Electrospun Si and Si/C Fiber Anodes for Li-Ion Batteries

• Published in: Batteries (Basel) 2023-12, Vol.9 (12), p.569
• Main Authors: Mondal, Abhishek N., Wycisk, Ryszard, Waugh, John, Pintauro, Peter N.
• Format: Article
• Language: English
• Subjects: Anodes; Carbon; Cycles; Design and construction; Discharge; Electrodes; Electrolytes; electrospinning; Graphene; Li-ion battery; Lithium; Lithium cells; Lithium-ion batteries; Materials; nanofibers; Nanoparticles; Polyacrylic acid; Polymers; Rechargeable batteries; Retention; Silicon; silicon anode; Silicon compounds; Solvents
• ISSN: 2313-0105; 2313-0105
• DOI: 10.3390/batteries9120569

Due to structural changes in silicon during lithiation/delithiation, most Li-ion battery anodes containing silicon show rapid gravimetric capacity fade upon charge/discharge cycling. Herein, we report on a new Si powder anode in the form of electrospun fibers with only poly(acrylic acid) (PAA) binder and no electrically conductive carbon. The performance of this anode was contrasted to a fiber mat composed of Si powder, PAA binder, and a small amount of carbon powder. Fiber mat electrodes were evaluated in half-cells with a Li metal counter/reference electrode. Without the addition of conductive carbon, a stable capacity of about 1500 mAh/g (normalized to the total weight of the anode) was obtained at 1C for 50 charge/discharge cycles when the areal loading of silicon was 0.30 mgSi/cm2, whereas a capacity of 800 mAh/g was obtained when the Si loading was increased to ~1.0 mgSi/cm2. On a Si weight basis, these capacities correspond to >3500 mAh/gSi. The capacities were significantly higher than those found with a slurry-cast powdered Si anode with PAA binder. There was no change in fiber anode performance (gravimetric capacity and constant capacity with cycling) when a small amount of electrically conductive carbon was added to the electrospun fiber anodes when the Si loading was ≤1.0 mgSi/cm2.