Optimization of physicochemical characteristics of a lithium anode interface for high-efficiency cycling: an effect of electrolyte temperature

Precycling of lithium (Li) metal on a nickel substrate at a low-temperature (−20°C) in propylene carbonate (PC) mixed with dimethyl carbonate (DMC) and Li hexafluorophosphate (LiPF6) (LiPF6–PC/DMC) enhanced Li cycleability in the subsequent cycles at a room temperature (25°C). In LiPF6–PC/DMC, not only the low-temperature precycling in the initial 10 cycles was effective in the improvement of Li cycle life but also the first low-temperature Li deposition followed by room temperature cycling enhanced the Li cycle life. Such a precycling effect was observed with various current densities at the initial Li deposition and the subsequent cycling. When the current density of the cycling was high, improved cycling efficiency was observed and the efficiency of the Li electrode undergoing the precycling was close to that at a constant temperature of −20°C.