Additive-Assisted Hydrophobic Li + -Solvated Structure for Stabilizing Dual Electrode Electrolyte Interphases through Suppressing LiPF 6 Hydrolysis.

Lithium-metal batteries have attracted much attention due to their high energy density. However, the hydrolysis of LiPF 6 leads to uncontrollable Li dendrites growth and fast capacity fading. Herein, a hydrophobic Li + -solvated structure is designed by inducing the hexafluoroisopropyl acrylate into the electrolyte system. Due to the alkene groups and non-polar perfluorocarbon (-CF 2 CF 2 CF 3 ) chain, a hydrophobic surface around Li-ion solvated aggregates can be obtained to protect the LiPF 6 against the attack from trace H 2 O. Moreover, the additive could also help to form an organic solid electrolyte interphase with rich polar C-F bonds, which can capture Li ions to restrain the dendrite growth. Therefore, the Li||Li symmetric cells show a stable cycling performance up to 500 h at a current density of 1 mA cm -2 . The Li||LiNi 0.6 Co 0.2 Mn 0.2 O 2 cells show good cycling stability, exhibiting a specific capacity of 111 mAh g -1 at 1 C with a capacity retention of 74 % after 200 cycles.