Browsing by Subject "lithium cobalt oxide"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Fundamental Investigation of Direct Cathode Regeneration Using Chemically Delithiated Lithium Cobalt Oxides
    (IOP Publishing, 2022-11-03) Bhuyan, Md. Sajibul Alam; Shin, Hosop; Mechanical and Energy Engineering, School of Engineering and Technology
    Reusing valuable cathode materials from end-of-life (EOL) Li-ion batteries can help decrease dependence on mining of raw materials for producing cathodes, while preventing commodity prices from rising. This study employed chemically delithiated cathodes that are analogous to spent cathodes but free of impurities to fundamentally elucidate the effectiveness of cathode regeneration. Two lithium cobalt oxides (LCOs) at different degrees of delithiation were synthesized via chemical delithiation. Their material and electrochemical characteristics were systematically compared before and after hydrothermal-based cathode regeneration. The material and electrochemical characteristics were further evaluated and compared with those of pristine LCO. Both LCOs, at high and low states of health (SOH), recovered their reversible capacity and cycle performance comparable to those of pristine LCO. However, the high-rate performance (2C) of the regenerated LCOs was not comparable to that of pristine LCO. The slight increase in cell resistance of the regenerated LCOs was attributed to their lower high-rate performance, which was identified as a key challenge of cathode regeneration. Our study provides valuable insights into the effectiveness of cathode regeneration by elucidating the process underlying regeneration of disordered Li-deficient LCOs at different levels of SOH.
  • Thumbnail Image
    Item
    Paper-Based Lithium-Ion Battery
    (Office of the Vice Chancellor for Research, 2013-04-05) Aliahmad, Nojan; Agarwal, Mangilal; Shrestha, Sudhir; Varahramyan, Kody
    Lithium-ion batteries have a wide range of applications including present day portable consumer electronics and large-scale energy storage. Realization of these batteries in flexible, light-weight forms will further expand the usage in current and future innovative electronic devices. Lithium titanium oxide (Li4Ti5O12), lithium magnesium oxide (LiMn2O4) and lithium cobalt oxide (LiCoO2) materials have been consistently studied for application in high capacity batteries, and thus considered in the devices that are presented in the poster. Carbon nanotube (CNT) coated wood microfiber papers are used as current collectors, which provide high surface area, flexibility, and texture of paper, with low CNT utilization (10.1μg/cm2). The CNT microfiber paper is fabricated by layer-by-layer (LbL) nano-assembly of CNT over cellulose microfibers. Results from paper-based half-cell batteries show capacities of 130 mAh/g for LiMn2O4, 150 mAh/g for LiCoO2, and 158 mAh/g for Li4Ti5O12 at C/5 rate. These results are comparable with metallic electrode based cells. The fabrication of CNT microfiber paper, assembly of batteries, experimental methods, and results are presented and discussed.
  • Thumbnail Image
    Item
    STUDY ON THE STRUCTURAL, THERMAL AND MECHANICAL PROPERTIES OF LICOO2 USING FIRST PRINCIPLES METHOD
    (Office of the Vice Chancellor for Research, 2014-04-11) Wu, Linmin; Zhang, Jing
    Thin film rechargeable battery has become a research hotspot because of its small size and high energy density. Lithium cobalt oxide as a typical cathode material in classical lithium ion batteries is also widely used in thin film rechargeable batteries. In this work, structural, mechanical and thermal properties of LiCoO2 were systematically investigated using first principles. Lattice constants, band gap and density of states were studied using Castep and VASP package, respectively. Elastic constants by applying various hydrostatic pressures between 0 to 40 GPa were computed. Specific heat and Debye temperature at low temperature were also discussed in this work. Other property including thermal conductivity was obtained using the imposed-flux method. The results show good agreement with experimental data and computational results in literature.