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Project

Electrodeposited silicon films on nanoporous metals for Li-ion battery anodes: linking nanoscale structure to macroscale performance (R-7251)

Lithium-ion battery (LIB) technology has dominated the portable electronics market for the last decade since they charge faster, last longer and have a higher power density compared to conventional lead-acid batteries. However, LIBs have failed commercial widespread in applications due to drawbacks such as high cost, low thermal stability and carbon-based anodes strongly dependent on the electrolyte solution that might delaminate and reduce drastically the battery cycle life. Recently, silicon (Si) has been identified as a very attractive anode material for LIBs since it exhibits a specific capacity that largerly exceeds that of carbon-based materials, high chemical stability and low toxicity. Nevertheless, the main issue of silicon as potential anode is its large volume expansion during lithiation, generating structural degradation and instability of the solid-electrolyte interphase severely reducing the life cycle of the battery. In this project we aim to circumvent this problem by optimizing electrode morphology with the development of nanostructured configurations capable of buffering the large volume change and assuring long life cycle and high specific capacity. Specifically we will employ nanoporous metals as templates for depositing Si as an anode material and explore the potential of RTILs as next generation battery electrolytes. The main purpose is to establish a link between the morphological structure of the anode at a nanoscale level (and related anode/electrolyte interface characteristics) and the macroscopic response of the battery performance and life cycle. It aims to answer fundamental questions which are poorly understood or unexplored and that have important implications. A bottom-up approach will be carried out to tune the complexity of the nanoporous structures starting from simpler nanoporous structures to different length scale hierarchical meso/nano structures. The formation of porous templates will be carried out using dealloying strategies, while Si deposition will be performed by electrodeposition or atomic layer deposition. Robust and versatile experimental characterization techniques will be employed such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), in-situ atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The project will highlight the use of Atom probe tomography (APT) to provide unprecedented information at the atomic scale on the chemical distribution of the nanoporous anode upon cycling. The combination of APT with state of the art electrochemical techniques and high resolution imaging such as AFM and SEM will answer fundamental questions that are poorly understood or unexplored and that have important implications in the development of next generation LIBs.
Date:1 Oct 2016 →  30 Sep 2023
Keywords:nanoparticles and -clusters
Disciplines:Ceramic and glass materials, Materials science and engineering, Semiconductor materials
Project type:Collaboration project