TEM in situ lithiation of tin nanoneedles for battery applications

Abstract

Materials such as tin (Sn) and silicon that alloy with lithium (Li) have attracted renewed interest as anode materials in Li-ion batteries. Although their superior capacity to graphite and other intercalation materials has been known for decades, their mechanical instability due to extreme volume changes during cycling has traditionally limited their commercial viability. This limitation is changing as processes emerge that produce nanostructured electrodes. The nanostructures can accommodate the repeated expansion and contraction as Li is inserted and removed without failing mechanically. Recently, one such nano-manufacturing process, which is capable of depositing coatings of Sn ''nanoneedles'' at low temperature with no template and at industrial scales, has been described. The present work is concerned with observations of the lithiation and delithiation behavior of these Sn nanoneedles during in situ experiments in the transmission electron microscope, along with a brief review of how in situ TEM experiments have been used to study the lithiation of Lialloying materials. Individual needles are successfully lithiated and delithiated in solid-state half-cells against a Li-metal counter-electrode. The microstructural evolution of the needles is discussed, including the transformation of one needle from single-crystal Sn to polycrystalline Sn-Li and back to single-crystal Sn.

Understanding materials challenges for rechargeable ion batteries with in situ transmission electron microscopy

“…( e ) A nanoscale thin-film battery studying solid-state electrolytes, where low ionic diffusivity and interface instability are the targeted problems. ( f ) Representative battery materials studied by in situ TEM 2 , 8 9 10 11 12 13 14 15 16 17 18 19 20 , 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 , 54 55 56 57 , 59 60 61 62 , 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 , 82 , 85 , 103 104 105 106 107 108 109 110 111 112 113 ...…”

Review—Promises and Challenges of In Situ Transmission Electron Microscopy Electrochemical Techniques in the Studies of Lithium Ion Batteries

“…[17][18][19][20] Achievements in the area of in situ microscopy in the past five years have brought material characterization techniques to the point where these questions may be studied. 21 Over 100 papers relating to the application of in situ TEM electrochemistry in LIB z E-mail: zhxie@cwnu.edu.cn; jzhang@gamry.com each year have been published according to an analysis by Web of Science.Typical reviews recently regarding in situ TEM in electrochemistry primarily focus on imaging of materials evolution in gas-and liquidphase chemical reactions, 22 economic production of graphene and two-dimensional (2D) transition of metal dichalcogenides (TMDCs) as well as their composites, 23 introduction of the advances and challenges of the device itself, 2,7,19 individual anode materials of LIBs such as nanoscale silicon, 24-27 tin nanoneedles, 21 Si/C hybrid nanostructures, 28 and germanium. 17 Here, we will first introduce the fundamental structure of LIBs and compare them with traditional electrochemical measurements for LIBs, especially in the aspect of quantitatively determining lithium diffusion coefficient (D Li ) on the electrode.…”

Microstructure evolution of novel Sn islands prepared by electrodeposition as anode materials for lithium rechargeable batteries

“…12,13 More recently, the microstructural changes of Sn nanowires and nano-needles during initial Li alloying/ dealloying were also observed via an in situ TEM. 14,15 Unfortunately, however, the transmission microscopes used in the previous research studies were not enough to trace the actual microstructure evolution of Sn anode because they could not observe the entire region of the Sn anode during long-term cycling. Instead, they primarily focused on an arbitrary single Sn particle just for the rst cycle.…”