Advancing structural batteries: cost-efficient high-performance carbon fiber-coated LiFePO₄ cathodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Structural batteries (SBs) integrate energy storage and structural support, primarily using carbon fibers (CFs).
• Developing high-performance CF-based cathode materials for SBs remains a significant challenge.
• Current SB technology requires improved cathode materials for broader applications in transportation.

Purpose of the Study:

• To develop a cost-efficient and straightforward method for fabricating high-performance structural lithium iron phosphate (LiFePO4) cathodes.
• To enhance the energy storage capabilities and structural integrity of structural batteries.
• To overcome limitations in current carbon fiber-based cathode materials for SBs.

Main Methods:

• Coating carbon fibers with lithium iron phosphate (LiFePO4) at mild temperatures and pressures.
• Characterization of the coated cathode using X-ray spectroscopy, scanning electron microscopy, and Raman spectroscopy.
• Electrochemical testing to evaluate capacity, rate performance, and cycling stability.

Main Results:

• Achieved high LiFePO4 loading (≥74%) with a smooth coating on carbon fibers.
• Demonstrated specific capacities of 144 mA h g-1 at 0.1 C and 108 mA h g-1 at 1.0 C.
• Exhibited excellent electrochemical stability with 96.4% capacity retention at 0.33 C and 81.2% at 1.0 C after 300 cycles.

Conclusions:

• The proposed method offers a promising route for fabricating advanced structural battery cathodes.
• The developed LiFePO4-coated CF cathode shows potential for enhancing both energy storage and structural performance.
• This work paves the way for next-generation structural batteries with improved functionality and efficiency.