Electrochemical investigation of ion-beam sputter-deposited carbon thin films for Li-ion batteries

Abstract The C-rate capability of 230 nm- and 16 nm-thin ion-beam sputter-deposited amorphous carbon films, an interesting class carbonaceous material for lithium-ion batteries, was investigated up to Li-platting. Stepwise ascending descending constant Li + currents after each fifth cycle, followed by hundreds cycles with the highest current were applied. films show similar cycling irreversible losses during first five cycles, reversible a capacity close that graphite. is significantly lower at high currents; however, it restored subsequent again low currents. Differential charge differential curves reveal three uptake release peaks located between 0 3 V. Irreversible as well bonding can be associated all these peaks. Irreversibly bonded found surface (solid electrolyte interphase) in bulk (Li trapping). Reversible might possible inside graphite-like nano-domains defects. thinner film reveals more pseudo-capacitive behavior, pointing enhanced kinetics. Graphical abstract