Reversible lithium-ion insertion in molybdenum oxide nanoparticles

A study was conducted to demonstrate the fabrication of anodes from crystalline MoO₃ nanoparticles that display both a durable reversible capacity of 630mA h g^-1 and durable high rate capability. The nanoparticle anodes show no capacity degradation for 150 cycles between 3.5 to 0.005 V with both charge and discharge at C/2, compared to micrometer-sized particles where the capacity quickly fades. The nanoparticles became highly disordered upon Li-insertion as evidenced by both X-ray diffraction (XRD) and in situ Raman measurements. FPMD calculations show that in spite of a large volume expansion the nanoparticles maintain some structural integrity due to the heavy Mo-framework. The results of the study also show that the large volume expansion allows for fully reversible Li-insertion only at the nanoscale.