1212
Electrochemical Liquid Liquid Solid Growth of Group IV Nanowires and Microwires for Recharge Battery Anode Applications

Wednesday, 16 May 2018: 11:20
Room 306 (Washington State Convention Center)
S. Maldonado (University of Michigan)
This presentation will describe our latest efforts in the synthesis of nanostructured Group IV semiconductor nanowires by the electrochemical liquid-liquid-solid (ec-LLS) process for preparing rechargeable battery anode materials. Briefly, we have developed a hybrid electrodeposition strategy that mimics high temperature, chemical vapor phase nanowire growth but at low temperatures with reactants dissolved in an electrolyte. The key concept is the use of a liquid metal electrode that also serves as a seed for the crystal growth of electrodeposited Group IV semiconductors. We will first show the basic generality of the ec-LLS process in terms of material, employed substrate, electrolyte composition, and applied electrochemical waveform. Then we will discuss details of battery electrode preparation by ec-LLS and the resultant cycling performance under various treatments. We will specifically show the influence of the liquid metal seed used in ec-LLS on the cycling properties of Ge nanowires and microwires for Li+ insertion/de-insertion. Electrochemical response patterns, ex-situ electron microscopy, atom probe tomography, and X-ray diffraction patterns indicate that certain metal impurities significantly extend cyclability of Ge microwires due to an 'atomic' binder effect imparted by metal impurities incurred by the ec-LLS process.