PNNL

Abstract

Nanowires (NWs) synthesized via chemical vapor deposition (CVD) process have demonstrated significant improvement in lithium storage performance along with their outstanding accommodation of large volume changes during charge/discharge process. Nevertheless, the NW electrodes have been only confined to research level due to the lack of scalability and severe side reactions by their high surface area. Here, we present nanoporous Ge nanofibers (NPGeNFs) having moderate nanoporosity via a combination of simple electrospinning and low energetic zincothermic reduction reaction. In contrast with the CVD assisted NW growth, our method provides high tunability of macro/microscopic morphologies such as a porosity, length, and diameter of the nanoscale 1D structures. Significantly, the customized NPGeNFs showed highly suppressed volume expansion less than 15% (for electrodes) after full lithation and excellent durability with high lithium storage performance over 500 cycles. Our approach offers effective 1D nanostructuring with highly customized geometries and can be extended to other applications including optoelectronics, catalysis, and energy conversion.