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公开(公告)号：US20210372001A1
公开(公告)日：2021-12-02
申请号：US17330922
申请日：2021-05-26
Applicant: Worcester Polytechnic Institute
Inventor： Yan Wang , Xiaotu MA , Eric Gratz , Jinzhao Fu , Panawan Vanaphuti
Abstract: A recycling and synthesis of charge material for secondary batteries generates single-crystal charge materials for producing batteries with greater charge cycle longevity. Charge material particles undergo a heating for fusing or enhancing grain boundaries between polycrystalline particles. The resulting, more well-defined grain boundaries are easily etched by a relatively weak mineral acid solution. The acid solution removes material at the grain boundaries to separate secondary particles into primary particles along the grain boundaries. The resulting single crystal (monocrystalline) charge material particles are washed and filtered, and typically re-sintered to accommodate any needed lithium (lithium carbonate), and result in a charge material with larger surface area, higher lithium diffusivity and lower cation ordering.
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公开(公告)号：US20250050394A1
公开(公告)日：2025-02-13
申请号：US18800633
申请日：2024-08-12
Applicant: Worcester Polytechnic Institute
IPC: B09B3/80 , B09B3/38 , B09B3/70 , B09B101/15 , C01B33/18
Abstract: A recycling process for exhausted, end-of-life solar panels achieves substantial recovery of silicon and silver, as well as other materials, from a recycling stream of discarded solar panels. Agitation and shredding of the solar panels yield a granular mass, which can be separated by particle size to yield the silicon rich solar cell material. Leaching with a strong base such as sodium hydroxide draws the silicon into the leach solution. Filtration of the leach solution draws off the silicon-rich solution and allows filtration of other valuable materials such as silver. Addition of an acid such as hydrochloric acid to the leach solution then precipitates the silicon into a nano silica powder of in the form of high purity silicon dioxide. The high purity silicon dioxide provides raw materials for recycled solar panels, lithium-ion batteries and other uses depending on the purity.
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公开(公告)号：US20240258596A1
公开(公告)日：2024-08-01
申请号：US18427320
申请日：2024-01-30
Applicant: Worcester Polytechnic Institute
CPC classification number: H01M10/54 , C01B32/21 , C22B1/16 , C22B7/007 , H01M4/583 , C01P2002/72 , C01P2002/82 , C01P2004/03 , C01P2006/40 , H01M2004/027
Abstract: A purification process for recycled graphite for use as anode material in Li-ion batteries includes a sequence of leaching and heat treatment followed by washing with deionized (DI) water and an acid wash. A graphite source results from a suitable process such as acid leaching of black mass from a battery recycling stream, where the leach removes a substantial portion of metal salts used for cathode materials. Impurities, most notably aluminum oxide and residual cathode materials, are often present in trace amounts in the graphite source. A sequence of heating (sintering) and pH adjusted washing further purifies the graphite into a modified, recycled graphite exceeding 99.5% purity for use in a recycled battery.
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公开(公告)号：US20220325378A1
公开(公告)日：2022-10-13
申请号：US17719080
申请日：2022-04-12
Applicant: Worcester Polytechnic Institute
Inventor： Yan Wang , Jiahui Hou , Xiaotu MA , Jinzhao Fu
Abstract: Lithium recycling from expended Li-Ion batteries occurs thought selective recovery of lithium charge materials from a recycling stream including transition metals used for the charge material. Li recovery includes dissolving the lithium based charge material in an organic acid having a resistance or lack of affinity to dissolution of transition metals, and distilling a leach solution formed from the dissolved charge material for generating a powder including lithium and trace impurities of the transition metals. Sintering of the generated powder forms lithium carbonate and carbonates of the trace impurities that eluded the selective leach, however, since the trace impurities are insoluble in water, the lithium carbonate is recoverable by water washing.
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公开(公告)号：US20180261894A1
公开(公告)日：2018-09-13
申请号：US15976981
申请日：2018-05-11
Applicant: Worcester Polytechnic Institute
IPC: H01M10/54 , C01B25/45 , H01M10/0525 , H01M4/58
CPC classification number: H01M10/54 , C01B25/45 , C01P2006/40 , C22B3/02 , C22B7/006 , C22B26/12 , C22B47/00 , H01M4/505 , H01M4/525 , H01M4/5825 , H01M10/0525 , H01M2004/028 , Y02P10/234 , Y02W30/84
Abstract: Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to produce active cathode materials for new batteries. The solution includes compounds of valuable charge materials such as cobalt, nickel, aluminum and manganese dissolved as compounds from the exhausted cathode material of spent cells. However, LiFePO4 is a waste stream charge material often discarded due to infeasibility of recycling. LiFePO4 is precipitated as FePO4 and remains as a by-product, along with graphite and carbon, which are not dissolved into the solution. FePO4 can be separated from graphite and carbon, FePO4 can be used to synthesize LiFePO4 as cathode materials and graphite can be regenerated as anode materials.
