High cycleability nano-GeO2/mesoporous carbon composite as enhanced energy storage anode material in Li-ion batteries

A novel nano-GeO2/mesoporous carbon (GeO2/MC) composite material was prepared by in-situ decomposition of germanium ethoxide (Ge(OC2H5)4) infiltrated in a mesoporous carbon (MC) obtained by soft-templating procedure. With GeO2 (<20 nm) homogeneously distributed in the carbon network, the GeO2/MC composite retains 93% of its initial charge capacity after 380 cycles at constant 1 C rate (1500 mA g−1) as electrode material vs. Li and shows high rate capability at variable current rates. A restructuration of the germanium phase into smaller particles during the first cycles is also evidenced. The composite presents a set of advantages such as low GeO2 content, convenient preparation approach and high coulombic efficiency (>99%).