Amorphous GeO2@C composite anodes for long cycling stability and performance in Li-ion batteries

Amorphous GeO 2 @C anode materials were successfully prepared from commercial GeO 2 and C 6 H 12 O 6 .H 2 O by a hydrothermal method combined with sintering under nitrogen atmosphere protection. The anode materials showed an ideal spherical shape of about 3 μm and their surface was uniformly covered with C. GeO 2 @C composite anodes exhibited better storage performance for Li-ion batteries. The discharge-specific capacities of GeO 2 @C-3 sample were 1143, 1049, 776, 551, and 308 mAh g -1 at current densities of 0.2, 0.5, 1, 2, and 5 A g -1 , and restored to 1136 mAh g -1 when the current density returned to 0.2 A g -1 . The reversible specific capacity was 756 mAhg -1 after 1000 cycles at a current density of 1 A g -1 . The GeO 2 @C anode was stable in the process of charge and discharge, and no obvious pulverization occurred. GeO 2 @C composites stabilized the electrochemical properties through carbon and amorphous structure to improve the overall electrical conductivity in Li + embedding/de-embedding processes.