The present application is generally directed to composites comprising a hard carbon material and an electrochemical modifier. The composite materials find utility in any number of electrical devices, for example, in lithium ion batteries. Methods for making the disclosed composite materials are also disclosed.

Electrochemical devices, such as batteries, supercapacitors, etc., which may be prepared from nanoscopic electrically conductive carbon materials, and optionally electrochemically active materials. Also, methods for preparing such electrochemical devices, including components, elements, etc., of such devices by using three-dimensional (3D) printing, fused deposition modeling (FDM), selective laser sintering (SLS), etc., techniques.

Provided is a production method that enables the production of a composite body of lithium titanate particles and a carbonaceous material, the composite body having excellent electrical characteristics and so on, and the composite body of lithium titanate particles and a carbonaceous material. A method for producing a composite body of lithium titanate particles and a carbonaceous material includes the steps of: preparing a raw material mixture using a titanium compound, a lithium compound, and an oligomer and/or raw material monomer of an alkali-soluble resin; and subjecting the raw material mixture to heat treatment under a non-oxidizing atmosphere to produce the composite body.

An objective of the present disclosure is to provide a method of producing metal compound particle group for an electricity storage device electrode that has an improved rate characteristic, the metal compound particle group, and an electrode formed of the metal compound particle group. The method of producing metal compound particle group applied for an electrode of an electricity storage device, the method includes a step of combining a precursor of metal compound particle with a carbon source to obtain a first composite material, a step of producing the metal compound particle by heat processing the first composite material under a non-oxidizing atmosphere to obtain a second composite material having the metal compound particle combined with carbon, and a step of eliminating carbon by heat processing the second composite material under an oxygen atmosphere to obtain the metal compound particle group having the metal compound particle coupled in a three-dimensional mesh structure.

A power storage device with high capacity is provided. Alternatively, a power storage device with excellent cycle characteristics is provided. Alternatively, a power storage device with high charge and discharge efficiency is provided. Alternatively, a power storage device with a long lifetime is provided. A negative electrode active material includes a first region and a second region. The first region includes at least one element selected from Si, Mg, Ca, Ga, Al, Ge, Sn, Pb, Sb, Bi, Ag, Zn, Cd, As, Hg, and In. The second region includes oxygen and the same element as the one included in the first region. The crystallite size of the element included in the first region is larger than or equal to 1 nm and smaller than or equal to 10 nm.

A power storage device with high capacity is provided. Alternatively, a power storage device with excellent cycle characteristics is provided. Alternatively, a power storage device with high charge and discharge efficiency is provided. Alternatively, a power storage device with a long lifetime is provided. A negative electrode active material includes a first region and a second region. The first region includes at least one element selected from Si, Mg, Ca, Ga, Al, Ge, Sn, Pb, Sb, Bi, Ag, Zn, Cd, As, Hg, and In. The second region includes oxygen and the same element as the one included in the first region. The crystallite size of the element included in the first region is larger than or equal to 1 nm and smaller than or equal to 10 nm.

A carbon coating-treatment apparatus configured to introduce organic gas into the furnace tube through the gas introduction tube while stirring raw material particles introduced into the furnace tube with the stirring blade to coat the raw material particles with carbon coating, wherein the stirring blade is configured to have a proportion satisfying relation of V.sub.2/V.sub.1≧0.1, where V.sub.1 is a time-averaged volume of a portion of the stirring blade positioned in the furnace tube, V.sub.2 is a time-averaged volume of a portion of the stirring blade positioned in a region of the furnace tube except for a cylindrical region being in a distance of R/10 or less from the central axis of the furnace tube, and R is the inner diameter of the furnace tube. A carbon coating-treatment apparatus that can sufficiently coat raw material particles with uniform carbon coating to produce particles having carbon coating in high productivity.

An electrochemical device includes a negative electrode containing a negative electrode active material, a positive electrode, and an electrolyte. The negative electrode active material has a crystal structure with an Fm3m space group and contains a compound represented by composition formula (1) below,

Li.sub.xTi.sub.yO.sub.z   Formula (1), where 0.4≦x/y<2 and x/2+3y/2≦z≦x/2+2y.

An electrochemical device includes a negative electrode containing a negative electrode active material, a positive electrode, and an electrolyte. The negative electrode active material has a crystal structure with an Fm3m space group and contains a compound represented by composition formula (1) below,

Li.sub.xTi.sub.yO.sub.z   Formula (1), where 0.4≦x/y<2 and x/2+3y/2≦z≦x/2+2y.

A method of making a prelithiated anode for use in a lithium-ion battery includes providing a current collector having an electrically conductive layer and a metal oxide layer overlaying the electrically conductive layer. The metal oxide layer has an average thickness of at least 0.01 μm. A continuous porous lithium storage layer is deposited onto the metal oxide layer by a CVD process. Lithium is incorporated into the continuous porous lithium storage layer to form a lithiated storage layer prior to a first electrochemical cycle when the anode is assembled into the battery. The anode may be incorporated into a lithium ion battery along with a cathode. The cathode may include sulfur or selenium and the anode may be prelithiated.