Aqueous rechargeable zinc batteries have the advantages of high safety, abundant resources, non-toxic and environmental protection, and have good application prospects in the field of large-scale energy storage. However, the traditional metal zinc anode is dominated by (101) texture, which has serious problems such as dendrite growth, hydrogen precipitation, corrosion, etc., poor reversibility and short cycle life, which hinders the development of aqueous zinc batteries.
Here,Zhang Ning's team at Hebei University proposed an iodine-assisted electrodeposition strategyBy adding an appropriate amount of iodide ions (such as sodium iodide) to the traditional zinc sulfate electrolyte, the electrodeposition of zinc ions can be guided, and the controllable preparation of highly (002) textured metal zinc (abbreviated as H-(002)-ZN) is realized, and the relative texture coefficient (RTC value) of the (002) crystal plane is as high as 9988%, and the strength ratio of (002) crystal plane to (101) crystal plane is 4009。
Combined with experimental characterization and theoretical simulation, the mechanism of iodide ion additives on the evolution of zinc crystal plane orientation, zinc nucleation and growth process was revealed. The H-(002)-ZN anode prepared in this work can effectively inhibit dendrite and hydrogen precipitation, and its average Coulombic efficiency is 9988% and achieved an extremely long cycle life (6700 h, > 9 months). Compared with the traditional (101)-Zn anode, the whole cell based on the H-(002)-Zn anode (such as H-(002)-Zn VOH and H-(002)-Zn MnO2) has better electrochemical performance.
Figure 1Preparation process
In conclusion, this work reports a simple iodide(i)-assisted electrodeposition strategy that can be used to prepare high(002)-textured Zn metal anodes (H-(002)-Zn) on a large scale. Theoretical and experimental characterization shows that the presence of I additives can significantly increase the growth rate of the Zn(100) plane, homogenize the nucleation of Zn, and promote the electroplating kinetics to achieve uniform H-(002)-Zn electrodeposition.
Using the traditional ZnSO4-based electrolyte and the electrolyzer on the commercial Cu substrate as the model system, the Zn texture gradually changed from (101) to (002) with the increase of Nai additive concentration. In the optimized 1M ZNSO4+0In the 8M Nai electrolyte, the prepared H-(002)-ZN has a compact structure and an ultra-high intensity ratio of (002) to (101) signal, but does not contain (100) signal. Therefore, this work will provide enlightenment for the efficient electrosynthesis of high-performance zinc anodes in aqueous zinc batteries.
Figure 2Battery performance
orientational electrodeposition of highly (002)-textured zinc metal anodes enabled by iodide ions for stable aqueous zinc batteries,acs nano2023 doi: 10.1021/acsnano.3c08095