National Institute of Advanced Industrial Science and Technology

Agency of Industrial Science and Technology

Nec Corporation

Tanaka Chemical Corporation

Kabushiki Kaisha Toyota Jidoshokki

Other

Nec C Orporation

Agency of Industrial Science and Technology Ministry of International

Agency of Industrial Science & Technology, Ministry of International Trade & Industry

Secretary, Agency of Industrial Science and Technology

Mitsuharu Tabuchi

Hiroyuki Kageyama

Kazuaki Ado

Tomonari Takeuchi

Ryota Yuge

Hideka Shibuya

Tetsuo Sakai

Noriyuki Tamura

Kuniaki Tatsumi

Osamu Nakamura

Kyousuke Doumae

Hironori Kobayashi

Masakazu Murase

Junichi Niwa

Toshikatsu Kojima

Kazuhito Kawasumi

Hikari Sakaebe

Akira Kojima

Sadanori Hattori

Takuhiro Miyuki

Kentaro Kuratani

Kaoru Narita

Kentaro Nakahara

Hiromitsu Misawa

Masataka Nakanishi

Tatsuya Nakamura

Masanori Morishita

Hiroshi Senoh

Yuya Sato

Takashi Ohtomo

Naoki Kawano

Yoko Nabeshima

Yuko Oka

Elisabeth Betourne

A lithium-manganese composite oxide containing a lithium-iron-manganese composite oxide represented by the composition formula. Li(FeNiMn)O, where 0&#x3c;x&#x3c;&#x2153;, 0&#x2264;w&#x3c;0.8, 0&#x3c;y&#x3c;1, 0&#x3c;z&#x3c;0.5, y+z&#x3c;1, and 0&#x2264;&#x3b4;&#x3c;0.5, in which at least in a state of charge of a lithium ion battery using the lithium-manganese composite oxide as a positive-electrode active material, at least some of iron atoms are pentavalent.

Lithium-manganese composite oxide, and method for producing same, and positive electrode material, positive electrode and lithium ion secondary battery using same

A lithium-manganese composite oxide represented by formula (1): Li[(FeNi)Mn]O(1) wherein x, y, and z satisfy the following: 0&#x3c;x&#x2264;&#x2153;, 0&#x2264;y&#x3c;1.0, and 0&#x3c;z&#x2264;0.6, and wherein the content ratio of Li to the total content of Fe, Ni, and Mn (Li/(Fe+Ni+Mn)) is 1.55 or less on a molar ratio basis, the lithium-manganese composite oxide containing a crystalline phase having a layered rock-salt structure. This composite oxide is a novel material made from less resource-constrained and cheaper elements, and exhibits a high specific capacity, excellent charge-and-discharge cycle characteristics, and a high discharge capacity at a high current density (excellent rate characteristics), when used in the positive electrode material for lithium-ion secondary batteries.

Lithium-manganese complex oxide and method for producing same

There is provided a lithium-iron-manganese-based composite oxide capable of providing a lithium-ion secondary battery which has a high capacity retention rate in charge/discharge cycles and in which the generation of a gas caused by charge/discharge cycles is suppressed. A lithium-iron-manganese-based composite oxide having a layered rock-salt structure, wherein at least a part of the surface of a lithium-iron-manganese-based composite oxide represented by the following formula is coated with an oxide of at least one metal selected from the group consisting of La, Pr, Nd, Sm and Eu:LiMMnMFeO wherein 1.05&#x2264;x&#x2264;1.32, 0.33&#x2264;y&#x2264;0.63, 0.06&#x2264;z&#x2264;0.50, 0&#x3c;p&#x2264;0.63, 0.06&#x2264;q&#x2264;0.50, 0&#x2264;&#x3b4;&#x2264;0.80, y&#x2265;p, and z&#x2265;q; Mis at least one element selected from Ti and Zr; and Mis at least one element selected from the group consisting of Co, Ni and Mn.

Lithium-iron-manganese-based composite oxide and lithium-ion secondary battery using same

There is provided a lithium-iron-manganese-based composite oxide capable of providing a lithium-ion secondary battery which has a high capacity retention rate in charge/discharge cycles and in which the generation of a gas caused by charge/discharge cycles is reduced. A lithium-iron-manganese-based composite oxide having a layered rock-salt structure, wherein at least a part of the surface of a lithium-iron-manganese-based composite oxide represented by the following formula (1) is coated with an inorganic material: LiMMnMFeO(1) (wherein 1.05&#x2264;x&#x2264;1.32, 0.33&#x2264;y&#x2264;0.63, 0.06&#x2264;z&#x2264;0.50, 0&#x3c;p&#x2264;0.63, 0.06&#x2264;q&#x2264;0.50, 0&#x2264;&#x3b4;&#x2264;0.80, y&#x2265;p, and z&#x2265;q; Mis at least one element selected from Ti and Zr; and Mis at least one element selected from the group consisting of Co, Ni and Mn).

The present invention provides a process for producing a lithium sulfide-carbon composite, the process comprising placing a mixture of lithium sulfide and a carbon material having a specific surface area of 60 m/g or more in an electrically-conductive mold in a non-oxidizing atmosphere, and applying a pulsed direct current to the mold while pressurizing the mixture in a non-oxidizing atmosphere, thereby subjecting the lithium sulfide and the carbon material to heating reaction; and a lithium sulfide-carbon composite obtained by this process, the composite having a carbon content of 15 to 70 weight %, and a tap density of 0.4 g/cmor more when the carbon content is 30 weight % or more, or a tap density of 0.5 g/cmor more when the carbon content is less than 30 weight %. The present invention can improve the electronic conductivity of lithium sulfide, which is expected to be put into practical use as a high-capacity positive electrode active material, so as to further enhance the performance of lithium sulfide as a positive electrode active material for lithium ion secondary batteries.

Lithium sulfide-carbon complex, process for producing the complex, and lithium ion secondary battery utilizing the complex

Provided is a novel lithium silicate-based material useful as a positive electrode material for lithium ion secondary battery. The lithium silicate-based compound is represented by LiFeSiO. The lithium silicate-based compound is a compound including: lithium (Li); iron (Fe); silicon (Si); and oxygen (O), and expressed by a composition formula, LiFeSiO(&#x2212;0.25&#x2266;&#x3b4;&#x2266;0.25, 0&#x2266;c&#x2266;0.5). The lithium silicate-based compound, of which iron (Fe) is trivalent, exerts a remarkable chemical stability as compared to LiFeSiO.

Lithium silicate-based compound, positive electrode active material for lithium ion secondary battery, and lithium ion secondary battery using the same

A lithium silicate-based compound according to the present invention is expressed by a general formula, LiAMnCoMSiOCl(In the formula: 'A' is at least one element selected from the group consisting of Na, K, Rb and Cs; 'M' is at least one member selected from the group consisting of Mg, Ca, Al, Ni, Fe, Nb, Ti, Cr, Cu, Zn, Zr, V, Mo and W; and the respective subscripts appear to be as follows: 0&#x2266;&#x201c;a&#x201d;&#x3c;0.2; 0&#x2266;&#x201c;b&#x201d;&#x3c;1; 0&#x3c;&#x201c;x&#x201d;&#x3c;1; 0&#x2266;&#x201c;y&#x201d;&#x2266;0.5; &#x2212;0.25&#x2266;&#x201c;&#x3b1;&#x201d;&#x2266;1.25; and 0&#x2266;&#x201c;&#x3b2;&#x201d;&#x2266;0.05). The lithium silicate-based compound is used as a positive-electrode active material for secondary battery whose discharge average voltage is higher, and which is able to sorb and desorb lithium ions.

Lithium silicate-based compound and production process for the same, positive-electrode active material and positive electrode for use in lithium-ion secondary battery as well as secondary battery

The present invention provides a lithium manganese-based composite oxide represented by the compositional formula: Li(MnFeTi)O, wherein 0&#x3c;x&#x3c;&#x2153;, 0&#x2266;m&#x2266;0.75, 0.01&#x2266;n&#x2266;0.75, and 0.01&#x2266;m+n&#x3c;1, and comprising a crystal phase of layered rock-salt type structure. The composite oxide is capable of maintaining an average discharge voltage of 3 V or more over long charge/discharge cycles. The composite oxide can be prepared using lower-cost starting materials, and exhibits improved charge/discharge characteristics over conventional low-cost positive electrode materials.

Lithium manganese-based composite oxide and method for preparing the same

The invention provides a lithium-manganese-based composite oxide containing Ti and Ni, which is represented by the compositional formula: Li(MnNiTi)O, wherein 0&#x3c;x&#x2266;0.33, 0.05&#x3c;m&#x3c;0.3, and 0.3&#x3c;n&#x3c;0.5, and includes a crystal phase of layered rock-salt type structure. The composite oxide is a novel material that is capable of maintaining an average discharge voltage of 3 V or more over long charge/discharge cycles, while providing a discharge capacity equal to or higher than those of lithium-cobalt-oxide-based positive electrode materials, and that can be prepared using starting materials that are inexpensive and less limited as natural resources, while exhibiting improved charge/discharge characteristics over known low-cost positive electrode materials.

Lithium-manganese-based composite oxide containing titanium and nickel

The present invention provides a single-phase lithium ferrite based oxide which is suitable as a cathode material for a secondary battery, a process for preparing the oxide, and its uses, the oxide having a layered rock salt-type structure and comprising lithium ferrite (LiFeO )&minus;Li MO solid solution wherein M is at least one species selected from the group consisting of Mn, Ti and Sn, 0&lE;x<2, 0&lE;y&lE;1 such that the proportion of iron is &lE;Fe/(Fe&plus;M)&lE;0.9.

Single-phase lithium ferrite based oxide

Tin-containing granular magnetic oxide particles and process for producing the same

A lithium cobalt oxide (LiCoO ) having a layered rock-salt type structure produced at low temperatures by hydrothermally treating at least one water-soluble cobalt salt in an aqueous solution containing a water-soluble lithium salt and an alkali metal hydroxide at 105 to 300&deg; C. in the presence of an oxidizing agent. An inexpensive salt of divalent cobalt is used as a starting material in this process. The lithium cobalt oxide thus obtained is useful as a cathode material for rechargeable lithium batteries.

Process for producing layered rock-salt type lithium cobalt oxide by hydrothermal oxidation

A sintered lithium titaniumphosphate is produced by subjecting the powder of a mixture consisting of a Li source, a Ti source, and a P source to spark plasma sintering under an increased pressure.

Method for production of sintered lithium titaniumphosphate and sintered pellets obtained by the method

Hydrothermal treatment of at least one manganese source material, for example, an oxide of manganese, such as Mn,O,, MnO, or MnO,, in an aqueous solution containing at least one water-soluble lithium salt, such as lithium hydroxide, lithium chloride, lithium nitrate, lithium fluoride, or lithium bromide, and an alkaline metal hydroxide, such as potassium hydroxide, at 130 to 300&deg; C. can realize the preparation of a lithium manganese oxide (LiMnO,) having a layered rock-salt structure in a single stage.

Process for preparing layered rock-salt type lithium manganese oxide by mixed alkaline hydrothermal method

A high sodium ion conducting inorganic composite solid electrolyte obtained by mixing Na.sub.4 Zr.sub.2 Si.sub.3 O.sub.12 with titanium oxide and sintering the resultant mixture and a method for the production of a high sodium ion conducting inorganic composite solid electrolyte, consisting essentially of the steps of mixing Na.sub.4 Zr.sub.2 Si.sub.3 O.sub.12 with titanium oxide and sintering the resultant mixture.

High sodium ion conducting inorganic composite solid electrolyte and

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Ikeda, Japan

Mitsuharu Tabuchi