This week I had a paper on nucleation phenomena in nanoparticles accepted to the journal Nano Letters. The major conclusions of the work is that nucleation of a second phase is likely to always occur at the surfaces of nanoparticles, and the barrier energy is size dependent as a result of coherency strain, and scales with a particle’s area/volume ratio. The barrier disappears below a critical size. A preprint of the paper is available here. Below is a video of a LiFePO4 nanoparticle being discharged. The lithiated phase forms at the edges of the particle and then moves inward as the particle fills.