Biphenylene-Based Crystalline Foam Carbon Allotropes

Area of Science:

• Materials Science
• Computational Chemistry
• Solid-State Physics

Background:

• Developing novel carbon allotropes with superior properties and synthetic accessibility is crucial for advanced materials.
• Biphenylene monolayers serve as a foundational structure for designing new carbon materials.

Purpose of the Study:

• To theoretically design and investigate novel three-dimensional crystalline foam carbon allotropes based on biphenylene.
• To evaluate the stability, mechanical properties, electronic characteristics, and potential applications of these designed carbon structures.

Main Methods:

• Theoretical design of three-dimensional crystalline foam carbon structures using biphenylene monolayers as a basis.
• Computational analysis of lattice dynamics, thermal stability, mechanical performance, and electronic properties (semiconducting/semimetallic behavior).
• Assessment of ion filtration, transport, and storage capabilities, with specific focus on lithium-ion battery applications.

Main Results:

• Designed foam carbon structures exhibit semimetallic or semiconducting properties with good lattice dynamic stability, thermal stability, and mechanical performance.
• A representative structure (3D-C48-Z2-R4R4-R6-trans) shows high theoretical lithium storage capacity (930.6 mAh·g-1), low diffusion barriers (0.079 eV), and suitable voltage for Li-ion batteries.
• A non-foam structure (BPN-diamond) demonstrates semiconductor properties with a 4.073 eV bandgap, ultrahigh hardness (76.4 GPa), and high carrier mobility (5.97 × 10^3 cm^2 V^-1 s^-1).

Conclusions:

• Biphenylene-based foam carbon allotropes are promising multifunctional materials with potential applications in flexible electronics, ion-electron mixed conductors, ion filtration, and anodes for Li-ion batteries.
• The designed materials exhibit a favorable combination of properties including stability, synthesizability, and performance for energy storage and separation technologies.