Electrospun titania-based fibers for high areal capacity Li-ion battery anodes

• Published in: Journal of power sources 2015-05, Vol.282, p.187-193
• Main Authors: Self, Ethan C., Wycisk, Ryszard, Pintauro, Peter N.
• Format: Article
• Language: English
• Subjects: Areal capacity; Electrospinning; Li-ion battery; Thick electrode; Titania anode
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2015.02.036

Electrospinning is utilized to prepare composite fiber Li-ion battery anodes containing titania and carbon nanoparticles with a poly (acrylic acid) binder. The electrospun material exhibits a stable charge/discharge capacity with only 5% capacity fade over 450 cycles at 0.5 C. Compared to a conventional slurry cast electrode of the same composition, the electrospun anode demonstrates 4-fold higher capacity retention (31% vs. 7.9%) at a charge/discharge rate of 5 C. Electrospinning is also used to prepare ultrathick anodes (>1 mm) with areal capacities up to 3.9 mAh cm−2. Notably, the thick electrodes exhibit areal capacities of 2.5 and 1.3 mAh cm−2 at 1 C and 2 C, respectively. Electrospun anodes with densely packed fibers have a 2 C volumetric capacity which exceeds that of the slurry cast material (21.2 and 17.5 mAh cm−3, respectively). The excellent performance of the electrospun anodes is attributed to interfiber voids which provide complete electrolyte intrusion, a large electrode/electrolyte interface, and short Li+ transport pathways between the electrolyte and titania nanoparticles. •Titania-based fiber anodes for Li-ion batteries were prepared using electrospinning.•Electrospun anodes demonstrate superior performance, as compared to slurry cast materials.•Thick electrospun anodes achieve high capacities and excellent rate capabilities.•The general approach is adaptable to prepare electrodes from other particle/polymer combinations.