2D Metal-Oxide Nanosheets\nas a Homogeneous Li-Ion\nFlux Regulator for High-Performance Anodeless Lithium Metal Batteries

The anodeless battery design has recently gained significant\ninterest\nby eliminating the direct use of a thick lithium (Li) foil. However,\nit suffers from inhomogeneous Li<sup>+</sup> flux, resulting in dendrite\ngrowth and a short cycling life. To address this, the exfoliation\nof layered-structure titanium oxide to 2D nanosheets (2DTiO<i>x</i>) is proposed to precisely control Li<sup>+</sup> flux\nat the atomic scale by maximizing Li<sup>+</sup> affinitive Ti sites.\nCompared to cells without these nanosheets, the Li|2DTiO<i>x</i>|Cu half-cell demonstrates stable cyclability over 900 cycles, with\na Coulombic efficiency (CE) over 99% at 0.5 mA cm<sup>–2</sup> and 0.5 mAh cm<sup>–2</sup>. Similarly, a long stable cycling\nlife over 1500 h at 1.0–3.0 mA cm<sup>–2</sup> is observed\nfor a 2DTiO<i>x</i>-based symmetric cell containing a limited\nLi amount from electrodeposited Li metal (e-Li|2DTiO<i>x</i>|e-Li). The full cells (e-Li|2DTiO<i>x</i>||NCM811 and\ne-Li|2DTiO<i>x</i>||LFP) coupled with NCM811 and LFP cathodes\nshowed a long cycle life of 400 cycles at 1.0 C and 0.5 C, respectively.\nThe exceptional battery performance is attributed to the uniform Li\ndisposition on the 2DTiO<i>x</i> electrode, emphasizing\nthe crucial role of the exposed basal plane in 2DTiO<i>x</i> as an efficient atomic scale Li<sup>+</sup> flux regulator. This\nstrategy is expected to advance next-generation lithium metal batteries\n(LMBs) by highlighting the significance of Li<sup>+</sup> affinity\nat the Ti sites of 2DTiO<i>x</i> nanosheets.