Valence Technology, Inc.

Other

Danionics A/s

Mhb Joint Venture

Rene Koksbang

Ib I Olsen

Jeremy Barker

M Yazid Saidi

Dale R Shackle

Keld West

Girts Vitins

Gert L Jensen

Hang Shi

Pia Tonder

The invention relates to a rechargeable electrochemical cell comprising a negative electrode, an electrolyte and a positive electrode in which the positive electrode structure comprises a lithium cobalt manganese oxide of the composition Li Co Mn O where 0<y<0.6. The lithium cobalt manganese oxide of the above formula can be the only active compound or can be used together with one or more other rechargeable compounds. The lithium cobalt manganese oxide of the above formula may be in air and moisture insensitive tetragonal form and provides additional active lithium to compensate for capacity losses in lithium ion cells and lithium-alloy cells.

Electrochemical cell

The invention relates to a rechargeable electrochemical cell comprising a negative electrode, an electrolyte and a positive electrode, characterized in that the positive electrode structure thereof comprises (a) one or more materials selected from the group consisting of LiMn O , LiCoO , LiNiO , LiNi Co O where 0<x<1, preferably LiMn O and (b) one or more materials selected from the group consisting of orthorhombic LiMnO , monoclinic LiMnO (m-LiMnO ), hexagonal LiFeO (h-LiFeO ), &agr;-NaMnO , &bgr;-NaMnO , &agr;-NaFeO , and lithium/sodium compounds of the formula Li Na M(II)O , where x&gE;0, y&gE;0 and x&plus;y&lE;2, and where M(II) is a transition metal in oxidation state &plus;2, selected from the group consisting of Mn, Co, Ni and Fe, preferably Li Na Mn(II)O , where x&gE;0, y&gE;0 and x&plus;y&lE;2, more preferably LiNa MnO , the material(s) of group (a) being present in the electrode structure in an amount corresponding to 20-98% by weight of the complete electrode structure, and the material(s) of group (b) being present in the electrode structure in an amount corresponding to 1-79% by weight of the complete electrode stucture.

Rechargeable electrochemical cell of lithium ion or lithium alloy-type possessing metal oxide modified cathode structure with high first charge capacity

Provided by the present invention is a new cathode material comprised of a lithiated zirconium, titanium or hafnium oxide. The oxide is of the formula Li.sub.2 MXO.sub.4, where M is preferably a transition metal such as Ni, Co, Fe, Mn, V, Cu, or Cr, and X is zirconium, titanium or hafnium. The cathode material provides a useful composite cathode when combined with a polymeric binder and carbon.

Solid secondary lithium cell based on lithiated zirconium, titanium or

Electrochemical cells having a current collector that includes a redox polymer film affords overdischarge protection. The redox polymers can reversibly insert anions and/or cations during oxidation and/or reduction thereby rendering the polymers conductive relatively to their neutral state.

Current collector for lithium ion electrochemical cell

The present invention provides an electrochemical cell or battery which has a non-metallic negative electrode (anode). That is, no solid metal, free metal, active material is used in the cell. Rather than the conventional solid lithium metal anode, the active material of the new electrode comprises substituted carbon active material. The substituted carbon is carbonaceous material arranged in a disordered or ordered graphite structure, where atoms of carbon have been substituted in such structure by at least one other element. The invention also provides carbonaceous materials which are non-graphitic and considered amorphous, non-crystalline, highly disordered, which also have substituted therein elements other than carbon. The invention also provides a process for making such substituted carbons and for preparing an anode containing the substituted carbon.

Carbonaceous active material and method of making same

In a preferred method, a lithium compound is reacted with a manganese compound in the presence of gaseous ammonia produced by the decomposition of an ammonium compound. In the preferred method, the decomposition of the ammonium compound is initiated before the reaction occurs to form the lithium manganese oxide product spinel. It is also possible to have the decomposition initiated at about the same time as the reaction. It is possible to have the decomposition continue while the reaction to form the spinel occurs. The reaction to form the spinel occurs at an elevated temperature to provide a product of the desired nominal general formula, having a quantity of lithium corresponding to more than 1 atomic units of lithium for every 2 atomic units of manganese. This lithium-rich product, having greater than a 1:1 ratio of Mn.sup.+3 to Mn.sup.+4 is made possible by the presence of the ammonia decomposition gas. It is preferred that the lithium compound, the manganese compound, and the ammonium compound each be in particle form and intermingled in a desired proportion prior to heating.

Method of making lithium manganese oxide compounds

A method for reducing capacity fading of an LiMn.sub.2 O.sub.4 spinel electrode active material comprising substituting a minor amount of Z for Mn in the LiMn.sub.2 O.sub.4 active material, where Z is a metal element having a +4 (IV) valence state and is characterized by an ability to form tetravalent chlorides. The Z substituted LiMn.sub.2 O.sub.4 active material is further characterized by a lesser rate of capacity loss with cycling as compared to LiMn.sub.2 O.sub.4 active material.

Lithium manganese oxide cathodes with high capacity and stability

A method of increasing the amount of alkali metal that is available during charge/discharge of an electrochemical cell that employs carbon based intercalation anodes is provided. The method comprises of prealkaliation of the carbon anode. By subjecting the anode carbon to the prealkaliation process prior to packaging the electrochemical cell, substantially all the alkali metal (e.g., lithium) which is originally present in the cathode will be available for migration between the anode and cathode during charge/discharge.

Process for prelithiation of carbon based anodes for lithium ion

Increasing the percentage of the 3R phase present in graphite reduces the first capacity loss of anodes employing the so modified graphite. Conversion of 2H phase graphite to 3R phase graphite can be achieved by grinding graphite. Non-aqueous solid electrochemical cells with improved performance can be fabricated by employing intercalation based carbon anodes comprising graphite with high percentage of 3R. When employed in an electrochemical cell, the first cycle capacity loss of only about 10%.

Carbon anode for lithium ion electrochemical cell

There is provided an electrochemical cell which has a non-metal negative electrode (anode on discharge). The anode is not a solid metal, is not metallic, and has no free metal. Rather, an amount of lithium ions are incorporated into the anode carbon-polymer structure. The anode of the invention has no more than a minor amount of lithium in a precharged or fully discharged state. The anode is used with lithium-containing cathodes (positive electrodes), preferably of the intercalation type. The anode of the invention is of a material which includes carbon, an electrolyte, and one or more constituents selected from the group consisting of metal and semi-metal elements and compounds and alloys thereof, other than lithium and its alloys. Such constituents are further characterized by an ability to react electrochemically with lithium by accepting and releasing lithium. Preferred metals and semi-metals include aluminum, boron and silicon, and compounds and alloys thereof, such as AlSi.

Electrodes for rechargeable lithium batteries

Process for prelithiation of carbon based anodes for lithium batteries

A method of making an electrode active material of the nominal general formula LiV.sub.y O.sub.z where y is greater than 0 and up to about 3 and z is greater than 0 and up to about 8, comprises a series of steps. In the first step, lithium hydroxide is dispersed in an alcohol of the general formula C.sub.n H.sub.2n+1 OH. The alcohol and the hydroxide are each in an amount sufficient to provide a lithium alkoxide of the general formula LiOC.sub.n H.sub.2n+1. Next, progressive amounts of an oxide of vanadium having the general formula V.sub.2 O.sub.5 (vanadium pentoxide) are added while stirring the mixture. The amount of vanadium pentoxide in the mixture is sufficient to provide about 3 moles of vanadium for each mole of lithium present in the alkoxide. Then, the mixture is heated to an elevated temperature for a time sufficient to change the color of the oxide of vanadium and provide a solid precipitate. The solid precipitate is separated from the mixture and dried to obtain a powder of an oxide of vanadium having the nominal general formula LiV.sub.y O.sub.z, 0&lt;y.ltoreq.3 and 0&lt;z.ltoreq.8.

Method of making lithium-vanadium-oxide active material

In an electrochemical lithium cell having a negative electrode, a positive electrode and an electrolyte separator there is provided a positive electrode current collector which comprises a redox active conductive polymer.

Current collectors for electrochemical cells and batteries

A process of making lithium battery electrode active material having fine particles of vanadium oxide (V.sub.x O.sub.y) or lithium-vanadium oxide (Li.sub.z V.sub.x O.sub.y) intimately mixed with fine particles of carbon. The process includes forming a wet solution of a vanadium oxide precursor and carbon, and then decomposing the precursor/carbon mixture at an elevated temperature or by atomization in a controlled atmosphere. Alternatively, fine particles of vanadium oxide are formed from precursor halogen compounds by atomization in oxygen.

Lithium battery electrode compositions

A lithium battery has a positive electrode with an active material comprising a manganese oxide compound represented by at least one of the nominal general formulas A.sub.x Z.sub.y Mn.sub.a O.sub.b and A.sub.x Mn.sub.a O.sub.b, where A and Z are each metals or semi-metals, A has a valance of +2, Z has a valence of +1, and where x, y, a and b are each greater than or equal to 1.

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San Jose, CA, United States of America

Rene Koksbang