Integrated Dual‐Phase Ion Transport Design Within Electrode for Fast‐Charging Lithium‐Ion Batteries

Abstract

AbstractThe development of fast‐charging lithium‐ion batteries with high energy density is hindered by the sluggish Li+ transport and substantial polarization within graphite electrodes. Herein, this study proposes that the integrated design of liquid electrolyte and solid electrolyte, a dual‐phase electrolyte (DP‐electrolyte), can facilitate Li+ transport within a thick electrode. A 3D Li3PS4 (LPS) network is constructed within the graphite electrode to form the LPS/graphite electrode. This is achieved through the in situ conversion of the P4S16 into the LPS, a process introduced during the slurry processing. Both experimental findings and simulation outcomes indicate that this design mitigates the concentration polarization due to the improved Li+ transport capability with an overall high Li+ transference number within the electrode. With a high capacity of ≈3.1 mAh cm−2 attributed to the graphite electrode, the LiNi0.6Co0.2Mn0.2O2 (NCM622)||LPS/graphite cells demonstrate superior fast‐charging capability (4 C, 15 min, charging to ≈87.7%) and stable cycling performance (4 C, 700 cycles, ≈80% capacity retention). Furthermore, they exhibit commendable low‐temperature performance. The Ah‐level pouch cell achieves 87.5% recharge in 15 min with an energy density of ≈221.5 Wh kg−1. This work offers an alternative avenue for the advancement of fast‐charging lithium‐ion batteries with practical high energy density.