Reinventing Phosphorus Anodes: Taming Pulverization via Strain-Induced Interfacial Coupling

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Alloy-type anodes have high theoretical capacity but suffer from volume expansion and particle pulverization, limiting their practical use in batteries.
• Developing stable and high-performance anodes is crucial for advancing energy storage technologies.

Purpose of the Study:

• To propose a proactive strategy that transforms the detrimental volume change of alloy anodes into a force for interfacial stabilization.
• To enhance the performance and cycle life of phosphorus anodes by integrating single-walled carbon nanotubes (SWCNTs).

Main Methods:

• Utilizing the flexibility of SWCNTs and the volume variation of phosphorus during lithiation to induce tensile strain.
• Employing operando Raman spectroscopy and density functional theory (DFT) calculations to investigate the chemomechanical coupling mechanism.
• Fabricating and testing phosphorus anodes with SWCNT incorporation and evaluating full cell performance.

Main Results:

• The SWCNT integration promoted interfacial coupling and P─C bond formation, stabilizing phosphorus clusters.
• The phosphorus anode with 1 wt% SWCNT achieved a specific capacity of 1981.6 mAh g^-1 at 0.1C and maintained 1301.9 mAh g^-1 after 500 cycles at 1C.
• A full cell (NCM811//BP─SWCNT) demonstrated high energy density (507 Wh kg^-1) and capacity retention.

Conclusions:

• A novel chemomechanical coupling mechanism was identified, effectively stabilizing fractured phosphorus clusters and suppressing dissolution.
• The developed active stress-utilization design principle offers new perspectives for creating high-energy-density alloy-type anodes.
• This approach provides a viable strategy for overcoming the limitations of alloy-type anodes in next-generation batteries.