Boosting Li-Ion Diffusion Kinetics of Na(2)Ti(6-x)Mo(x)O(13 )via Coherent Dimensional Engineering and Lattice Tailoring: An Alternative High-Rate Anode

Abstract

Featured with an exposed active facet, favorable ion diffusion pathway, and tailorable interfacial properties, low-dimensional structures are extensively explored as alternative electroactive materials with game-changing redox properties. Through a stepwise "proton exchange-insertion-exfoliation" procedure, in this article, we develop Na2Ti6-xMoxO13 (NTMO) nanosheets with weakened out-of-plane bonding and in-plane Mo6+ doping of the tunnel structure. Real-time phase tracking of the laminated NTMO structures upon the lithiation/delithiation process suggests mitigated lattice variation; meanwhile, the kinetics simulation shows a mitigated Li-ion diffusion barrier along the [010] orientation. At an industrial-level areal capacity loading (2.5 mAh cm(-2)), the NTMO electrode maintains robust cycling endurance (91% capacity retention for 2000 cycles) even at 40 C, as well as the high energy/power densities in the as-constructed NTMO parallel to LiFePO4 full cell prototype. The dimensional and lattice modifications presented in this study thus encourage further exploration of the tailored cation diffusion pathway for the construction of fast-charging batteries.