School of Chemical Engineering and Technology, Tianjin University , Tianjin 300350, P. R. China.
National Key Laboratory of Science and Technology on Power Sources, Tianjin Institute of Power Sources , Tianjin 300384, P. R. China.
ACS Appl Mater Interfaces. 2017 Sep 6;9(35):29820-29828. doi: 10.1021/acsami.7b09119. Epub 2017 Aug 24.
Different contents of fluoroethylene carbonate (FEC) as cosolvent is added into succinonitrile (SN) solution to form a novel electrolyte for lithium batteries. The SN-based electrolyte with 20 wt % FEC exhibits the most favorable properties involving the good thermal stability, wide electrochemical window and high ionic conductivity. Comparing with the commercial electrolyte, the 20% FEC-SN electrolyte demonstrates the advantage of high safety and excellent interfacial compatibility with lithium due to the form of compact and smooth solid electrolyte interphase layer on the anode. LiCoO/Li cells using the SN-based electrolyte behave a high reversible discharge capacity of 122.4 mAh g and keep an outstanding capacity retention of 91% (122.1 mAh g) at 0.5 C after 100 cycles at 25 °C, 50 °C, respectively. More importantly, the soft-package cells with the SN-based electrolyte can withstand harsh surroundings at 120 °C for 30 min without gas emitted, and can still keep the capacity retention of 77% compared to that before heat treatment, significantly higher than traditional commercial electrolyte (0%). All above results indicate the novel SN-based electrolyte can be an excellent alternative electrolyte in a practical lithium battery.
不同含量的氟代碳酸乙烯酯（FEC）作为共溶剂被添加到丁二腈（SN）溶液中，形成一种新型的锂电池电解质。在含有 20wt%FEC 的 SN 基电解液中，表现出最有利的性质，包括良好的热稳定性、宽电化学窗口和高离子电导率。与商业电解液相比，由于在阳极上形成了致密、光滑的固体电解质界面层，20%FEC-SN 电解液具有高安全性和优异的与锂的界面相容性的优点。使用 SN 基电解液的 LiCoO/Li 电池具有较高的可逆放电容量，在 25°C 和 50°C 下，经过 100 次循环后，在 0.5C 下的容量保持率分别为 122.4mAh g 和 91%（122.1mAh g）。更重要的是，软包电池在 120°C 下能耐受 30min 的恶劣环境，而不会产生气体，与热处理前相比，其容量保持率仍为 77%，明显高于传统商业电解液（0%）。所有这些结果表明，新型 SN 基电解液是一种实用锂电池的优秀替代电解质。
