Shear-Exfoliated Phosphorene for Rechargeable Nanoscale Battery

TL;DR

This study demonstrates the use of shear-exfoliated phosphorene as an anode material in nanoscale lithium-ion batteries, revealing thickness-dependent stability and a scalable production method for potential large-scale energy storage applications.

Contribution

It introduces a scalable shear exfoliation technique for high-quality phosphorene and provides real-time TEM insights into its structural stability during battery cycling.

Findings

Few-layer phosphorene resists structural decomposition during cycling.

Shear exfoliation can produce ultrathin phosphorene using household blenders.

Thickness influences lithium diffusion and battery stability.

Abstract

Discovery of atomically thin black phosphorus (called phosphorene) holds promise to be used as an alternative two-dimensional material to graphene and transition metal dichalcogenides especially as an anode material for lithium-ion batteries (LIBs). However, at present bulk black phosphorus (BP) still suffers from rapid capacity fading that results in poor rechargeable performance. Here, for the first time, we use in situ transmission electron microscopy (TEM) to construct nanoscale phosphorene LIBs and visualize the capacity fading mechanism in thick multilayer phosphorene by real time capturing delithiation-induced structural decomposition that reduces electrical conductivity and thus causes irreversibility of lithiated Li3P phase. We further demonstrate that few-layer phosphorene successfully circumvents the structural decomposition and holds superior structural restorability, even subjected to multi-cycle lithiation/delithiation processes and concomitant huge volume expansion. This finding affords new experimental insights into thickness-dependent lithium diffusion kinetics in phosphorene. Additionally, a scalable liquid-phase shear exfoliation route has been developed to produce high-quality ultrathin (monolayer or few-layer) phosphorene, only by a high-speed shear mixer or even a household kitchen blender with the shear rate threshold, which will pave the way for potential large-scale applications in LIBs once the rechargeable phosphorene nanoscale batteries can be transferred to industrialized enlargement in the future.