High-Performance Germanium Microstructure-Based Li-Ion Battery Anodes Prepared By the Electrochemical Liquid-Liquid-Solid Process

• Published in: Meeting abstracts (Electrochemical Society) Vol. MA2016-03; no. 2; p. 521
• Main Authors: Ma, Luyao, Fahrenkrug, Eli, Gerber, Eric, Venable, Frances, Crowe, Adam, Bartlett, Bart M., Maldonado, Stephen
• Format: Journal Article
• Language: English
• Published: 10.06.2016
• ISSN: 2151-2043; 2151-2035
• DOI: 10.1149/MA2016-03/2/521

Microstructured Ge grown by the electrochemical liquid-liquid-solid (ec-LLS) process at < 100 °C demonstrated high specific capacity, excellent capacity retention and rate capabilities. The Ge microwires were first prepared on Su-8 patterned Cu plate in an aqueous solution through ec-LLS at 90 °C. Ge microstructure-based anodes were synthesized through acid etching of Ge microwires. The Ge anode demonstrated specific capacity of 1114 mAh/g at 1 st cycle and retained 94% of the capacity after 25 cycles at 0.2 C. Ge microstructure-based anode was cycled at a series of charge/discharge rates and performed well up to 1 C. Ec-LLS grown microstructured Ge can be assembled into button cells for Li-ion battery application without any binder or additive, and this method is highly scalable for different battery prototypes. Microstructured Ge exhibited excellent capacity retention due to both its ability to accommodate volume expansion and mild solid-electrolyte interface (SEI) layer formation. The specific capacities of Ge anode can be plotted as a function of different cycle rates, and the result indicates that the charge/discharge process is limited by solid-state diffusion of Li in Ge.