"Laser-Induced Heterostructuring of Graphene Passivated Nanoscale Black Phosphorus Frameworks for Lithium-Ion Battery Anodes."

Two-dimensional black phosphorus (BP or phosphorene) has drawn significant interest in alkali metal ion storage due to its capacity to adsorb alkali atoms and high theoretical prediction of specific capacity. But the problem persists in large-scale production of the nanoscale BP, low electronic conductivity, considerable volume change (≈300%), and polyphosphide-induced shuttle effect. To solve this problem, a single-step lasing method is employed to prepare nanoscale BP covalently bound to the sp2 bonded carbon framework through a P─O─C/P─C bond. The sp2 bonded carbon provides exceptional electrical conductivity, while BP offers high theoretical capacity. The possible bond formation between carbon, oxygen, and phosphorus atoms was studied using synchrotron-based X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy. The experimental findings were supported by the ab-initio density functional theory modelling and REAX FF molecular dynamics simulations. By adopting such structure, an ultrastable lithium-ion battery (LIB) cell was developed with ≈100 % coulombic efficiency till 700 cycles at 2 A g^-1 current density. Theoretical computation reveals that interlayer covalent bonding is a crucial mechanism for this stable device performance during Li⁺ intercalation/deintercalation process. This study provides valuable insights into the customized fabrication of nanoscale 2D heterostructure using laser techniques, focusing on long-lasting LIBs.