In this work, we present a comprehensive study on the effect of adding different conductive salt additives including LiPF₆, LiBF₄ and LiDFOB, as well as the fluorinated solvent additive methyl difluoroacetate (MDFA) to a bis(fluorosulfonyl)imide (FSI)-based ionic liquid (IL) electrolyte, i.e. Pyr₁₄FSI/LiFSI, to protect the Al current collector (ACC) from anodic dissolution and, thus, enable reversible charge/discharge cycling in a high performance dual-ion cell. Chronocoulometry and scanning electron microscopy measurements were conducted to evaluate the specific ACC passivation ability of each electrolyte. Furthermore, the influence of these additives on anion intercalation behavior into the graphite positive electrode with special emphasis on the Coulombic efficiency (CE), reversible capacity, as well as capacity retention is presented. Overall, we can show that the addition of small amounts of LiPF₆, LiBF₄ and MDFA (0.5 wt%) into the FSI-based IL electrolyte significantly increases the overall cell performance, whereas LiDFOB as electrolyte additive deteriorates the dual-ion cell performance. In addition, an excellent cycling performance for 1000 cycles is obtained for the Pyr₁₄FSI electrolyte having 5 wt% LiPF₆, displaying an average reversible capacity of 40 mAh g⁻¹, a CE exceeding 98% and a capacity retention of 91%, which has not been reported so far.

在这项工作中，我们对将不同的导电盐添加剂（包括LiPF ₆，LiBF ₄和LiDFOB）以及氟化溶剂添加剂二氟乙酸甲酯（MDFA）添加到双（氟磺酰基）酰亚胺（FSI）-中的效果进行了全面研究。离子液体（IL）的电解质，即Pyr ₁₄FSI / LiFSI，以保护Al集电器（ACC）免受阳极溶解，从而在高性能双离子电池中实现可逆的充电/放电循环。进行了计时容量法和扫描电子显微镜测量，以评估每种电解质的特定ACC钝化能力。此外，提出了这些添加剂对阴离子向石墨正极中插层行为的影响，其中特别强调了库仑效率（CE），可逆容量以及容量保持率。总的来说，我们可以证明添加了少量的LiPF ₆，LiBF ₄FFA基IL电解质中添加的MDFA（0.5 wt％）和MDFA（0.5 wt％）会显着提高整体电池性能，而LiDFOB作为电解质添加剂会降低双离子电池性能。此外，具有5 wt％的LiPF ₆的Pyr ₁₄ FSI电解质在1000次循环中具有出色的循环性能，表现出40 mAh g ^-1的平均可逆容量，超过98％的CE和91％的容量保持率，到目前为止，尚未有报道。