In-Situ Laser Synthesis of Molecularly Dispersed and Covalently Bound Phosphorus-Graphene Adducts as Self-Standing 3D Anodes for High-Performance Fast-Charging Lithium-Ion Batteries

Abstract

Phosphorus shows promise as a next-generation anode material due to its high theoretical capacity of 2596 mAh g−1. However, challenges such as low conductivity, severe volume expansion, and the dissolution and migration of electrolyte-soluble lithium polyphosphides hamper high-performance capabilities. While carbon composites are widely researched as a solution through the physical encapsulation of micro-nano-phosphorus domains, anodes still exhibit low cycling stability and rate performance. In response, this work proposes a new approach, focusing on chemical anchoring and molecular dispersion of phosphorus within the carbon host. Through laser irradiation of a red phosphorus/phenolic resin blend, in-situ covalent binding of molecular phosphorus adducts to the as-forming laser-induced graphene is observed; directly synthesizing an additive-free, flexible and 3-dimensional mesoporous composite anode with high phosphorus content (33 wt.%), specific surface area (163.4 m2 g−1) and intrinsic conductivity (12 S cm−1). These anodes demonstrate remarkable cycling stability, with capacity retention of 98% after 3000 cycles at a high current density of 2 A g−1 and capacity of 673 mAh g−1. The high cycling stability is further confirmed through the complete inhibition of lithium polyphosphide “shuttle effect” by chemical anchoring of the molecularly dispersed active material. Furthermore, scale-up prospects utilizing laser-assisted additive manufacturing are investigated.