Conductive-free Zn2GeO4 @multi-walled carbon nanotubes for high-performance lithium-ion storage

A new composite of Zn 2 GeO 4 @multi-walled carbon nanotubes (Zn 2 GeO 4 @MWCNTs) has been synthesized by using a facial microwave assisted hydrothermal method , and found that the Zn 2 GeO 4 nanorods were anchored on the surface of MWCNTs and embedded into the voids of MWCNTs aggregation, which could provide a conductive network for fast transport of ion and a buffer space for volumetric change during the charge-discharge process. The MWCNTs in the composite has also acted as conductive agent, avoiding the use of additional conductive agents. When used as an anode for LIBs , this composite delivered a high specific capacity of 1397.9 mA h g −1 at 0.2 A g −1 after 300 cycles, an excellent rate capability and long cycling stability over1800 cycles at a high rate of 1.0 A g −1 . The results of in situ X-ray diffraction (XRD) measurements showed that the Li 22 Ge 5 was formed during the discharge process, and others were amorphous phase, which can provide more active sites for lithium storage, and is beneficial to the fast diffusion of lithium ion , resulting in superb cycling performance.