Interlayer engineering regulated high Li-ion diffusion kinetics of layered materials for fast charging batteries

: The layered materials with favorite interlayer space for guest-ion diffusion show great advantages for fast-charging batteries. However, how to precisely control their interlayer spacing experimentally and quantify the impact on their rate capability remains a challenge. Herein, taking layered GeP 5 as a case-study, we develop a distinctive atomic substitution strategy to continuously enlarge its interlayer spacing from 3.287 Å (Ge 0.8 Si 0.2 P 5 ) to 3.458 Å (Ge 0.7 Sn 0.3 P 5 ). Such interlayer expansion greatly boosts Li-ion diffusivity from 5.71×10 −12 to 6.00×10 −9 cm 2 /s, corresponding to a three-order-of-magnitude improvement, while reducing the Li diffusion barrier (from 0.898 to 0.587 eV) and voltage hysteresis (from 0.59 to 0.42 V). Owing to the expanded interlayer spacing and optimized electronic structure, the fabricated Ge 0.7 Sn 0.3 P 5 /C composite delivers outstanding fast-charging capability. It achieves a high specific capacity of 1362 mAh/g within 12.5 min and 1003 mAh/g within 6 min of rapid charging, which is ten times higher than that of commercial graphite anodes. Furthermore, the universality of this atomic substitution-induced interlayer regulation strategy is verified on six additional layered materials, including graphite, MXene, and MoS 2 etc. This work demonstrates a general and efficient approach to accelerate lithium-ion diffusion and improve the fast-charging performance of various layered electrode materials for advanced battery systems.