Spontaneous displacement reactions regulate reversible dendrite-free zinc deposition to achieve long-life iodized zinc batteries

July 28, 2022,Professor Zhang Jintao, School of Chemistry and Chemical Engineering, Shandong UniversityNano Research Energy, an energy journal hosted by Tsinghua University on the publication title“A highly reversible dendrite-free Zn anode via spontaneous galvanic replacement reaction for advanced zinc-iodine batteries”Latest research results.

Figure 1. (a) Zn| Sn anode synthesis process and Zn electrode and (b) Zn | Schematic diagram of the Sn electrode during the cycle. (c) Pure Zn and (d) Zn | SEM image of Sn.

Research Background:Zn-based water-based batteries have received widespread attention because of their abundant reserves (Crust Zn content of 0.0075%), high theoretical specific capacity (820 mAh·g–1), and safety and stability, and are regarded as the main competitors of the next generation of energy storage equipment. However, like other metal batteries, the disorderly growth of zinc dendrites and complex by-products during the cycle will cause the cell coulomb efficiency to be reduced, at the same time, the corrosion reaction of water molecules in the electrolyte to the metal negative electrode will produce insulating corrosion products, which will cause the cell impedance to increase, and the continuous hydrogen evolution reaction (HER) during the cycle will cause the battery to swell and reduce the cycle life of the battery. Therefore, solving the problem of dendrite formation and volume expansion of the metal zinc anode during charging and discharging, and improving its cycle stability and safety will be the key to achieving the application of high energy density zinc metal batteries

In view of the current challenges, Professor Zhang Jintao’s team of Shandong University constructed an Sn protective layer in situ on the surface of the zinc anode to inhibit dendrites through a simple spontaneous displacement reaction. When it is assembled with the iodine positive electrode to assemble the zinc iodine full battery, it has a good effect of inhibiting the formation of zinc dendrites and alleviating the occurrence of zinc negative side reactions. Through mechanism studies, it was found that Zn | Sn coating can not only provide an effective nucleation site, greatly reduce the nucleation overpotent, to achieve uniform zinc deposition, while the chemical inertness of Sn can also effectively avoid the occurrence of side reactions, alleviate the corrosion of zinc anode and hydrogen evolution, thereby prolonging battery life. The work demonstrates a simple and versatile strategy for protecting the negative electrode and limiting dendrites, and provides a reference for subsequent developments of advanced metal negative electrodes.

Figure 1 shows that the Zn electrode is soaked in the solution of SnCl4 for 5 minutes to obtain a homogeneous Sn coating. Compared to untreated pure Zn electrodes, Zn | The Sn negative electrode can effectively inhibit dendrite growth and achieve reversible Zn deposition/stripping. Subsequently, by adjusting the concentration of Sn4+ ions, the influence of morphological structure of Sn coating on performance was explored. Experimental results show that when the Sn4+ ion is 0.1 M, a uniform coating composed of Sn particles of uniform size can be obtained. Optimized nucleation sites can speed up deposition kinetics, significantly reduce nucleation overpotentials, and effectively avoid side reactions, alleviate corrosion of zinc anodes, and hydrogen evolution. Among them, the most outstanding sample Zn | The Sn-0.1 symmetrical battery exhibits a low overpotential (13.9 mV) and stable cycles for more than 900 hours. In addition, | by Zn Zn | assembled with the iodine cathode of Sn anode The Sn-I2 battery still has a capacity retention rate of 90.7% after 1200 cycles, which fully demonstrates the Zn | Excellent performance of the Sn-0.1.

Figure 2. (a) XRD profile of pure Zn and Zn | Sn. (b) Pure Zn and Zn | Tafel curve of Sn-X in 2 M ZnSO4 electrolyte. (c) Zn| Comparison of Sn-0.10 and pure Zn deposition stripping and (d) and literature reports. (e) Pure Zn and Zn | in symmetrical batteries Cyclic performance of Sn-X at 1 mA cm-2 and 1 mAh cm-2.

Figure 3. Zn| Comparison of electrochemical properties of Sn and pure Zn in Zn-I2 batteries. (a) CV curve of 0.1 mV/s. (b) Zn| Magnification performance of Sn-I2 batteries and Zn-I2 batteries. (c) Corresponding charge and discharge curves at different current densities. (d) Cyclic performance and coulomb efficiency at 5 C. (e) Zn| EIS for Sn-I2 batteries and Zn-I2 batteries.

Related thesis information: Tian, Y. D.; Chen, S.; He, Y. L.; Chen, Q. W.; Zhang, L. L.; Zhang, J. T. A highly reversible dendrite-free Zn anode via spontaneous galvanic replacement reaction for advanced zinc-iodine batteries. Nano Res. Energy 2022, 1: e9120025. DOI: 10.26599/NRE.2022.9120025. .

As a sister journal of Nano Research, Nano Research Energy (ISSN: 2791-0091; e-ISSN: 2790-8119; Official website: was launched in March 2022 and is co-edited by Professor Qu Liangti of Tsinghua University and Professor Chunyi Zhi of the City University of Hong Kong. Nano Research Energy is an international multidisciplinary, all-English open access journal, focusing on the cutting-edge research and application of nanomaterials and nanoscience technology in new energy-related fields, benchmarking against the top international energy journals, and committed to publishing high-level original research and review papers. Open access, by 2023No APC feesTeachers are welcome to submit articles. Please contact:

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