A Random-Aligned Carbon Nanofiber Interface Enhancing the Intrinsic Electric Field for High-Performance Lithium Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Lithium metal batteries are limited by dendrite growth and interfacial side reactions at the negative electrode.
• Stable lithium deposition requires a better understanding of current collector (CC) structure-performance relationships.

Purpose of the Study:

• To develop a new current collector strategy for uniform lithium-ion deposition.
• To investigate the role of hierarchical porous carbon nanofibers in regulating ion transport and electric fields.

Main Methods:

• Fabrication of a "random-to-aligned hierarchical porous carbon nanofibers" (r/a-HPCNFs) current collector.
• Analysis of ion transport within aligned carbon nanofiber channels.
• Construction of a top-random/bottom-aligned interface to tune dielectric properties and electric fields.

Main Results:

• The r/a-HPCNFs strategy achieved uniform bottom-up lithium-ion deposition.
• Symmetric cells with pre-deposited lithium on r/a-HPCNFs showed stable operation for over 6500 hours at 5 mA cm^-2.
• Full cells using r/a-HPCNFs with minimal lithium predeposition demonstrated excellent capacity retention over hundreds of cycles with various cathode materials (LiFePO₄, LiNi_0.8Co_0.1Mn_0.1O₂, sulfur).

Conclusions:

• The random-aligned hierarchical architecture of r/a-HPCNFs is key for intrinsic electric field regulation.
• This CC design effectively suppresses lithium dendrite growth and enables stable battery cycling.
• The strategy offers a promising pathway for developing high-performance and safe lithium metal batteries.