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

Abstract The 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 Li 3 PS 4 (LPS) network is constructed within the graphite electrode to form the LPS/graphite electrode. This is achieved through the in situ conversion of the P 4 S 16 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 LiNi 0.6 Co 0.2 Mn 0.2 O 2 (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.