Concept of hydrophobic Li⁺-solvated structure for high performances lithium metal batteries

The large-scale application of lithium metal batteries remains a challenge due to the hydrolysis of LiPF₆, which can induce capacity fade and series of safety issues. Prof. Ma and his co-workers have designed a hydrophobic Li⁺-solvated structure to obtain high performances lithium metal batteries. The specific functional groups of the additive, hexafluoroisopropyl acrylate, can promote the formation of a hydrophobic surface, which can protect the LiPF₆ from trace H₂O. The hexafluoroisopropyl acrylate can also promote the formation of a robust and stable solid electrolyte interphase (SEI) with rich polar C–F bonds, which can suppress the dendrite growth and improve battery performances by capturing lithium ions. This work reveals the mechanism that the introduction of hexafluoroisopropyl acrylate can improve lithium anode performances and further feature the innovative design of advanced materials for energy devices beyond lithium.

摘要

由于LiPF₆的水解会诱发容量衰减和一系列的安全问题, 大规模应用对于锂金属电池仍然是一个挑战。马教授和他的同事们设计了一种疏水性的Li⁺溶剂化结构, 以获得高性能的锂金属电池。六氟异丙基丙烯酸酯的特定官能团可以促进疏水表面的形成, 从而保护LiPF₆免受微量H₂O的影响。丙烯酸六氟异丙酯还能促进形成具有丰富极性C‒F键的坚固稳定的固体电解质界面 (SEI), 从而抑制枝晶的生长, 并通过捕获锂离子提高电池性能。这项工作揭示了引入丙烯酸六氟异丙酯可以改善锂电负极性能的机制, 并进一步为锂电以外的能源设备设计先进材料提供思路。