title: In Situ Investigation of Li and Na Ion Transport with Single Nanowire Electrochemical Devices.
abstract: In the past decades, Li ion batteries are widely considered to be the most promising rechargeable batteries for the rapid development of mobile devices and electric vehicles. There arouses great interest in Na ion batteries, especially in the field of static grid storage due to their much lower production cost compared with Li ion batteries. However, the fundamental mechanism of Li and Na ion transport in nanoscale electrodes of batteries has been rarely experimentally explored. This insight can guide the development and optimization of high-performance electrode materials. In this work, single nanowire devices with multicontacts are designed to obtain detailed information during the electrochemical reactions. This unique platform is employed to in situ investigate and compare the transport properties of Li and Na ions at a single nanowire level. To give different confinement for ions and electrons during the electrochemical processes, two different configurations of nanowire electrode are proposed; one is to fully immerse the nanowire in the electrolyte, and the other is by using photoresist to cover the nanowire with only one end exposed. For both configurations, the conductivity of nanowire decreases after intercalation/deintercalation for both Li and Na ions, indicating that they share the similar electrochemical reaction mechanisms in layered electrodes. However, the conductivity degradation and structure destruction for Na ions is more severe than those of Li ions during the electrochemical processes, which mainly results from the much larger volume of Na ions and greater energy barrier encountered by the limited layered spaces. Moreover, the battery performances of coin cells are compared to further confirm this conclusion. The present work provides a unique platform for in situ electrochemical and electrical probing, which will push the fundamental and practical research of nanowire electrode materials for energy storage applications.
authors.affiliation: †State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.|‡Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States.
authors.forename: Xu
authors.initials: X
authors.lastname: Xu
authors.affiliation: †State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
authors.forename: Mengyu
authors.initials: M
authors.lastname: Yan
authors.affiliation: †State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
authors.forename: Xiaocong
authors.initials: X
authors.lastname: Tian
authors.affiliation: †State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
authors.forename: Chuchu
authors.initials: C
authors.lastname: Yang
authors.affiliation: †State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
authors.forename: Mengzhu
authors.initials: M
authors.lastname: Shi
authors.affiliation: †State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
authors.forename: Qiulong
authors.initials: Q
authors.lastname: Wei
authors.affiliation: §Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States.
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.affiliation: †State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
authors.forename: Liqiang
authors.initials: L
authors.lastname: Mai
mesh_terms: D055664:Electrochemical Techniques; D004566:Electrodes; D008094:Lithium / Q000737:chemistry*; D053770:Nanowires / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry*
chemical_list: D008094:Lithium; D012964:Sodium
keywords: Li ion batteries; Na ion batteries; Single nanowire electrodes; electrical transport