Polyplus Battery Company, Inc.

Other

May-Ying Chu

Steven J Visco

Lutgard C De Jonghe

Yevgeniy S Nimon

Lutgard C DeJonghe

Bruce D Katz

Floris Y Tsang

Jiro K Takemoto

Batteries including a lithium anode stabilized with a metal-lithium alloy and battery cells comprising such anodes are provided. In one embodiment, an electrochemical cell having an anode and a sulfur electrode including at least one of elemental sulfur, lithium sulfide, and a lithium polysulfide is provided. The anode includes a lithium core and a ternary alloy layer over the lithium core where the ternary alloy comprises lithium and two other metals. The ternary alloy layer is effective to increase cycle life and storageability of the electrochemical cell. In a more particular embodiment, the ternary alloy layer is comprised of lithium, copper and tin.

Coated lithium electrodes

A method employing a bonding layer is used to form active metal electrodes having barrier layers. Active metals such as lithium are highly reactive in ambient conditions. The method involves fabricating a lithium electrode or other active metal electrode without depositing the barrier layer on a layer of metal. Rather a smooth barrier layer is formed on a smooth substrate such as a web carrier or polymeric electrolyte. A bonding or alloying layer is formed on top of the barrier layer. Lithium or other active material is then attached to the bonding layer to form the active metal electrode. A current collector may also be attached to the lithium or active metal during the process.

Encapsulated lithium alloy electrodes having barrier layers

A method for forming lithium electrodes having protective layers involves plating lithium between a lithium ion conductive protective layer and a current collector of an &ldquo;electrode precursor.&rdquo; The electrode precursor is formed by depositing the protective layer on a very smooth surface of a current collector. The protective layer is a glass such as lithium phosphorus oxynitride and the current collector is a conductive sheet such as a copper sheet. During plating, lithium ions move through the protective layer and a lithium metal layer plates onto the surface of the current collector. The resulting structure is a protected lithium electrode. To facilitate uniform lithium plating, the electrode precursor may include a &ldquo;wetting layer&rdquo; which coats the current collector.

Plating metal negative electrodes under protective coatings

Disclosed are oxidizer-treated lithium electrodes, battery cells containing such oxidizer-treated lithium electrodes, battery cell electrolytes containing oxidizing additives, and methods of treating lithium electrodes with oxidizing agents and battery cells containing such oxidizer-treated lithium electrodes. Battery cells containing SO as an electrolyte additive in accordance with the present invention exhibit higher discharge capacities after cell storage over cells not containing SO . Pre-treating the lithium electrode with SO gas prior to battery assembly prevented cell polarization. Moreover, the SO treatment does not negatively impact sulfur utilization and improves the lithium's electrochemical function as the negative electrode in the battery cell.

Electrolytes with strong oxidizing additives for lithium/sulfur batteries

Batteries including a lithium anode stabilized with a metal-lithium alloy and battery cells comprising such anodes are provided. In one embodiment, an electrochemical cell having an anode and a sulfur electrode including at least one of elemental sulfur, lithium sulfide, and a lithium polysulfide is provided. The anode includes a lithium core and an aluminum-lithium alloy layer over the lithium core. In another embodiment, a surface coating, which is effective to increase cycle life and storageability of the electrochemical cell, is formed on the anode. In a more particular embodiment, the anode is in an electrolyte solution, and, more particularly, an electrolyte solution including either elemental sulfur, a sulfide, or a polysulfide where the surface coating is composed of Al S .

Layered arrangements of lithium electrodes

Disclosed are positive electrodes containing active-sulfur-based composite electrodes. The cells include active-sulfur, an electronic conductor, and an ionic conductor. These materials are provided in a manner allowing at least about 10% of the active-sulfur to be available for electrochemical reaction. Also disclosed are methods for fabricating active-sulfur-based composite electrodes. The method begins with a step of combining the electrode components in a slurry. Next, the slurry is homogenized such that the electrode components are well mixed and free of agglomerates. Thereafter, before the electrode components have settled or separated to any significant degree, the slurry is coated on a substrate to form a thin film. Finally, the coated film is dried to form the electrode in such a manner that the electrode components do not significantly redistribute.

Rechargeable positive electrodes

A high performance lithium-sulfur battery cell includes the following features: (a) a negative electrode including a metal or an ion of the metal; (b) a positive electrode comprising an electronically conductive material; and (c) a liquid catholyte including a solvent and dissolve electrochemically active material comprising sulfur in the form of at least one of a sulfide of the metal and a polysulfide of the metal. Such battery cells are characterized by an energy density, calculated based upon a laminate weight, of at least about 400 Watt-hours/kilogram when discharged at a rate of at least 0.1 mA/cm . Cells meeting these criteria often find use as primary cells.

Liquid electrolyte lithium-sulfur batteries

Disclosed is an electrochemical device having a shuttle-type redox mechanism for overcharge protection in which the redox reaction is &ldquo;tuned&rdquo; with a tuning agent to adjust the potential at which the redox reaction occurs. Such device may be characterized as including the following elements: (1) a negative electrode (e.g., lithium); (2) a positive electrode containing one or more intermediate species (e.g., polysulfides) which are oxidized to one more oxidized species during overcharge; and (3) a tuning species (e.g., an organosulfur compound) which adjusts the rate at which the oxidized species are reduced and thereby adjusts the voltage at which overcharge protection is provided. The oxidized species produced during overcharge move to the negative electrode where they are reduced back to said intermediate species as in a normal redox shuttle. However, the oxidized species react more rapidly than the intermediate species at the negative electrode. Thus, the overcharge protection mechanism becomes more active as the oxidized species' concentration increases&mdash;as occurs during more severe overcharge.

Overcharge protection systems for rechargeable batteries

Disclosed are dioxolane-treated lithium electrodes, battery cells containing such dioxolane-treated lithium electrodes, battery cell electrolytes containing dioxolane, and methods of treating lithium electrodes with dioxolane and battery cells containing such dioxolane-treated lithium electrodes. Treating lithium with dioxolane prevents the lithium from reacting with a wide range of substances which can contaminate battery cells, particularly moisture and other protic impurities, that might otherwise react with the lithium to the detriment of its function as a negative electrode in a battery cell. Battery cells containing dioxolane as an electrolyte co-solvent in accordance with the present invention exhibit improved cycling performance over cells not containing dioxolane. Moreover, the dioxolane treatment does not negatively impact sulfur utilization and improves the lithium's electrochemical function as the negative electrode in the battery cell.

Dioxolane as a proctector for lithium electrodes

Disclosed is a redox electrode for a battery cell that has a coating to mitigate plugging by precipitated discharge products. The coating comprises a mixed ionic electronic conductor (MIEC) which is applied to the surface of a redox electrode. The presence of the MIEC coating allows for rapid removal of discharge product precipitates from redox electrodes since it is capable of conducting both electrons and ions. As a result, the chemical action necessary to remove such precipitates may take place on both the electrolyte side of the precipitate and at the precipitate/electrode interface. MIEC coatings in accordance with the present invention may be composed of any suitable material having ionic conductivity for a metal ion in a negative electrode with which the redox electrode is to be paired in a battery cell, and reversible redox capacity. Examples include titanium sulfide (TiS,), iron sulfide (FeS,), and cobalt oxides.

Mixed ionic electronic conductor coatings for redox electrodes

High capacity/high discharge rate rechargeable positive electrode

An electrochemical timer is described that is compact, lightweight, inexpensive to manufacture, and simple to use in which the consumption of reactive materials in an electrochemical reaction provides a visual indication of the passage of time. In one embodiment, the electrochemical timer includes a first electrode, an electrolyte, and a second electrode. The electrodes and electrolyte are chosen such that the first electrode is consumed at a predetermined rate upon electrochemical contact of the electrodes and electrolyte. The electrodes and electrolyte are further configured such that the consumption of the first electrode can be monitored to provide an indication of the passage of time. In one embodiment, the electrochemical timers provided herein are used to monitor the shelf-life of perishables.

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Oakland, CA, United States of America

May-Ying Chu