Solution-grown GeO2 nanoparticles with a nearly 100% yield as lithium-ion battery anodesElectronic supplementary information (ESI) available: Cycling life curve for GeO2 nanoparticles at different electrolyte systems at 0.1C and 1C. See DOI: 10.1039/c6ra20171g

• Main Authors: Li, Guo-An, Li, Wei-Chin, Chang, Wei-Chung, Tuan, Hsing-Yu
• Format: Article
• Language: English
• ISSN: 2046-2069
• DOI: 10.1039/c6ra20171g

Germanium oxide (GeO 2 ) nanoparticles were synthesized with a nearly 100% production yield in a nonionic reverse micelle system at ambient temperature. The procedure is a facile and energy saving strategy for producing germanium oxide nanoparticles with ultra large throughput. As-prepared GeO 2 nanoparticles can be directly used as anode materials without any post-treatment or other supplementary additives for lithium ion batteries. GeO 2 -anodes exhibited good electrochemical performance in terms of both gravimetric and volumetric capacity. The GeO 2 anodes have a reversible capacity of approximately 1050 mA h g −1 at a rate of 0.1C, close to its theoretical capacity (1100 mA h g −1 ), and good rate capability without severe capacity decade. The volumetric capacity of the GeO 2 anodes reaches 660 mA h cm −3 , which is higher than the performance of commercial graphite anode (370-500 mA h cm −3 ). Coin type and pouch type full cells assembled for electronic devices applications were also demonstrated. A single battery is shown to power LED array over 120 bulbs with a driving current of 650 mA. Based on the above, the micelle process of GeO 2 nanoparticle synthesis provides a possible solution to high-capacity nanoparticles' scalable manufacturing for lithium ion battery applications. Germanium oxide (GeO 2 ) nanoparticles were synthesized with a nearly 100% production yield in a nonionic reverse micelle system at ambient temperature as high performance lithium-ion battery anodes.