Improving Fast‐Charging Performance of Lithium‐Ion Batteries through Electrode–Electrolyte Interfacial Engineering

Abstract

Abstract The solid‐electrolyte interphase (SEI) is a key element in anode–electrolyte interactions and ultimately contributes to improving the lifespan and fast‐charging capability of lithium‐ion batteries. The conventional additive vinyl carbonate (VC) generates spatially dense and rigid poly VC species that may not ensure fast Li+ transport across the SEI on the anode. Here, a synthetic additive called isosorbide 2,5‐dimethanesulfonate (ISDMS) with a polar oxygen‐rich motif is reported that can competitively coordinate with Li+ ions and allow the entrance of PF6– anions into the core solvation structure. The existence of ISDMS and PF6− in the core solvation structure along with Li+ ions enables the movement of anions toward the anode during the first charge, leading to a significant contribution of ISDMS and LiPF6 to SEI formation. ISDMS leads to the creation of ionically conductive and electrochemically stable SEI that can elevate the fast‐charging performance and increase the lifespan of LiNi0.8Co0.1Mn0.1O2 (NCM811)/graphite full cells. Additionally, a sulfur‐rich cathode–electrolyte interface with a high stability under elevated‐temperature and high‐voltage conditions is constructed through the sacrificial oxidation of ISDMS, thus concomitantly improving the stability of the electrolyte and the NCM811 cathode in a full cell with a charge voltage cut‐off of 4.4 V.

Keywords

• cathode‐electrolyte interface
• electrolytes
• lithium‐ion batteries
• solid‐electrolyte interphase
• solvation structures