Browsing by Author "Babu, Ganguli"

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    A common tattoo chemical for energy storage: henna plant-derived naphthoquinone dimer as a green and sustainable cathode material for Li-ion batteries
    (The Royal Society of Chemistry, 2018) Miroshnikov, Mikhail; Kato, Keiko; Babu, Ganguli; Divya, Kizhmuri P.; Arava, Leela Mohana Reddy; Ajayan, Pulickel M.; John, George
    The burgeoning energy demands of an increasingly eco-conscious population have spurred the need for sustainable energy storage devices, and have called into question the viability of the popular lithium ion battery. A series of natural polyaromatic compounds have previously displayed the capability to bind lithium via polar oxygen-containing functional groups that act as redox centers in potential electrodes. Lawsone, a widely renowned dye molecule extracted from the henna leaf, can be dimerized to bislawsone to yield up to six carbonyl/hydroxyl groups for potential lithium coordination. The facile one-step dimerization and subsequent chemical lithiation of bislawsone minimizes synthetic steps and toxic reagents compared to existing systems. We therefore report lithiated bislawsone as a candidate to advance non-toxic and recyclable green battery materials. Bislawsone based electrodes displayed a specific capacity of up to 130 mA h g−1 at 20 mA g−1 currents, and voltage plateaus at 2.1–2.5 V, which are comparable to modern Li-ion battery cathodes.
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    Energy storage devices including at least one electrode comprising a metal diboride, and related methods
    (2020-09-15) Zhou, Zhou; Kato, Keiko; Babu, Ganguli; Khabashesku, Valery N.; Ajayan, Pulickel M.; Rice University; Baker Hughes, a GE company, LLC; United States Patent and Trademark Office
    An energy storage device including a first electrode comprising lithium, a second electrode comprising a metal diboride, an electrolyte disposed between the first electrode and the second electrode and providing a conductive pathway for lithium ions to move to and from the first electrode and the second electrode, and a separator within the electrolyte and between the first electrode and the second electrode. A method of forming an energy storage device including forming a first electrode to include lithium, forming a second electrode to include a metal diboride, disposing an electrolyte between the first electrode and the second electrode, the electrolyte providing a conductive pathway for lithium ions to move to and from the first electrode and the second electrode, and disposing a separator within the electrolyte and between the first electrode and the second electrode.
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    Fluorinated Multi-Walled Carbon Nanotubes Coated Separator Mitigates Polysulfide Shuttle in Lithium-Sulfur Batteries
    (MDPI, 2023) Salpekar, Devashish; Dong, Changxin; Oliveira, Eliezer F.; Khabashesku, Valery N.; Gao, Guanhui; Ojha, Ved; Vajtai, Robert; Galvao, Douglas S.; Babu, Ganguli; Ajayan, Pulickel M.
    Li-S batteries still suffer from two of the major challenges: polysulfide shuttle and low inherent conductivity of sulfur. Here, we report a facile way to develop a bifunctional separator coated with fluorinated multiwalled carbon nanotubes. Mild fluorination does not affect the inherent graphitic structure of carbon nanotubes as shown by transmission electron microscopy. Fluorinated carbon nanotubes show an improved capacity retention by trapping/repelling lithium polysulfides at the cathode, while simultaneously acting as the “second current collector”. Moreover, reduced charge-transfer resistance and enhanced electrochemical performance at the cathode-separator interface result in a high gravimetric capacity of around 670 mAh g−1 at 4C. Unique chemical interactions between fluorine and carbon at the separator and the polysulfides, studied using DFT calculations, establish a new direction of utilizing highly electronegative fluorine moieties and absorption-based porous carbons for mitigation of polysulfide shuttle in Li-S batteries.
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    Generation of intense phase-stable femtosecond hard X-ray pulse pairs
    (National Academy of Sciences, 2022) Zhang, Yu; Kroll, Thomas; Weninger, Clemens; Michine, Yurina; Fuller, Franklin D.; Zhu, Diling; Alonso-Mori, Roberto; Sokaras, Dimosthenis; Lutman, Alberto A.; Halavanau, Aliaksei; Pellegrini, Claudio; Benediktovitch, Andrei; Yabashi, Makina; Inoue, Ichiro; Inubushi, Yuichi; Osaka, Taito; Yamada, Jumpei; Babu, Ganguli; Salpekar, Devashish; Sayed, Farheen N.; Ajayan, Pulickel M.; Kern, Jan; Yano, Junko; Yachandra, Vittal K.; Yoneda, Hitoki; Rohringer, Nina; Bergmann, Uwe
    Coherent nonlinear spectroscopies and imaging in the X-ray domain provide direct insight into the coupled motions of electrons and nuclei with resolution on the electronic length scale and timescale. The experimental realization of such techniques will strongly benefit from access to intense, coherent pairs of femtosecond X-ray pulses. We have observed phase-stable X-ray pulse pairs containing more than 3 × 107 photons at 5.9 keV (2.1 Å) with ∼1 fs duration and 2 to 5 fs separation. The highly directional pulse pairs are manifested by interference fringes in the superfluorescent and seeded stimulated manganese Kα emission induced by an X-ray free-electron laser. The fringes constitute the time-frequency X-ray analog of Young’s double-slit interference, allowing for frequency domain X-ray measurements with attosecond time resolution.
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    High-K dielectric sulfur-selenium alloys
    (AAAS, 2019) Susarla, Sandhya; Tsafack, Thierry; Owuor, Peter Samora; Puthirath, Anand B.; Hachtel, Jordan A.; Babu, Ganguli; Apte, Amey; Jawdat, BenMaan I.; Hilario, Martin S.; Lerma, Albert; Calderon, Hector A.; Hernandez, Francisco C. Robles; Tam, David W.; Li, Tong; Lupini, Andrew R.; Idrobo, Juan Carlos; Lou, Jun; Wei, Bingqing; Dai, Pengcheng; Tiwary, Chandra Sekhar; Ajayan, Pulickel M.
    Upcoming advancements in flexible technology require mechanically compliant dielectric materials. Current dielectrics have either high dielectric constant, K (e.g., metal oxides) or good flexibility (e.g., polymers). Here, we achieve a golden mean of these properties and obtain a lightweight, viscoelastic, high-K dielectric material by combining two nonpolar, brittle constituents, namely, sulfur (S) and selenium (Se). This S-Se alloy retains polymer-like mechanical flexibility along with a dielectric strength (40 kV/mm) and a high dielectric constant (K = 74 at 1 MHz) similar to those of established metal oxides. Our theoretical model suggests that the principal reason is the strong dipole moment generated due to the unique structural orientation between S and Se atoms. The S-Se alloys can bridge the chasm between mechanically soft and high-K dielectric materials toward several flexible device applications.
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    Recycling Li-ion batteries using green chemicals and processes
    (2023-02-28) Tran, Mai K.; Rodrigues, Marco-tulio F.; Babu, Ganguli; Gullapalli, Hemtej; Ajayan, Pulickel M.; Rice University; William Marsh Rice University; United States Patent and Trademark Office
    A process for extracting, recovering and recycling metals and materials from spent lithium ion batteries (LIB) that comprises the contacting battery waste products with a deep eutectic solvent, and leaching the metal from the battery waste product and extracting the metal into the deep eutectic solvent with heat and agitation. After the leaching and extracting, the process further includes recovering the dissolved metals ions from the deep eutectic solvent solution, followed by a step of regeneration of cathode materials.