Browsing by Author "Thakur, Madhuri"

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    Anode battery materials and methods of making the same
    (2016-05-17) Biswal, Sibani Lisa; Thakur, Madhuri; Wong, Michael S.; Sinsabaugh, Steven L.; Isaacson, Mark; Rice University; United States Patent and Trademark Office
    In some embodiments, the present invention provides novel methods of preparing porous silicon films and particles for lithium ion batteries. In some embodiments, such methods generally include: (1) etching a silicon material by exposure of the silicon material to a constant current density in a solution to produce a porous silicon film over a substrate; and (2) separating the porous silicon film from the substrate by gradually increasing the electric current density in sequential increments. In some embodiments, the methods of the present invention may also include a step of associating the porous silicon film with a binding material. In some embodiments, the methods of the present invention may also include a step of splitting the porous silicon film to form porous silicon particles. Additional embodiments of the present invention pertain to anode materials derived from the porous silicon films and porous silicon particles.
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    Inexpensive method for producing macroporous silicon particulates (MPSPs) with pyrolyzed polyacrylonitrile for lithium ion batteries
    (Springer Nature, 2012) Thakur, Madhuri; Sinsabaugh, Steven L.; Isaacson, Mark J.; Wong, Michael S.; Biswal, Sibani Lisa
    One of the most exciting areas in lithium ion batteries is engineering structured silicon anodes. These new materials promise to lead the next generation of batteries with significantly higher reversible charge capacity than current technologies. One drawback of these materials is that their production involves costly processing steps, limiting their application in commercial lithium ion batteries. In this report we present an inexpensive method for synthesizing macroporous silicon particulates (MPSPs). After being mixed with polyacrylonitrile (PAN) and pyrolyzed, MPSPs can alloy with lithium, resulting in capacities of 1000 mAhg−1 for over 600+ cycles. These sponge-like MPSPs with pyrolyzed PAN (PPAN) can accommodate the large volume expansion associated with silicon lithiation. This performance combined with low cost processing yields a competitive anode material that will have an immediate and direct application in lithium ion batteries.
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    Porous silicon particulates with micropores and mesopores within macropores
    (2018-04-17) Biswal, Sibani Lisa; Wong, Michael S.; Thakur, Madhuri; Sinsabaugh, Steven L.; Rice University; United States Patent and Trademark Office
    Embodiments of the present disclosure pertain to porous silicon particulates and anode materials that contain them. In some embodiments, each of the porous silicon particulates include a plurality of macropores, mesopores and micropores such that the micropores and mesopores are within the macropores. The porous silicon particulates also contain: a coating associated with the porous silicon particulates; and a binding material associated with the porous silicon particulates. The binding material can include binders, carbon materials, polymers, metals, additives, carbohydrates, and combinations thereof.