Figure 3: Reversible facilitating lithium electrodeposition by positively charged lithium substrate.

(a) Dependence of sweep rate and potential range on the CE of lithium electrodeposition during CV measurements of a Li|Cu cell at 25 °C. (b) The first anodic sweep at different sweep rates (c) the first two cycles of Li|Cu cell at 5.0 mV s⁻¹ and 25 °C in the range of −0.3–3.0 V (d) two plateaus of lithium electrodeposition onto Cu electrode with CV premodulation at 5.0 mA cm⁻², 3 C cm⁻² and 25 °C along with two typical images of morphology of lithium electrodeposits at different height positions. Scale bar, 20 μm. (e) In situ CV/QCM study on the underpotential Li deposition/stripping in the second cycle using three-electrode cell, where Ni-coated quartz crystal was used as the working electrode and Li as the reference and counter electrode, respectively.