Electrodeposited Germanium/Carbon Composite as an Anode Material for Lithium Ion Batteries

By Kim, Sang-Wan; Ngo, Duc Tung; Heo, Jaeyeong; Park, Choong-Nyeon; Park, Chan-Jin
Published in Electrochimica Acta NULL 2017

Abstract

Abstract We demonstrate the synthesis of nano Ge/C composite using a facile and cost-effective electrochemical deposition method, and its application as an anode material in Li-ion batteries. Nano Ge/C composite is electrodeposited directly on Cu foil in ethylene glycol containing GeCl4 and carbon black. The Ge particles with an average size of ?20 nm are uniformly covered with carbon. Compared with the pure Ge electrode, the Ge/C electrode exhibits a higher first reversible capacity of 1224 mA g?1, and maintains a capacity of 1095 mAh g?1 at 0.1C over 50 cycles. Even at the high rate of 2C, the capacity of the Ge/C electrode is still high at 972 mAh g?1. The presence of carbon black and pores in the Ge/C electrode improves the conductivity of the electrode, and mitigates the stress inside the electrode by supplying buffer volume, leading to the enhanced electrochemical characteristics of the electrode. Further, the full Li-ion cell composed of Ge/C anode and LiCoO2 cathode exhibits good cyclability, rate capability, and coulombic efficiency.

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