Ge@C core–shell nanostructures for improved anode rate performance in lithium-ion batteries

Abstract

Ge@C core–shell nanostructures were successfully synthesized by a facile n-hexane pyrogenation-reducing process. The Ge@C core–shell nanostructures exhibit excellent cycling performance and rate capability in comparison with pure Ge nanoparticles when used as an anode material for a lithium ion battery. The thin carbon shell endows the obtained Ge@C nanostructures with a high specific capacity of 985 mA h g⁻¹ at a current density of 500 mA g⁻¹ after 50 cycles. Furthermore, a discharge capacity of 850 mA h g⁻¹ was observed at a current density of 4000 mA g⁻¹. The excellent lithium storage performance can be attributed to the unique carbon shell structure. The carbon shell not only acts as the buffer layer to maintain structural stability during lithiation, but also increases electrical conductivity during the charge/discharge processes. The high rate capacity of the Ge@C nanostructures demonstrates it a promising anode material for high power lithium-ion batteries.