An active material includes, as constituent elements, silicon, oxygen, a first element, a second element, and a third element. The first element includes boron, phosphorus, or both. The second element includes at least one of an alkali metal element, a transition element, or a typical element. The typical element excludes silicon, oxygen, boron, phosphorus, an alkali metal element, and an alkaline earth metal element. The third element includes an alkaline earth metal element. The content of silicon with respect to all the constituent elements excluding oxygen and carbon is 60 at % or greater and 98 at % or less. The content of the first element with respect to all the constituent elements excluding oxygen and carbon is 1 at % or greater and 25 at % or less. The content of the second element with respect to all the constituent elements excluding oxygen and carbon is 1 at % or greater and 34 at % or less. The content of the third element with respect to all the constituent elements excluding oxygen and carbon is 0 at % or greater and 6 at % or less. A first peak is detected in an XPS spectrum of Si2p relating to the active material. The XPS spectrum of Si2p is measured using X-ray photoelectron spectroscopy (XPS). The first peak includes an apex within a range of a binding energy of 102 eV or greater and 105 eV or less, and a shoulder on a smaller binding energy side of the apex. A second peak is detected in a Raman spectrum relating to the active material. The Raman spectrum is measured using Raman spectroscopy. The second peak includes an apex within a range of a Raman shift of 435 cm.sup.−1 or greater and 465 cm.sup.−1 or less.

A positive electrode for a lithium-sulfur secondary battery includes a positive electrode active material layer having an intaglio pattern formed therein. A method for manufacturing the same, and a lithium-sulfur secondary battery including the same are also provided. The positive electrode active material layer has a porosity of 50 to 65%. The intaglio pattern has a width of 1 to 100 μm and a depth of 30 to 99% based on the thickness of the positive electrode active material layer. The volumetric ratio of the positive electrode active material layer and the intaglio pattern is 4:1 to 40:1. When the positive electrode is applied to a lithium-sulfur secondary battery, the energy density per unit volume can be remarkably improved.

The present disclosure provides an energy storage device comprising a negative electrode, a molten electrolyte in electrical communication with the negative electrode, and a positive electrode in electrical communication with the molten electrolyte. One or more of the negative electrode, positive electrode, and molten electrolyte may be at least partially liquid at an operating temperature of the energy storage device. The positive electrode may be at least partially solid at the operating temperature of the energy storage device.

An electrochemical device includes an air cathode using air as the cathodic gas; a discharge product of sodium peroxide dihydrate; an anode comprising sodium metal; a porous fiber separator; and a non-aqueous electrolyte comprising a sodium salt and a solvent.

Provided herein are energy storage devices. In some cases, the energy storage devices are capable of being transported on a vehicle and storing a large amount of energy. An energy storage device is provided comprising at least one liquid metal electrode, an energy storage capacity of at least about 1 MWh and a response time less than or equal to about 100 milliseconds (ms).

Provided herein are energy storage devices. In some cases, the energy storage devices are capable of being transported on a vehicle and storing a large amount of energy. An energy storage device is provided comprising at least one liquid metal electrode, an energy storage capacity of at least about 1 MWh and a response time less than or equal to about 100 milliseconds (ms).

Alkali metal secondary batteries that include anodes constructed from alkali metal foil applied to only one side of a porous current collector metal foil. Openings in the porous current collectors permit alkali metal accessibility on both sides of the anode structure. Such anode constructions enable the utilization of lower-cost and more commonly available alkali metal foil thickness, while still achieving high cell cycle life at a significantly reduced cost. Aspects of the present disclosure also include batteries with porous current collectors having increased volumetric and gravimetric energy densities, and methods of manufacturing anodes with porous current collectors.

An electrolytic solution for a secondary battery, a secondary battery containing the electrolytic solution, and a module including the same. The secondary battery includes comprising a positive electrode and a negative electrode containing an alkali metal. The positive electrode includes at least one compound selected from an alkali metal-containing transition metal composite oxide and an alkali metal-containing transition metal phosphate compound. The electrolytic solution contains a compound represented by the following formula (1) and/or a compound represented by the following formula (2):

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A main object of the present disclosure is to provide an anode material that is used in a fluoride ion battery and can prevent the decrease in operating voltage while inhibiting occurrence of short circuit. The present disclosure achieves the object by providing an anode material to be used in a fluoride ion battery, the anode material comprising a Mg material containing a Mg element, and a fluoride ion conductive material containing at least one kind of metal element excluding a Mg element, and a F element.

An electrochemical cell comprising:

an anode comprising lithium or sodium metal, or lithium or sodium metal alloy;
an ionically conductive cathode comprising an electroactive sulfur material; and
a liquid electrolyte comprising at least one lithium salt or at least one sodium salt, wherein the polysulfide solubility of the electrolyte is less than 500 mM.