香港城市大学Chunyi Zhi团队报道了N-改性石墨烯稳定无枝晶高速水溶液锌离子电池界面pH。相关研究成果于2021年11月19日发表在国际顶尖学术期刊《德国应用化学》。
该文通过调节锌离子流量，对锌枝晶问题进行了深入研究。pH变化严重影响枝晶的形成，但其重要性尚未揭示。
该文中，研究人呢有构建了一个N-改性石墨烯界面（NGI），通过调节水合锌离子去溶剂化来稳定pH值。Operando pH检测显示NGI的pH值稳定。其与NGI中的孔一起工作，以实现无枝晶锌沉积，并将对称电池寿命延长116倍。实验和理论结果表明，pH值的稳定是由于从溶剂化鞘层到N原子的电子转移降低了活化能而导致的去溶剂化。有效的去溶剂化确保电子直接从衬底转移到Zn2+（而不是配位的H2O），避免O-H键裂解。因此，Zn-V6O13电池在20.65 mA cm-2和1.07 mAh cm-2时可实现较长的寿命。
该工作揭示了界面pH值的重要性，为解决锌枝晶问题提供了新的途径。
附：英文原文
Title: Stabilizing Interface pH by N-Modified Graphdiyne for Dendrite-Free and High-Rate Aqueous Zn-ion Batteries
Author: Qi Yang, Liang Li, Tanveer Hussain, Donghong Wang, Lan Hui, Ying Guo, Guojin Liang, Xinliang Li, Ze Chen, Zhaodong Huang, Yongjun Li, Yurui Xue, Zicheng Zuo, Jieshan Qiu, Yuliang Li, Chunyi Zhi
Issue&Volume: 2021-11-19
Abstract: Zn dendrite issue was intensively studied via tuning zinc ion flux. pH change seriously influences dendrite formation, while its importance has not been revealed. Here, we construct a N-modification graphdiyne interface (NGI) to stabilize pH by mediating hydrated zinc ion desolvation. Operando pH detection reveals pH stabilization by NGI. This works with pores in NGI to achieve dendrite-free Zn deposition and an increased symmetric cell lifespan by 116 times. Experimental and theoretical results owe pH stabilization to desolvation with a reduced activation energy achieved by electron transfer from solvation sheath to N atom. The efficient desolvation ensures that electron directly transfers from substrate to Zn2+ (rather than the coordinated H2O), avoiding O-H bond splitting. Hence, Zn-V6O13 battery achieves a long lifespan at 20.65 mA cm-2 and 1.07 mAh cm-2. This work reveals the significance of interface pH and provides a new approach to address Zn dendrite issue.
DOI: 10.1002/anie.202112304
Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202112304
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