Enhanced rate capability and capacity of LIB full cells achieved through aerosol jet printing

Abstract

Thick lithium-iron phosphate (LFP) cathodes (31 mg cm-2) with rationally engineered pore structure and tortuosity were manufactured with an aerosol jet (AJ) printer. Cathode pore structuring was tuned by controlling the rate at which the printed ink dried. Slow-drying prints yielded smoother cathodes while fast-drying prints resulted in mesoscale structuring with substantial surface roughness. X-ray tomography further revealed that the rapid drying of AJ printed LFP cathodes produced low-tortuosity pore channels which were preserved after calendering. Full cells comprised of AJ print optimized LFP cathodes, with 30 mg cm-2 active material loadings, and capacity-matched, AJ printed lithium titanate anodes were assembled and electrochemically tested. Performance of the AJ printed full cells was compared to tape-cast (TC) full cells. At equivalent electrode loadings, compositions, and thicknesses, the AJ full cells outperformed the TC cells, averaging approximately 14% greater capacity per cycle after 100 cycles at a C/2 rate. Furthermore, at 1C, the AJ printed full cells realized a near two-fold increase in discharge capacity over the TC cells.