Powder-impregnated carbon fibers with lithium iron phosphate as positive electrodes in structural batteries

• A structural battery is a multifunctional battery that can carry a load while storing energy. Structural batteries have been a cutting-edge research focus in the last decade and are mainly based on polyacrylonitrile (PAN)-carbon fibers (CFs). In this work, positive electrodes based on PAN-carbon fibers were manufactured with powder impregnation (siphon impregnation) technique using a water-based slurry containing lithium iron phosphate (LFP) as the active electrode material and the water-soluble binder polyethylene glycol (PEG). Different coating compositions, electrode-drying temperatures, and coating parameters were investigated to optimize the coating uniformity and the electrochemical performances. Scanning electron microscopy results showed that the electrode materials coat the CFs uniformly, conformably, and individually. Electrochemical characterization of pouch cells shows that the electrodes containing 6 wt% PEG dried at 140 °C have the best battery performance, delivering a first discharge capacity of 151 mAh g−1 and capacity retention higher than 80% after 100 cycles. Moreover, excellent capacity reversibility was achieved when the electrodes were cycled at multiple C-rates attesting to their stability. The results demonstrate that CFs perform excellently as current collectors in positive electrodes. 

Subject headings

NATURVETENSKAP  -- Kemi -- Materialkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Materials Chemistry (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Kompositmaterial och -teknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Composite Science and Engineering (hsv//eng)

Keyword

Carbon fibers

LiFePO₄

Lithium-ion battery

Siphon impregnation

Structural positive electrode

Coatings

Electric discharges

Electrochemical electrodes

Impregnation

Iron compounds

Lithium-ion batteries

Scanning electron microscopy

Active electrode materials

Cutting edges

Energy

Impregnated carbons

Positive electrodes

Research focus

Structural batteries

Water-based slurry

Lithium compounds

Publication and Content Type

ref (subject category)

art (subject category)