Development and Investigation of Tape-Casted Multi-Wall Carbon Nanotube Freestanding Sheets Infused with Ferric Oxide (Fe2O3) Nanoparticles as A Freestanding Negative Electrode for Lithium-Ion Battery

Abstract

Multiwalled carbon nanotube (MWCNT) freestanding sheets, also known as buckypapers, enable the MWCNT exceptional nanoscopic properties in easy-to-handle macrostructures. MWCNT and MWCNT-infused sheets have been applied in various applications such as electrically-conductive membranes for water purification, electromagnetic interference shielding for aerospace electronics, and especially as electrode materials in energy storage and conversion devices. Although MWCNTbased sheets are very promising in the laboratory, they failed to meet the technology readiness level for commercialization due to the use of non-scalable fabrication techniques. These techniques are typically associated with long processing time and high capital and operating costs, and require energy-intensive equipment. Herein, we developed a facile and scalable preparation method to fabricate freestanding, flexible and foldable MWCNT and MWCNT-infused sheets using a tape-casting technique without a mold. The advantages of tape-casting technique over conventional methods is that we can produce buckypapers with superior properties, can be implemented in both batch and roll-to-roll processing, has a high throughput, produces a large area with tunable length, thickness, density and composition. Specifically, we infused and modified the tape-casted MWCNT buckypaper with iron (III) oxide (Fe2O3) nanoparticles to tailor its properties for lithium-ion battery negative electrode. Different mass ratios of Fe2O3 and different C-rates were tested to study the performance of the tape-casted MWCNT-Fe2O3 buckypaper. The newly developed negative electrode performed better than conventional graphite on copper foil electrode. Conventional graphite has a specific capacity of 188 mAhg-1 after 20 cycles and 14.3 mAhg-1 after 400 cycles at 0.1 and 1 charge/discharge rate (C-rate), respectively. In comparison, the tape-casted MWCNT-Fe2O3 buckypaper shows a specific capacity of 681 mAhg-1 after 20 cycles at C-rate of 0.1. At higher C-rate of 1, the tape-casted MWCNT-Fe2O3 buckypaper shows a specific capacity of 286 mAhg -1 after 400 cycles. These results show that our tape-casted MWCNT-Fe2O3 buckypaper is a promising negative electrode material for lithium-ion batteries.

Date of Award	May 2017
Original language	American English
Supervisor	Saif Al Mheiri (Supervisor)