Orientation-Engineered Anderson-Type Polyoxometalate Sub-1 nm Nanosheets for High-Performance Lithium-Ion Battery...

The unique atomic-scale active site exposure of two-dimensional sub-1 nm nanosheets (2D SNSs) effectively shorten the electron/ion diffusion distance, significantly enhancing the rapid charge-discharge performance of lithium-ion batteries (LIBs). However, it is still challenging to precisely regulate the exposed sites of the building blocks. Herein, Zn-ZnMo₆ sub-1 nm nanosheets (Zn-ZnMo₆ SNSs) were successfully synthesized through the cluster self-assembly strategy. Molecular dynamics (MD) simulations confirmed two stable configurations (Zn-ZnMo₆-1 and Zn-ZnMo₆-0.05) with distinct active sites exposure. Notably, Zn-ZnMo₆-1 exhibited excellent performance as lithium-ion battery (LIB) anodes, with a reversible capacity of 1361.9 mAh g^-1 for 1500 cycles at 1 A g^-1, significantly outperforming Zn-ZnMo₆-0.05 (258.5 mAh g^-1). Electrochemical mechanism and density functional theory (DFT) calculations revealed that the terminal-oxygen (O_t) sites exposed in Zn-ZnMo₆-1 enabled optimal lithium-ions adsorption (E_ads = -6.54 eV), which facilitated rapid lithium storage behavior and exhibited exceptional redox reversibility. This study would provide a promising novel approach for the design and synthesis of 2D SNSs at molecule level.