface solvation regulation stabilizing the Zn metal anode in aqueous Zn batteries

“…6f). [40][41][42][43][44][45] The results conrm the promoted electrochemical performance by the EC additive for not only the Zn anode but also full cells.…”

Structure Evolution of V2O5 as Electrode Materials for Metal‐Ion Batteries

“…α-V 2 O 5 has been frequently used as a cathode material in the aqueous ZIBs. [120][121][122] It has been confirmed that during the discharge process of aqueous ZIBs, the hydrated Zn-ions will be inserted into the interlayer space of V 2 O 5 , during which the hydration sheath of Zn-ions plays a critical role in reducing the electrostatic interactions between Zn-ions and the host structure and facilitating the Zn-ions diffusion. However, the structure evolution of α-V 2 O 5 during Zn-ions insertion is ambiguous, which is attributed to the acidic environment of the electrolyte.…”