A Long‐Life Lithium Ion Battery with Enhanced Electrode/Electrolyte Interface by Using an Ionic Liquid Solution

In this paper, we report an advanced long‐life lithium ion battery, employing a Pyr₁₄TFSI‐LiTFSI non‐flammable ionic liquid (IL) electrolyte, a nanostructured tin carbon (Sn‐C) nanocomposite anode, and a layered LiNi_1/3Co_1/3Mn_1/3O₂ (NMC) cathode. The IL‐based electrolyte is characterized in terms of conductivity and viscosity at various temperatures, revealing a Vogel–Tammann–Fulcher (VTF) trend. Lithium half‐cells employing the Sn‐C anode and NMC cathode in the Pyr₁₄TFSI‐LiTFSI electrolyte are investigated by galvanostatic cycling at various temperatures, demonstrating the full compatibility of the electrolyte with the selected electrode materials. The NMC and Sn‐C electrodes are combined into a cathode‐limited full cell, which is subjected to prolonged cycling at 40 °C, revealing a very stable capacity of about 140 mAh g^?1 and retention above 99 % over 400 cycles. The electrode/electrolyte interface is further characterized through a combination of electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) investigations upon cell cycling. The remarkable performances reported here definitively indicate that IL‐based lithium ion cells are suitable batteries for application in electric vehicles.