A rotating disk electrode was used to study the effect of mass transport on the electrodeposition and electrodissolution of Li in LiPF6-containing electrolytes with different HF contents. The morphology and composition of the deposit on a Ni substrate was investigated with scanning electron microscopy (SEM), transmission electron microscopy, and X-ray photoelectron spectroscopy (XPS). The cycling efficiency and SEM were used to study the dissolution process. It was found that mass transport has a considerable effect on Li deposition and dissolution. In particular, the transport rate of HF to the electrode surface influences the morphology; of the deposit. Quite smooth deposits were obtained at rotating electrodes in an electrolyte with a relatively high HF content of 60 ppm, even at high current densities. XPS analysis showed that smooth deposits are covered with LiF, whereas needle-like deposits contain more Li2O and LiOH. The cycling efficiency was mainly influenced by the morphology and distribution of the nuclei initially formed at the Ni substrate. In the presence of 6 ppm HF a random distribution of particles with various shapes and sizes was obtained. whereas in an electrolyte with 60 ppm HF homogeneously distributed spherical nuclei of a uniform size were formed. The cycling efficiency was markedly higher in the latter case.