Freeze-drying-assisted Synthesis of Mesoporous CoMoO4 Nanosheets as Anode Electrode Material for Enhanced Lithium Batteries

摘要

A facile and green freeze-drying-assisted method was proposed to synthesize C0MoO4 mesoporous nano-sheets(MPNSs).The resulting product exhibits a Mgh specific capacity and good rate perfomance when evalimte an anode material for lithium-ion batteries(LIBs).The reversible specific capacity can be kept at 1105.2 mA·h·g^-1 after 100 cycles at a current density of 0.2 A/g.Even at the current densities of 1 and 4 A/gs the CoMoO4 MPNSs electrode can still retain the reversible capacities of 1148.7 and 540 mA·h·g^-1,respectively.Furthermore,the full cell(LiPePO4 catliode/CoMoO4 MPNSs anode)displays a stable discharge capacity of 146.7 mA·h·g^-1 at 0.1 C(1 C=170 mA/g)together with an initial coulombic efficiency of 98.2%.In addition,the CoMoO4 crystal structure is destroyed and reduced into Co^0 and Mo^0 in the first discharge process.In the subsequent cycles,the attractive Li storage properties come from the reversible conversions between Co/Co^2+and Mo/Mo^6+.The improved electroche-mical performance of CoMoO4 MPNSs is mainly attributed to their unique porous structures,which not only possess a good ion diffusion and electronic conduction pathway,but also provide many cavities to alleviate the volume changes during repeated cycling.This work offers a new perspective to the design of other porous electrode materials with a good energy storage performance.