BUNDLED AND DENSIFIED CARBON NANOTUBES (CNT) FABRICS AS FLEXIBLE ULTRA-LIGHT WEIGHT LI-ION BATTERY ANODE CURRENT COLLECTORS

Carbon nanotubes (CNT) fabrics were studied and evaluated as anode current collectors, replacing the traditional copper foil current collector in Li-ion batteries. As seen in the figure, glavanostatic measurements reveal high values of irreversible capacities (as high as 28%), resulted mainly from the formation of the solid electrolyte interphase (SEI) layer at the CNT fabric surface. Various pre-treatments to the CNT fabric prior to active anode material loading have shown that the lowest irreversible capacity is achieved by immersing and washing the CNT fabric with iso-propanol (IPA), which dramatically modified the fabric surface. Additionally, the use of very thin CNT fabrics (5 µm) results in a substantial irreversible capacity minimization. A combination of IPA rinse action and utilization of the thinnest CNT fabric provides the lowest irreversible capacity of 13%. The poster presents innovative and rather simple techniques towards a complete implementation of CNT fabric as an anode current collector in Li-ion batteries, instead of the relatively heavy and expensive copper foil, enabling an improvement in the gravimetric and volumetric energy densities of such advanced batteries.

First charge-discharge profiles of half-cells (graphite vs. Li metal) analysis measured with different pre-treatments to the CNT fabric current collector (originally 5-10 µm). A cell utilizing Cu foil current collector is presented for comparison. Capacity is expressed in mAh gr^-1 and is related only to the mass of the loaded graphite.