Red Phosphorus Confined in Porous Structures Formed by Pvdf-Derived Carbon as Superior Anode Material for Sodium-Ion Batteries

Abstract

Given the widespread availability of sodium on our planet, sodium-ion batteries (SIBs) hold substantial promise as cost-effective energy storage solutions. Red Phosphorus (red P) has emerged as a promising candidate for SIBs anodes due to its impressive theoretical capacity of 2596mAh g-1. However, red P faces inherent challenges, mainly due to its insulating nature and significant volume changes during cycling, which adversely affect its cycling and rate performance. To overcome these challenges, we have developed a novel material called P@C, composed of carbon-coated and porous carbon structures. The synthesis of P@C involves integrating red P with PVDF and a series of carefully controlled steps, including ultrasonic dispersion, magnetic stirring, centrifugation, and high-temperature calcination. This well-designed composite material facilitates electron transfer and provides ample space within its porous carbon structure to accommodate the substantial volume changes associated with phosphorus during sodium insertion/extraction. The use of PVDF as a carbon source contributes to the creation of a defined porous carbon framework, enhancing the material's flexibility, mechanical strength, and ease of processing. As a result, when employed as an anode material for SIBs, the P@C composite material exhibits exceptional cycling stability and remarkable rate performance. Notably, it demonstrates superior capacity retention, maintaining 336.7mAh g-1 after 200 cycles at 0.2 A g-1, and excellent cycling durability, with minimal capacity degradation even after 500 cycles at 1 A g-1.This innovative work, characterized by its strategic carbon-coating approach that effectively encapsulates the active material within porous structures, provides valuable insights into the development of high-performance electrode materials for metal-ion batteries and other energy storage applications.

Keywords: polyvinylidene fluoride (PVDF), ultrasonic dispersion, Porous structure, anode materials, Sodium-ion batteries