摘要
锌表面自然形成的非均匀氧化层(ZnO)会与电解液发生反应形成Zn_(4)(OH)_(6)SO_(4)·xH_(2)O(ZSH)副产物,导致锌负极表面非均匀沉积,从而阻碍水性锌离子电池实际应用.为了排除氧化层分布形式的影响,本文利用表面终止化学设计策略在锌负极表面制备了一层完全氧化的ZnO层,研究发现锌负极均匀分布的ZnO层会原位演化形成致密的ZSH功能层.均匀且致密的ZSH能够有效隔绝电解液的腐蚀,从而有效提高锌负极界面的稳定性.此外,ZSH(002)晶面边缘的不饱和悬空键(如-O)更容易和Zn(H_(2)O)_(6)^(2+)结构中的锌离子形成强Zn-O键,可以促进Zn(H_(2)O)_(6)^(2+)的脱溶剂化和锌离子沿边扩散,实现了高度可逆的锌沉积行为并限制了副反应.基于此,本文提出与“表面脱水-晶体通道转移”机制明显不同的“边缘脱水-沿边缘转移”锌离子输运新机制.更重要的是,基于此组装的全电池显示出高循环稳定性(超过1000次循环)和高库仑效率(99.07%),验证了其潜在的实际应用价值.
An oxidation layer on a Zn surface is considered to play a negative role in hindering the practical applications of aqueous zinc ion batteries(AZBs).Herein,we demonstrate the importance of Zn-surface termination on the overall electrochemical behavior of AZBs by revisiting the well-known bottleneck issues.Experimental characterizations in conjugation with theoretical calculations reveal that the formation of a dense Zn_(4)(OH)_(6)SO_(4)·xH_(2)O(ZSH)layer from the well-designed surface-oxide termination layer improves the interface stability of the Zn anode and reduces the dehydration energy of Zn(H_(2)O)_(6)^(2+),thereby accelerating the interface transport kinetics of Zn^(2+).Moreover,instead of directly diffusing over the ZSH layer,a new“edge dehydration-along edge transfer”mechanism of Zn^(2+) is discovered.Owing to the presence of a Zn anode with a ZnO-derived ZSH layer,an ultrahigh stability of over 1200 h with a high cumulative-plated capacity of 6.24 mAh cm^(-2)is achieved with a symmetrical cell.Furthermore,high cycling stability(over 1000 cycles)and Coulombic efficiency(99.07%)are obtained in the entire AZBs with a MnO_(2)cathode.An understanding of the oxygen surface termination mechanism is beneficial to Zn-anode protection and is a timely forward step toward the long-pursued practical application of AZBs.
作者
刘宇
陈树麟
袁豪
熊方宇
刘琴
安永康
张建勇
吴璐
孙建国
Yong-Wei Zhang
安琴友
John Wang
Yu Liu;Shulin Chen;Hao Yuan;Fangyu Xiong;Qin Liu;Yongkang An;Jianyong Zhang;Lu Wu;Jianguo Sun;Yong-Wei Zhang;Qinyou An;John Wang(State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China;Department of Materials Science and Engineering,National University of Singapore,Singapore 117574,Singapore;Institute of High Performance Computing,Agency for Science,Technology and Research(A*Star),Singapore 138632,Singapore;Institute of Materials Research and Engineering(IMRE),Agency for Science,Technology and Research(A*Star),Singapore 138634,Singapore)
基金
supported by the National Key Research and Development Program of China(2020YFA0715000)
the National Natural Science Foundation of China(521722315197225951832004)
the Fundamental Research Funds for the Central Universities(WUT:2020Ⅲ043GX2020Ⅲ015GX)
the support by MOE,Singapore Ministry of Education(Tier 1,A-8000186-01-00)
the funding support from Singapore A*STAR CRF Award
the scholarship support from China Scholarship Council(CSC)under No.202106950024。
作者简介
Corresponding authors:Jianguo Sun is currently a research fellow in Prof.John Wang’s group at the Department of Materials Science and Engineering,NUS.He received his Ph.D.degree from NUS in 2021.His current research interest focuses on the structure-mechanism of energy materials and their applications in energy storage devices including all solid state battery,sodium ion battery and Li-S batteries etc.E-mail addresses:sjg07@nus.edu.sg;Corresponding authors:Qinyou An is a professor of Materials Science and Engineering at Wuhan University of Technology.He received his Ph.D.degree from Wuhan University of Technology in 2014.He carried out his postdoctoral research in the laboratory of Prof.Yan Yao at the University of Houston in 2014–2015.Currently,his research interest includes energy storage materials and devices.anqinyou86@whut.edu.cn;Corresponding authors:John Wang is a professor at the Department of Materials Science and Engineering,NUS.His research focuses on energy materials and devices,2D materials chemistry,and nanostructured materials for energy and water technologies.msewangj@nus.edu.sg Yu Liu is now a postdoctoral research fellow at Wuhan University of Science and Technology.He received his Ph.D.degree in Material Science and Engineering from Wuhan University of Technology in 2023.In 2022–2023,he was a visiting Ph.D.student at National University of Singapore(NUS).His current research focuses on rechargeable multivalent ion batteries and Li metal batteries.contributed equally to this work;Shulin Chen is an undergraduate student of Materials Science and Engineering at Wuhan University of Technology.His current research focuses on Zn metal batteries.contributed equally to this work;Hao Yuan is a research scientist at Institute of High Performance Computing,Agency for Science,Technology and Research.He received his Ph.D.degree from University of Science and Technology of China in 2021.His current research focuses on charge/discharge mechanisms and electrode materials design for batteries.contributed equally to this work。
