A Nanoarchitectured Porous Electrode Assembly of NiSi Thin Film for Lithium Ion Batteries

摘要

This study proposes to produce well-aligned nanorod arrays containing NiSi thin film to improve the electrochemical performance of Si based anodes. In this respect, NiSi thin films made of nanorods are produced via glancing angle electron beam deposition (GLAD) technique. The structural and morphological properties are investigated using thin film X-ray diffraction (XRD) and scanning electron microscopy (SEM). The well aligned nanorod arrays containing NiSi thin film anode exhibits a long cycle life with a moderate capacity retention (around 1100mAhg~(-1) for 100 cycles). This remarkable electrochemical performance can be explained by the electrode composition, structure and morphology: During Li~+ insertion into the alloyed thin film electrodes, Si acts as active center, which reacts with Li~+ to form amorphous Li_xSi alloys, while the nanosized Ni particles are believed to provide electrical conduction network inside the active material and buffer volume expansions with the help of the homogenously distributed nanosized interspaces (porosities among the nanorods) present in the thin film.