ZnxGe1-xO 3D micronano structures with excellent performance as anode material in lithium ion battery

As anode material used in power storage device, lithium ion battery (LIB) for example, ZnO has not been recognized as a promising candidate, although which shows advantages like environmental benign, low cost, and large reservation. Several problems, such as volume expansion, pulverization, and active substance detachment because of the particular lithiation kinetics, which result in very high irreversible capacity and following fading, can account for the present situation. Here in this work, we report the self-assembly of ZnxGe1-xO three-dimensional (3D) micronano structures and achieve enormous improvement on both recyclability and rate performance. After the 100th cycle, the capacity remains ∼690 mAh/g at the rate of 100 and ∼510 mA/g at the rate of 500 mAh/g. The capacity recovered rapidly even the rates alternating repeatedly between 50 mA/g and 3.5A/g. Ex situ observation reveals that substance detachment and nanoparticle agglomeration were avoided, benefiting from the firm 3D space configuration. As the Li(+) insertion, the 3D architectures fracture hierarchically with releasing the volume-expansion produced strain. Stable and smooth Li(+)/electrons path would form in these nanoparticles integrated microfragments, which act as the working unit free of further detachment. These facts demonstrate that ZnO based anode materials are anticipant to be good candidate in LIB device through rational design of advanced mirco-nano structures without introduction of carbon coating.