Fabrication of GeO2 microspheres /hierarchical porous N-doped carbon with superior cyclic stability for Li-ion batteries

Abstract

GeO2 microspheres/N-doped hierarchical porous carbon (NHPC) composites are solvothermally prepared and subsequent calcinated employing ginger as biotemplate. The SEM and TEM images demonstrate the GeO2 microspheres are uniformly dispersed or embedded in NHPC matrix. Evaluating the performances of GeO2/NHPC composites as Li-ion battery electrodes, they deliver a specific capacities of 2261.4 ​mA ​h ​g−1 at 200 ​mA ​g−1, after 100 cycles it remains a high reversible capacity of 1014.3 ​mA ​h ​g−1 and close to 100% coulomb efficiency. The enhanced lithium storage capability is chalked up to high specific surface area and properly hierarchical porous structure of GeO2/NHPC. The synthetic technique is a feasible and successful paradigm for other large capacity materials with large change in volume and poor electroconductivity.