Regensburg 2013 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 15: Poster Session
MM 15.38: Poster
Montag, 11. März 2013, 18:00–20:00, Poster E
Electrochemical lithiation/delithiation analysis of silicon as anode material for lithium-ion batteries — •Gibaek Lee1,2, Stefan L. Schweizer2, and Ralf B. Wehrspohn1,2 — 1Fraunhofer Institute for Mechanics of Materials — 2Martin-Luther-University Halle-Wittenberg
It has been known for some time that silicon can incorporate large amounts of Li with a specific capacity of 4200 mAh/g, about a factor of 11 larger than for state of the art graphite anodes. However, silicon and silicon-based negative electrodes exhibit huge volume expansion (ca. 270%) during lithiation/delithiation, resulting in mechanical disintegration of electrode and rapid capacity fading. Therefore, relaxation of the stress caused by the expansion and contraction of Li-Si alloy materials is important to obtain a good cyclability.
In this study, we prepared oriented silicon nanowire arrays (SiNWs) on n-type silicon substrate by metal-assisted chemical etching in aqueous HF solution containing AgNO3. The electrochemical properties of the SiNWs electrode were systematically investigated. The material characteristics have been analyzed by Cyclic voltammetry (CV), XRD, SEM and TEM. The performance of SiNWs electrode have been examined by galvanostatic charge/discharge cycling. In addition, to compare the battery cycle behavior of the different structure of silicon anode material, we have investigated the characteristic and transformation of other types silicon anode such as black silicon and macro-porous silicon obtained by reactive ion etching (RIE) etching and electrochemical etching, respectively.